A simple trick to find all the system paths used in FreeSWITCH
In our last few posts we got CGrateS setup in order to have rates and tariffs in the system, so we can price a call. Where we ended we were able to use the APIerSv1.GetCost method to get the cost of a call, and today, we’re going to actually create some rated CDRs. So again […]
Extracting SDP Parameters with Kamailio
A quick look at a possible cause for “INCOMPATIBLE DESTINATION” errors in FreeSWITCH.
Bad Extension is nothing to do with the Dialplan…
Quirks and gotchas of working with SMS on IMS on iPhones.
Some tricks to handle if you’ve got multiple headers all with the same name in Kamailio
Starting calls from FreeSWITCH
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 […]
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 […]
How SIP hold using RFC6336 is implemented and how it looks in production.
An overview of FreeSWITCH’s ESL
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 […]
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.
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.