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Re: [Sip] Questions on Max-Forwards
Hi,
Again as per section 16.3 Request Validation, sub-section 3
Max-Forwards check,
"If the request contains a Max-Forwards header field with a field
value greater than zero, the check is passed.
If the request contains a Max-Forwards header field with a field
value of zero (0), the element MUST NOT forward the request."
So the ACK with Max-Forwards 0 should be silently discarded.
Best Regards
Ajit
Loh Kok Jeng wrote:
> Hi,
>
> One more question on Max-Forwards. How should an ACK with Max-Forwards 0
> be handled by a proxy or UAS? One normally does not send a respond to ACK,
> so should ACK with Max-Forwards 0 be silently discarded? Thanks.
>
> regards,
> KJ Loh
>
> > -----Original Message-----
> > From: manoj mallik [mailto:m.manoj@ipnetfusion.com]
> > Sent: Wednesday, October 23, 2002 11:28 PM
> > To: Loh Kok Jeng; Krishna, Samaga; sip@ietf.org
> > Subject: RE: [Sip] Questions on Max-Forwards
> >
> >
> > inline
> >
> > -----Original Message-----
> > From: sip-admin@ietf.org [mailto:sip-admin@ietf.org]On Behalf
> > Of Loh Kok
> > Jeng
> > Sent: Wednesday, October 23, 2002 7:10 AM
> > To: Krishna, Samaga; sip@ietf.org
> > Subject: RE: [Sip] Questions on Max-Forwards
> >
> >
> > Hi,
> >
> > Thanks for your reply. Section 11 says:
> >
> > Alternatively, a server receiving an OPTIONS request with a Max-
> > Forwards header field value of 0 MAY respond to the request
> > regardless of the Request-URI.
> >
> > Does it mean that a proxy may send 483 instead of 200?
> >
> > >>>>Manoj: It indicates that if the Request is OPTIONS with
> > Max-Forwards 0,
> > then it MAY act as final receiptant and respond to the
> > Request irrespective
> > of the target in Request-URI. i.e even if the Request-URI is
> > not meant for
> > him, it will respond to that OPTIONS request. It doesn't say
> > about the kind
> > of Response. However RFC-3261, sec 11.2 Processing of OPTIONS
> > Request, says
> > that
> >
> > "If the response to an OPTIONS is generated by a proxy server, the
> > proxy returns a 200 (OK), listing the capabilities of the server.
> > The response does not contain a message body."
> >
> > What if the value of Max-Forwards is outside the permitted range
> > 0-255? Should a 400 response be sent?
> >
> > Manoj>>>> This is a good question. I think nothing is
> > mentioned in the RFC
> > if Max-Forwards is outside the permitted range 0-255. So it
> > is really hard
> > to say what should be the response, may be it is
> > implementation dependent.
> >
> > regards,
> > KJ Loh
> >
> > > -----Original Message-----
> > > From: Krishna, Samaga [mailto:samaga.krishna@intel.com]
> > > Sent: Wednesday, October 23, 2002 5:53 PM
> > > To: 'Loh Kok Jeng'; sip@ietf.org
> > > Subject: RE: [Sip] Questions on Max-Forwards
> > >
> > >
> > > Hi Loh,
> > > If proxy receives a request with Max-Forward : 1, the proxy
> > > will decrement
> > > the count and forward the message.
> > > If proxy receives the request with Max-Forward: 0, it should
> > > not forward the
> > > request. It shall send 483 response. If the request is for
> > > OPTIONS, proxy
> > > will act as final recipient and respond to it as in the RFC
> > > 3261 section 11.
> > >
> > >
> > > have a nice day
> > > Prasanna
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Loh Kok Jeng [mailto:kokjeng.loh@siemens.com]
> > > Sent: Wednesday, October 23, 2002 1:00 PM
> > > To: sip@ietf.org
> > > Subject: [Sip] Questions on Max-Forwards
> > >
> > >
> > > Dear all,
> > >
> > > If a valid SIP message with "Max-Forwards: 1" is received by
> > > a proxy, should
> > >
> > > the proxy decrement Max-Forwards and forward it, or should it
> > > respond with
> > > 483?
> > >
> > > Likewise, how should the proxy handle a message with with
> > > Max-Forwards: 0
> > > or a negative value?
> > >
> > > regards,
> > > KJ Loh
> > > _______________________________________________
> > > Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> > > This list is for NEW development of the core SIP Protocol
> > > Use sip-implementors@cs.columbia.edu for questions on current sip
> > > Use sipping@ietf.org for new developments on the application of sip
> > >
> > _______________________________________________
> > Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> > This list is for NEW development of the core SIP Protocol
> > Use sip-implementors@cs.columbia.edu for questions on current sip
> > Use sipping@ietf.org for new developments on the application of sip
> >
> _______________________________________________
> Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> This list is for NEW development of the core SIP Protocol
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> Use sipping@ietf.org for new developments on the application of sip
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