Does Asterisk support SIP Outbound mechanism, RFC 5626

Asterisk Asterisk Support
1

Hi there,

Basically subj, does Asterisk provide support for SIP Outbound mechanism as defined by RFC 5626 when Asterisk is acting as the Registrar?

What I’m seeing is when a UAC advertises header ‘Supported: outbound’ with ‘Contact: <sip:user@domain.com; +sip.instance=xxxyyyzzzz’ in the REGISTER request, in reply Asterisk removes the ‘Supported: outbound’ header, which leads me to believe Asterisk does not support SIP Outbound?

Can someone confirm?

Thanks!

2

SIP outbound is not implemented in either chan_sip or chan_pjsip.

3

Thanks for confirming.

PJSIP datasheet shows support for SIP outbound.

Does Asterisk have a plan on implementing it in the near future?

Thanks.

4

Their SIP outbound support is in regards to their “pjsua” library which Asterisk does not use.

I know of noone actively working on any kind of outbound support.

5

Since Asterisk 17, thanks to ASTERISK-27971, SIP Outbound can be added to the Header Supported with support_outbound=yes. This is mentioned in the Wiki but not in the file pjsip.conf.sample (bug?). However, I am not sure if this is just a ‘fake’ support by adding the header without any functionality. Please, double-check.

Out of curiosity: Why are you asking exactly? UDP Double-CRLF-Refresh (not this ping pong from RFC 5626) is available since Asterisk 11. Is that not sufficient in your case?