Since the proxy is call stateful, the INVITE which goes to UA2 shall have Sesssion-Expires field and hence UA2 can reject with 422.
Somesh * Please do not take print out of this e-mail unless its absolutely necessary * -----Original Message----- From: [email protected] on behalf of Radha krishna Sent: Wed 2/18/2009 8:18 AM To: [email protected] Subject: [Sip-implementors] Sending 422 Hi Consider the following topology UA1 ----- Call-stateful-proxy ------ UA2 UA1 does not support session timer, Make a call to UA2. Call-stateful-proxy adds Session-Expires:100 header and forwards to UA2. UA2 minimum session expires is 900. But in this case INVITE will not contain "support: timer". According section 9, UAS can reject with 422 only if there is a timer tag in supported header <Snip from RFC> If an incoming request contains a Supported header field with a value 'timer' and a Session Expires header field, the UAS MAY reject the INVITE request with a 422 (Session Interval Too Small) response if the session interval in the Session-Expires header field is smaller than the minimum interval defined by the UAS' local policy. When sending the 422 response, the UAS MUST include a Min-SE header field with the value of its minimum interval. This minimum interval MUST NOT be lower than 90 seconds. </Snip from RFC> Also UAS cannot increase the session expires duration <Snip from RFC> The UAS MUST NOT increase the value of the Session-Expires header field. </Snip from RFC> What should be the behavior of UAS here? 1) accept the call with 100 seconds? 2) Increase the duration to 900 seconds while sending 200 Ok? Note: Session timer should not be turned-off Regards S.Radha krishna _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors EMAIL DISCLAIMER : This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Any unauthorised distribution or copying is strictly prohibited. If you receive this transmission in error, please notify the sender by reply email and then destroy the message. Opinions, conclusions and other information in this message that do not relate to official business of Mascon shall be understood to be neither given nor endorsed by Mascon. Any information contained in this email, when addressed to Mascon clients is subject to the terms and conditions in governing client contract. Whilst Mascon takes steps to prevent the transmission of viruses via e-mail, we can not guarantee that any email or attachment is free from computer viruses and you are strongly advised to undertake your own anti-virus precautions. Mascon grants no warranties regarding performance, use or quality of any e-mail or attachment and undertakes no liability for loss or damage, howsoever caused. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
