Kamailio 101 – Part 3 – Routing Blocks & Structure
Nick How to use routing blocks and structure your code in Kamailio.
VoIP
Kamailio 101 – Part 2 – Installation & First Run
Installing Kamailio on Ubuntu, basic rules for wring config files and we respond to SIP messages!
Kamailio 101 – Part 1 – Introduction
Introducing Kamailio SIP Server & explaining it's uses.
What is a SIP Registrar?
Explanation of what a SIP Registrar does, Contact header and Address on Record, and how it all fits together to route messages correctly.
SIP REGISTER status & why it’s not what you think it is.
SIP Register status, expires and why it's often misunderstood.
SIP Concepts – Record Routing
Explanation of Record-Routing, why it exists and how it's used.
SDP – Session Description Protocol – Overview
Understanding the SDP protocol and how it's used to negotiate and setup media sessions.
RTPengine – Installation & Configuration (Debian 11 / Ubuntu 19.04 and below)
Installation & basic configuration of the Sipwise NGCP rtpengine
Why z9hG4bK?
Why does every SIP branch start with z9hG4bK?
SIP Via Header
What a Via header does, how to interpret it and how it's used in SIP routing.
Kamailio Bytes – MySQL Database Backend for Module Config
Many Kamailio modules require, or have additional functionality, when you’re using a database backend. There’s a few options, but for this tutorial we’ll use a MySQL database backend. To begin…
DTMF over IP – SIP INFO, Inband & RTP Events
DTMF's implementation in VoIP and the 3 types of DTMF encoding (Inband, RTP Event and SIP INFO)
RFC2976 / RFC6086 – SIP INFO
SIP INFO was designed to carry session related information during a session. SIP was designed to setup and tear down sessions, with little thought given to what happens after the…
RFC2833 – RTP Events
RFC2833 was designed to carry DTMF signalling, other tone signals and telephony events in RTP packets. This was later superseded by RFC4733, but everyone still referrers to this protocol as…
Reverse MD5 on SIP Auth
How the SIP Authentication mechanism works, and how we can reverse it to check the password we're expecting is the encrypted value we're seeing in captures.