Categories
EPC LTE Mobile Networks RFCs & Standards SDM Voice over IP

Basics of EPC/LTE Online Charging (OCS)

A glimpse into the complexities of prepaid billing (Online Charging) Diameter based networks.

Categories
FreeSWITCH Voice over IP

HTTP PUT call recordings from FreeSWITCH

Using mod_httpapi to HTTP POST call recordings to a remote server

Categories
Kamailio Voice over IP

ENUM in Practice with Kamailio

Using ENUM to resolve E.164 numbers into SIP URIs using Kamailio.

Categories
EPC Mobile Networks RFCs & Standards Voice over IP

Docker & BIND as an ENUM Playground

A Bind environment in a Docker container for experimenting and learning ENUM for DNS based Call Routing.

Categories
IMS / VoLTE Mobile Networks RFCs & Standards SDM Voice over IP

ENUM – DNS based Call Routing

Using DNS to resolve E.164 phone numbers to routable SIP URIs

Categories
5G SA EPC IMS / VoLTE LTE Mobile Networks SDM Voice over IP

IMS Routing with iFCs

Peer behind the magic curtain at how IMS networks route your VoLTE and VoNR calls, and how iFC (Initial Filter Criteria) achieve this.

Categories
FreeSWITCH IMS / VoLTE Mobile Networks Voice over IP

Adding support for AMR Codec in FreeSWITCH

Adding support for AMR Codec in FreeSWITCH

Categories
EPC Kamailio LTE Mobile Networks SDM Software

A very unstable Diameter Routing Agent (DRA) with Kamailio

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, […]

Categories
Software Voice over IP

VoIP is an only child – ‘Gotchas’ on running VoIP applications inside Containers

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 […]

Categories
Asterisk Kamailio Voice over IP

Using Docker to develop SIP solutions with Kamailio

Using Docker to spin up environments to test Kamailio in

Categories
Kamailio Voice over IP

Kamailio Bytes – OnReply Route

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 […]

Categories
Australian Telco Voice over IP

I like big Butts and I cannot lie.

The buttinski test phones I know and love.

Categories
Voice over IP

SIP Hold – With RFC6337

How SIP hold using RFC6336 is implemented and how it looks in production.

Categories
RFCs & Standards Voice over IP

FreeSWITCH WebRTC with sipML5

Using FreeSWITCH to serve WebSocket / WebRTC connections

Categories
Asterisk Kamailio Voice over IP

Kamailio Bytes – Gotchas with Kamailio as an Asterisk Load Balancer

Things to keep in mind before using Kamailio as a Load Balancer for Asterisk

Categories
Kamailio Voice over IP

Kamailio World 2020

Kamailio world was an online event this year, but you can find all the videos here now they’ve all been posted.

Categories
Voice over IP

FreeSWITCH + ESL = Programmable Voice

An overview of FreeSWITCH’s ESL

Categories
Kamailio Voice over IP

Kamailio Bytes – UAC – Authenticate Outbound Calls

Using UAC module to authenticate outbound calls where you need to respond to a 401 Unauthorised Response, or a 407 Proxy Authentication required

Categories
EUTRAN IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM Voice over IP

Diameter and SIP: Registration-Termination-Request / Answer

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 […]

Categories
EPC IMS / VoLTE LTE Mobile Networks RFCs & Standards SDM Voice over IP

Diameter and SIP: User-Authorization-Request/Answer

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.