Unregister SIP UAC message

Solution 1:

An "unregister" is a REGISTER wherein you set the expires for one or more Contact URIs to 0. You may do so either with the Expires header - Expires: 0 - which applies to all Contact URIs in the REGISTER, or with a parameter - Contact: <sip:foo@bar>;expires=0 - which will only affect that URI's registration.

You may also unregister ALL contact URIs for your address-of-record by adding Contact: * and Expires: 0.

Solution 2:

Well, I asked this question after hours of searching, and finally I found something relevant:

I cloned my initial Registration request, took the contact headers, and added expires(0) values to them, and I added an expires=0 header, worked like a charm though I didn't get the contact headers back from the server with expires=0, but it did unregister me since I stoped getting 102 Options from it (it used to send 5 of these every few seconds).

So thanks anyway to who ever was trying to help! Adam.