No it is not valid to send SDP in ACK as offer-answer is complete for call setup and any new SDP thereafter shall be treated as new offer. Unlike PRACK, ACK message do not have a response so it is not correct to send SDP in the ACK. Any new offer after call setup should be made through ReINVITE or UPDATE and not through ACK.
Regards Anuradha Gupta ARICENT -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Alejandro Orellana Sent: Friday, November 14, 2008 12:11 AM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] SDP offer/answer question All, in the following call flow, is it valid for endpoint A to send a ACK with SDP? endpointA GW ------------INVITE w/SDP (offer)--------------------------------------> <------------100 trying----------------------------------------------------- <---------------200 OK w/SDP (answer)------------------------------ ----------------ACK w/SDP (identical to the answer) ------------> . thanks in advance Alejandro _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error,please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors