An overview of FreeSWITCH’s ESL
Some of the lesser used / utilized features of the SIP REGISTER method.
Running multiple instances of Kamailio on the same server using init.d
Using Transport Layer Security (TLS) to protect SIP traffic from modification / manipulation and guarantee message authenticity.
Lessons learned about setting up VoLTE / IMS Networks at small scale.
How the P-CSCF address is assigned to a UE in Protocol Configuration Options (PCO) during bearer establishment.
Using sipcmd to test SIP Services from the command line
Using Kamailio’s UAC module to send outbound SIP REGISTER messages
The exchange between a UE and P-CSCF to put SIP traffic into IPsec encapsulated payloads.
Using KEMI to write routing logic using languages like Python, Ruby, Lua and JS
Viewing the payload of an Encapsulated Security Payload in Wireshark.
Function of Supported & Require headers in SIP.
AP, IX, IP & DX – The meaning of Dispatcher states in Kamailio’s Dispatcher module.
Stateless Kamailio SIP proxy example for changing Caller ID values
Robust Header Compression (ROHC) and it’s use for compressing RTP / VoLTE traffic headers.
SIPp (a performance testing tool for SIP) to simulate many concurrent calls leading to many concurrent transcoding sessions.
Some TM (Transaction Module) use cases in Kamailio