Re: [MMUSIC] E.164 and visual separators in draft-ietf-mmusic-sdp-cs

[Paul Kyzivat <[e-mail]>]

At end...

On 11/15/12 10:51 AM, Flemming Andreasen wrote:
>
> On 11/15/12 4:06 AM, [e-mail] wrote:
>>
>> Hi Flemming, Paul, Keith, and all,
>>
>> When going through
>> http://tools.ietf.org/id/draft-ietf-mmusic-sdp-cs-13.txt
>> <http://tools.ietf.org/id/draft-ietf-mmusic-sdp-cs-13.txt> for
>> publication, Flemming had a comment on the format of global telephone
>> numbers.
>>
>> The draft currently says in Section 5.2.1:
>>
>>   This memo exclusively uses the international representation of E.164
>>
>> numbers, i.e., those initiated with a '+' sign.  The syntax (see
>>
>> Section 5.7) refers to the representation of a 'global-number'
>>
>> construction already specified in RFC 3966 [RFC3966].  This
>>
>> representation requires the presence of the '+' sign. Additionally,
>>
>> this representation allows for the presence of one or more 'visual-
>>
>> separator' constructions.  Implementations confirming to this
>>
>> specification and using the "E164" address type together with the
>>
>> "PSTN" network type MUST only use international E.164, i.e., those
>>
>> starting with a '+' sign and SHOULD NOT use visual-separators.
>>
>> This was discussed earlier on the list, see
>> http://www.ietf.org/mail-archive/web/mmusic/current/msg09630.html
>>
>> Flemming’s comment was that referencing to RFC3966 but saying that the
>> syntax is invalid because we only use parts of it is not a good idea.
>>
>> The question is, could we just refer to RFC3966 and allow visual
>> separators?
>>
> To be clear, the "global-number" production in RFC 3966 allows for a
> number of parameters that are not part of the International E.164 format
> and thus I have two concerns with the current text
> 1) The visual-separator exclusion although the ABNF allows for it
> 2) The apparent disconnect between all of these optional extra
> parameters and the above text suggesting they are not allowed.

IIRC there was discussion on this. There are a number of symbols defined 
in 3966 that *could* be used here: telephone-subscriber, global-number, 
global-number-digits. All of them permit separators. Which one to choose 
depends on how much flexibility one wants to permit. The flexibility 
brings with it more parsing demands which people might object to if the 
flexibility will never be used.

I don't really care which one it is. global-number-digits is probably 
enough for common uses.

	Thanks,
	Paul