These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Location-Information-Request/Answer commands are used so a SIP Server query a Diameter to find which P-CSCF a Subscriber is being served by Basics: The RFC’s definition is actually pretty […]
These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Multimedia-Authentication-Request/Answer commands are used to Authenticate subscribers / UAs using a variety of mechanisms such as straight MD5 and AKAv1-MD5. Basics: When a SIP Server (S-CSCF) receives a […]
Connecting an external / 3rd party HSS to Open5GS
Note: I’m running version 19.12.0 which I installed from the repos due to issues with 20.4.0 (latest when I wrote this) and stability on LimeSDR. I wrote the other day about installing SRS LTE stack, But installing it is one thing, meeting all the requirements to use it with your SDR hardware turns out to […]
Sending SMS over LTE using OsmoMSC and OsmoHLR and the SGs interface for SMSoS
Looking into the SGi interface for Circuit Switched Fallback in LTE to use GSM/UMTS networks for Calls & SMS
Using Wireshark to view and analyze MAC layer LTE traffic
Accessing the Field Testing suite on an iOS Device
My first Pull / Merge in the Kamailio project was to fix the IMS P-CSCF config
A while ago I wrote a Python library for interfacing Open5GS HSS to Python. The Open5GS HSS uses a MongoDB backend, so the library is just running formatted Mongo queries. You can create, edit and delete subscribers in the HSS, along with modifying any parameters you can from the WebUI. Take a look: https://github.com/open5gs/open5gs/tree/master/misc/db/python
Multi-tenancy on the RAN side of the network, allowing an eNB to broadcast multiple PLMN IDs (MCC/MNC) in the System Information Block (SIB).
Using Ansible to orchestrate EPC Network Elements
A quick look at the Interface Types in the F-TIED field in GTPv2
Lessons learned about setting up VoLTE / IMS Networks at small scale.
Configuring BaiCells Neutrino eNB
How the P-CSCF address is assigned to a UE in Protocol Configuration Options (PCO) during bearer establishment.
Using SRS LTE Stack with the BladeRF x40 Software Defined Radio (SDR)
An update to PyHSS to support IMS Authentication for VoLTE
The exchange between a UE and P-CSCF to put SIP traffic into IPsec encapsulated payloads.
Viewing the payload of an Encapsulated Security Payload in Wireshark.