Subject: RE: [Sip] Outbound: Multiple flows and forking

From: "Christer Holmberg \(JO/LMF\)" <[email-masked]>
Date: Wed, 5 Apr 2006 15:33:12 +0200

Hi Jonathan, 

>A couple of issues on chapter 4.2.
> 
>The text says:
> 
>"However, a UA MUST support sets with at least two outbound proxy URIs 
>(primary and backup) and SHOULD support sets with up to four URIs.  
>For each outbound proxy URI in the set, the UA MUST send a REGISTER in
the 
>normal way using this URI as the default outbound proxy."
> 
>I don't think we should mandate this, because it is very much 
>dependent on the architecture, transport techniques etc.

Mandate what? The minimal number of outbound proxies that should be
supported? Or the fact that you register on each?

[CHH] Both, but ESPECIALLY the fact that you register on all of them.

>For the latter, its an essential part of the story so I don't see how
you can make it optional.

[CHH] It may very well be a good thing to do, but because of the battery
issue (and maybe other issues I can't think of at the moment) I think it
should be optional. 

>In the former case, if you don't specify a minimum that is supported,
how do you have interop?

[CHH] I don't see what this has to do with interop. The entities are
supposed to work no matter if a single flow, or multiple flows, have
been created. A registrar shall of course be prepared to support
multiple flows, even if the spec doesn't mandate the user to creat them.

Regards,

Christer

-- 
Jonathan D. Rosenberg, Ph.D.                   600 Lanidex Plaza
Cisco Fellow                                   Parsippany, NJ 07054-2711
Cisco Systems
[email-masked]                              FAX:   (973) 952-5050
http://www.jdrosen.net                         PHONE: (973) 952-5000
http://www.cisco.com

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---

From: "Hadriel Kaplan" <[email-masked]>
Date: Wed, 5 Apr 2006 10:30:17 -0400

Hi Christer,
I'm confused.  You can't "connect" to two outbound proxies simultaneously
without Registering on each.  There would be no point to being connected to
the one you didn't register through.  For battery life, wouldn't the STUN or
TCP keep-alive drain it even more?  The register message does not need to be
sent very often relative to those.

What is a little screwed up is that the spec strongly implies (or mandates)
a UA has to support two simultaneous connections, which is clearly not the
case.  

-hadriel

> -----Original Message-----
> From: Christer Holmberg (JO/LMF) [mailto:[email-masked]]
> Sent: Wednesday, April 05, 2006 9:33 AM
> To: Jonathan Rosenberg
> Cc: [email-masked]
> Subject: RE: [Sip] Outbound: Multiple flows and forking
> 
> 
> Hi Jonathan,
>