The ACK needs to be sent on the address that is mentioned in the Contact header of reponse, unless it is overridden by Record-Route etc. I assume that there is some error in UAS here which is causing this. However, if UAC acts according to protocol it would send ACK to 172.20.16.1.
regards Rayees -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joerg Scholz Sent: Tuesday, May 08, 2007 3:46 PM To: '[email protected]' Subject: [Sip-implementors] echot contact field in 401 Hi all, I have a quick question regarding the usage of the Contact field in 401 message. In the trace here you can see that in the 401 the contact field from the invite is just send back. So for my understanding the ack to the 401 is send then to the own IP address in such a case. Is there any rule for that specific behaviour? INVITE sip:[EMAIL PROTECTED] SIP/2.0 Max-Forwards: 50 Via: SIP/2.0/UDP 172.20.16.1:5060;rport;branch=z9hG4bK23268366631621974202502 From: <sip:[EMAIL PROTECTED]>;tag=723776519979065179735928398741 To: <sip:[EMAIL PROTECTED]> Call-ID: [EMAIL PROTECTED] CSeq: 1 INVITE Contact: <sip:[EMAIL PROTECTED]> User-Agent: TELES.VoIPBOX FX 13.0b 885 Allow: INVITE,ACK,CANCEL,BYE,UPDATE,REGISTER,PRACK,INFO,NOTIFY,REFER Timestamp: 1175605035 Content-Type: application/sdp Content-Length: 520 v=0 o=- 6 1 IN IP4 172.20.16.1 s=- c=IN IP4 172.20.16.1 t=0 0 m=audio 29000 RTP/AVP 18 18 18 18 4 0 8 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=ptime:20 a=rtpmap:18 G729A/8000 a=fmtp:18 annexb=no a=ptime:20 a=rtpmap:18 G729B/8000 a=fmtp:18 annexb=yes a=ptime:20 a=rtpmap:18 G729AB/8000 a=fmtp:18 annexb=yes a=ptime:20 a=rtpmap:4 G723/8000 a=fmtp:4 annexa=yes a=ptime:60 a=rtpmap:0 PCMU/8000 a=ptime:20 a=rtpmap:8 PCMA/8000 a=ptime:20 SIP/2.0 401 Unauthorized Via: SIP/2.0/UDP 172.20.16.1:5060;rport;branch=z9hG4bK23268366631621974202502 From: <sip:[EMAIL PROTECTED]>;tag=723776519979065179735928398741 To: <sip:[EMAIL PROTECTED]>;tag=GR52RWG346-34 Call-ID: [EMAIL PROTECTED] CSeq: 1 INVITE Contact: <sip:[EMAIL PROTECTED]> WWW-Authenticate: Digest realm="192.168.1.1", nonce="1D9C86B49DD0C77FB73188939DA7E174", opaque="9CCC512F6BCF46A90987581E8F4FCCD9", algorithm=md5 User-Agent: TELES.VoIPBOX FX 13.0b 885 Timestamp: 1175605035 Content-Length: 0 Thanks in Advance Joerg _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ ---------------------------------------------------------------------------------- IMPORTANT The information contained in this e-mail any attachments is intended only for the named recipient and may be privileged or confidential. If you are not the intended recipient, please notify us immediately on +44 (0)1908 425000 and do not disclose, copy, distribute or take any action based on the contents of this e-mail. You should understand and accept that, when communicating with us by e-mail, it is not a totally secure communication medium. We accept no liability for any direct, indirect or consequential loss arising from any action taken in reliance on the information contained in this e-mail and give no warranty or representation as to its accuracy or reliability. DIGITALK has the facility to monitor and read both incoming and outgoing communications by e-mail. In line with industry efforts to reduce the proliferation of Un-Solicited SPAM messages, DIGITALK uses various methods including Reverse-DNS lookups and ban-lists to prevent malicious content reaching our users. This message and any attachments has been scanned for known viruses. However, we would advise you to ensure the content is indeed virus free. We do not, to the extent permitted by law, accept any liability (whether in contract, negligence or otherwise) for any virus infection and/or external compromise of security and/or breach of confidentiality in relation to transmissions sent by e-mail. VAT No: GB 876 3287 81. Reg No: 3080801 Place of Registration: England Registered Office Address: 2 Radian Court, Knowlhill, Milton Keynes ----------------------------------------------------------------------------------" _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
