Thanks Brett,
So I think same should be added for UAS
<Snip from RFC section 8.1>
If the request doesn't indicate support for the session timer but
contains a session interval that is too small, the proxy cannot
usefully
reject the request, as this would result in a call failure.
Rather, the
proxy SHOULD insert a Min-SE header field containing its
minimum
interval. If a Min-SE header field is already present, the
proxy SHOULD
increase (but MUST NOT decrease) the value to its
minimum interval. The
proxy MUST then increase the Session-Expires
header field value to be equal to the value in the
Min-SE header
field, as described above.
</Snip from RFC>
Regards
S.Radha krishna
________________________________
From: Brett Tate <[email protected]>
To: Radha krishna <[email protected]>;
"[email protected]"
<[email protected]>
Sent: Wednesday, February 18, 2009 6:42:31 PM
Subject: RE: [Sip-implementors] Sending 422
It looks like Section 9 may have forgotten to indicate the behavior when UAC
timer support not indicated. Section 8.1 allows a proxy to increase the
Session-Expires; I see no reason why the same cannot be done by the UAS.
> -----Original Message-----
> From: [email protected] [mailto:sip-
> [email protected]] On Behalf Of Radha krishna
> Sent: Tuesday, February 17, 2009 9:48 PM
> 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
>
>
>
>
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> Sip-implementors mailing list
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