Re: [AVTCORE] [Technical Errata Reported] RFC4733 (3489)

[Marc Petit-Huguenin <[e-mail]>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On 04/03/2013 07:55 AM, Magnus Westerlund wrote:
> AVTCORE and Payload WG,
> 
> There appear to exist an interoperability issue around the the need to use
> the same timestamp rate for the DTMF and the audio. Thus, I think we should
> serioulsy consider to approve this erratum. And if the text is not correct,
> propose a better text.
> 
> I personally believe the proposal is significantly clearer than the old 
> text and also reflect what must have been intended.
> 
> This issues a 2-week last call on input on this erratum. After the 17th of
> April I will issue a final recommendation on this erratum.
> 

I support this text.

BTW I would like to applaud the way this erratum was handled. i.e. discussed
and refined first in the WG, as it should be[1].

Thanks.

[1] http://www.rfc-editor.org/pipermail/rfc-interest/2012-August/004839.html

> 
> For previous discussion that resulted in this updated erratum proposal see
> this AVTCORE mailing list discussion: 
> http://www.ietf.org/mail-archive/web/avt/current/msg15669.html
> 
> Cheers
> 
> Magnus Westerlund AVTCORE WG chair
> 
> On 2013-02-19 08:42, RFC Errata System wrote:
>> 
>> The following errata report has been submitted for RFC4733, "RTP Payload
>> for DTMF Digits, Telephony Tones, and Telephony Signals".
>> 
>> -------------------------------------- You may review the report below
>> and at: http://www.rfc-editor.org/errata_search.php?rfc=4733&eid=3489
>> 
>> -------------------------------------- Type: Technical Reported by:
>> Xavier Marjou <[e-mail]>
>> 
>> Section: 2.1
>> 
>> Original Text ------------- Named telephone events are carried as part of
>> the audio stream and MUST use the same sequence number and timestamp base
>> as the regular audio channel to simplify the generation of audio
>> waveforms at a gateway.
>> 
>> Corrected Text -------------- Named telephone events are carried as part
>> of the audio stream and if they use the same SSRC (therefore the same
>> timing and sequence number space), they MUST use the same timestamp clock
>> rate as the regular audio channel.
>> 
>> Notes ----- RFC4733 was written in a way to avoid the multiple clock-rate
>> problem by mandating the use of the same SSRC for DTMF and audio. However
>> it's not explicitly written, which brings an ambiguity. It was commented
>> that RFC4733 needs to be updated. (c.f.
>> http://tools.ietf.org/wg/avtext/minutes?item=minutes-85-avtext.html).
>> This errata obsoletes the previous proposed errata (ID: 3451).
>> 
>> Instructions: ------------- This errata is currently posted as
>> "Reported". If necessary, please use "Reply All" to discuss whether it
>> should be verified or rejected. When a decision is reached, the verifying
>> party (IESG) can log in to change the status and edit the report, if
>> necessary.
>> 
>> -------------------------------------- RFC4733
>> (draft-ietf-avt-rfc2833bis-15) -------------------------------------- 
>> Title               : RTP Payload for DTMF Digits, Telephony Tones, and
>> Telephony Signals Publication Date    : December 2006 Author(s)
>> : H. Schulzrinne, T. Taylor Category            : PROPOSED STANDARD 
>> Source              : Audio/Video Transport Area                :
>> Real-time Applications and Infrastructure Stream              : IETF 
>> Verifying Party     : IESG

- -- 
Marc Petit-Huguenin
Email: [e-mail]
Blog: http://blog.marc.petit-huguenin.org
Profile: http://www.linkedin.com/in/petithug
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
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=MkAX
-----END PGP SIGNATURE-----