[Serusers] Support for Gateway still on RFC2543

[Jan Janak]

The gateway should not use To, it should use the Request-URI as the
final destination. The reason is that the value put into the To header
field is generated by the calling user agent and it is not guaranteed
that the final recipient (gateway in this case) would know how to
interpret it.

This is different with the Request-URI since this is generated by the
previous hop (usually the proxy in front of the gateway) and it can make
sure that the Request-URI is in the format the gateway would recognize.

For example, if I create alias foo at iptel.org that would be mapped to
+123456 at iptel.org and call sip:foo at iptel.org, my user agent would put
foo at iptel.org in To, but the proxy server would rewrite
sip:foo at iptel.org in the Request-URI into sip:+123456 at iptel.org. The
gateway would not know how to handle sip:foo at iptel.org, but would know
how to handle sip:+123456 at iptel.org

  Jan.

On 11-01 23:26, Simon Miles wrote:
> RFC2543 states in the opening paragraph of section 2 :-
> 
> "SIP URLs are used within SIP messages to indicate the originator
>    (From), current destination (Request-URI) and final recipient (To) of
>    a SIP request...."
> 
> I am using a MultiTech 3010 and it certainly dials what is in the To
> field. I assume that are using the 'final recipient' field and not the
> URI. This does mean that any mangling of the URI is lost. If I mangle
> the To field then the unique reference created from the To field
> together with From and Call-ID fields is lost and the server does not
> recognise any response form the gateway.
> 
> Is this gateway unique in it's interpretation of the RFC2543 ?
> 
> Simon
> 
> -----Original Message-----
> From: serusers-bounces at iptel.org [mailto:serusers-bounces at lists.iptel.org] On
> Behalf Of Klaus Darilion
> Sent: 11 January 2005 23:18
> To: Simon Miles
> Cc: Serusers
> Subject: Re: [Serusers] Support for Gateway still on RFC2543
> 
> 
> 
> 
> Simon Miles wrote:
> > Klaus,
> > 
> > Thanks for the feedback, but I still think it is a problem.
> > 
> > If I use the prefix command, this effects the URI field but not the To
> 
> > field. According to RFC2543 the To field is the one to use for 
> > dialling when the INVITE gets to it's final destination.
> 
> Are you sure that the To: field is used fpr dialing - not the request 
> URI? Can you point me to the relevant sections in RFC2543?
> 
> regards,
> klaus
> 
> PS: Please CC to the list.
> 
> > 
> > Hence the prefix command can't be used ! ! ! If I mangle the To field 
> > then this effects the Call-ID so the SIP software sees a reply to the 
> > INVITE as another message ! !
> > 
> > Simon
> > 
> > -----Original Message-----
> > From: Klaus Darilion [mailto:klaus.mailinglists at pernau.at]
> > Sent: 10 January 2005 22:27
> > To: Simon Miles
> > Cc: serusers at lists.iptel.org
> > Subject: Re: [Serusers] Support for Gateway still on RFC2543
> > 
> > 
> > There should be no problem at all - RFC 3261 is compatible with the 
> > old
> > RFC. ser will look for the "lr" parameter in the via headers and will 
> > use strict routing if the lr parameter is not found in the topmost via
> 
> > header.
> > 
> > regards,
> > klaus
> > 
> > Simon Miles wrote:
> > 
> > 
> >>Dear Community,
> >> 
> >>I still have gateways that confirm to RFC2543 and not the newer
> >>RFC3261. This means the use of URI and To fields are different. Is 
> >>there any way of telling sip_router that it needs to conform to the 
> >>old spec ?
> >> 
> >>Thanks
> >> 
> >> 
> >>Simon
> >>
> >>
> >>
> >>----------------------------------------------------------------------
> >>--
> >>
> >>_______________________________________________
> >>Serusers mailing list
> >>serusers at lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers
> > 
> > 
> > 
> 
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