A look at the 4 types of Diameter Agent
Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.
Getting to know IPfilterRules and the Flow-Description AVP
New database time to support slicing and a migration path for existing users.
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, […]
Using Wireshark to sniff communication between your computer and Smart Card / SIM Card
Sending commands/APDUs to a real life Smart Card.
A look at the Confidentiality Algorithms used in 3GPP Networks, MILENAGE, XOR & Comp128
A look at APDUs and Interacting with Cards
The basics of Smart Cards & their File System
Getting up close and personal with Smart Card / SIM Cards
I put together some laser cut case designs for the Osmocom SIMtrace, Quite happy with the results. If you want to cut your own, I’ve sent the DXF files to the mailing list, and will try and add to the project. Also uploaded here as seems some folks had issues getting them from the mailing […]
Acronyms and cryptography – a look at Subscriber Identifiers in 5G
What do Unlock SIMs sold online actually do and how do they do it?
Using Wireshark to filter S1 messaging to find signalling from a specific subscriber,
Unlocking Carrier Privileges through certificate on a UICC
This is part of a series of posts focusing on common Diameter request pairs, looking at what’s inside and what they do. The Authentication Information Request (AIR) and Authentication Information Answer (AIA) are one of the first steps in authenticating a subscriber, and a very common Diameter transaction. The Process The Authentication Information Request (AIR) […]
Why the BaiCells PLMN changes?
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 Registration-Termination Request / Answer allow a Diameter Client (S-CSCF) to indicate to the HSS (Diameter Server) that it is no longer serving that user and the registration has […]
The Diameter User-Authorization-Request and User-Authorization-Answer commands are used as the first line of authorization of a user and to determine which Serving-CSCF to forward a request to.