Hi Jagan,

I think UAS behavior is not correct as per SIP RFC.
In no case a UAS (US which receive calls) can send a Cancel. It can only
send Responses. 

Can you provide us the logs (tcpdump) of UDP messages send by UAS and
Gateway? Also give us some more description regarding the UAS and Media
Gateway device (company, model and version). Probably it might be a bug
/ issue in UAS SIP stack code.

PS: Try the same case with other device and contact vendor of UAS
regarding this issue. They might has new version of firmware already.

Regards,

Vishal Mathur 
Jabber ID: [EMAIL PROTECTED]
Symantec Corporation
www.symantec.com
_________________________________
Office: +91-20-66067655

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Jagan Mohan
Sent: Wednesday, November 14, 2007 5:35 PM
To: [email protected]
Subject: [Sip-implementors] UAS sending a CANCEL

Hi All,

   I have the following call flow:

PSTN===Media Gateway-----UAS

   Call flow is made from PSTN phone to UAS.

 Media --------------UAS
Gateway

 INVITE-------->
           <--------100 Trying
            <--------180 Ringing

    At this point, can UAS send a CANCEL to the media gateway?

    From the discussion in various mailing lists, I understand that UAS
can
not send a CANCEL request in this scenario. It can send a 4xx/6xx

    But, I could not find any RFC which talks about this. Could any one
please provide info. on the RFC which talks about the above scenario?

TIA,
Jagan
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors

_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors

Reply via email to