[asterisk-users] PJSIP Contact User in Dial INVITE

[Juan van Rooyen]

Hi all,

This is a followup from my "Getting around semi-colons" question.

I've specified:
contact_user=01234567\;tgrp=01234567\;trunkcontext=telecom.co.nz under my
registration section for the trunk.

This is all fine and I successfully got Asterisk 13 + pjsip registered to
our BroadWorks-based provider.
However, I see the contact_user field only gets used upon registration, and
not during an INVITE.

During Registration:

Contact: <sip:
01234567;tgrp=01234567;trunkcontext=telecom.co.nz at 192.168.252.10:5060> 

During INVITE:

Contact: <sip:746775a8-e08c-4b73-a37e-fa48fe45a36b at 192.168.252.10:5060>

The only questions I have is:
1. Is this expected/known behaviour? eg. pjsip won't use the contact user
for anything else?
2. If not, where should I be specifying the contact_user to make pjsip use
it in INVITEs? Is this where the AoRs come in?
3. Are those Contact headers used for some internal reference/record keeping
for the calls? Or... 
4. Can I mess with the Contact Header with the PJSIP_HEADER function?

Thanks again for the help, just wrapping my head around this new channel
driver :)
Juan