I have requirement to pass-on the User-to-User SIP header which appears in both "INVITE" and later in "REFER" message back to the new INVITE.
CUCM 10.5 does the new INVITE based on the "Refer-To" header in the "REFER" message, but do not pass-through the "User-to-User" information in the newly INVITE.
Yes. Cisco acting as B2BUA and then dropping the "User-to-User" header for the new SIP invite created based on the "Refer-To" telephone number.
Are there any way to STORE this information in variable for the INCOMING message?
Add it back to the OUTBOUND messages on the same trunk based on above STORED values?
Sorry for the delayed reply.
Yes, if you are in the same INVITE dialog. Have a look at the Transparency section of the developer guide, you would use that feature to preserve consumed headers.
I tried that earlier and I can see the values remain as it is if I use Pass-through, but to the same message dialogues.
As I understand more on Cisco, for the REFER-TO, Cisco actually create a new SIP Invite dialogues with different call ID, so pass-through/transparency do not help here as Cisco acting here as B2BUA.
Open for any other ideas if anyone having to 1) Store the values in variable 2) call the stored values in new Invites/dialogues
Sorry for missing the REFER-TO part. Is this an in-dialog REFER or an out-of-dialog one. If it is in-dialog, you can use the built-in refer-passthrough script, copy it, and add what you need. If it is out-of-dialog, I don't believe there's no way to use Normalization to get at those headers.