Sachin,
That is an interesting question. I could make a case that this should be handled
independently for each user. (For instance, there is no guarantee that the same result
will be returned for all users. A proxy might prioritize requests for favored clients.
OTOH, the same argument applies, to a lesser extent, to different requests by the same
client. And from a practical point of view there is much to be said for sharing this
knowledge among multiple clients when available.
I will have to defer to somebody more expert on this one.
Paul
Sachin Shenoy wrote:
>
> Hi Paul,
>
> On the same lines I have a query regarding handling of 503.
>
> According to RFC
>
> "21.5.4 503 Service Unavailable
> ...
> A client (proxy or UAC) receiving a 503 (Service Unavailable) SHOULD
> attempt to forward the request to an alternate server. It SHOULD NOT
> forward any other requests to that server for the duration specified
> in the Retry-After header field, if present."
>
> Consider that 2 users, user-A & user-B, who are sharing the same code
> on the same server ( ie. using the same UA process).
>
> User A sends request out. (The destination was resolved and the request was
> sent out).
> But the request was rejected with a 503 response which had retry-after header.
>
> Now User B tries to send a request out, which resolved to the same server.
> Should the stack send the request out without bothering about the previous 503
> that it had received, or should it try another server?
>
> I think in this case we should not send the request to the server. Because
> in a
> gateway there could be thousands of users using the same UA, and if a server
> is down for maintenance, there is no point in again and again sending requests
> (from different users) to the server that had already responded with 503.
>
> Hope I got it right?
>
> Thanks
> Sachin
>
> At 10:30 AM 11/17/02 -0500, you wrote:
> >Dinesh,
> >
> >I think there is a problem with the formulation of your question. You are
> >asking about two users using the same UA. But a UA is an agent for a user.
> >If you have two users, then you have two UAs. Their UAs may both be hosted
> >by the same server, running the same code, and they might share the same
> >From address, but they should still be considered to be two UAs.
> >
> >Each UA is constrained by the rules about concurrent messages, but one UA
> >is not constrained by the actions of the other UA.
> >
> > Paul
> >
> >Dinesh wrote:
> > >
> > > Hi,
> > >
> > > I was not able to find a reply to the below posting
> > > by Ravi. I too have a similar issue with the MESSAGE
> > > request.
> > >
> > > Consider the scenario of two users using the same UA.
> > > If user A has sent a MESSAGE request or any out-of-
> > > dialog request to a URI say sip:[EMAIL PROTECTED]
> > > and the user A is yet to get a final response for the
> > > request.
> > > Now user B is trying to send a MESSAGE request
> > > to the same URI. Should the UA allow the second
> > > MESSAGE request to pass through or not?
> > >
> > > Can somebody clarify this?
> > >
> > > Regards,
> > > Dinesh
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>
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