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

["Liess, Laura" <Laura.Liess@t-systems.com>]

Rohan, 

I don't think moving UDP support out of the core SIP document is a good idea. Doing so will probably solve many technical problems, but in my opinion doing such important changes all the time leads to interoperability problems and to additional delays in adoption of SIP as a basis for real customer solutions. SIP over UDP works fine within enterprise networks and IP-VPNs.
  
I also can remember UDP was one of our main arguments again H.323 about 3 years ago...

Thanks, Laura     



> -----Ursprungliche Nachricht-----
> Von: Rohan Mahy [mailto:rohan@cisco.com]
> Gesendet: Mittwoch, 23. Oktober 2002 21:03
> An: Victor Paulsamy
> Cc: sip@ietf.org
> Betreff: 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