I would tend to disagree that a policy of "Use UDP preferably and switch to TCP if message is too big" is a good policy. Especially considering that you'd have to keep the TCP connection alive anyways.
I believe that always using the TCP connection in this case would make more sense. But it's definitively legal. > -----Original Message----- > From: Lawrence, Scott (BL60:9D30) > Sent: Monday, August 31, 2009 09:56 > To: Vavilapalli Srikanth-A19563 > Cc: Audet, Francois (SC100:3055); sip@ietf.org; > s...@core3.amsl.com; sip-implement...@lists.cs.columbia.edu > Subject: Re: [Sip] Question on draft-ietf-sip-outbound-20 > draft: multipleflowcreation > > On Mon, 2009-08-31 at 12:31 -0400, Scott Lawrence wrote: > > On Mon, 2009-08-31 at 22:33 +0800, Vavilapalli > Srikanth-A19563 wrote: > > > True, UDP flow may not be required if TCP flow has been setup to > > > route incoming traffic towards UA. But Won't it be an additional > > > bonus if UA creates a UDP FLOW in addition to TCP FLOW, so that > > > network can still reach the UA over the other transport FLOW when > > > one FLOW is down (Unless if both FLOWs got created with same host > > > and all the FLOWs connected to that host is down)? > > > > > > Also assume a UA has some local policy to prefer UDP > transport over > > > TCP to transmit the outgoing SIP messages of size less > than MTU. In > > > such scenarios, UA might want to establish both UDP and TCP FLOWs > > > with the same edge proxy and keep alive both the > connections and use > > > the corresponding FLOW based on DNS lookup preferences and User's > > > local policy preferences to transport outgoing messages. > > > > That would not be a very sensible proxy if the phone is > behind a NAT > > and supports TCP. > > s/proxy/policy/ > > > > _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use sip-implement...@cs.columbia.edu for questions on current sip Use sipp...@ietf.org for new developments on the application of sip
