Re: [sipcore] RFC4028 : Very basic question in 8.1

[Roman Shpount <[e-mail]>]

On Sat, Jul 11, 2020 at 4:15 PM Paul Kyzivat <[e-mail]> wrote:

> On 7/11/20 12:11 AM, OKUMURA Shinji wrote:
> > P.13
> >     If the value of the Session-Expires header field is lower
> >     than the value of the Min-SE header field (possibly because the proxy
> >     increased the value of the Min-SE header field, as described below),
> >     the proxy MUST increase the value of the Session-Expires header field
> >     to make it equal to Min-SE header field value.
> >
> > Of course, negotiation with downstream proxies and UAS will occur.
>
> OK. But that only allows increasing up to the value of Min-SE. It
> doesn't otherwise allow increasing SE.
>

This is a very specific case where UAC does not support Session-Timer. In
other cases proxy should not increase Min-SE over the value of
Session-Timer and should fail the request with 422. It is not the reason to
drop session timer negotiation when both UA actually support this.

_____________
Roman Shpount