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, […]
It’s 2021, and everyone loves Containers; Docker & Kubernetes are changing how software is developed, deployed and scaled. And yet so much of the Telco world still uses bare metal servers and dedicated hardware for processing. So why not use Containers or VMs more for VoIP applications? Disclaimer – When I’m talking VoIP about VoIP […]
Using Docker to spin up environments to test Kamailio in
So far with most of our discussions about Kamailio we’ve talked about routing the initial SIP request (INVITE, REGISTER, SUBSCRIBE, etc), but SIP is not a one-message protocol, there’s a whole series of SIP messages that go into a SIP Dialog. Sure the call may start with an INVITE, but there’s the 180 RINGING, the […]
The buttinski test phones I know and love.
How SIP hold using RFC6336 is implemented and how it looks in production.
Using FreeSWITCH to serve WebSocket / WebRTC connections
Things to keep in mind before using Kamailio as a Load Balancer for Asterisk
Kamailio world was an online event this year, but you can find all the videos here now they’ve all been posted.
An overview of FreeSWITCH’s ESL
Using UAC module to authenticate outbound calls where you need to respond to a 401 Unauthorised Response, or a 407 Proxy Authentication required
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 […]
How call routing in GSM works and it’s application in the Osmocom suite
Using Docker to containerize Kamailio instanances
My first Pull / Merge in the Kamailio project was to fix the IMS P-CSCF config
Some of the lesser used / utilized features of the SIP REGISTER method.
Using Kamailio to send HTTP requests (POST & GET) to a HTTP server and store the result.