[SR-Users] SIP contact header question

Alex Balashov abalashov at evaristesys.com
Tue Mar 7 22:49:32 CET 2017

On Tue, Mar 07, 2017 at 03:44:31PM -0600, Jack Davis wrote:

> What kind of problems can arise from inserting said header?

Theoretically, none. It should be ignored, as per the RFC. Moreover, the
RFC doesn't _prohibit_ such a header in an in-dialog request, so you are
probably clear to add it. Fundamentally, ยง 12.2 says:

   Requests within a dialog MAY contain Record-Route and Contact header
   fields. However, these requests do not cause the dialog's route set
   to be modified...

I have certainly seen instances in the field where RRs in in-dialog
requests are not ignored, however. That's on the endpoints, of course,
but it can make things worse.

> I'm trying to find a way to get a pesky setup to start behaving, of course,
> without requiring them to make any changes.

That's always a tough gig.

Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) 
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

More information about the sr-users mailing list