Category Archives: Software

Creating a Fixed Line IMS subscriber in PyHSS

I generally do this with Python or via the Swagger UI for the Web UI, but here’s how we can create a fixed-line IMS subscriber in PyHSS, so we can register it with a softphone, without using EAP-AKA.


Firstly we create the AuC object for this password combo.

curl -X 'PUT' \
'http://10.97.0.36:8080/auc/' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"ki": "yoursippassword123",
"opc": "",
"amf": "8000",
"sqn": "1"
}'

Get back the AuC ID from the JSON body, we’ll use this to provision the Sub:

 "auc_id": 110,

Next we create the subscriber, the speeds will be 0 as there is no data on the service, but we will add an default APN so the validation passes:

curl -X 'PUT' \
'http://10.97.0.36:8080/subscriber/' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"default_apn": 1,
"roaming_rule_list": null,
"apn_list": "0",
"subscribed_rau_tau_timer": 600,
"msisdn": "123451000001",
"ue_ambr_dl": 0,
"ue_ambr_ul": 0,
"imsi": "001001000090001",
"nam": 2,
"enabled": true,
"roaming_enabled": null,
"auc_id": 110
}'

Alright, that’s the basics done, now we’ll create the IMS subscriber.

Provision it:

curl -X 'PUT' \
'http://10.97.0.36:8080/ims_subscriber/' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"pcscf_realm": null,
"scscf_realm": null,
"pcscf_active_session": null,
"scscf_peer": null,
"msisdn": "123451000001",
"pcscf_timestamp": null,
"sh_template_path": "default_sh_user_data.xml",
"msisdn_list": "123451000001",
"pcscf_peer": null,
"last_modified": "2024-04-25T00:33:37Z",
"imsi": "001001000090001",
"xcap_profile": null,
"ifc_path": "default_ifc.xml",
"sh_profile": "\n<!-- This container for the XCAP Data for the Subscriber -->\n<RepositoryData>\n <ServiceIndication>ApplicationServer</ServiceIndication>\n <SequenceNumber>0</SequenceNumber>\n <ServiceData>\n <!-- This is the actual XCAP Data for the Subscriber -->\n \n <!-- XCAP Default Template (no XCAP Data stored in Database) -->\n <simservs xmlns=\"http://uri.etsi.org/ngn/params/xml/simservs/xcap\" xmlns:cp=\"urn:ietf:params:xml:ns:common-policy\">\n <originating-identity-presentation active=\"true\" />\n <originating-identity-presentation-restriction active=\"true\">\n <default-behaviour>presentation-not-restricted</default-behaviour>\n </originating-identity-presentation-restriction>\n <communication-diversion active=\"true\">\n <!-- No Answer Time -->\n <NoReplyTimer>20</NoReplyTimer>\n <cp:ruleset>\n <!-- Call Forward All Rule -->\n <cp:rule id=\"rule0\">\n <cp:conditions>\n <communication-diverted />\n </cp:conditions>\n <cp:actions>\n <forward-to>\n <target>sip:[email protected]</target>\n </forward-to>\n </cp:actions>\n </cp:rule>\n <!-- Call Forward Not Registered Rule -->\n <cp:rule id=\"rule1\">\n <cp:conditions>\n <not-registered />\n </cp:conditions>\n <cp:actions>\n <forward-to>\n <target>sip:[email protected]</target>\n </forward-to>\n </cp:actions>\n </cp:rule>\n <!-- Call Forward No Answer Rule -->\n <cp:rule id=\"rule2\">\n <cp:conditions>\n <no-answer />\n </cp:conditions>\n <cp:actions>\n <forward-to>\n <target>sip:[email protected]</target>\n </forward-to>\n </cp:actions>\n </cp:rule>\n <!-- Call Forward Busy Rule -->\n <cp:rule id=\"rule3\">\n <cp:conditions>\n <busy />\n </cp:conditions>\n <cp:actions>\n <forward-to>\n <target>sip:[email protected]</target>\n </forward-to>\n </cp:actions>\n </cp:rule>\n <!-- Call Forward Unreachable Rule -->\n <cp:rule id=\"rule4\">\n <cp:conditions>\n <not-reachable />\n </cp:conditions>\n <cp:actions>\n <forward-to>\n <target>sip:[email protected]</target>\n </forward-to>\n </cp:actions>\n </cp:rule>\n </cp:ruleset>\n </communication-diversion>\n \n <incoming-communication-barring active=\"true\">\n <cp:ruleset>\n <cp:rule id=\"rule0\">\n <cp:conditions />\n <cp:actions>\n <allow>true</allow>\n </cp:actions>\n </cp:rule>\n </cp:ruleset>\n </incoming-communication-barring>\n\n <outgoing-communication-barring active=\"false\">\n </outgoing-communication-barring>\n </simservs>\n\n </ServiceData>\n \n</RepositoryData>\n",
"pcscf": null,
"scscf": null,
"scscf_timestamp": null
}'

And with that we’re done,

We can now register 001001000090001 at our IMS, with password yoursippassword123 which has the MSISDN / phone number 123451000001.

Easy!

Virtualizing VMware to run inside Proxmox

Like a lot of companies, we’re moving away from VMware, and in our case, shifting to Proxmox.

But that doesn’t mean we can get entirely away from VMware, but more that it’s not our hypervisor of choice anymore, and this means shifting our dev environments and lab off VMware to Proxmox first.

So today I sat down to try and shift everything to Proxmox, while keeping the VMware based VMs accessible until they can slowly die of bitrot.

A sane person would probably utilize Proxmox’s fancy new tool for migrating VMs from VMware to Proxmox, and it’s great, but in our case at least, it required logging into each VM and remapping NICs, etc, which is tricky on boxes I don’t have access to – Plus we need to keep some VMware capability for testing / labbing stuff up.

So I decided into install Proxmox onto the bare metal servers, and then create a VMware virtual machine inside the Proxmox stack, to host a VMware ESXi instance.

I started off inside VMware (Before installing any Proxmox) by moving all the VMs onto a single physical disk, which I then removed from the server, so as to not accidentally format the one disk I didn’t want to format.

Next I nuked the server and setup the new stack with Proxmox, which is a doddle, and not something I’ll cover.

Then I loaded a VMware ISO into Proxmox and started setting up the VM.

Now, nested virtualization is a real pain in the behind.

VMware doesn’t like not being run on bare metal, and it took me a good long amount of time to find the hardware config that I could setup in Proxmox that VMware would accept.

Create the VM in the Web UI; I found using a SATA drive worked while SCSI failed, so create a SATA based LVM image to use, and mount the datastore ISO.

Then edit /etc/pve/qemu-server/your_id.conf and replace the netX, args, boot and ostype to match the below:

args: -cpu host,+invtsc,-vmx
boot: order=ide2;net0
cores: 32
cpu: host
ide2: local:iso/VMware-VMvisor-Installer-8.0U2b-23305546.x86_64.iso,media=cdrom,size=620274K
memory: 128000
meta: creation-qemu=8.1.5,ctime=1717231453
name: esxi
net0: vmxnet3=BC:24:11:95:8A:50,bridge=vmbr0
numa: 0
ostype: l26
sata0: ssd-3600gb:vm-100-disk-1,size=32G
scsihw: pvscsi
smbios1: uuid=6066a9cd-6910-4902-abc7-dfb223042630
sockets: 1
vmgenid: 6fde194f-9932-463e-b38a-82d2e7e1f2dd

Now you can go and start the VM, but once you’ve got the VMware splash screen, you’ll need to press Shift + O to enter the boot options.

At the runweasle cdromBoot after it add allowLegacyCPU=true – This will allow ESXi to use our (virtual) CPU.

Next up you’ll install VMware ESXi just like you’ve probably done 100 times before (is this the last time?), and once it’s done installing, power off, we’ll have to make few changes to the VM definition file.

Then after install we need to change the boot order, by updating:

boot: order=sata0

And unmount the ISO:

ide2: none,media=cdrom

Now remember how I’d pulled the hard disk containing all the VMware VMs out so I couldn’t break it? Well, don’t drop that, because now we’re going to map that physical drive into the VM for VMware, so I can boot all those VMs.

I plugged in the drive and I used this to find the drive I’d just inserted:

fdisk -l

Which showed the drive I’d just added last, with it’s VMware file system.

So next we need to map this through the VM we just created inside Proxmox, so VMware inside Proxmox can access the VMware file system on the disk filled with all our old VMware VMs.

VM. VM. VM. The word has lost all meaning to me at this stage.

We can see the mount point of our physical disk; in our case is /dev/sdc so that’s what we’ll pass through to the VM.

Here’s my final .conf file for the Proxmox VM:

args: -cpu host
balloon: 1024
boot: order=sata0
cores: 32
ide2: none,media=cdrom
kvm: 1
memory: 128000
meta: creation-qemu=8.1.5,ctime=1717231453
name: esxi
net0: vmxnet3=BC:24:11:95:8A:50,bridge=vmbr0
numa: 0
ostype: l26
sata0: ssd-3600gb:vm-100-disk-1,size=32G
sata1: /dev/sda
scsihw: pvscsi
smbios1: uuid=6066a9cd-6910-4902-abc7-dfb223042630
sockets: 1
vmgenid: 6fde194f-9932-463e-b38a-82d2e7e1f2dd

Now I can boot up the VM, log into VMware and behold, our disk is visible:

Last thing we need to do is get it mounted as a VMware Datastore so we can boot all those VMs.

For that, we’ll enable SSH on the ESXi box and SSH into it.

We’ll use the esxcfg-volume -l command to get the UUID of our drive

[root@localhost:~] esxcfg-volume -l
Scanning for VMFS-6 host activity (4096 bytes/HB, 1024 HBs).
VMFS UUID/label: 6513c05a-43db8c20-db0f-c81f66ea471a/FatBoy
Can mount: Yes
Can resignature: Yes
Extent name: t10.ATA_____QEMU_HARDDISK___________________________QM00007_____________:1 range: 0 - 1716735 (MB)

In my case the drive is aptly named “FatBoy”, so we’ll grab the UUID up to the slash, and then use that as the Mount parameter:

[root@localhost:~] esxcfg-volume -M 6513c05a-43db8c20-db0f-c81f66ea471a
Persistently mounting volume 6513c05a-43db8c20-db0f-c81f66ea471a

And now, if everything has gone well, after logging into the Web UI, you’ll see this:

Then the last step is going to be re-registering all the VMs, you can do this by hand, by selecting the .vmx file and adding it.

Alternately, if you’re lazy like me, I wrote a little script to do the same thing:

[root@localhost:~] cat load_vms3.sh 


#!/bin/bash

# Datastore name
DATASTORE="FatBoi/"

# Log file to store the output
LOG_FILE="/var/log/register_vms.log"

# Clear the log file
> $LOG_FILE

echo "Starting VM registration process on datastore: $DATASTORE" | tee -a $LOG_FILE

# Check if datastore directory exists
if [ ! -d "/vmfs/volumes/$DATASTORE" ]; then
echo "Datastore $DATASTORE does not exist!" | tee -a $LOG_FILE
exit 1
fi

# Find all .vmx files in the datastore and register them
find /vmfs/volumes/$DATASTORE -type f -name "*.vmx" | while read VMX_PATH; do
echo "Registering VM: $VMX_PATH" | tee -a $LOG_FILE
vim-cmd solo/registervm "$VMX_PATH" | tee -a $LOG_FILE
done

echo "VM registration process completed." | tee -a $LOG_FILE

[root@localhost:~] sh load_vms3.sh

Now with all your VMs loaded, you should almost be ready to roll and power them all back on.

And here’s where I ran into another issue:

Luckily the Proxmox wiki had the answer:

For an Intel CPU here’s what you run on the Proxmox hypervisor:

echo "options kvm-intel nested=Y" > /etc/modprobe.d/kvm-intel.conf

But before we reboot the Hypervisor (Proxmox) we’ll have to reboot the VMware hypervisor too, because here’s something else to make you punch the screen:

Luckily we can fix this one globaly.

SSH into the VMware box, edit /etc/vmware/config.xml file and add:

vhv.enable = "FALSE"

Which will disable the performance counters.

Now power off the VMware VM, and reboot the Proxmox hypervisor, when it powers on again, Proxmox will allow nested virtualization, and when you power back on the VMware VM, you’ll have performance counters disabled, and then, you will be done.

Yeah, not a great use of my Saturday, but here we are…

Grafana and CGrateS

I’m a really big fan of CGrateS, and I’m a fan of Grafana,

So what if you combined the two?

CGrateS uses a StoreDB – In my case MySQL, but could be Postgres or MongoDB, etc, and Grafana can get data from these sources too.

So let’s join them together!

For starters, I’ve got a bunch of CDRs in my cgrates.cdrs table inside MySQL.

Setting it up is a doddle, firstly inside Grafana we link it into MySQL:

Next up we create a dashboard and add a panel.

For this instance I’m metering data usage, so I’ve set the units to Bytes/SI (but if you’re using Voice you’ll need to adjust this to time).

Here’s my Query to find the Usage:

SELECT
DATE(setup_time) AS time,
SUM(`usage`) AS total_usage
FROM
cgrates.cdrs
GROUP BY
DATE(setup_time)
ORDER BY
time ASC

And I’ve created another one for Cost:

Keep in mind for the units it’s up to you what the units are, dollars, cents, 1/10th of a cent, etc, etc – In my case 1 in CGrateS equates to 1 cent:

SELECT

DATE(setup_time) AS time,
SUM(`cost`)/100 AS cost
FROM
cgrates.cdrs
GROUP BY
DATE(setup_time)
ORDER BY
time ASC

Lastly I’ve added a board to show the usage per Account, which I get with the below query:

SELECT
account AS label,
SUM(`usage`) AS value
FROM
cgrates.cdrs
GROUP BY
account
ORDER BY
value DESC

Not complete by any means, but shows what you can do with CGrateS and Grafana.

Importing CDRs into CGrateS with Event Reader Service

After we setup CgrateS the next thing we’d generally want to do would be to rate some traffic.

Of course, that could be realtime traffic, from Diameter, Radius, Kamailio, FreeSWITCH, Asterisk or whatever your case may be, but it could just as easily be CSV files, records from a database or a text file.

We’re going to be rating CDRs from simple CSV files with the date of the event, calling party, called party, and talk time, but of course your CDR exports will have a different format, and that’s to be expected – we tailor the Event Reader Service to match the format of the files we need.

The Event Reader Service, like everything inside CgrateS, is modular.
ERS is a module we load that parses files using the rules we define, and creates Events that CgrateS can process and charge for, based on the rules we define.

But before I can tell you that story, I have to tell you this story…

Nick’s imaginary CSV factory

In the repo I’ve added a DummyCSV.csv, it’s (as you might have guessed) a CSV file.

This CSV file is like a million other CSV formats out there – We’ve got a CSV file with Start Time, End Time, Customer, Talk Time, Calling Party, Called Party, Animal (for reasons) and CallID to uniquely identify this CDR.

Protip: The Rainbow CSV VScode extension makes viewing/editing/querying CSV files in VScode much easier.

Call Start TimeRow 0
Call End TimeRow 1
CustomerRow 2
Talk TimeRow 3
Calling PartyRow 4
Called PartyRow 5
AnimalRow 6
CallIDRow 7
File Format

Next we need to feed this into CGrateS, and for that we’ll be using the Event Reporter Service.

JSON config files don’t make for riveting blog posts, but you’ve made it this far, so let’s power through.

ERS is setup in CGrateS’ JSON config file, where we’ll need to define one or more readers which are the the logic we define inside CGrateS to tell it what fields are what, where to find the files we need to import, and set all the parameters for the imports.

This means if we have a CSV file type we get from one of our suppliers with CDRs in it, we’d define a reader to parse that type of file.
Likewise, if we’ve got a CSV of SMS traffic out of our SMSc, we’d need to define another reader to parse the CDRs in that format – Generally we’ll do a Reader for each file type we want to parse.

So let’s define a reader for this CSV spec we’ve just defined:


"ers": {
	"enabled": true,
	"readers": [
		{
			"id": "blog_example_csv_parser",
			"enabled": true,
			"run_delay":  "-1",
			"type": "*file_csv",
			"opts": {
				"csvFieldSeparator":",",
				"csvLazyQuotes": true,
				//csvLazyQuotes Counts the row length and if does not match this value declares an error
				//-1 means to look at the first row and use that as the row length
				"csvRowLength": -1
			},
			"source_path": "/var/spool/cgrates/blog_example_csv_parser/in",
			"processed_path": "/var/spool/cgrates/blog_example_csv_parser/out",
			"concurrent_requests": 1024,	//How many files to process at the same time
			"flags": [
				"*cdrs",
				"*log"
			],
			"tenant": "cgrates.org",
			"filters": [
				"*string:~*req.2:Nick", //Only process CDRs where Customer column == "Nick"
			],
			"fields":[]
}]}

This should hopefully be relatively simple (I’ve commented it as best I can).

The ID of the ERS object is just the name of this reader – you can name it anything you like, keeping in mind we can have multiple readers defined for different file formats we may want to read, and setting the ID just helps to differentiate them.

The run_delay of -1 means ERS will run as soon as a file is moved into the source_path directory, and the type is a CSV file – Note that’s moved not copied. We’ve got to move the file, not just copy it, as CGrateS waits for the inode notify.

In the opts section we set the specifics for the CSV we’re reading, field separator if how we’re separating the values in our CSV, and in our case, we’re using commas to delineate the fields, but if you were using a file using semicolons or another delineator, you’d adjust this.

Lastly we’ve got the paths, the source path is where we’ll need to move the files to get processed into, and the processed_path is where the processed files will end up.

For now I’ve set the flags to *log and *cdrs – By calling log we’ll make our lives a bit easier for debugging, and CDRs will send the event to the CDRs module to generate a rated CDR in CGrateS, which we could then use to bill a customer, a supplier, etc, and access via the API or exporting using Event Exporter Service.

Lastly under FilterS we’re able to define the filters that should define if we should process a row or not.
You don’t know how much you need this feature until you need this feature.
The filter rule I’ve included will only process lines where the Customer field in the CSV (row #2) is equal to “Nick”. You could use this to also filter only calls that have been answered, only calls to off-net, etc, etc – FilterS needs a blog post all on it’s own (and if you’re reading this in the future I may have already written one).

Alright, so far so good, we’ve just defined the metadata we need to do to read the file, but now how do we actually get down to parsing the lines in the file?

Well, that’s where the data in Fields: [] comes in.

If you’ve been following along the CgrateS in baby steps series, you’ll have rated a CDR using the API, that looked something like this:

{"method": "CDRsV1.ProcessExternalCDR", "params": [ { \
"Category": "call",
"RequestType": "*raw",
"ToR": "*monetary",
"Tenant": "cgrates.org",
"Account": "1002",
"Subject": "1002",
"Destination": "6141111124211",
"AnswerTime": "2022-02-15 13:07:39",
"SetupTime": "2022-02-15 13:07:30",
"Usage": "181s",
"OriginID": "API Function Example"
}], "id": 0}

ERS is going to use the same API to rate a CDR, calling more-or-less the same API, so we’re going to set the parameters that go into this from the CSV contents inside the fields:

			"fields":[

				//Type of Record (Voice)
				{"tag": "ToR", "path": "*cgreq.ToR", "type": "*constant", "value": "*voice"},

				//Category set to "call" to match RatingProfile_VoiceCalls from our RatingProfile
				{"tag": "Category", "path": "*cgreq.Category", "type": "*constant", "value": "call"},

				//RequestType is *rated as we won't be deducting from an account balance
				{"tag": "RequestType", "path": "*cgreq.RequestType", "type": "*constant", "value": "*rated"},
				
]

That’s the static values out of the way, next up we’ll define our values we pluck from the CSV. We can get the value of each row from “~*req.ColumnNumber” where ColumnNumber is the column number starting from 0.


				//Unique ID for this call - We get this from the CallID field in the CSV
				{"tag": "OriginID", "path": "*cgreq.OriginID", "type": "*variable","value":"~*req.7"},
				
				//Account is the Source of the call 
				{"tag": "Account", "path": "*cgreq.Account", "type": "*variable", "value": "~*req.4"},
				
				//Destination is B Party Number - We use 'Called Party Number'
				{"tag": "Destination", "path": "*cgreq.Destination", "type": "*variable", "value": "~*req.5"},
				{"tag": "Subject", "path": "*cgreq.Subject", "type": "*variable", "value": "~*req.5"},

				//Call Setup Time (In this case, CGrateS can already process this as a datetime object)
				{"tag": "SetupTime", "path": "*cgreq.SetupTime", "type": "*variable", "value": "~*req.0"},

				//Usage in seconds - We use 'Call duration'
				{"tag": "Usage", "path": "*cgreq.Usage", "type": "*variable", "value": "~*req.3"},

				//We can include extra columns with extra data - Like this one:
				{"tag": "Animal", "path": "*cgreq.Animal", "type": "*variable", "value": "~*req.6"},
]

Perfect,

If you’re struggling to get your JSON file right, that’s OK, I’ve included the JSON CGrateS.config file here.

You’ll need to restart CGrateS after putting the config changes in, but your instance will probably fail to start as we’ll need to create the directories we specified CGrateS should monitor for incoming CSV files:

mkdir /var/spool/cgrates/blog_example_csv_parser/
mkdir /var/spool/cgrates/blog_example_csv_parser/in
mkdir /var/spool/cgrates/blog_example_csv_parser/out

Right, now if we start CGrateS it should run.

But before we can put this all into play, we’ll need to setup some rates. My previous posts have covered how to do this, so for that I’ve included a Python script to setup all the rates, which you can run once you’ve restarted CGrateS.

Alright, with that out of the way, we can test it out, move our Dummy.csv file to /var/spool/cgrates/blog_example_csv_parser/in and see what happens.

mv Dummy.csv /var/spool/cgrates/blog_example_csv_parser/in/

All going well in your CGrateS log you’ll see all the events flying past for each row.

Then either via the CGrateS API, or just looking into the MySQL “cdrs” table you should see the records we just created.

And with that, you’ve rated CDRs from a CSV file and put them into CGrateS.

Libpython3.11 problems with Kamailio on Ubuntu 22.04

I run Ubuntu on my desktop and I mess with Kamailio a lot.

Recently I was doing some work with KEMI using Python, but installing the latest versions of Kamailio from the Debian Repos for Kamailio wasn’t working.

The following packages have unmet dependencies:
 kamailio-python3-modules : Depends: libpython3.11 (>= 3.11.0) but 3.11.0~rc1-1~22.04 is to be installed

Kamailio’s Python modules expect libpython3.11 or higher, but Ubuntu 22.04 repos only contain the release candidate – not the final version:

root@amanaki:/home/nick# apt-cache policy libpython3.11
libpython3.11:
  Installed: 3.11.0~rc1-1~22.04
  Candidate: 3.11.0~rc1-1~22.04
  Version table:
 *** 3.11.0~rc1-1~22.04 500
        500 http://au.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages
        100 /var/lib/dpkg/status

Luckily the deadsnakes PPA to the rescue!

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update
sudo apt-get purge kamailio
sudo apt --fix-broken install
sudo apt-get upgrade
apt-get install kamailio kamailio-python3-modules

And done!

vCenter – Partition Folder Isolation

While vCenter doesn’t really do contexts / mutli-tenants / VPCs like the hyperscalers, there are simple (ish) ways to do context separation inside VMware vCenter.

This means you can have a user who only has access to say a folder of VMs, but not able to see VMs outside of that folder.

Create a new Role inside vCenter from Administration -> Roles -> Add

Give the role all Virtual Machine privileges:

Create a new account (Can be on AD if you’re not using Local accounts, this is just our lab so I’ve created it as a Local account) for the user. We’re using this account for Ansible so we’ve used “Demo-Ansible-User” as the username

Now create a folder for the group of VMs, or pick an existing folder you want to give access to.

Right click on the folder and select “Add Permission”.

We give permission to that user with that role on the folder and make sure you tick “Propagate to children” (I missed this step before and had to repeat it):

If you are using templates, make sure the template is either in the folder, or apply the same permission to the template, by right clicking on it, Add Permission, same as this.

Finally you should be able to log in as that user and see the template, and clone it from the web UI, or create VMs but only within that folder.

CGrateS – Exporting CDRs

Having rated CDRs in CGrateS is great, but in reality, you probably want to get them into a billing system, CSV file, S3 bucket, CRM, invoice, Grafana, SQL table, etc, etc.

The Event Exporter Service (EES (previously called CDRe)) handles exporting CDRs from CGrateS.

Like everything in CGrateS, it’s highly configurable, and, again, like everything in CGrateS, supports every combination of services you can think of, plus a stack you haven’t thought of.

CDRs can be exported one of two ways, in real time, as the CDR is generated (online), or after the fact, exporting from the database containing the CDRs (offline).

Exporting in realtime (online) is a great option if you don’t want (or need) to store the CDRs in CGrateS; if you’re just using CGrateS to rate calls and spit them into a seperate system, this is a fantastic option, as it allows your CGrateS instances to remain light and not get clogged up with lots of old CDRs – That said, of course you can export the CDRs in realtime and still store them in CGrateS, that’s also a totally valid approach as well.

The more traditional approach is offline CDR export, where periodically or when an event is triggered, you scrape up a pile of CDRs and send them to your external systems.

For both options, we’ll need to define at least one exporter in our cgrates.json config file. For this example we’ll define a HTTP POST that we will trigger for realtime (online) CDR exporting, and a CSV file we dump to periodically when called from the API.

So first things first, we enable the EES module in the config:

"ees": {
		"enabled": true,
		"exporters": [
		]
	}

We’ll start with defining one exporter, named CSVExporter, that will output files to a folder named “testCSV” in the /tmp/ directory, but you can plonk these files wherever you like:

"ees": {
		"enabled": true,
		"synchronous": true,
		"exporters": [
			{
				"id": "CSVExporter",
				"type": "*file_csv",
				"export_path": "/tmp/testCSV",
				"flags": ["*log"],
				"attempts": 1,
				"synchronous": true,
				"field_separator": ",",
			},
		]
	}

We’ve got a lot of different types of export available to us, but type *file_csv is the easiest, so that’s where we’ll start.

Setting synchronous to true will mean we’ll only run one export job at a time, but it also means we’ll get back the result via the API, which will allow us to keep track of the ID of the last record we updated, so we don’t export the same record multiple times, more on this later.

Flags allows us to, if we wanted, bounce the event through AttributeS, for example, by adding *attributes to the flags, but in this case, it’s just logging to syslog.

Of course, just enabling ees won’t actually send calls to it, we’ll need to add “ees_conns“: [“*localhost”], to “apiers”: and “cdrs” so they know to bounce the events through it:

	"apiers": {
		"enabled": true,
                ...
		"ees_conns": ["*localhost"],
	},

	"cdrs": {
		"enabled": true,
		...
		"ees_conns": ["*localhost"],
	},

Okay, enough talk, let’s get exporting some CDRs!

If you’ve already got CDRs on your system from our previous tutorial, fantastic, but if not, let’s get up and running with a quick and dirty script to define some destinations, a charger, an account balance and then use some of the balance to generate a CDR:

import cgrateshttpapi
import pprint
import uuid
import datetime
now = datetime.datetime.now()
CGRateS_Obj = cgrateshttpapi.CGRateS('localhost', 2080)

#Define Destinations
CGRateS_Obj.SendData({'method':'ApierV2.SetTPDestination','params':[{"TPid":'cgrates.org',"ID":"Dest_AU_Mobile","Prefixes":["614"]}]})

#Load TariffPlan we just defined from StorDB to DataDB
CGRateS_Obj.SendData({"method":"APIerSv1.LoadTariffPlanFromStorDb","params":[{"TPid":'cgrates.org',"DryRun":False,"Validate":True,"APIOpts":None,"Caching":None}],"id":0})

#Define default Charger
print(CGRateS_Obj.SendData({"method": "APIerSv1.SetChargerProfile","params": [{"Tenant": "cgrates.org","ID": "DEFAULT",'FilterIDs': [],'AttributeIDs' : ['*none'],'Weight': 0,}]}))

account = "Nick_Test_123"

#Add a balance to the account with type *sms with 100 sms events
pprint.pprint(CGRateS_Obj.SendData({"method": "ApierV1.SetBalance","params": [{"Tenant": "cgrates.org","Account": account,"BalanceType": "*sms","DestinationIDs": 'Dest_NZ_Mobile;Dest_AU_Mobile',"Categories": "*any","Balance": {"ID": "100_SMS_Bundle_AU_NZ_Mobile","Value": 100,"Weight": 25}}]}))

#Process CDR Event for a single SMS
pprint.pprint(CGRateS_Obj.SendData({"method": "CDRsV2.ProcessExternalCDR","params": [{"OriginID": str(uuid.uuid1()),"ToR": "*sms","RequestType": "*pseudoprepaid","AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),"SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),"Tenant": "cgrates.org","Account": account,"Destination" : "61412345678","Usage": "1",}]}))

Right, with that out of the way, we should now have something in our CDRs table, a quick SQL query confirms this is the case:

Bingo, there we go.

So let’s try an offline export via the API:

result = CGRateS_Obj.SendData({
	"method": "APIerSv1.ExportCDRs",
	"params": [
		{
			"ExporterIDs": [
				"CSVExporter"
			],
			"Verbose": True,
			"Accounts": [account
			]
		}
	]
})
pprint.pprint(result)

So, as you may have guessed, we’ve called the ExportCDRs API endpoint, we’ve specified which ExporterIDs we want to reference (these link back to the objects in the config, and the one we have defined currently is named CSVExporter).

Setting Verbose: True means that CGrateS gives us back a lot of info from the API call, here’s what we get back:

{"error": None,
 "id": None,
 "result": {"CSVExporter": {"ExportPath": "/tmp/testCSV/CSVExporter_21e9bc2.csv",
                            "FirstEventATime": "2024-01-02T18: 09: 29+11: 00",
                            "FirstExpOrderID": 14,
                            "LastEventATime": "2024-01-02T18: 40: 53+11: 00",
                            "LastExpOrderID": 25,
                            "NegativeExports": [],
                            "NumberOfEvents": 12,
                            "PositiveExports": ["f45dd29",
                                                ...
                                                "6163255"
            ],
                            "TimeNow": "2024-01-02T18: 40: 53.791517662+11: 00",
                            "TotalCost": 0,
                            "TotalSMSUsage": 12
        }
    }
}

Now that looks pretty positive, we got 12 events of SMS usage exported, which we can see in the file /tmp/testCSV/CSVExporter_21e9bc2.csv – and if we cat out the file, yeap, there’s all the CDRs.

But it’s a bit of a mess, there’s a lot of fields in there, so let’s adjust what goes into the CSV.

Let’s start by filtering what goes into the exporter, to only give us SMS events, of course you could adjust the filters here to target exporting only the records you want, based on anything you can define with Filters (and there’s a lot you can define with filters).

	"ees": {
		"enabled": true,
		"exporters": [
			{
				"id": "CSVExporter",
				"type": "*file_csv",
				"export_path": "/tmp/testCSV",
				"flags": ["*log"],
				"attempts": 1,
				"filters": ["*string:~*req.ToR:*sms"],
				"synchronous": true,
				"field_separator": ",",
				...

Now we’re only exporting SMS records, so let’s clean up the output of the CSV to just give us the data we want, which is the CDR ID, time, account, destination and usage.

	"ees": {
		"enabled": true,
		"exporters": [
			{
				"id": "CSVExporter",
				"type": "*file_csv",
				"export_path": "/tmp/testCSV",
				"flags": ["*log"],
				"attempts": 1,
				"filters": ["*string:~*req.ToR:*sms"],
				"synchronous": true,
				"field_separator": ",",
				"fields":[
					//Headers
					{"tag": "CGRID", "path": "*hdr.CGRID", "type": "*constant", "value": "CGRID"},
					{"tag": "AnswerTime", "path": "*hdr.AnswerTime", "type": "*constant", "value": "AnswerTime"},
					{"tag": "Account", "path": "*hdr.Account", "type": "*constant", "value": "Account"},
					{"tag": "Destination", "path": "*hdr.Destination", "type": "*constant", "value": "Destination"},
					{"tag": "Usage", "path": "*hdr.Usage", "type": "*constant", "value": "Usage"},
					//Values
					{"tag": "CGRID", "path": "*exp.CGRID", "type": "*variable", "value": "~*req.CGRID"},
					{"tag": "AnswerTime", "path": "*exp.AnswerTime", "type": "*variable", "value": "~*req.AnswerTime{*time_string:2006-01-02T15:04:05Z}"},
					{"tag": "Account", "path": "*exp.Account", "type": "*variable", "value": "~*req.Account"},
					{"tag": "Destination", "path": "*exp.Destination", "type": "*variable", "value": "~*req.Destination"},
					{"tag": "Usage", "path": "*exp.Usage", "type": "*variable", "value": "~*req.Usage"},

				],
			},
...

Now after a restart of CGrateS, our exports look like this:

Stunning, truly beautiful, look at that output!

Right, well you may at this point have noticed a problem if you’ve run this more than once. The problem is that is every time we run this, we get all the CDRs since the beginning of time.

Now there’s a few ways we can handle this, if we only want CDRs generated in the past day for example, we can filter that as an input on the ExportCDRs API call, using the multitude of filters available to us as documented in the API docs.

But where filtering by date/time falls down, is that if an offline CDR of a call on Monday, only got ingested on Tuesday, it would be missed by the export.

But, setting Verbose: True on the ExportCDRs API call gives us a handy trick, we’ve been told what the highest ID in the CDRs table we just exported in the response from the API in LastExpOrderID field.

If we jump over to the SQL database we use for StorDB, we can see that 33 is the ID of the highest CDR in the system.

So let’s try something, let’s run the exporter again, but this time let’s get all the CDRs where the ID is higher than 33:

#Process CDR Event for a single SMS
pprint.pprint(CGRateS_Obj.SendData({"method": "CDRsV2.ProcessExternalCDR","params": [{"OriginID": str(uuid.uuid1()),"ToR": "*sms","RequestType": "*pseudoprepaid","AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),"SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),"Tenant": "cgrates.org","Account": account,"Destination" : "61412345678","Usage": "1",}]}))

#Trigger export where the OrderID is above 33
result = CGRateS_Obj.SendData({"method":"APIerSv1.ExportCDRs","params":[
    {"ExporterIDs": ["CSVExporter"],
     "Verbose" : True,
     "ExtraArgs" : {
        "OrderIDStart" : int(33),
     },
     "Accounts" : [account]}
]})
pprint.pprint(result)

Boom, now if we have a look at the output we can see the export covered two records, and the last ID was 35.

{'method': 'APIerSv1.ExportCDRs', 'params': [{'ExporterIDs': ['CSVExporter'], 'Verbose': True, 'ExtraArgs': {'OrderIDStart': 33}, 'run_id': 'carrier_interconnect', 'Accounts': ['Nick_Test_123']}]}
{'error': None,
 'id': None,
 'result': {'CSVExporter': {'ExportPath': '/tmp/testCSV/CSVExporter_c444cd9.csv',
                            'FirstEventATime': '2024-01-02T19:19:59+11:00',
                            'FirstExpOrderID': 34,
                            'LastEventATime': '2024-01-02T19:20:08+11:00',
                            'LastExpOrderID': 35,
                            'NegativeExports': [],
                            'NumberOfEvents': 2,
                            'PositiveExports': ['034aba2', '22e4fa7'],
                            'TimeNow': '2024-01-02T19:20:08.355664133+11:00',
                            'TotalCost': 0,
                            'TotalSMSUsage': 2}}}

So as long as we keep track of the LastExpOrderID value, and feed that as in input every time we run ExportCDRs, we can ensure we never miss a CDR, and never get the same CDR twice.

Uncomfortable Questions to ask about 5G Standalone at MWC – Part 2 – Has this Cash cow got Milk?

This is the second post of 3 presenting the argument against introducing 5G-SA.

There’s an old adage that businesses spend money for one of three reasons:

  • To Save Money (Which I covered yesterday)
  • To make more Money (This post, congratulations, you’re reading it!)
  • Because they have to (Regulatory compliance, insurance, taxes, etc) – That’s the next post

So let’s look at SA in this context.

5G-SA can drive new revenue streams

We (as an industry) suck at this.

Last year on the Telecoms.com podcast, Scott Bicheno made the point that if operators took all the money they’d gambled (and lost) on trying to play in the sports rights, involvement in media companies, building their own streaming apps, attempts at bundling other utilities, digital identity, etc, and just left the cash in the bank and just operated the network, they’d be better off.

Uber, Spotify, “OTTs”, etc, utilize MNOs to enable their services, but operators don’t see this extra revenue.
While some operators may talk of “fair share” the truth is, these companies add value to our product (connectivity) which as an industry, we’ve failed to add ourselves.

Last year at MWC we saw vendors were still beating the drum about 5G being critical for the “Metaverse”, just weeks before Meta announced they were moving away from the Metaverse.

Today the only device getting any attention from consumers is Apple’s Vision Pro, a very pricey, currently niche offering, which has no SIM card or cellular connectivity.

If the Metaverse does turn out to be a cash cow, it is unlikely the telecommunications industry will be the ones milking it.

Claim: Customers are willing to pay more for 5G-SA

This myth seems to be fairly persistent, but with minimal data to support this claim.

While BSS vendors talk about “5G Monetization”, the truth is, people use their MNO to provide them connectivity. If the coverage is adequate, and the speed enough to do what they need to do, few would be willing to pay any additional cash each month to see higher numbers on a speedtest result (enabled by 5G-NSA) and even fewer would pay extra cash for, well, whatever those features only enabled by 5G-Standalone are?

With most consumers now also holding onto their mobile devices for longer periods of time, and with interest rates reining in consumer spending across the board, we are seeing the rise of a more cost conscious consumer than ever before. If we want to see higher ARPUs, we need to give the consumer a compelling reason to care and spend their cash, beyond a speed test result.

We talk a little about APIs lower down in the post.

Claim: Users want Ultra-Low Latency / High Reliability Comms that only 5G-SA delivers

Wanting to offer a product to the market, is not the same as the market wanting a product to consume.

Telecom operators want customers to want these services, but customer take up rates tell a different story. For a product like this to be viable, it must have a wide enough addressable market to justify the investment.

Reliability

The URLCC standards focus on preventing packet loss, but the world has moved on from needing zero packet loss.

The telecom industry has a habit of deciding what customers want without actually listening.
When a customer talks about wanting “reliable” comms, they aren’t saying they want zero packet loss, but rather fewer dropouts or service flaps.
For us to give the customer what they are actually asking for involves us expanding RAN footprint and adding transmission diversity, not 5G-SA.

The “protocols of the internet” (TCP/IP) have been around for more than 50 years now.

These protocols have always flowed over transport links with varied reliability and levels of packet loss.

Thanks to these error correction and retransmission techniques built into these protocols, a lost packet will not interrupt the stream. If your nuclear command and control network were carried over TCP/IP over the public internet (please don’t do this), a missing packet won’t lead to worldwide annihilation, but rather the sender will see the receiver never acknowledged the receipt of the packet at the other end, and resend it, end of.

If you walk into a hospital today, you’ll find patient monitoring devices, tracking the vital signs for patients and alerting hospital staff if a patient’s vital signs change. It is hard to think of more important services for reliability than this.

And yet they use WiFi, and have done for a long time, if a packet is lost on WiFi (as happens regularly) it’s just retransmitted and the end user never knows.

Autonomous cars are unlikely to ever rely on a 5G connection to operate, for the simple reason that coverage will never be 100%. If your car stops because you’re in a not-spot, you won’t be a happy customer. While plenty of cars have cellular modems in them, that are used to upload telemetry data back to the manufacturer, but not to drive the car.

One example of wireless controlled vehicles in the wild is autonomous haul trucks in mines. Historically, these have used WiFi for their comms. Mine sites are often a good fit for Private LTE, but there’s nothing inherent in the 5G Standalone standard that means it’s the only tool for the job here.

Slicing

Slicing is available in LTE (4G), with an architecture designed to allow access to others. It failed to gain traction, but is in networks today.

See: Pre-5G Network Slicing.

What is different this time?

Low Latency

The RAN a piece of the latency puzzle here, but it is just one piece of the puzzle.

If we look at the flow a packet takes from the user’s device to the server they want to talk to we’ve got:

  1. Time it takes the UE to craft the packet
  2. Time it takes for the packet to be transmitted over the air to the base station
  3. Time it takes for the packet to get through the RAN transmission network to the core
  4. Time it takes the packet to traverse the packet core
  5. Time it takes for the packet to get out to transit/peering
  6. Time it takes to get the packet from the edge of the operators network to the edge of the network hosting the server
  7. Time it takes the packet through the network the server is on
  8. Time it takes the server to process the request

The “low latency” bit of the 5G puzzle only involves the two elements in bold.

If you’ve got to get from point A to point B along a series of roads, and the speed limit on two of the roads you traverse (short sections already) is increased. The overall travel time is not drastically reduced.

I’m lucky, I have access to a well kitted out lab which allows me to put all of these latency figures to the test and provide side by side metrics. If this is of interest to anyone, let me know. Otherwise in the meantime you’ll just have to accept some conjecture and opinion.

You could rebut this talking about Edge Compute, and having the datacenter at the base of the tower, but for a number of fairly well documented reasons, I think this is unlikely to attract widespread deployment in established carrier networks, and Intel’s recent yearly earning specifically called this out.


Claim: Customers want APIs and these needs 5G SA

Companies like Twilio have made it easy to interact with the carrier network via their APIs, but yet again, it’s these companies producing the additional value on a service operated by the MNOs.

My coffee machine does not have an API, and I’m OK with this because I don’t have a want or need to interact with it programatically.

By far, the most common APIs used by businesses involving telco markets are APIs to enable sending an SMS to a user.

These have been around for a long time, and the A2P market is pretty well established, and the good news is, operators already get a chunk of this pie, by charging for the SMS.

Imagine a company that makes medical booking software. They’re a tech company, so they want their stack to work anywhere in the world, and they want to be able to send reminder SMS to end users.

They could get an account manager with each of the telcos in each of the markets they work in, onboard and integrate the arcane complexities of each operators wholesale SMS system, or they could use Twilio or a similar service, which gives them global reach.

Often the cost of services like Twilio are cheaper than working directly with the carriers in each market, and even if it is marginally more expensive, the cost savings by not having to deal with dozens of carriers or integrate into dozens of systems, far outweighs this.

GSMA’s OpenGateway Initiative has sought to rectify this, but it lacks support for the use case we just discussed.

While it’s a great idea, in the context of 5G Standalone and APIs, it’s worth noting that none of the use cases in OpenGateway require 5G Standalone (Except possibly Edge discovery, but it is debatable).

Even Slicing existed before in LTE.

Critically, from a developer experience perspective:

I can sign up to services like Twilio without a credit card, and start using the service right away, with examples in my programming language of choice, the developer user experience is fantastic.

Jump on the OpenGateway website today and see if you can even find a way to sign up to use the service?

Claim: Fixed Wireless works best with 5G-SA

Of all the touted use cases and applications for 5G, Fixed Wireless (FWA) has been the most successful.

The great thing about FWA on Cellular networks is you can use the same infrastructure you use for your mobile customers, and then sell excess capacity in the network to deliver Fixed Wireless Access services, better utilizing an asset (great!).

But again, this does not require Standalone 5G. If you deploy your FWA network using 5G SA, then you won’t be able to sweat that same asset for both mobile subscribers and FWA subscribers.

Today at least, very few handsets short of this generation of flagship phones, supports 5G SA. Even the phones sold as supporting 5G over the past few years, are almost all only supporting 5G-NSA, so if you rolled out your FWA network as Standalone, you can’t better utilize the asset by sharing with your existing LTE/5G-NSA customers.

Claim: The Killer App is coming for 5G and it needs 5G SA

This space is reserved for the killer app that requires 5G Standalone.

Whenever that comes?

Anyone?

I’m not paying to build a marina berth for my mega yacht, mostly because I don’t have one. Ditto this.

Could you explain to everyone on an investor call that you’re investing in something where the vessel of the payoff isn’t even known to exist? Telecom is “blue chip”, hardly speculative.

The Future for Revenue Growth?

Maybe there isn’t one.

I know it’s an unthinkable thought for a lot of operators, but let’s look at it rationally; in the developed world, everyone who wants a mobile service already has one.

This leaves operators with two options; gaining market share from their competitors and selling more/higher priced services to existing customers.

You don’t steal away customers from other operators by offering a higher priced product, and with reduced consumer spending people aren’t queuing up to spend more each month.

But there is a silver lining, if you can’t grow revenues, you can still shrink expenditure, which in the end still gets the same result at the end of the quarter – More cash.

Simplify your operations, focus on what you do really well (mobile services), the whole 80/20 rule, get better at self service, all that guff.

There’s no shortage of pain points for consumers telecom operators could address, to make the customer experience better, but few that include the word Slicing.

CGrateS – AttributeS

The docs describe AttributeS as a Key-Value-Store, but that’s probably selling it short – You can do some really cool stuff with AttributeS, and in this post, we’re going to learn about using AttributeS to transform stuff.

Note: Before we get started, I’d suggest copying this config file to use for testing.

Let’s look at a really basic example, where we add some data into AttributeS, match based on Account in CGrateS, and get back that data.

Let’s look at how this would look on the API:

{
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_Nick_Key_Value_Example",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Account:1234"
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.ExampleKey",
            "Type": "*constant",
            "Value": "ExampleValue"
            }
        ],
        "Blocker": False,
        "Weight": 10

    }],
}

So what are we doing in this API call?

Well, for starters we’re calling the SetAttributeProfile endpoint, this is where we go to create / update Attribute Profiles, but in this case, because we’re hitting it for the first time with this ID, we’re creating a new entry called “ATTR_Nick_Key_Value_Example“, this will match any Contexts (more on them later) where the FilterIDs is a string, where the request Account, is equal to 1234.

Let’s run this against the CGrateS API and take a look at the result:

import cgrateshttpapi
import pprint

CGRateS_Obj = cgrateshttpapi.CGRateS('localhost', 2080)

SetAttributeProfile = {
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_Nick_Key_Value_Example",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Account:1234"
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.ExampleKey",
            "Type": "*constant",
            "Value": "ExampleValue"
            }
        ],
        "Blocker": False,
        "Weight": 10
    }],
}
result = CGRateS_Obj.SendData(SetAttributeProfile)
pprint.pprint(result)

result = CGRateS_Obj.SendData({"method":"AttributeSv1.ProcessEvent",
                               "params":[
                                   {"Tenant":"cgrates.org",
                                    "Event":{"Account":"1234"},"APIOpts":{}}]})
pprint.pprint(result)

All going well you should have got the following back:

{'method': 'AttributeSv1.ProcessEvent', 'params': [{'Tenant': 'cgrates.org', 'Event': {'Account': '1234'}, 'APIOpts': {}}]}
{'error': None,
 'id': None,
 'result': {'APIOpts': {},
            'AlteredFields': ['*req.ExampleKey'],
            'Event': {'Account': '1234', 'ExampleKey': 'ExampleValue'},
            'ID': '',
            'MatchedProfiles': ['cgrates.org:ATTR_Nick_Key_Value_Example'],
            'Tenant': 'cgrates.org',
            'Time': None}}

This tells us we matched the Attribute with the ID ATTR_Nick_Key_Value_Example, and inside Event we can see that ExampleKey was added with value ExampleValue.

Okay, you’re saying, well what was the point of that?

Well, what if as a key in the attributes, we had the password for the SIP account, which we passed to our SIP switch (Kamailio, FreeSWITCH or Asterisk for example), and used that to authenticate?

Let’s see how that would look:

{
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_Nick_Password_Example",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Account:1234"
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.SIP_password",
            "Type": "*constant",
            "Value": "sosecretiputitonthewebsite"
            }
        ],
        "Blocker": False,
        "Weight": 10
    }],
}

Now if the CGrateS Agent for your SIP Switch, includes the *attributes flag, and the call is coming from 1234, we’ll get back a key called “SIP_password” with the value “sosecretiputitonthewebsite”, which you can use to auth the SIP account.

We can also return multiple AttributeS, for example, we created two Attributes (ATTR_Nick_Password_Example and ATTR_Nick_Key_Value_Example) which match on the account 1234. This means we’ll get back the SIP Password from ATTR_Nick_Password_Example and the key:value we set in ATTR_Nick_Key_Value_Example:

{'method': 'AttributeSv1.ProcessEvent', 'params': [{'Tenant': 'cgrates.org', 'Event': {'Account': '1234'}}]}
{'error': None,
 'id': None,
 'result': {'APIOpts': {},
            'AlteredFields': ['*req.SIP_password', '*req.ExampleKey'],
            'Event': {'Account': '1234',
                      'ExampleKey': 'ExampleValue',
                      'SIP_password': 'sosecretiputitonthewebsite'},
            'ID': '',
            'MatchedProfiles': ['cgrates.org:ATTR_Nick_Password_Example',
                                'cgrates.org:ATTR_Nick_Key_Value_Example'],
            'Tenant': 'cgrates.org',
            'Time': None}}

The order can be controlled by the Weight flag in the attribute, and if you want to stop matching any other AttributeS rules after the current Attribute, you can set the Blocker=True flag when you create/update the Attribute.

Okay, I hear you saying, that’s all well and good, I can add arbitrary key/values to stuff. Here endeth the lesson right?

Well not quite, because we can add key/values, but we can also rewrite variables using AttributeS.

Let’s imagine we’ve got 3 phone numbers (DIDs) associated with an account inside CGrateS, for example’s sake let’s say we have 12340001, 12340002 and 12340003, and we want any calls from these numbers to be billed to a CGrateS account called “NickTest1234”.

Our SIP switch doesn’t need to know anything about “NickTest1234”, just the 3 DIDs it can use to call out from your SIP stack. But to do this, we’d need CGrateS to transform any events from these DIDs to replace the Account value inside CGrateS, with NickTest1234.

Let’s see how that would look:

{'method': 'APIerSv2.SetAttributeProfile', 'params': [{'Tenant': 'cgrates.org', 'ID': 'ATTR_Calling_NickTest1234_12340001', 'Contexts': ['*any'], 'FilterIDs': ['*string:~*req.Account:12340001'], 'Attributes': [{'Path': '*req.Account', 'Type': '*constant', 'Value': 'NickTest1234'}], 'Weight': 0}], 'id': 1}

{'method': 'APIerSv2.SetAttributeProfile', 'params': [{'Tenant': 'cgrates.org', 'ID': 'ATTR_Calling_NickTest1234_12340002', 'Contexts': ['*any'], 'FilterIDs': ['*string:~*req.Account:12340002'], 'Attributes': [{'Path': '*req.Account', 'Type': '*constant', 'Value': 'NickTest1234'}], 'Weight': 0}], 'id': 2}

{'method': 'APIerSv2.SetAttributeProfile', 'params': [{'Tenant': 'cgrates.org', 'ID': 'ATTR_Calling_NickTest1234_12340003', 'Contexts': ['*any'], 'FilterIDs': ['*string:~*req.Account:12340003'], 'Attributes': [{'Path': '*req.Account', 'Type': '*constant', 'Value': 'NickTest1234'}], 'Weight': 0}], 'id': 3}

In the example code to go with this I’ve put together a simple for loop to add these – You can find the code on Github (link at the bottom).

So with these defined, let’s try and rate something, we’ll add a default Charger, and add an SMS balance, before simulating an SMS where the account is set to 12340003:

#Define default Charger
print(CGRateS_Obj.SendData({"method":"APIerSv1.SetChargerProfile","params":[{"Tenant":"cgrates.org","ID":"DEFAULT","FilterIDs":[],"AttributeIDs":["*none"],"Weight":0}]}))

#Add an SMS Balance
print(CGRateS_Obj.SendData({"method":"ApierV1.SetBalance","params":[{"Tenant":"cgrates.org","Account":"Nick_Test_123","BalanceType":"*sms","Categories":"*any","Balance":{"ID":"SMS_Balance_1","Value":"100","Weight":25}}],"id":13}))

import uuid
import datetime
now = datetime.datetime.now()
result = CGRateS_Obj.SendData({
    "method": "CDRsV2.ProcessExternalCDR",
    "params": [
        {
            "OriginID": str(uuid.uuid1()),
            "ToR": "*sms",
            "RequestType": "*pseudoprepaid",
            "AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "Tenant": "cgrates.org",
            #This is going to be transformed to Nick_Test_123 by Attributes
            "Account": "12340003",
            "Usage": "1",
        }
    ]
})
pprint.pprint(result)

Right, so all going well, here’s what you should see in the CDRs table:

Bing, despite the fact the Account in the ProcessExternalCDR was set to 12340003, and had no mention of “NickTest1234”, CGrateS transformed it to NickTest1234.

How did that happen? Well, inside our cgrates.json file we have set the cdrs and chargers modules to have a link to Attributes, which means that when we call CDRs or Chargers modules via the API, these will in turn bounce the data through AttributesS for any transformations.

This means we don’t need to run AttributeSv1.ProcessEvent ourselves, when we call CDRsV2.ProcessExternalCDR, the CDRs module will call AttributeSv1.ProcessEvent for us.

We can actually see this happening, using ngrep, which as you work more with CGrateS, is a tool you’ll get very familiar with, let’s take a peek:

sudo ngrep -t -W byline port 2012 -d lo

Now if we run the CDRsV2.ProcessExternalCDR again, we’ll see the CDRs module has called Attributes for us:

Boom, there it is, same as we ran, but it’s being handled by CGrateS for us.

If you look carefully you’ll see the context in the API request is set to “*cdrs”, this means the CDRs module is calling Attributes.

When we define each of our Attributes, as we did earlier in the post, we can set what contexts they are valid in, for example we may want to apply the transformation when called by CDRs, but not other modules, you can restrict that when you define the Attribute by setting “Contexts”: [“*cdrs”].

Okay, so we’ve done some account replacement, what else can we do?

Well, let’s look at some other use cases,

Here in Australia we’ve got a few valid dialing formats, you could dial E.164 format (Numbers look like: +61212341234), 0NSN format (Numbers look like: 02 1234 1234) or NSN format (Numbers look like: 1234 1234 assuming you’re in the 03 area code yourself).
If we want to define all our Destinations in E.164 format, we’ll need to to normalise the format using AttributeS, so the numbers always come as E.164.

Let’s give it a whirl with a static translation:

{
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_0NSN_to_E164_Single",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Subject:0212341234"
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.Subject",
            "Type": "*constant",
            "Value": "61212341234"
            }
        ],
        "Blocker": False,
        "Weight": 10
    }],
}

Now this will work, if we simulate an Event to AttributeS with the Subject 0212341234, it’ll get transformed by AttributeS to 61212341234.

The issue here is probably pretty obvious, the only matches one number, if we dial 0212341235 this all falls apart.

Enter our old friend Regex.

For starters, we’ll change the FilterIDs to match where the Account is NickTest7, this way we can set the rules on a per CGrateS account basis.

{
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_0NSN_to_E164_02_Area_Code",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Account:NickTest7"
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.Subject",
            "Type": "*variable",
            "Value": "~*req.Subject:s/^0(\d{1})(\d{8})$/61${1}${2}/"
            },
            {
            "FilterIDs": [],
            "Path": "*req.Subject",
            "Type": "*variable",
            "Value": "~*req.Subject:s/^(\d{8})$/612${1}/"
            },
        ],
        "Blocker": False,
        "Weight": 10
    }],
}

And then under AttributeS we’ve defined a rule to replace anything matching the 0NSN regex, to strip the first digit and append a 61, to put it in E.164 format, and in SN format as the second entry.

We can now test this out:

{'method': 'AttributeSv1.ProcessEvent', 'params': [{'Tenant': 'cgrates.org', 'Event': {'Account': 'NickTest7', 'Subject': '0312341234'}, 'APIOpts': {'*processRuns': 5, '*profileRuns': 5, '*subsys': '*sessions'}}]}
{'error': None,
 'id': None,
 'result': {'APIOpts': {'*processRuns': 5,
                        '*profileRuns': 5,
                        '*subsys': '*sessions'},
            'AlteredFields': ['*req.Subject'],
            'Event': {'Account': 'NickTest7', 'Subject': '61312341234'},
            'ID': '',
            'MatchedProfiles': ['cgrates.org:ATTR_0NSN_to_E164_02_Area_Code'],
            'Tenant': 'cgrates.org',
            'Time': None}}



{'method': 'AttributeSv1.ProcessEvent', 'params': [{'Tenant': 'cgrates.org', 'Event': {'Account': 'NickTest7', 'Subject': '12341234'}, 'APIOpts': {'*processRuns': 5, '*profileRuns': 5, '*subsys': '*sessions'}}]}
{'error': None,
 'id': None,
 'result': {'APIOpts': {'*processRuns': 5,
                        '*profileRuns': 5,
                        '*subsys': '*sessions'},
            'AlteredFields': ['*req.Subject'],
            'Event': {'Account': 'NickTest7', 'Subject': '61212341234'},
            'ID': '',
            'MatchedProfiles': ['cgrates.org:ATTR_0NSN_to_E164_02_Area_Code'],
            'Tenant': 'cgrates.org',
            'Time': None}}

And there you have it folks; our number format standardized.

We can combo / cascade AttributeS rules together, with the aid of the Weight and Blocker flags in the API.

Let’s imagine the 61212341234 number has been ported from Operator1 to Operator2, and the Destinations we’ve defined in CGrateS for this prefix are currently set to DST_Operator1.
But because this number has been ported we should use DST_Operator2, so we charge the Operator2, as this number has been ported.

This means we don’t need to duplicate destination definitions to show this number has been ported, as this will be updated as the call gets rated, so we just assign the Attribute to each ported number.

So let’s match where the Subject of the call is 61212341234 (even though we’re going to input the Subject as 12341234), and rewrite the Destination attribute to DST_Operator2:

{
    "method": "APIerSv2.SetAttributeProfile",
    "params": [{
        "Tenant": "cgrates.org",
        "ID": "ATTR_Ported_61212341234",
        "Contexts": ["*any"],
        "FilterIDs": [
            "*string:~*req.Subject:61212341234",
        ],
        "Attributes": [
            {
            "FilterIDs": [],
            "Path": "*req.Destination",
            "Type": "*constant",
            "Value": "DST_Operator2"
            },
        ],
        "Blocker": False,
        "Weight": 5
    }],
}

From the results we can see we matched two AttributeS rules, the first, ATTR_0NSN_to_E164_02_Area_Code reformatted the Subject of the call from 12341234 to 61212341234, then the updated Subject was passed through to ATTR_Ported_61212341234, which updated the Destination attribute to DST_Operator2.

{'method': 'AttributeSv1.ProcessEvent', 'params': [{'Tenant': 'cgrates.org', 'Event': {'Account': 'NickTest7', 'Subject': '12341234'}, 'APIOpts': {'*processRuns': 5, '*profileRuns': 5, '*subsys': '*sessions'}}]}
{'error': None,
 'id': None,
 'result': {'APIOpts': {'*processRuns': 5,
                        '*profileRuns': 5,
                        '*subsys': '*sessions'},
            'AlteredFields': ['*req.Subject', '*req.Destination'],
            'Event': {'Account': 'NickTest7',
                      'Destination': 'DST_Operator2',
                      'Subject': '61212341234'},
            'ID': '',
            'MatchedProfiles': ['cgrates.org:ATTR_0NSN_to_E164_02_Area_Code',
                                'cgrates.org:ATTR_Ported_61212341234'],
            'Tenant': 'cgrates.org',
            'Time': None}}

Hopefully this has helped you to dip a toe into the CGrateS AttributeS pool, and give you some ideas of what we can achieve inside AttributeS.

A complete working code & config is available on my Github here.

If you’re having issues, make sure you have loaded the config file, are running the latest version, and if in doubt (and not on a production system), this script will clear all the data for you so you can rule out anything interfering.

CGrateS – ActionTriggers

In our last post we looked at Actions and ActionPlans, and one of the really funky things we can do is setting ActionPlans to trigger on a time schedule or setting ActionTriggers to trigger on an event.

We’re going to build on the examples we had on the last post, so we’ll assume your code is up to the point where we’ve added a Signup Bonus to an account, using an ActionPlan we assigned when creating the account.

In this post, we’re going to create an action that charges $6, called “Action_Monthly_Charge“, and tie it to an ActionPlan called “ActionPlan_Monthly_Charge“, but to demo how this works rather than charging this Monthly, we’re going to charge it every minute.

Then with our balances ticking down, we’ll set up an ActionTrigger to trigger when the balance drops below $95, and alert us.

Defining the Monthly Charge Action

The Action for the Monthly charge will look much like the other actions we’ve defined, except the Identifier is *debit so we know we’re deducting from the balance, and we’ll log to the CDRs table too:

# Action to add a Monthly charge of $6
Action_Monthly_Charge = {
    "id": "0",
    "method": "ApierV1.SetActions",
    "params": [
        {
          "ActionsId": "Action_Monthly_Charge",
          "Actions": [
              {
                'Identifier': '*debit',
                'BalanceType': '*monetary',
               'Units': 6,
               'Id': 'Action_Monthly_Charge_Debit',
               'Weight': 70},
              {
                  "Identifier": "*log",
                  "Weight": 60,
                  'Id' : "Action_Monthly_Charge_Log"
              },
              {
                  "Identifier": "*cdrlog",
                  "BalanceId": "",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 0,
                  "ExpiryTime": "",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 0,
                  "ExtraParameters": "{\"Category\":\"^activation\",\"Destination\":\"Recurring Charge\"}",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 80
              },
          ]}]}
pprint.pprint(CGRateS_Obj.SendData(Action_Monthly_Charge))

Next we’ll need to wrap this up into an ActionPlan, this is where some of the magic happens. Inside the action plan we can set a once off time, or a recurring time, kinda like Cron.

We’re setting the time to *every_minute so things will happen quickly while we watch, this action will get triggered every 60 seconds. In real life of course, for a Monthly charge, we’d want to trigger this Action monthly, so we’d set this value to *monthly. If we wanted this to charge on the 2nd of the month we’d set the MonthDays to “2”, etc, etc.

# # Create ActionPlan using SetActionPlan to trigger the Action_Monthly_Charge
SetActionPlan_Daily_Action_Monthly_Charge_JSON = {
    "method": "ApierV1.SetActionPlan",
    "params": [{
        "Id": "ActionPlan_Monthly_Charge",
        "ActionPlan": [{
            "ActionsId": "Action_Monthly_Charge",
            "Years": "*any",
            "Months": "*any",
            "MonthDays": "*any",
            "WeekDays": "*any",
            "Time": "*every_minute",
            "Weight": 10
        }],
        "Overwrite": True,
        "ReloadScheduler": True
    }]
}
pprint.pprint(CGRateS_Obj.SendData(
    SetActionPlan_Daily_Action_Monthly_Charge_JSON))

Alright, but now what’s going to happen?

If you think the accounts will start getting debited every 60 seconds after applying this, you’d be wrong, we need to associate this ActionPlan with an Account first, this is how we control which accounts get which ActionPlans tied to them, to do this we’ll use the SetAccout API again we’ve been using to create accounts:

# Create the Account object inside CGrateS & assign ActionPlan_Signup_Bonus and ActionPlan_Monthly_Charge
Create_Account_JSON = {
    "method": "ApierV2.SetAccount",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": str(Account),
            "ActionPlanIds": ["ActionPlan_Signup_Bonus", "ActionPlan_Monthly_Charge"],
            "ActionPlansOverwrite": True,
            "ReloadScheduler":True
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Account_JSON))

So what’s going to happen if we run this?

Well, for starters the ActionPlan named “ActionPlan_Signup_Bonus” is going to be triggered, as in the ActionPlan it’s Timing is set to *asap, so CGrateS will apply the corresponding Action (“Action_Add_Signup_Bonus“) right away, which will credit the account $99.

But a minute after that, we’ll trigger the ActionPlan named “ActionPlan_Monthly_Charge”, as the timing for this is set to *every_minute, when the Action “Action_Monthly_Charge” is triggered, it’s going to be deducting $6 from the balance.

We can check this by using the GetAccount API:

# Get Account Info
pprint.pprint(CGRateS_Obj.SendData({'method': 'ApierV2.GetAccount', 'params': [
              {"Tenant": "cgrates.org", "Account": str(Account)}]}))

You should see a balance of $99 to start with, and then after 60 seconds, it should be down to $93, and so on.

{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*monetary': [{'Blocker': False,
                                          'Categories': {},
                                          'DestinationIDs': {},
                                          'Disabled': False,
                                          'ExpirationDate': '2023-11-17T14:57:20.71493633+11:00',
                                          'Factor': None,
                                          'ID': 'Balance_Signup_Bonus',
                                          'RatingSubject': '',
                                          'SharedGroups': {},
                                          'TimingIDs': {},
                                          'Timings': None,
                                          'Uuid': '3a896369-8107-4e32-bcef-2d078c981b8a',
                                          'Value': 99,
                                          'Weight': 1200}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-17T14:57:21.802521707+11:00'}}

Triggering Actions based on Balances with ActionTriggers

Okay, so we’ve set up recurring charges, now let’s get notified if the balance drops below $95, we’ll start, like we have before, with defining an Action, this will log to the CDRs table, HTTP post and write to syslog:


#Define a new Action to send an HTTP POST
Action_HTTP_Notify_95 = {
    "id": "0",
    "method": "ApierV1.SetActions",
    "params": [
        {
          "ActionsId": "Action_HTTP_Notify_95",
          "Actions": [
              {
                  "Identifier": "*cdrlog",
                  "BalanceId": "",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 0,
                  "ExpiryTime": "",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 0,
                  "ExtraParameters": "{\"Category\":\"^activation\",\"Destination\":\"Balance dipped below $95\"}",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 80
              },
              {
                  "Identifier": "*http_post_async",
                  "ExtraParameters": "http://10.177.2.135/95_remaining",
                  "ExpiryTime": "*unlimited",
                  "Weight": 700
              },
              {
                  "Identifier": "*log",
                  "Weight": 1200
              }
          ]}]}
pprint.pprint(CGRateS_Obj.SendData(Action_HTTP_Notify_95))

Now we’ll define an ActionTrigger to check if the balance is below $95 and trigger our newly created Action (“Action_HTTP_Notify_95“) when that condition is met:


#Define ActionTrigger
ActionTrigger_95_Remaining_JSON = {
    "method": "APIerSv1.SetActionTrigger",
    "params": [
        {
            "GroupID" : "ActionTrigger_95_Remaining",
            "ActionTrigger": 
                {
                    "BalanceType": "*monetary",
                    "Balance" : {
                        'BalanceType': '*monetary',
                        'ID' : "*default",
                        'BalanceID' : "*default",
                        'Value' : 95,
                        },
                    "ThresholdType": "*min_balance",
                    "ThresholdValue": 95,
                    "Weight": 10,
                    "ActionsID" : "Action_HTTP_Notify_95",
                },
            "Overwrite": True
        }
    ]
}
pprint.pprint(CGRateS_Obj.SendData(ActionTrigger_95_Remaining_JSON))

We’ve defined the ThresholdType of *min_balance, but we could equally set this to ThresholdType to *max_balance, *balance_expired or trigger when a certain Counter has been triggered enough times.

Adding an ActionTrigger to an Account

Again, like the ActionPlan we created before, before the ActionTrigger we just created will be used, we need to associate it with an Account, for this we’ll use the AddAccountActionTriggers API, specify the Account and the ActionTriggerID for the ActionTrigger we just created.


#Add ActionTrigger to Account 
Add_ActionTrigger_to_Account_JSON = {
    "method": "APIerSv1.AddAccountActionTriggers",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": str(Account),
            "ActionTriggerIDs": ["ActionTrigger_95_Remaining"],
            "ActionTriggersOverwrite": True
        }
    ]
}
pprint.pprint(CGRateS_Obj.SendData(Add_ActionTrigger_to_Account_JSON))

If we run this all together, creating the account with the “ActionPlan_Signup_Bonus” will give the account a $99 Balance. But after 60 seconds, “ActionPlan_Monthly_Charge” will kick in, and every 60 seconds after that, at which point the balance will get to below $95 when CGrateS will trigger the ActionTriggerActionTrigger_95_Remaining” and get the HTTP POST to the HTTP endpoint and log entry:

We can check on this using the ApierV2.GetAccount method, where we’ll see the ActionTrigger we just defined.

Checking out the LastExecutionTime we can see if the ActionTrigger been triggered or not.

So using this technique, we can notify a customer when they’ve used a certain amount of their balance, but we can lock out Accounts who have spent more than their allocated spend limit by setting an Action that suspends the Account once it reaches a certain level. We notify customers when balance expires, or if a certain number of counters has been triggered.

As always I’ve put all the code used in this example, from start to finish, up on GitHub.

CGrateS – Actions & Action Plans

In our last post we added a series of different balances to an account, these were actions we took via the API specifically to add a balance.

But there’s a lot more actions we may want to do beyond just adding balance.

CGrateS has the concept of “Actions” which are, as the name suggests, things we want to do to the system.

Some example Actions would be:

  • Adding / Deducting / Resetting a balance
  • Adding a CDR log
  • Enable/Disable an account
  • Sending HTTP POST request or email notification
  • Deleting / suspending account
  • Transferring balances

We can run these actions on a timed basis, or when an event is triggered, and group Actions together to run multiple actions via an ActionTrigger, this means we can trigger these Actions, not just by sending an API request, but based on the state of the subscriber / account.

Let’s look at some examples,

We can define an Action named “Action_Monthly_Fee” to debit $12 from the monetary balance of an account, and add a CDR with the name “Monthly Account Fee” when it does so.
We can use ActionTriggers to run this every month on the account automatically.

We can define an Action named “Usage_Warning_10GB” to send an email to the Account owner to inform them they’ve used 10GB of usage, and use ActionTriggers to send this when the customer has used 10GB of their *data balance.

Using Actions

Note: The Python script I’ve used with all the examples in this post is available on GitHub here.

Let’s start by defining an Account, just as we have before:

# Create the Account object inside CGrateS
Account = "Nick_Test_123"
Create_Account_JSON = {
    "method": "ApierV2.SetAccount",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": str(Account)
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Account_JSON))

Let’s start basic; to sweeten the deal for new Accounts, we’ll give them $99 of balance to use in the first month they have the service. Rather than hitting the AddBalance API, we’ll define an Action named “Action_Add_Signup_Bonus” to credit $99 of monetary balance to an account.

If you go back to our last post, you should know what we’d need to do to add this balance manually with the AddBalance API, but let’s look at how we can create the same balance add functionality using Actions:

#Add a Signup Bonus of $99 to the account with type *monetary expiring a month after it's added
Action_Signup_Bonus = {
    "id": "0",
    "method": "ApierV1.SetActions",
    "params": [
        {
          "ActionsId": "Action_Add_Signup_Bonus",
          "Actions": [
              {
                  "Identifier": "*topup",
                  "BalanceId": "Balance_Signup_Bonus",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 99,
                  "ExpiryTime": "*month",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 1200,
                  "ExtraParameters": "",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 10
              }
]}]}
pprint.pprint(CGRateS_Obj.SendData(Action_Signup_Bonus))

Alright, this should look pretty familiar if you’ve just come from Account Balances.
You’ll notice we’re no longer calling, SetBalance, we’re now calling SetActions, to create the ActionsId with the name “Action_Add_Signup_Bonus“.
In “Action_Add_Signup_Bonus” we’ve got an actions we’ll do when “Action_Add_Signup_Bonus” is called.
We can define multiple actions, but for now we’ve only got one action defined, which has the Identifier (which defines what the action does) set to *topup to add balance.
As you probably guessed, we’re triggering a top up, and setting the BalanceId, BalanceType, Units, ExpiryTime and BalanceWeight just as we would using SetBalance to add a balance.

So how do we use the Action we just created? Well, there’s a lot of options, but let’s start with the most basic – Via the API:

# Trigger ExecuteAction
Account_Action_trigger_JSON = {"method": "APIerSv1.ExecuteAction", "params": [
    {"Tenant": "cgrates.org", "Account": str(Account), "ActionsId": "Action_Add_Signup_Bonus"}]}
pprint.pprint(CGRateS_Obj.SendData(Account_Action_trigger_JSON))

Boom, we’ve called the ExecuteAction API call, to execute the Action named “Action_Add_Signup_Bonus“.

We can check on this with GetAccount again and check the results:

# Get Account Info
pprint.pprint(CGRateS_Obj.SendData({'method': 'ApierV2.GetAccount', 'params': [
              {"Tenant": "cgrates.org", "Account": str(Account)}]}))
{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*monetary': [{'Blocker': False,
                                          'Categories': {},
                                          'DestinationIDs': {},
                                          'Disabled': False,
                                          'ExpirationDate': '2023-11-15T10:27:52.865119544+11:00',
                                          'Factor': None,
                                          'ID': 'Balance_Signup_Bonus',
                                          'RatingSubject': '',
                                          'SharedGroups': {},
                                          'TimingIDs': {},
                                          'Timings': None,
                                          'Uuid': '01cfb471-ba38-453a-b0e2-8ddb397dfe9c',
                                          'Value': 99,
                                          'Weight': 1200}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-15T10:27:52.865144268+11:00'}}

Great start!

Making Actions Useful

Well congratulations, we took something we previously did with one API call (SetBalance), and we did it with two (SetAction and ExcecuteAction)!

But let’s start paying efficiency dividends,

When we add a balance, let’s also add a CDR log event so we’ll know the account was credited with the balance when we call the GetCDRs API call.

We’d just modify our SetActions to include an extra step:

Action_Signup_Bonus = {
    "id": "0",
    "method": "ApierV1.SetActions",
    "params": [
        {
          "ActionsId": "Action_Add_Signup_Bonus",
          "Actions": [
              {
                  "Identifier": "*topup",
                  "BalanceId": "Balance_Signup_Bonus",
...
              }, 
              {
                  "Identifier": "*cdrlog",
                  "BalanceId": "",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 0,
                  "ExpiryTime": "",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 0,
                  "ExtraParameters": "{\"Category\":\"^activation\",\"Destination\":\"Your sign up Bonus\"}",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 10
              }
]}]}
pprint.pprint(CGRateS_Obj.SendData(Action_Signup_Bonus))

Boom, now we’ll get a CDR created when the Action is triggered.

But let’s push this a bit more and add some more steps in the Action:

As well as adding balance and putting in a CDR to record what we did, let’s also send a notification to our customer via an HTTP API (BYO customer push notification system) and log to Syslog what’s going on.

# Add a Signup Bonus of $99 to the account with type *monetary expiring a month after it's added
Action_Signup_Bonus = {
    "id": "0",
    "method": "ApierV1.SetActions",
    "params": [
        {
          "ActionsId": "Action_Add_Signup_Bonus",
          "Actions": [
              {
                  "Identifier": "*topup",
                  "BalanceId": "Balance_Signup_Bonus",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 99,
                  "ExpiryTime": "*month",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 1200,
                  "ExtraParameters": "",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 90
              },
              {
                  "Identifier": "*cdrlog",
                  "BalanceId": "",
                  "BalanceUuid": "",
                  "BalanceType": "*monetary",
                  "Directions": "*out",
                  "Units": 0,
                  "ExpiryTime": "",
                  "Filter": "",
                  "TimingTags": "",
                  "DestinationIds": "",
                  "RatingSubject": "",
                  "Categories": "",
                  "SharedGroups": "",
                  "BalanceWeight": 0,
                  "ExtraParameters": "{\"Category\":\"^activation\",\"Destination\":\"Your sign up Bonus\"}",
                  "BalanceBlocker": "false",
                  "BalanceDisabled": "false",
                  "Weight": 80
              },
              {
                  "Identifier": "*http_post_async",
                  "ExtraParameters": "http://10.177.2.135/example_endpoint",
                  "ExpiryTime": "*unlimited",
                  "Weight": 70
              },
              {
                  "Identifier": "*log",
                  "Weight": 60
              }
          ]}]}
pprint.pprint(CGRateS_Obj.SendData(Action_Signup_Bonus))

Phew! That’s a big action, but if we execute the action again using ExecuteAction, we’ll get all these things happening at once:

Okay, now we’re getting somewhere!

ActionPlans

Having an Action we can trigger manually via the API is one thing, but being able to trigger it automatically is where it really comes into its own.

Let’s define an ActionPlan, that is going to call our Action named “Action_Add_Signup_Bonus” as soon as the ActionPlan is assigned to an Account.

# Create ActionPlan using SetActionPlan to trigger the Action_Signup_Bonus ASAP
SetActionPlan_Signup_Bonus_JSON = {
    "method": "ApierV1.SetActionPlan",
    "params": [{
        "Id": "ActionPlan_Signup_Bonus",
        "ActionPlan": [{
            "ActionsId": "Action_Add_Signup_Bonus",
            "Years": "*any",
            "Months": "*any",
            "MonthDays": "*any",
            "WeekDays": "*any",
            "Time": "*asap",
            "Weight": 10
        }],
        "Overwrite": True,
        "ReloadScheduler": True
    }]
}
pprint.pprint(CGRateS_Obj.SendData(SetActionPlan_Signup_Bonus_JSON))

So what have we done here? We’ve made an ActionPlan named “Action_Add_Signup_Bonus”, which, when associated with an account, will run the Action “Action_Add_Signup_Bonus” as soon as it’s tied to the account, thanks to the Time*asap“.

Now if we create or update an Account using the SetAccount method, we can set the ActionPlanIds to reference our “ActionPlan_Signup_Bonus” and it’ll be triggered straight away.

# Create the Account object inside CGrateS
Create_Account_JSON = {
    "method": "ApierV2.SetAccount",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": str(Account),
            "ActionPlanIds": ["ActionPlan_Signup_Bonus"],
            "ActionPlansOverwrite": True,
            "ReloadScheduler":True
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Account_JSON))

Now if we were to run a GetAccount API call, we’ll see the Account balance assigned that was created by the action Action_Add_Signup_Bonus which was triggered by ActionPlan assigned to the account:

{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*monetary': [{'Blocker': False,
                                          'Categories': {},
                                          'DestinationIDs': {},
                                          'Disabled': False,
                                          'ExpirationDate': '2023-11-16T12:41:02.530985381+11:00',
                                          'Factor': None,
                                          'ID': 'Balance_Signup_Bonus',
                                          'RatingSubject': '',
                                          'SharedGroups': {},
                                          'TimingIDs': {},
                                          'Timings': None,
                                          'Uuid': '7bdbee5c-0888-4da2-b42f-5d6b8966ee2d',
                                          'Value': 99,
                                          'Weight': 1200}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-16T12:41:12.7236096+11:00'}}

But here’s where it gets interesting, in the ActionPlan we just defined the Time was set to “*asap“, which means the Action is triggered as soon as it was assigned to the account, but if we set the Time value to “*monthly“, the Action would get triggered every month, or *every_minute to trigger every minute, or *month_end to trigger at the end of every month.

Code for these examples is available here.

I’m trying to keep these posts shorter as there’s a lot to cover. Stick around for our next post, we’ll look at some more ActionTriggers to keep decreasing the balance of the account, and setting up ActionTriggers to send a notification to the customer to tell them when their balance is getting low, or any other event based Action you can think of!

CGrateS – Accounts & Balances

So far we’ve used CGrateS to rate a basic CDR and get a cost for it, but in the real world, we’d usually associate the cost with an account, which would represent a business or a person, who will ultimately be charged for using the service.

Note: I’ve put the code for all this in Github, if you’ve got issues following along, or don’t want to copy and paste the code from the website, you can grab the code here.

Creating an Account

Let’s start off by creating an account inside CGrateS – This is kinda pointless, but we’ll talk more about that later:

#Create the Account object inside CGrateS 
Create_Account_JSON = {
    "method": "ApierV2.SetAccount",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123"
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Account_JSON))

Running this onto the API should create an account named “Nick_Test_123”, but let’s confirm that’s the case:

#Print the Account Information
pprint.pprint(CGRateS_Obj.SendData({'method':'ApierV2.GetAccount','params':[{"Tenant":"cgrates.org","Account": "Nick_Test_123"}]}))

Running this will give us the information about the account we just created:

{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
OrderedDict([('id', None),
             ('result',
              OrderedDict([('ID', 'cgrates.org:Nick_Test_123'),
                           ('BalanceMap', None),
                           ('UnitCounters', None),
                           ('ActionTriggers', None),
                           ('AllowNegative', False),
                           ('Disabled', False),
                           ('UpdateTime',
                            '2023-10-09T16:53:37.524466041+11:00')])),
             ('error', None)])

That was easy!

There’s not really much to see on our account at this stage, other than the UpdateTime, there’s nothing really going on, we don’t have any Balances.

Adding Balance for Voice

Accounts exist for spending, so let’s add a balance to this account to send from.

We’ll use the SetBalance API to create a new balance with 5 minutes of talk time, that we can use for making a call, and talking, for (you guessed it) – 5 minutes, so and we’ll use the balance “5_minute_voice_balance” that we’ll create:

#Add a balance to the account with type *voice with 5 minutes of Talk Time
Create_Voice_Balance_JSON = {
    "method": "ApierV1.SetBalance",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "BalanceType": "*voice",
            "Categories": "*any",
            "Balance": {
                "ID": "5_minute_voice_balance",
                "Value": "5m",
                "Weight": 25
            }
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Voice_Balance_JSON))

Now if we run the GetAccount API command again, we should see the new balance we just created:

#Print the Account Information
pprint.pprint(CGRateS_Obj.SendData({'method':'ApierV2.GetAccount','params':[{"Tenant":"cgrates.org","Account": "Nick_Test_123"}]}))
{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*voice': [{'Blocker': False,
                                       'Categories': None,
                                       'DestinationIDs': None,
                                       'Disabled': False,
                                       'ExpirationDate': '0001-01-01T00:00:00Z',
                                       'Factor': None,
                                       'ID': '5_minute_voice_balance',
                                       'RatingSubject': '',
                                       'SharedGroups': None,
                                       'TimingIDs': None,
                                       'Timings': None,
                                       'Uuid': '37423d07-d99a-40b1-851a-981c3df02cb3',
                                       'Value': 300000000000,
                                       'Weight': 25}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-14T17:58:23.801531205+11:00'}}

So now we’ve got a new balance named ‘5_minute_voice_balance‘:

  • The type is *voice, because this balance is storing talk time
  • The weight of this balance is 25, this means this balance should take priority over any balances with a lower value than 25 (that’s right, we can (and will) do tiered balances)
  • The value is 300000000000 nanoseconds, which equates to 5 minutes (yes, that’s the correct number of zeros)

Okay, but Nick_Test_123 probably wants to make some calls, so let’s generate a 2.5 minute call event and check out what happens.


#Generate a new call event for a 2.5 minute (150 second) call
Process_External_CDR_JSON = {
    "method": "CDRsV2.ProcessExternalCDR",
    "params": [
        {
            "OriginID": str(uuid.uuid1()),
            "ToR": "*voice",
            "RequestType": "*pseudoprepaid",
            "AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "Usage": "150s",
        }
    ]
}
print(CGRateS_Obj.SendData(Process_External_CDR_JSON))

Alright, now we’ve got a call event, let’s call the GetAccount API again to check the balance:

#Print the Account Information
pprint.pprint(CGRateS_Obj.SendData({'method':'ApierV2.GetAccount','params':[{"Tenant":"cgrates.org","Account": "Nick_Test_123"}]}))
{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*voice': [{'Blocker': False,
                                       'Categories': None,
                                       'DestinationIDs': None,
                                       'Disabled': False,
                                       'ExpirationDate': '0001-01-01T00:00:00Z',
                                       'Factor': None,
                                       'ID': '5_minute_voice_balance',
                                       'RatingSubject': '',
                                       'SharedGroups': None,
                                       'TimingIDs': None,
                                       'Timings': None,
                                       'Uuid': '37423d07-d99a-40b1-851a-981c3df02cb3',
                                       'Value': 150000000000,
                                       'Weight': 25}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-14T17:58:23.80925546+11:00'}}

And there you have it, we’ve used 150 seconds of our 300 second (5 minutes) of talk time in this balance, leaving with us 150000000000 nanoseconds (150 seconds) remaining!

And with that progress, now is a great time to pause and talk about some theory that’s really important to grasp!

Balance Types

But *voice is just one balance type – We can support multiple balance types; we’ve just given a balance of *voice for talk time, but we could also give a credit to the balance for *sms or *data, you name it (*generic) and cash (*monetary) and we can have multiple separate balances for each.

This means we can have one account with something like:

  • 100 minutes of Local / National Calls (Expires at the end of the month)
  • 40 minutes of Mobile Calls (Expires 24 hours after it’s been created)
  • 80 minutes of Mobile Calls (During “Happy Hour” from 6 to 7pm)
  • 50 minutes of International Calls (Expires in 30 days)

And not just voice balance, the same account could also have:

  • 1GB of Data usage
  • 50 SMS to on-net destinations
  • $200 of Cash (expiring never)

Phew! That’s a lot of balances, but we can do it all through CGrateS!

What Balance to Use

So if we’ve got a stack of balances defined, how does CGrateS know what balance to use?

Firstly CGrateS is going to evaluate the BalanceType, this is set on events, so if we get an event for *data CGrateS will check out the balances available for *data, and evaluate the balances by Weight, with the highest weight evaluated first.
If we get to the end of all the available balances for that BalanceType, CGrateS then evaluates *generic and then *monetary balances, again, ordered by Weight.

We can set what balance gets used based on the Destination; using DestinationIDs we can filter the Balance to only apply for calls to Local/National numbers, so a call to an International destination won’t use that balance.

We can also set an Expiry on the Balance, for example we can give a customer 30 days to use the balance, after which it expires and can’t be used, likewise we can set Timings so enable scenarios like a “Happy hour” with extra calls between 6pm and 7pm.

When we define a balance we can also set the Blocker flag to True, if this is set, it means CGrateS will not look evaluate any balances after reaching that balance.

Adding a Balance for Local / National & Mobile Calls

Let’s jump back into the practice, and define two new Balances; one for Local/National calls, and another for Mobile calls.
But first we’ll need to know what destinations are mobiles and what are local/national (fixed). We’ve covered setting Destinations previously, so let’s set up the Destinations:


CGRateS_Obj.SendData({'method':'ApierV2.SetTPDestination','params':[{"TPid":"cgrates.org","ID":"Dest_AU_Fixed","Prefixes":["612", "613", "617", "618"]}]})
CGRateS_Obj.SendData({'method':'ApierV2.SetTPDestination','params':[{"TPid":"cgrates.org","ID":"Dest_AU_Mobile","Prefixes":["614"]}]})
CGRateS_Obj.SendData({'method':'ApierV2.SetTPDestination','params':[{"TPid":"cgrates.org","ID":"Dest_AU_TollFree","Prefixes":["6113", "6118"]}]})
#Load TariffPlan we just defiend from StorDB to DataDB
print(CGRateS_Obj.SendData({"method":"APIerSv1.LoadTariffPlanFromStorDb","params":[{"TPid":"cgrates.org","DryRun":False,"Validate":True,"APIOpts":None,"Caching":None}],"id":0}))

Alright, now let’s add a balance for our local/national (fixed) calls.

To do this, we’ll add two new balances, but we’ll need to differentiate this from the 5_minute_voice_balance we created earlier, and to achieve this we weill:

  • Set a higher Weight value than we have set on 5_minute_voice_balance (25) so this balance will get consumed before 5_minute_voice_balance does
  • Set the DestinationIDs to match the destinations (Dest_AU_Mobile for Mobile and Dest_AU_Fixed for Local/National) we want the balance to apply to

ProTip: When you we create our Balance we can set what Destinations we want to use this balance for, if you want to specify multiple balances, we can do it by setting the Balance names as a string delimited by semicolons, like “DestinationIDs”: “Dest_AU_Fixed;Dest_AU_Mobile;Dest_AU_TollFree”

We’ll also set a balance expiry, which we’ll cover shortly, but now let’s define out 100 minutes for Local/National expiring at the end of the month:

#Add a balance to the account with type *voice with 100 minutes of talk time to Local / National Destinations expiring at the end of the month
Create_Local_National_Voice_Balance_JSON = {
    "method": "ApierV1.SetBalance",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "BalanceType": "*voice",
            "Categories": "*any",
            "Balance": {
                "ID": "Local_National_100_minutes_voice_balance",
                "Value": "100m",
                "ExpiryTime": "*month_end",
                "Weight": 60,
                "DestinationIDs": "Dest_AU_Fixed",
            }
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Local_National_Voice_Balance_JSON))

We’ll also add our 24 hours to use to use 40 minutes of talk to mobiles, and a GetAccount to check the result:

#Add a balance to the account with type *voice with 40 minutes of talk time to Mobile Destinations expiring in 24 hours
Create_Mobile_Voice_Balance_JSON = {
    "method": "ApierV1.SetBalance",
    "params": [
        {
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "BalanceType": "*voice",
            "Categories": "*any",
            "Balance": {
                "ID": "Mobile_40_minutes_voice_balance",
                "Value": "40m",
                "ExpiryTime": "*daily",
                "Weight": 60,
                "DestinationIDs": "Dest_AU_Mobile",
            }
        }
    ]
}
print(CGRateS_Obj.SendData(Create_Mobile_Voice_Balance_JSON))

# Get Account Info Again
pprint.pprint(CGRateS_Obj.SendData({"method": "ApierV2.GetAccount", "params": [
              {"Tenant": "cgrates.org", "Account": "Nick_Test_123"}]}))

Alright, let’s try running that:

{'method': 'ApierV2.GetAccount', 'params': [{'Tenant': 'cgrates.org', 'Account': 'Nick_Test_123'}]}
{'error': None,
 'id': None,
 'result': {'ActionTriggers': None,
            'AllowNegative': False,
            'BalanceMap': {'*voice': [{'Blocker': False,
                                       'Categories': None,
                                       'DestinationIDs': None,
                                       'Disabled': False,
                                       'ExpirationDate': '0001-01-01T00:00:00Z',
                                       'Factor': None,
                                       'ID': '5_minute_voice_balance',
                                       'RatingSubject': '',
                                       'SharedGroups': None,
                                       'TimingIDs': None,
                                       'Timings': None,
                                       'Uuid': 'ad9d8bdd-64df-430f-af9d-3fc0410fd16b',
                                       'Value': 150000000000,
                                       'Weight': 25},
                                      {'Blocker': False,
                                       'Categories': None,
                                       'DestinationIDs': {'Dest_AU_Fixed': True},
                                       'Disabled': False,
                                       'ExpirationDate': '2023-10-31T23:59:59+11:00',
                                       'Factor': None,
                                       'ID': 'Local_National_100_minutes_voice_balance',
                                       'RatingSubject': '',
                                       'SharedGroups': None,
                                       'TimingIDs': None,
                                       'Timings': None,
                                       'Uuid': 'e4a2c211-8112-4e40-b3e6-250863404cc9',
                                       'Value': 6000000000000,
                                       'Weight': 60},
                                      {'Blocker': False,
                                       'Categories': None,
                                       'DestinationIDs': {'Dest_AU_Mobile': True},
                                       'Disabled': False,
                                       'ExpirationDate': '2023-10-15T18:15:11.521636734+11:00',
                                       'Factor': None,
                                       'ID': 'Mobile_40_minutes_voice_balance',
                                       'RatingSubject': '',
                                       'SharedGroups': None,
                                       'TimingIDs': None,
                                       'Timings': None,
                                       'Uuid': 'd4cbf6d8-50a5-4c97-82c2-dfe9936ae8d1',
                                       'Value': 2400000000000,
                                       'Weight': 60}]},
            'Disabled': False,
            'ID': 'cgrates.org:Nick_Test_123',
            'UnitCounters': None,
            'UpdateTime': '2023-10-14T18:15:11.524242437+11:00'}}

Alright! We now have 3 balances defined!

Notice in the API in the expiry I put *daily and *month_end, but in the output it’s got a real date and time (I wrote this 14/10/23 around 07:00 UTC, hence why those dates are what they are).
I could have specified the date and time in the API of a specific time I wanted the balance to expire (You can too, just replace “*daily” with “2024-01-01T00:00:00Z” for example), but that’s a pain in the butt, especially considering most of the time these values will be something common.
The *month_end is a special “meta” value, there’s a heap of these that allow us to do things like “current time + 20 minutes” (+20m), this time next month (*monthly), “this time tomorrow” (*daily), or “this time next week” (+168h) – You can find the full list of special dates here.

From a product perspective, setting an expiry on balances means we can set credit to expire 2 years after the subscriber tops up, but the same logic can be used so a subscriber could purchase a 7 day addon pack, that expires in 7 days, or a monthly plan can automatically expire in 30 days.

Now if we call the ProcessExternalCDR API again with a call to a Mobile and a Fixed number, we’ll see the respective balances get deducted.


#Generate a new call event for a 2.5 minute (150 second) call to a mobile number
Process_External_CDR_JSON = {
    "method": "CDRsV2.ProcessExternalCDR",
    "params": [
        {
            "OriginID": str(uuid.uuid1()),
            "ToR": "*voice",
            "RequestType": "*pseudoprepaid",
            "AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "Subject": "61412341234",
            "Destination": "61412341234",
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "Usage": "30s",
        }
    ]
}
print(CGRateS_Obj.SendData(Process_External_CDR_JSON))

#Generate a new call event for a 2.5 minute (150 second) call to a fixed line local/national number
Process_External_CDR_JSON = {
    "method": "CDRsV2.ProcessExternalCDR",
    "params": [
        {
            "OriginID": str(uuid.uuid1()),
            "ToR": "*voice",
            "RequestType": "*pseudoprepaid",
            "AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "Subject": "61212341234",
            "Destination": "61212341234",
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "Usage": "30s",
        }
    ]
}
print(CGRateS_Obj.SendData(Process_External_CDR_JSON))

# Get Account Info Again
pprint.pprint(CGRateS_Obj.SendData({"method": "ApierV2.GetAccount", "params": [
              {"Tenant": "cgrates.org", "Account": "Nick_Test_123"}]}))

We should see the minutes reduced by 30 seconds for our Local_National_100_minutes_voice_balance and Mobile_40_minutes_voice_balance balances, while our 5_minute_voice_balance hasn’t been touched.

{
   "Blocker":false,
   "Categories":"None",
   "DestinationIDs":"None",
   "Disabled":false,
   "ExpirationDate":"0001-01-01T00:00:00Z",
   "Factor":"None",
   "ID":"5_minute_voice_balance",
   "RatingSubject":"",
   "SharedGroups":"None",
   "TimingIDs":"None",
   "Timings":"None",
   "Uuid":"29f21735-1d62-49b1-9c53-80eab6f7b005",
   "Value":150000000000,
   "Weight":25
},
{
   "Blocker":false,
   "Categories":"None",
   "DestinationIDs":{
      "Dest_AU_Fixed":true
   },
   "Disabled":false,
   "ExpirationDate":"2023-10-31T23:59:59+11:00",
   "Factor":"None",
   "ID":"Local_National_100_minutes_voice_balance",
   "RatingSubject":"",
   "SharedGroups":"None",
   "TimingIDs":"None",
   "Timings":"None",
   "Uuid":"54db4f60-342e-4738-aaf1-a1304badc41d",
   "Value":5970000000000,
   "Weight":60
},
{
   "Blocker":false,
   "Categories":"None",
   "DestinationIDs":{
      "Dest_AU_Mobile":true
   },
   "Disabled":false,
   "ExpirationDate":"2023-10-15T18:32:34.888821482+11:00",
   "Factor":"None",
   "ID":"Mobile_40_minutes_voice_balance",
   "RatingSubject":"",
   "SharedGroups":"None",
   "TimingIDs":"None",
   "Timings":"None",
   "Uuid":"501eb00e-e947-4675-926f-080911e66897",
   "Value":2370000000000,
   "Weight":60
}

One last thing we’ll try before we end, our Mobile_40_minutes_voice_balance has still got 39.5 minutes left, and our 5_minute_voice_balance has still got minutes remaining, so if we try and make a call that’s 2450 seconds (~41 minutes), we should consume all the remaining minutes in Mobile_40_minutes_voice_balance and the go onto consume the remaining 1 minute out of 5_minute_voice_balance.

Let’s test this theory!

#Generate a new call event for a 42 minute call to a mobile to use all of our Mobile_40_minutes_voice_balance and start consuming 5_minute_voice_balance
Process_External_CDR_JSON = {
    "method": "CDRsV2.ProcessExternalCDR",
    "params": [
        {
            "OriginID": str(uuid.uuid1()),
            "ToR": "*voice",
            "RequestType": "*pseudoprepaid",
            "AnswerTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "SetupTime": now.strftime("%Y-%m-%d %H:%M:%S"),
            "Subject": "61412341234",
            "Destination": "61412341234",
            "Tenant": "cgrates.org",
            "Account": "Nick_Test_123",
            "Usage": "2450s",
        }
    ]
}
print(CGRateS_Obj.SendData(Process_External_CDR_JSON))

# Get Account Info Again
pprint.pprint(CGRateS_Obj.SendData({"method": "ApierV2.GetAccount", "params": [
              {"Tenant": "cgrates.org", "Account": "Nick_Test_123"}]}))

Let’s check the output:

{
   "Blocker":false,
   "Categories":"None",
   "DestinationIDs":"None",
   "Disabled":false,
   "ExpirationDate":"0001-01-01T00:00:00Z",
   "Factor":"None",
   "ID":"5_minute_voice_balance",
   "RatingSubject":"",
   "SharedGroups":"None",
   "TimingIDs":"None",
   "Timings":"None",
   "Uuid":"29f21735-1d62-49b1-9c53-80eab6f7b005",
   "Value":70000000000,
   "Weight":25
},
...
{
   "Blocker":false,
   "Categories":"None",
   "DestinationIDs":{
      "Dest_AU_Mobile":true
   },
   "Disabled":false,
   "ExpirationDate":"2023-10-15T18:44:18.161474861+11:00",
   "Factor":"None",
   "ID":"Mobile_40_minutes_voice_balance",
   "RatingSubject":"",
   "SharedGroups":"None",
   "TimingIDs":"None",
   "Timings":"None",
   "Uuid":"501eb00e-e947-4675-926f-080911e66897",
   "Value":0.0161939859,
   "Weight":60
}

Boom, there we have it! Used all of the minutes in Mobile_40_minutes_voice_balance and started eating into the 5_minute_voice_balance.

Alright, that was a long post! Sorry about that, and props for making it to the end, still so much to learn about CGrateS.

GNS3 vCenter / ESXi – Allow Traffic

The other day I setup GNS3 in the lab for some testing, we run vCenter for our server workloads, so I chucked the OVA on there.

One issue I ran into is that when linking a Cloud Component to a router, I simply could not get a path in/out of the router, I wasn’t learning MAC addresses and my ARP requests were going unanswered.

Wireshark showed the ARP requests going down that interface, and broadcast traffic from the rest of the network, so what gives?

The answer was pretty simple, on the vHost itself I needed to enable Promiscuous mode to allow L2 addresses that aren’t the VM, to be sent from within the VM.

Under Networking -> Port Groups -> the NICs you have assigned in GNS3:

Make sure Promiscuous mode, MAC address changes and Forged transmits are allowed – By default they’re denied on the vSwitch which it inherits from.

There’s obviously security concerns here, so think before you do, but that should have packets flowing.

Logging DSL Line Rate & SNR on a Draytek Modem

I am connected on a VDSL line, not by choice, but here we are.
DSL is many things, but consistent it not one of them, so I thought it’d be interesting to graph out the SNR and the line rate of the connection.

This is an NBN FTTN circuit, I run Mikrotiks for the routing, but I have a Draytek Vigor 130 that acts as a dumb modem and connects to the Tik.

Draytek exposes this info via SNMP, but the OIDs / MIBs are not part of the standard Prometheus snmp_exporter, so I’ve added them into snmp_exporter.yaml and restarted the snmp_exporter service.

draytek:
  walk:
  - 1.3.6.1.2.1.10.94.1.1.3.1.8
  - 1.3.6.1.2.1.10.94.1.1.3.1.4
  - 1.3.6.1.2.1.10.94.1.1.5.1.2.4
  - 1.3.6.1.2.1.10.94.1.1.4.1.2.4
  metrics:
  - name: Draytek_dsl_LineRate
    oid: 1.3.6.1.2.1.10.94.1.1.3.1.8
    type: gauge
    help: adslAtucCurrAttainableRate

  - name: Draytek_dsl_Linerate_Down
    oid: 1.3.6.1.2.1.10.94.1.1.4.1.2.4
    type: gauge
    help: Draytek_dsl_Linerate_Down

  - name: Draytek_dsl_Linerate_Up
    oid: 1.3.6.1.2.1.10.94.1.1.5.1.2.4
    type: gauge
    help: Draytek_dsl_Linerate_Up

  - name: Draytek_dsl_SNR
    oid: 1.3.6.1.2.1.10.94.1.1.3.1.4
    type: gauge
    help: adslAturCurrSnrMgn

Then I added this as a target in Prometheus:

  - job_name: Draytek Logger
    scrape_interval: 1m
    scrape_timeout: 30s
    static_configs:
          - targets: ['10.0.2.1']  # My modem

    metrics_path: /snmp
    params:
      module: ['draytek']
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: localhost:9116  # SNMP exporter address

And then from Grafana I can quantify exactly how bad my line is over time!

Only two dropouts today!

Using Wireshark to search a SIM

Today I was updating a SIM profile for work, the client is rebranding and we need to remove all references to their old brand from the SIM profile.

I’ve written about using Wireshark to view APDU traces on SIM cards before, but today I had a simple need, to find all files with the client’s brand name in them.

I started off just updating the SPN, OPN, etc, etc, but I had a suspicion there were still references.

I confirmed this pretty easily with Wireshark, first I started a trace in Wireshark of the APDUs: I enabled capturing on a USB Interface:

modprobe usbmon

Then we need to find where our card reader is connected, running ‘lsusb‘ lists all the USB devices, and you can see here’s mine on Bus 1, Device 49.

Then fired up Wireshark, selected USB Bus 01 to capture all the USB traffic on the bus.

Then I ran the “export” command in PySIM to read the contents of all the files on the SIM, and jumped back over to Wireshark. (PySIM decodes most files but not all – Whereas this method just looks for the bytes containing the string)

From the search menu in Wireshark I searched the packet bytes for the string containing the old brand name, and found two more EFs I’d missed.

For anyone playing along at home, using this method I found references to the old brand name in SMSP (which contains the network name) and ADN (Which had the customer support number as a contact with the old brand name).

Another great use for Wireshark!

SQN Sync in IMS Auth

So the issue was a head scratcher.

Everything was working on the IMS, then I go to bed, the next morning I fire up the test device and it just won’t authenticate to the IMS – The S-CSCF generated a 401 in response to the REGISTER, but the next REGISTER wouldn’t pass.

Wireshark just shows me this loop:

UE -> IMS: REGISTER
IMS -> UE: 401 Unauthorized (With Challenge)
UE -> IMS: REGISTER with response
IMS -> UE: 401 Unauthorized (With Challenge)
UE -> IMS: REGISTER with response
IMS -> UE: 401 Unauthorized (With Challenge)
UE -> IMS: REGISTER with response
IMS -> UE: 401 Unauthorized (With Challenge)

So what’s going on here?

IMS uses AKAv1-MD5 for Authentication, this is slightly different to the standard AKA auth used in cellular, but if you’re curious, we’ve covered by IMS Authentication and standard AKA based SIM Authentication in cellular networks before.

When we generate the vectors (for IMS auth and standard auth) one of the inputs to generate the vectors is the Sequence Number or SQN.

This SQN ticks over like an odometer for the number of times the SIM / HSS authentication process has been performed.

There is some leeway in the SQN – It may not always match between the SIM and the HSS and that’s to be expected.
When the MME sends an Authentication-Information-Request it can ask for multiple vectors so it’s got some in reserve for the next time the subscriber attaches, and that’s allowed.

Information stored on USIM / SIM Card for LTE / EUTRAN / EPC - K key, OP/OPc key and SQN Sequence Number

But there are limits to how far out our SQN can be, and for good reason – One of the key purposes for the SQN is to protect against replay attacks, where the same vector is replayed to the UE. So the SQN on the HSS can be ahead of the SIM (within reason), but it can’t be behind – Odometers don’t go backwards.

So the issue was with the SQN on the SIM being out of Sync with the SQN in the IMS, how do we know this is the case, and how do we fix this?

Well there is a resync mechanism so the SIM can securely tell the HSS what the current SQN it is using, so the HSS can update it’s SQN.

When verifying the AUTN, the client may detect that the sequence numbers between the client and the server have fallen out of sync.
In this case, the client produces a synchronization parameter AUTS, using the shared secret K and the client sequence number SQN.
The AUTS parameter is delivered to the network in the authentication response, and the authentication can be tried again based on authentication vectors generated with the synchronized sequence number.

RFC 3110: HTTP Digest Authentication using AKA

In our example we can tell the sub is out of sync as in our Multimedia Authentication Request we see the SIP-Authorization AVP, which contains the AUTS (client synchronization parameter) which the SIM generated and the UE sent back to the S-CSCF. Our HSS can use the AUTS value to determine the correct SQN.

SIP-Authorization AVP in the Multimedia Authentication Request means the SQN is out of Sync and this AVP contains the RAND and AUTN required to Resync

Note: The SIP-Authorization AVP actually contains both the RAND and the AUTN concatenated together, so in the above example the first 32 bytes are the AUTN value, and the last 32 bytes are the RAND value.

So the HSS gets the AUTS and from it is able to calculate the correct SQN to use.

Then the HSS just generates a new Multimedia Authentication Answer with a new vector using the correct SQN, sends it back to the IMS and presto, the UE can respond to the challenge normally.

This feature is now fully implemented in PyHSS for anyone wanting to have a play with it and see how it all works.

And that friends, is how we do SQN resync in IMS!

Kamailio Diameter Routing Agent Support

Recently I’ve been working on open source Diameter Routing Agent implementations (See my posts on FreeDiameter).

With the hurdles to getting a DRA working with open source software covered, the next step was to get all my Diameter traffic routed via the DRAs, however I soon rediscovered a Kamailio limitation regarding support for Diameter Routing Agents.

You see, when Kamailio’s C Diameter Peer module makes a decision as to where to route a request, it looks for the active Diameter peers, and finds a peer with the suitable Vendor and Application IDs in the supported Applications for the Application needed.

Unfortunately, a DRA typically only advertises support for one application – Relay.

This means if you have everything connected via a DRA, Kamailio’s CDP module doesn’t see the Application / Vendor ID for the Diameter application on the DRA, and doesn’t route the traffic to the DRA.

The fix for this was twofold, the first step was to add some logic into Kamailio to determine if the Relay application was advertised in the Capabilities Exchange Request / Answer of the Diameter Peer.

I added the logic to do this and exposed this so you can see if the peer supports Diameter relay when you run “cdp.list_peers”.

With that out of the way, next step was to update the routing logic to not just reject the candidate peer if the Application / Vendor ID for the required application was missing, but to evaluate if the peer supports Diameter Relay, and if it does, keep it in the game.

I added this functionality, and now I’m able to use CDP Peers in Kamailio to allow my P-CSCF, S-CSCF and I-CSCF to route their traffic via a Diameter Routing Agent.

I’ve got a branch with the changes here and will submit a PR to get it hopefully merged into mainline soon.

Diameter Routing Agents – Part 5 – AVP Transformations with FreeDiameter and Python in rt_pyform

In our last post we talked about why we’d want to perform Diameter AVP translations / rewriting on our Diameter Routing Agent.

Now let’s look at how we can actually achieve this using rt_pyform extension for FreeDiameter and some simple Python code.

Before we build we’ll need to make sure we have the python3-devel package (I’m using python3-devel-3.10) installed.

Then we’ll build FreeDiameter with the rt_pyform, this branch contains the rt_pyform extension in it already, or you can clone the extension only from this repo.

Now once FreeDiameter is installed we can load the extension in our freeDiameter.conf file:

LoadExtension = "rt_pyform.fdx" : "<Your config filename>.conf";

Next we’ll need to define our rt_pyform config, this is a super simple 3 line config file that specifies the path of what we’re doing:

DirectoryPath = "."        # Directory to search
ModuleName = "script"      # Name of python file. Note there is no .py extension
FunctionName = "transform" # Python function to call

The DirectoryPath directive specifies where we should search for the Python code, and ModuleName is the name of the Python script, lastly we have FunctionName which is the name of the Python function that does the rewriting.

Now let’s write our Python function for the transformation.

The Python function much have the correct number of parameters, must return a string, and must use the name specified in the config.

The following is an example of a function that prints out all the values it receives:

def transform(appId, flags, cmdCode, HBH_ID, E2E_ID, AVP_Code, vendorID, value):
    print('[PYTHON]')
    print(f'|-> appId: {appId}')
    print(f'|-> flags: {hex(flags)}')
    print(f'|-> cmdCode: {cmdCode}')
    print(f'|-> HBH_ID: {hex(HBH_ID)}')
    print(f'|-> E2E_ID: {hex(E2E_ID)}')
    print(f'|-> AVP_Code: {AVP_Code}')
    print(f'|-> vendorID: {vendorID}')
    print(f'|-> value: {value}')
    
    return value

Note the order of the arguments and that return is of the same type as the AVP value (string).

We can expand upon this and add conditionals, let’s take a look at some more complex examples:

def transform(appId, flags, cmdCode, HBH_ID, E2E_ID, AVP_Code, vendorID, value):
    print('[PYTHON]')
    print(f'|-> appId: {appId}')
    print(f'|-> flags: {hex(flags)}')
    print(f'|-> cmdCode: {cmdCode}')
    print(f'|-> HBH_ID: {hex(HBH_ID)}')
    print(f'|-> E2E_ID: {hex(E2E_ID)}')
    print(f'|-> AVP_Code: {AVP_Code}')
    print(f'|-> vendorID: {vendorID}')
    print(f'|-> value: {value}')
    #IMSI Translation - if App ID = 16777251 and the AVP being evaluated is the Username
    if (int(appId) == 16777251) and int(AVP_Code) == 1:
        print("This is IMSI '" + str(value) + "' - Evaluating transformation")
        print("Original value: " + str(value))
        value = str(value[::-1]).zfill(15)

The above look at if the App ID is S6a, and the AVP being checked is AVP Code 1 (Username / IMSI ) and if so, reverses the username, so IMSI 1234567 becomes 7654321, the zfill is just to pad with leading 0s if required.

Now let’s do another one for a Realm Rewrite:

def transform(appId, flags, cmdCode, HBH_ID, E2E_ID, AVP_Code, vendorID, value):

    #Print Debug Info
    print('[PYTHON]')
    print(f'|-> appId: {appId}')
    print(f'|-> flags: {hex(flags)}')
    print(f'|-> cmdCode: {cmdCode}')
    print(f'|-> HBH_ID: {hex(HBH_ID)}')
    print(f'|-> E2E_ID: {hex(E2E_ID)}')
    print(f'|-> AVP_Code: {AVP_Code}')
    print(f'|-> vendorID: {vendorID}')
    print(f'|-> value: {value}')
    #Realm Translation
    if int(AVP_Code) == 283:
        print("This is Destination Realm '" + str(value) + "' - Evaluating transformation")
    if value == "epc.mnc001.mcc001.3gppnetwork.org":
        new_realm = "epc.mnc999.mcc999.3gppnetwork.org"
        print("translating from " + str(value) + " to " + str(new_realm))
        value = new_realm
    else:
        #If the Realm doesn't match the above conditions, then don't change anything
        print("No modification made to Realm as conditions not met")
    print("Updated Value: " + str(value))

In the above block if the Realm is set to epc.mnc001.mcc001.3gppnetwork.org it is rewritten to epc.mnc999.mcc999.3gppnetwork.org, hopefully you can get a handle on the sorts of transformations we can do with this – We can translate any string type AVPs, which allows for hostname, realm, IMSI, Sh-User-Data, Location-Info, etc, etc, to be rewritten.

NB-IoT NIDD Basics

NB-IoT introduces support for NIDD – Non-IP Data Delivery (NIDD) which is one of the cool features of NB-IoT that’s gaining more widespread adoption.

Let’s take a deep dive into NIDD.

The case against IP for IoT

In the over 40 years since IP was standardized, we’ve shoehorned many things onto IP, but IP was never designed or optimized for low power, low throughput applications.

For the battery life of an IoT device to be measured in years, it has to be very selective about what power hungry operations it does. Transmitting data over the air is one of the most power-intensive operations an IoT device can perform, so we need to do everything we can to limit how much data is sent, and how frequently.

Use Case – NB-IoT Tap

Let’s imagine we’re launching an IoT tap that transmits information about water used, as part of our revolutionary new “Water as a Service” model (WaaS) which removes the capex for residents building their own water treatment plant in their homes, and instead allows dynamic scaling of waterloads as they move to our new opex model.

If I turn on the tap and use 12L of water, when I turn off the tap, our IoT tap encodes the usage onto a single byte and sends the usage information to our rain-cloud service provider.

So we’re not constantly changing the batteries in our taps, we need to send this one byte of data as efficiently as possible, so as to maximize the battery life.

If we were to transport our data on TCP, well we’d need a 3 way handshake and several messages just to transmit the data we want to send.

Let’s see how our one byte of data would look if we transported it on TCP.

That sliver of blue in the diagram is our usage component, the rest is overhead used to get it there. Seems wasteful huh?

Sure, TCP isn’t great for this you say, you should use UDP! But even if we moved away from TCP to UDP, we’ve still got the IPv4 header and the UDP header wasting 28 bytes.

For efficiency’s sake (To keep our batteries lasting as long as possible) we want to send as few messages as possible, and where we do have to send messages, keep them very short, so IP is not a great fit here.

Enter NIDD – Non-IP Data Delivery.

Through NIDD we can just send the single hex byte, only be charged for the single hex byte, and only stay transmitting long enough to send this single byte of hex (Plus the NBIoT overheads / headers).

Compared to UDP transport, NIDD provides us a reduction of 28 bytes of overhead for each message, or a 96% reduction in message size, which translates to real power savings for our IoT device.

In summary – the more sending your device has to do, the more battery it consumes.
So in a scenario where you’re trying to maximize power efficiency to keep your batter powered device running as long as possible, needing to transmit 28 bytes of wasted data to transport 1 byte of usable data, is a real waste.

Delivering the Payload

NIDD traffic is transported as raw hex data end to end, this means for our 1 byte of water usage data, the device would just send the hex value to be transferred and it’d pop out the other end.

To support this we introduce a new network element called the SCEFService Capability Exposure Function.

From a developer’s perspective, the SCEF is the gateway to our IoT devices. Through the RESTful API on the SCEF (T8 API), we can send and receive raw hex data to any of our IoT devices.

When one of our Water-as-a-Service Taps sends usage data as a hex byte, it’s the software talking on the T8 API to the SCEF that receives this data.

Data of course needs to be addressed, so we know where it’s coming from / going to, and T8 handles this, as well as message reliability, etc, etc.

This is a telco blog, so we should probably cover the MME connection, the MME talks via Diameter to the SCEF. In our next post we’ll go into these signaling flows in more detail.

If you’re wondering what the status of Open Source SCEF implementations are, then you may have already guessed I’m working on one!

Hopefully by now you’ve got a bit of an idea of how NIDD works in NB-IoT, and in our next posts we’ll dig deeper into the flows and look at some PCAPs together.

Diameter Routing Agents – Part 5 – AVP Transformations

Having a central pair of Diameter routing agents allows us to drastically simplify our network, but what if we want to perform some translations on AVPs?

For starters, what is an AVP transformation? Well it’s simply rewriting the value of an AVP as the Diameter Request/Response passes through the DRA. A request may come into the DRA with IMSI xxxxxx and leave with IMSI yyyyyy if a translation is applied.

So why would we want to do this?

Well, what if we purchased another operator who used Realm X, and we use Realm Y, and we want to link the two networks, then we’d need to rewrite Realm Y to Realm X, and Realm X to Realm Y when they communicate, AVP transformations allow for this.

If we’re an MVNO with hosted IMSIs from an MNO, but want to keep just the one IMSI in our HSS/OCS, we can translate from the MNO hosted IMSI to our internal IMSI, using AVP transformations.

If our OCS supports only one rating group, and we want to rewrite all rating groups to that one value, AVP transformations cover this too.

There are lots of uses for this, and if you’ve worked with a bit of signaling before you’ll know that quite often these sorts of use-cases come up.

So how do we do this with freeDiameter?

To handle this I developed a module for passing each AVP to a Python function, which can then apply any transformation to a text based value, using every tool available to you in Python.

In the next post I’ll introduce rt_pyform and how we can use it with Python to translate Diameter AVPs.