Asterisk 12 - PRACK (100rel) Support

I have been running Asterisk 12 between two servers to try out the PRACK (100rel) support that is required by one of our customers.

Each server is set-up to look like one end of a SIP trunk and I can make calls between the two using the Asterisk CLI and a dial-plan that sends back Ringing (180) and waits 10 seconds before answering the call. I was expecting the calling server to send a PRACK message when it received the 180 Ringing with a Require: 100rel from the called server.

What I am confused about is that the calling server does not send ‘Require: 100rel’ in the Ringing (180) response even though the Invite clearly has 'Require: 100rel. I have used the same configuration below in pjsip.conf at each end.


Am I missing something, does Asterisk 12 not support reliable responses to incoming invites that have 100rel supported or required, it seems whatever I set the 100rel field to in the called server’s pjsip.conf it basically ignores it. For example if I set the field to ‘no’ but the calling sever’s 100rel field is set to ‘required’ I would expect it to not accept the call, however it answers OK.

Can someone help, do I have to set-up called server differently to the calling server, is this a bug/issue, or am I misunderstanding the operation in Asterisk. BTW I am currently using version 12.0.


Push your query to the asterisk-users mailing list -

You’re more likely to get a better response there than here, based on who reads that list vs. who reads and responds on the forums.