On Jul 18, 2004 at 11:22, Linus Surguy linus@magrathea-telecom.co.uk wrote:
Contacts are used to advertised wherebouts for subsequent in-dialog requests coming back to your UAC. For that reason, I don't entirely understand why the UAC includes Contact in CANCEL at all -- all in all CANCEL is used to discontinued estabslishment of a dialog. Anyhow, it should not matter the Contact content is invalid since there is no use for the header field in this case at all.
Sorry, just realised that in a half-awake state I typed rubbish. I meant that the 'call-id' was not rewritten - don't know why I mentioned contact! (In the INVITE to the Cisco it is blah@213.x.x.x and in the CANCEL to Cisco it is blah@10.x.x.x
Then it's even stranger. ser/nathelper doesn't re-write the callid. Maybe you have a nat box on the way, which is trying to be smart and fix sip messages.
Andrei