Re: [Stox] core: response code mappings

Peter Saint-Andre <stpeter@stpeter.im> Mon, 19 August 2013 03:20 UTC

Message-ID: <52118EE9.3090002@stpeter.im>
Date: Sun, 18 Aug 2013 21:20:09 -0600
From: Peter Saint-Andre <stpeter@stpeter.im>
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To: "Olle E. Johansson" <oej@edvina.net>
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Cc: "stox@ietf.org" <stox@ietf.org>
Subject: Re: [Stox] core: response code mappings
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Hi Olle, that is helpful feedback.

On 8/17/13 1:28 AM, Olle E. Johansson wrote:
> 
> 17 aug 2013 kl. 04:28 skrev Peter Saint-Andre <stpeter@stpeter.im>:
> 
>> The SIP Parameters Registry has a list of SIP response codes:
>>
>> http://www.iana.org/assignments/sip-parameters/sip-parameters.xml#sip-parameters-7
>>
>> A number of those are not specified in RFC 3261. Thus the question
>> arises: for which codes do we need to define mappings? We could define
>> mappings for all of them, but I wonder if that's advisable. Some of the
>> additional codes are specified in RFCs that update RFC 3261 (e.g., code
>> 440 from RFC 5393), whereas other codes are specified in "non-core" RFCs
>> that don't update RFC 3261 (e.g., code 470 from RFC 5360). Would it
>> perhaps make sense to map the "core" codes and not the "non-core" codes?
> 
> I don't really have any good answer. Can just look into the Asterisk code and see
> that we've implemented a selection... :-)
> 
> The important part is to have a generic mapping for 2xx, 3xx, 4xx, 5xx and 6xx codes,
> so that if a gateway gets an unknown code, it knows how to map it to something. In SIP,
> an unknown 4xx code is the same as 400 etc.

True. I think we can provide that information in the stox-core spec
(e.g., in XMPP <bad-request/> is like a default 400). That way, if an
entity encounters a response code that it doesn't understand, at least
it can map it appropriately.

> After years of struggling with translations between SIP and ISDN in the Asterisk core,
> I know that this is a hard problem. Especially in the case where you have SIP -> xmpp -> SIP 
> and want the same error code on the other side. You simply can't please everyone when
> mapping between two protocols.

Agreed. Those round-trip mappings are especially difficult, but it would
be good to look at a few examples because I think we'll end up at
default things like SIP 400 codes in a lot of situations. I'll
investigate the matter soon and post some proposed text to this list.


Peter

-- 
Peter Saint-Andre
https://stpeter.im/

[Stox] core: response code mappings Peter Saint-Andre
Re: [Stox] core: response code mappings Olle E. Johansson
Re: [Stox] core: response code mappings Peter Saint-Andre
Re: [Stox] core: response code mappings Saúl Ibarra Corretgé
Re: [Stox] core: response code mappings Paul Kyzivat
Re: [Stox] core: response code mappings Peter Saint-Andre
Re: [Stox] core: response code mappings Daniel-Constantin Mierla
Re: [Stox] core: response code mappings Peter Saint-Andre
Re: [Stox] core: response code mappings Daniel-Constantin Mierla
Re: [Stox] core: response code mappings Olle E. Johansson
Re: [Stox] core: response code mappings Daniel-Constantin Mierla
Re: [Stox] core: response code mappings Peter Saint-Andre
Re: [Stox] core: response code mappings Daniel-Constantin Mierla