A look at attack vectors the NRF opens up in #5G Core networks, and the mitigations recommended by 3GPP.
Category Archives: SDM
If you like Pina Coladas, and service the control plane – Intro to NRF in 5GC
Looking for Love in the 5G Core?
Let’s look at our matchmaker – The Network Repository Function in 5G Core.
Backing up and Restoring Open5GS
How to backup and restore Open5Gs config between servers
Jaffa Cakes explain the nuances between Centralized vs Decentralized Online Charging in 3GPP Networks
A look at Centralized vs DeCentralized Online Charging with the aid of sugar.
EIR in 5G Networks (N5g-eir_EquipmentIdentityCheck)
A look at the Equipment Identity Register in 5G Core
Basics of EPC/LTE Online Charging (OCS)
A glimpse into the complexities of prepaid billing (Online Charging) Diameter based networks.
Diameter – Insert Subscriber Data Request / Response
A look at how the HSS can update the profile of an already in-use subscription using Insert Subscriber Data Request/Response.
PS Data Off
How turning mobile data off, doesn’t, in LTE and 5G.
ENUM – DNS based Call Routing
Using DNS to resolve E.164 phone numbers to routable SIP URIs
Telephony binary-coded decimal (TBCD) in Python with Examples
Chances are if you’re reading this, you’re trying to work out what Telephony Binary-Coded Decimal encoding is. I got you. Again I found myself staring at encoding trying to guess how it worked, reading references that looped into other references, in this case I was encoding MSISDN AVPs in Diameter. How to Encode a number … Continue reading Telephony binary-coded decimal (TBCD) in Python with Examples
The PLMN Problem for Private LTE / 5G
As the number of Private Networks built on LTE and 5G grow, how will PLMN allocation be managed?
Diameter Agents
A look at the 4 types of Diameter Agent
IMS Routing with iFCs
Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.
Diameter Droplets – The Flow-Description AVP and IPFilterRules
Getting to know IPfilterRules and the Flow-Description AVP
Open5Gs Database Schema Change
New database time to support slicing and a migration path for existing users.
A very unstable Diameter Routing Agent (DRA) with Kamailio
I’d been trying for some time to get Kamailio acting as a Diameter Routing Agent with mixed success, and eventually got it working, after a few changes to the codebase of the ims_diameter_server module. It is rather unstable, in that if it fails to dispatch to a Diameter peer, the whole thing comes crumbling down, … Continue reading A very unstable Diameter Routing Agent (DRA) with Kamailio
SIM Card Sniffing with Wireshark
Using Wireshark to sniff communication between your computer and Smart Card / SIM Card
SIM / Smart Card Deep Dive – Part 4 – Interacting with Cards IRL
Sending commands/APDUs to a real life Smart Card.
Confidentiality Algorithms in 3GPP Networks: MILENAGE, XOR & Comp128
A look at the Confidentiality Algorithms used in 3GPP Networks, MILENAGE, XOR & Comp128
SIM / Smart Card Deep Dive – Part 3 – APDUs and Hello Card
A look at APDUs and Interacting with Cards
Random Posts on SDM
Open5GS EPC: Static IP Addresses for UEs / APNs / Subscribers
Kamailio Bytes – UAC – Authenticate Outbound Calls
Magma – Facebook’s Open Source LTE / 4G EPC/OSS Platform
My first 5G Core: Open5Gs and UERANSIM
SIP Extensions – 100rel SIP (RFC3262)
1938 ATE PAX50 Step By Step Exchange
Basics of EPC/LTE Online Charging (OCS)
Kamailio World 2020
Forsk Atoll – WMS Map Tiles
