Missing Require: 100rel on 180 ringing and 183 session progress

Hello, I’m using an Asterisk 15.6 with PJSIP. A provider requires PRACK support from us and we have therefore enabled the value “100rel = yes” in the configuration.

The provider sends INVITE to Asterisk with the header “Supported: 100rel” and expects in our responses 180 and 183 to have a “Require: 100rel” as well as the “Rseq” field filled in. Asterisk, however, doesn’t put “Require: 100rel” in the 18X responses.

Any idea ?

Waiting for your comments, thanks in advance.

Upgrade to an actual recent supported version of Asterisk. 15.6.0 is over 5 years old, and I know there have been fixes to 100rel.

And in recent versions you would most likely want to set it to peer_supported[1].

[1] res_pjsip - Asterisk Documentation

We will try to update to version 20. I will keep you posted.

Hello, we installed Asterisk 18 where I see that function “peer_supported” is present btw on reload I got “Error parsing 100rel=peer_supported at line 118…” it seems that value is not allowed. What I did it wrong ?

You haven’t specified what version of 18. If it’s an old version, then that value wouldn’t exist.

Hi, version running is 18.12.1, is this too older ?

That option first appeared in 18.16.0.

Hello, everything works fine using Asterisk version 20.6.0. Thanks for your support.