[Sipping] Re: I-D ACTION:draft-bryan-sipping-midi-01.txt

[Cullen Jennings <[e-mail]>]

On Jun 8, 2007, at 7:27 AM, Colin Perkins wrote:

> On 4 Jun 2007, at 20:50, [e-mail] wrote:
>> A New Internet-Draft is available from the on-line Internet-Drafts
>> directories.
>>
>>
>> 	Title		: Telephony Tones Using MIDI in SIP
>> 	Author(s)	: C. Jennings, D. Bryan
>> 	Filename	: draft-bryan-sipping-midi-01.txt
>> 	Pages		: 68
>> 	Date		: 2007-6-4
>> 	
>> This document describes conventions for using MIDI to generate tones
>>    on SIP UAs.  This does not define any changes to SIP but describes
>>    how to use the existing Alert-Info header to play tones that  
>> can be
>>    used to indicate specialized PSTN tones such as the ringback tones
>>    from various countries.  The tones are described using MIDI which
>>    results in a compact representation that is simple for a UA to
>>    generate and easy to render into audio.
>>
>>    This work is being discussed on the [e-mail] mailing list.
>>    This draft was revived at request of a few people so it could be
>>    discussed.  Parts of it need to be updated since it was written in
>>    2003.
>>
>> A URL for this Internet-Draft is:
>> http://www.ietf.org/internet-drafts/draft-bryan-sipping-midi-01.txt
>
> Interesting draft. A couple of comments:

Interesting is fair :-) David and I just resubmitted this based on a  
request of a few people want to have a current version to talk about.

>
> How would this compare to sending audio/tone [RFC 4733 section  
> 4.3.3] data in SIP? (I realise the audio/tone format is currently  
> only defined for transport via RTP, but it could easily be extended  
> for this use, and is simpler than MIDI).

Uh, this is likely larger, and far more complicated to implement for  
the receiver. I like the idea of using tones.

>
> Also, one could presumably achieve a similar effect using early  
> media with either the RFC 4733 or RFC 4695 RTP payload formats.  
> Some discussion of the trade-off between the approaches would be  
> valuable.

If we did go forward with something based on midi, it would need to  
be brought inline with 4695 but totally agree with you, the pro' s  
and con's of doing this in SIP signaling vs. what we have now where  
it is done in RTP with early media would need to be discussed.  
Including the interaction with HERFP.

>
> -- 
> Colin Perkins
> http://csperkins.org/


_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [e-mail] for questions on current sip
Use [e-mail] for new developments of core SIP