Re: [reSIProcate] How to answer a refer that was cancelled
On 2011 September 20, Tuesday 04:30:12 you wrote:
> On Mon, Sep 19, 2011 at 2:05 PM, SZOKOVACS Robert
>
> <rszokovacs@xxxxxxxxxxxxxxx> wrote:
> > Hi,
> >
> > I have a resiprocate-based server accessed by a not-resiprocate-based
> > client,
> > sending a REFER. Sometimes I encounter the following situation:
> > Since I do some async processing, it is possible that the client changes
> > it's
> > mind and cancels the REFER with expires=0.
> > And then I'm left with an unanswered request and I can't see a way around
> > it,
> > if I answer it from onExpiredByClient(), it will send the reply to the
> > second
> > REFER, the one with expires=0.
> > I suspect it's illegal for the client to send two messages in the same
> > subscription without waiting for an answer, but the client does it
> > anyway, so
> > I need to handle it.
> > Any advise?
> >
> > TIA
> >
> > br
> >
> > Szo
> > _______________________________________________
> > resiprocate-devel mailing list
> > resiprocate-devel@xxxxxxxxxxxxxxx
> > https://list.resiprocate.org/mailman/listinfo/resiprocate-devel
>
> Hi Robert,
>
> I'm curious about the two REFER requests, are you receiving them as
> two separate transactions (for the same dialog)?
>
> Also, what would you want the behavior to be? I'm thinking it should
> only cancel the implied subscription in the REFER but leave the
> creation of the new invite (to the Refer-To target) as is. This seems
> to be what is suggested in RFC 3515, Section 2.4.4.
>
> So, I guess you should process the REFERs as usual: accept (202) the
> first one, let the DUM generate the sip frag NOTIFYs when it needs to
> (i.e. when you are sending the new call leg) then, upon receiving the
> REFER / Expires: 0, properly accept it then end the implied
> subscription (I'm rusty when it comes to handling subscriptions in
> DUM, but I can check tomorrow).
The problem is that I can't accept the first one, because I need some async
magic to determine if I can accept it or not, and while I'm doing it the
second REFER arrives, and from that point whatever I do with the
ServerSubscription, resip will generate a packet answering the second REFER. I
can't find a way to send anything with the CSeq of the firts one.
br
Szo