Re: [Sip] draft-ietf-sip-outbound

["Francois Audet" <audet at nortel.com>]

Again, this is very simple.

The questions is "is the mininum 1 or 2".

Juha is arguing for 2.
I'm fine with 2 also (in fact, that's how I read the spec in the first place).

Which minimum is acceptable to you:
a) 1
b) 2
c) Either but I prefer 1
d) Either but I prefer 2

> -----Original Message-----
> From: Christer Holmberg [mailto:christer.holmberg at ericsson.com] 
> Sent: Monday, May 12, 2008 13:15
> To: Audet, Francois (SC100:3055); Juha Heinanen; Dean Willis
> Cc: Hadriel Kaplan; sip at ietf.org; drage at alcatel-lucent.com; 
> Elwell, John
> Subject: RE: [Sip] draft-ietf-sip-outbound
> 
> Hi Francois,
>  
> If you, as you propose, say:
>  
> "If the set has more than one URI, the UAC MUST send a 
> REGISTER request to at least two of the  default outbound 
> proxies from the set."
>  
> ...do you then really need the sentence saying:
>  
> "For each outbound proxy URI in the set, the UAC SHOULD send 
> a REGISTER request using this URI as the default outbound proxy."
>  
> Wouldn't it be enough to say that the UAC MUST register with 
> at least two?
>  
> I guess the question is whether UACs "with battery life 
> issues" want to be able to establish single flows or not. 
> Since the current draft does seem to allow it (at least it 
> doesn't explicitly forbid it) it could be rather unwise to 
> remove that possibility at this point, because it COULD be 
> seen as a rather big change. Maybe one solution would be to 
> strongly recommend against it, and add some words about the 
> lost functionality by doing so, but not explicitly forbid it.
>  
> On the other hand, assuming the keep-draft moves forward: if 
> you are only going to establish a single flow I am not sure 
> you would need Outbound in the first place - keep would be enough :)
>  
> Regards,
>  
> Christer 
> 
>  
>  
>  
>  
> 
> ________________________________
> 
> From: Francois Audet [mailto:audet at nortel.com]
> Sent: Mon 12/05/2008 19:46
> To: Juha Heinanen; Dean Willis
> Cc: Christer Holmberg; Hadriel Kaplan; sip at ietf.org; 
> drage at alcatel-lucent.com; Elwell, John
> Subject: RE: [Sip] draft-ietf-sip-outbound
> 
> 
> 
> Let me try to summarize where we are at with the 
> draf-ietf-sip-outbound thread, and let's try to conclude.
> 
> The current text says the following:
> 
>    At configuration time, UAs obtain one or more SIP URIs representing
>    the default outbound-proxy-set.  This specification assumes the set
>    is determined via any of a number of configuration mechanisms, and
>    future specifications can define additional mechanisms 
> such as using
>    DNS to discover this set.  How the UA is configured is outside the
>    scope of this specification.  However, a UA MUST support 
> sets with at
>    least two outbound proxy URIs and SHOULD support sets with 
> up to four
>    URIs.
> 
>    For each outbound proxy URI in the set, the UAC SHOULD send a
>    REGISTER request using this URI as the default outbound proxy.
>    (Alternatively, the UA could limit the number of flows formed to
>    conserve battery power, for example).  UAs that support this
>    specification MUST include the outbound option tag in a Supported
>    header field in a REGISTER request.  Each of these 
> REGISTER requests
>    will use a unique Call-ID.  Forming the route set for the 
> request is
>    outside the scope of this document, but typically results 
> in sending
>    the REGISTER such that the topmost Route header field contains a
>    loose route to the outbound proxy URI.
> 
> What Juha is worried about is that there is enough wiggle 
> room in there that some UAs will not register with the 
> minimum of 2.  It is true that it is unclear if the text 
> about battery life was meant to allow for not registering 
> with all the entries in the route set, but still keep the 
> minimum of two, or not.
> 
> I propose is that the text would look like this:
> 
>    At configuration time, UAs obtain one or more SIP URIs representing
>    the default outbound-proxy-set.  This specification assumes the set
>    is determined via any of a number of configuration mechanisms, and
>    future specifications can define additional mechanisms 
> such as using
>    DNS to discover this set.  How the UA is configured is outside the
>    scope of this specification.  However, a UA MUST support 
> sets with at
>    least two outbound proxy URIs and SHOULD support sets with 
> up to four
>    URIs.
> 
>    For each outbound proxy URI in the set, the UAC SHOULD send a
>    REGISTER request using this URI as the default outbound proxy. 
>    (Alternatively, the UA could limit the number of flows formed to
>    conserve battery power, for example).  If the set has more than one
>    URI, the UAC MUST send a REGISTER request to at least two of the
>    default outbound proxies from the set. UAs that support 
> this specification
>    MUST include the outbound option tag in a Supported header 
> field in a
>    REGISTER request.  Each of these REGISTER requests will 
> use a unique
>    Call-ID. Forming the route set for the request is outside 
> the scope of this
>    document, but typically results in sending the REGISTER 
> such that the
>    topmost Route header field contains a loose route to the outbound
>    proxy URI.
> 
> I think this is reasonable. Basically, what this boils down 
> to is very simple:
> is the minimum number of registration for a proxy set that is 
> bigger than one 2 or 1.
> If you are against this proposal, it it is presumably because 
> you believe a UA should be allowed to use only ONE proxy from 
> the set and ignore the second one.
> 
> I'd like to get opinions from the list, and close on the issue.
> 
> 
> 
> 
> 
> 
> 
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