Subject: Re: [Sip] [Sip-implementors] Question on draft-ietf-sip-outbound-20 draft: multipleflowcreation

From: Iñaki Baz Castillo <[email-masked]>
Date: Tue, 1 Sep 2009 18:53:33 +0200

2009/8/31 Francois Audet <[email-masked]>:
> 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.

I agree totally.
If a client uses UDP then it uses UDP and the same for TCP, but don't
mix please, as mixing both protocols in the same client is an exotic
and idealistic concept just feasible in a "ideal" world (the world
described in RFC 3261).

-- 
Iñaki Baz Castillo
<[email-masked]>

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From: Nils Ohlmeier <[email-masked]>
Date: Wed, 02 Sep 2009 09:52:50 +0200

Am 31.08.09 19:11, schrieb Francois Audet:
> But it's definitively legal.

I totally agree with this.

But from several years attending SIPit's I would highly recommend you to 
NOT mix UDP and TCP. From time to time I had already interoperability 
issues when my proxy did for example UDP to TCP conversion (and back). 
If you are talking/thinking about an UA implementation which mixes UDP 
and TCP on the first hop already I would anticipate lots of 
interoperability issues down the road. You should at least attend a 
SIPit to check how other proxy and UA implementations react on this. In 
the end any benefits which you might get from this design decision might 
be easily eaten up by the support efforts later.

Best regards
   Nils Ohlmeier

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From: Nils Ohlmeier <[email-masked]>
Date: Wed, 02 Sep 2009 09:52:50 +0200

Best regards
   Nils Ohlmeier