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 […]
Some of the lesser used / utilized features of the SIP REGISTER method.
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.
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.
Function of Supported & Require headers in SIP.
How to encode and decode MCC and MNC as PLMN Identifiers
Feature Update on PyHSS the Python Home Subscriber Server
Using osmo-sim-auth to query USIM/SIM cards authentication mechanism.
Why and How GTP is used in LTE networks to carry user data.
Technical FAQs on Number Porting in Australia
What goes on in the background with Local Number Porting in Australia
Robust Header Compression (ROHC) and it’s use for compressing RTP / VoLTE traffic headers.
SDPs ptime values, what it means, how it can go wrong and how to fix it.
In vanilla RFC3261 SIP, a UA can only send a REGISTER request to a SIP Registrar. It can’t go via any intermediary proxies. That’s obviously a bit of a problem, as we build out our network we might have a series of load balancers that send traffic to a pool of Registrars, but according to […]