>>But is there a good way to determine INVITE vs re-INVITE statelessly?

Thinking about it, I guess one way is for the stateless proxy
to look at the Record-Route and Route.

Obviously the stateless proxy would have to use Record-Route
because otherwise it wouldn't see the re-INVITE anyway.

Then, an INVITE usually won't have a Route header.
Whereas a re-INVITE usually will.

But this won't work for all cases.
(For example, if using the Path header to a SIP REGISTRAR/PROXY.
 The REGISTRAR/PROXY will set Route headers to route the call
 to the UA so in this case this will be a INVITE with Route headers)




-----Original Message-----
From: Attila Sipos 
Sent: 01 May 2007 10:49
To: 'Vikram Chhibber'
Cc: chozhan A; [EMAIL PROTECTED]; sip implementors
Subject: RE: [Sip-implementors] RFC 2543: INVITE vs re-INVITE



I agee, if the proxy has knowledge then looking for
a matching existing dialog is the best way.


But is there a good way to determine INVITE vs re-INVITE statelessly?





-----Original Message-----
From: Vikram Chhibber [mailto:[EMAIL PROTECTED]
Sent: 01 May 2007 10:16
To: Attila Sipos
Cc: chozhan A; [EMAIL PROTECTED]; sip implementors
Subject: Re: [Sip-implementors] RFC 2543: INVITE vs re-INVITE


The better approach is if the proxy has the knowledge of confirmed SIP
dialog, if the re-invite is received, it can search for the dialog and
if it exists, it is a re-invite.
Checking of Tags is not a reliable approach as the initial invite's
>From header may not have tag. If you rely on checking the presence of
To header tag as re-invite, then re-invite from the termination may
not have a To tag and you may confuse this with initial invite
(Remember To and From headers are swapped if a mid-dialog request is
sent from termination side).

On 5/1/07, Attila Sipos <[EMAIL PROTECTED]> wrote:
>
>
> I have a different question.
>
> An RFC 2543 re-INVITE could have just a From tag, just like an RFC3261 INVITE.
>
> So, how to distinguish between an RFC2543 re-INVITE and an RFC3261 INVITE?
>
>
> Regards,
>
> Attila
>
>
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Behalf Of chozhan A
> Sent: 01 May 2007 04:31
> To: [EMAIL PROTECTED]; 'sip implementors'
> Subject: Re: [Sip-implementors] RFC 2543: INVITE vs re-INVITE
>
>
> Hi,
>
>   Does RFC 2543 says initial INVITE MUST NOT have from tag or is it optional
>
>   Thanks/Regards
>   AC
>
> Bala Neelakantan <[EMAIL PROTECTED]> wrote:
>   In the original INVITE there will be no From and To Tags. In the Re-INVITE
> there will be a To Tag.
>
> Thanks,
> Neel
>
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:sip-implementors-
> > [EMAIL PROTECTED] On Behalf Of chozhan A
> > Sent: Monday, April 30, 2007 2:54 AM
> > To: sip implementors
> > Subject: [Sip-implementors] RFC 2543: INVITE vs re-INVITE
> >
> > Hi all,
> >
> > If the Caller and Callee both are 2543 end points.
> > How to distinguish between INVITE and re-INVITE at a proxy(transaction
> > stateful) that establishes the call between them and record routes.
> >
> > Regards
> > AC
> >
> >
> > ---------------------------------
> > Check out what you're missing if you're not on Yahoo! Messenger
> > _______________________________________________
> > Sip-implementors mailing list
> > [email protected]
> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>
>
>
>
> ---------------------------------
>  Check out what you're missing if you're not on Yahoo! Messenger
> _______________________________________________
> Sip-implementors mailing list
> [email protected]
> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>
> _______________________________________________
> Sip-implementors mailing list
> [email protected]
> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>

_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors

Reply via email to