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
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, […]
Peculiar padding problem perplexes poor programmer.
Info on PyHSS new support for SCTP as well as TCP.
How to find a subscriber location within the network.
Thanks to some recent developments, PyHSS has had a major overhaul recently, and is getting better than ever, Some features that are almost ready for public release are: Config File Instead of having everything defined all over the place a single YAML config file is used to define how the HSS should function. SCTP Support […]
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) […]
What the Origin-State-Id AVP does and how it is used to track if a Diameter peer restarts.
A look into the signalling messages between Network elements in an Evolved Packet Core exchanged during the Attach Procedure
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.
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 Server-Assignment-Request/Answer commands are used so a SIP Server can indicate to a Diameter server that it is serving a subscriber and pull the profile information of the subscriber. […]
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 […]
An update to PyHSS to support IMS Authentication for VoLTE
Introducing C Diameter Peer module in Kamailio to manage Diameter Peers, monitor their state and handle the connections.
Feature Update on PyHSS the Python Home Subscriber Server
Using osmo-sim-auth to query USIM/SIM cards authentication mechanism.
Periodic Tracking Area Update timer purpose