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RE: [Sip] moving UDP support out of the core SIP document



I agree with Rohan to have a default value.

Thanks, Henry

> -----Original Message-----
> From: sip-admin@ietf.org [mailto:sip-admin@ietf.org] On 
> Behalf Of Kevin McCandless
> Sent: Wednesday, October 23, 2002 3:57 PM
> To: 'Rohan Mahy'; Victor Paulsamy
> Cc: sip@ietf.org
> Subject: RE: [Sip] moving UDP support out of the core SIP document
> 
> 
> Rohan:
> 
> At first I would have to agree with Victor but you are right 
> we need a base for SIP transport.  I remember a white paper 
> that looked at SCTP, TCP and UDP as transport protocols for 
> SIP.  If you were a carrier with large amounts of SIP traffic 
> SCTP would be the better transport protocol.  For less 
> traffic that would be seen between proxy and UA then TCP 
> could be used. Is it possible to the draft address the three 
> transport protocols and the necessary security mechanism to 
> support them.  By recommending only one protocol don't we 
> several limit the deployment.
> 
> Just my thoughts....
> 
> Kevin... 
> 
> > -----Original Message-----
> > From: Rohan Mahy [mailto:rohan@cisco.com]
> > Sent: Wednesday, October 23, 2002 2:03 PM
> > To: Victor Paulsamy
> > Cc: sip@ietf.org
> > Subject: Re: [Sip] moving UDP support out of the core SIP document
> > 
> > 
> > Hi Victor,
> > 
> > Having no default transport does not encourage 
> interoperability which
> > is a major goal of Internet protocols.
> > 
> > thanks,
> > -rohan
> > 
> > On Wednesday, October 23, 2002, at 11:23 AM, Victor Paulsamy wrote:
> > 
> > > If SIP is "truly" independent of underlying transport protocols,
> > > wouldn't it
> > > be appropriate to make all transports "optional"?
> > >
> > > Regards,
> > >
> > > --victor
> > >
> > >> -----Original Message-----
> > >> From: sip-admin@ietf.org [mailto:sip-admin@ietf.org]On
> > Behalf Of Rohan
> > >> Mahy
> > >> Sent: Wednesday, October 23, 2002 11:02 AM
> > >> To: sip@ietf.org
> > >> Subject: [Sip] moving UDP support out of the core SIP document
> > >>
> > >>
> > >> Hello Everyone,
> > >>
> > >> I wanted to share some thoughts that I had about removing
> > UDP from the
> > >> core SIP document when we go to draft standard. We are 
> probably at 
> > >> least one year away from going to Draft Standard. I hope
> > that during
> > >> this time most implementations will support RFC3261, and 
> therefore 
> > >> support TCP.  In addition, it is quite likely that when 
> moving to 
> > >> Draft Standard that the IESG will REQUIRE TLS support on 
> SIP User 
> > >> Agents. This would ensure a ubiquitous hop-by-hop 
> channel security
> > mechanism,
> > >> but which requires a reliable transport (TCP or SCTP).
> > >>
> > >> Obviously UDP is still very attractive in wireless
> > networks (due to
> > >> RTT
> > >> issues) and in other typically private networks with
> > well-understood
> > >> delay and loss characteristics. To make most
> > implementations simpler
> > >> however, I am proposing that we make unreliable 
> transports (UDP and
> > >> DCCP) of SIP optional in User Agents, and that we put the
> > UDP-specific
> > >> mechanism (ex: much of the complication of the transaction
> > layer for
> > >> handling retransmissions) in a separate Draft Standard
> > document.  It
> > >> is
> > >> very likely that if we did this there would also be a baseline
> > >> security
> > >> mechanism for UDP as well (probably some profile of 
> > IPsec).  The net
> > >> effect is that SIP User Agents could also talk to each
> > other using TCP
> > >> or TLS+TCP, and that User Agents with a strong preference for UDP
> > >> would
> > >> have a consistent security mechanism.  Proxies would 
> still support 
> > >> both
> > >> transports, so you could easily communicate between a 
> TCP-only User
> > >> Agent, and as User Agent which prefers UDP without 
> > requiring the User
> > >> Agent to switch over to TCP.
> > >>
> > >> I welcome your discussion and comments on this idea.
> > >>
> > >> thanks,
> > >> -rohan
> > >>
> > >> _______________________________________________
> > >> 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
> 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