Has the SIP stack changed over the past years?


We want to implement a Asterisk version 16.x at a customer site and their PBX partner has only ‘certified’ the version 13.x of the Asterisk. So we’re on the brink of re-certification. However if the SIP stack didn’t change over those past years then re-certification is not needed.

Could someone help with this question ?


That depends on what “SIP stack didn’t change” actually means. There are two channel drivers for SIP, chan_sip and chan_pjsip. They each use their own stack. The chan_sip module rarely, if ever, receives changes. The chan_pjsip module does receive changes and also is updated to new versions of the PJSIP stack.

Thanks for the quick reply. Could you explain what is the difference between those two ?

We’re looking at the SIP stack needed for a SIP trunk to another PBX.

The chan_sip module is a self-written SIP implementation which has been deprecated. The chan_pjsip module uses a third party SIP stack called PJSIP by a company called Teluu.

Thanks for the quick help!

With (nearly) each (minor) Asterisk release, the SIP channel driver(s) changes. Consequently, a statement like ‘13.x’ was rather useless already because even back then two SIP channel drivers existed. Which one did they support, or even both? And I would not call Asterisk 13.0.0 the same as Asterisk 13.38.3, seven years apart.

Those certified statements better suite closed-source phone systems which only patch security fixes but do not improve interoperability or fix bugs over time. Therefore, bad news: You have to run tests yourself before upgrading a live system. Actually, you should have Asterisk 16 LTS in place already and do your tests with Asterisk 18 LTS. The good news: Thanks to Asterisk’s openness you can roll-back changes and/or start in-depth investigations of the bugs yourself.

Long story short, there is a easy answer to your question. It is simply work to be done.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.