Vijay/John,
How can the Stateless proxy be prohibited from gerenating requests and
responses? For example if the Proxy cannot determine the route, it has to
initiate a 4xx response to the client that sent an Invite.
Lets say the proxy is looking up a Location Server when it receives an
Invite. While it is waiting for a response from the LS, if the client sends
a Cancel both(Invite and Cancel) requests are pending in the proxy. The
proxy could potentially send a 200 ok for the Cancel and a 487 for the
Invite. Another option is to just cancel the invite and not send any
response. In this case the client could keep retransmitting the Cancels and
probably Invites also.
Please comment.
Thanks
Sreedhar
[EMAIL PROTECTED] wrote:
>
> Hi,
> I have the following questions on a statelss proxy(refer the flow)!
> If P receives the 200ok from B and Cancel from A at the same time, should
> it follow the following flow? If so the stateless proxy is generating
> requests on its own (ACK and BYE to B)? Is it ok for the stateless proxy
to
> generate requests on its own?
>
> A-----Invite------>P B
> A P-----Invite------>B
> A------Cancel----->P<----200 OK-------B
> A P-------ACK------->B
> A P-------BYE------->B
> A<-----200 OK------P B
> A<-----487---------P B
> A P<----200 OK-------B
> A------ACK-------->P B
Sreedhar:
In your case, P will proxy the 200 OK upstream and the CANCEL
downstream.
It cannot correlate the CANCEL to the INVITE sent downstream earlier.
Stateless proxies do not generate responses (like the 487 shown in your
figure), nor do they generate requests like CANCEL/BYE on their own.
They are really dumb entities which proxy requests downstream and
responses upstream.
Since they are stateless, they tend to scale very well; the downside is
that there are not a whole lot of services (like forking) you can
provide within stateless proxies.
- vijay
--
Vijay K. Gurbani vkg@{lucent.com,research.bell-labs.com,acm.org}
eServices and Internet Software Group
Lucent Technologies/Bell Labs Innovations 263 Shuman Blvd., Rm 1A-413
Naperville, Illinois 60566 Voice: +1 630 224 0216 Fax: +1 630 713
0184
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