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

On 4 Jun 2007, at 20:50, Internet-Drafts@ietf.org 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 sipping@ietf.org 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:

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).

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.

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

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