[SIPForum-discussion] Using the Contact-URI in the Request-URI field of the INVITE

[Giannis Gonianakis]

Hi all,

I am new to SIP and i'd like a little help on this:
In case the session initiator UA knows the contact-uri of the other  
party (the UA being called), is it possible to send the INVITE method  
using the contact-uri in the Request-URI field instead of using the  
Address-Of-Record?

e.g.
INVITE sip:user at the_contact_URI.domain.org
To: user at domain.org
From: caller at anotherdomain.org
contact: caller at the_contact_URI.anotherdomain.org
...
instead of

INVITE sip:user at domain.org
To: user at domain.org
From: caller at anotherdomain.org
contact: caller at the_contact_URI.anotherdomain.org
...

Thanks in Advance,
-Giannis