Re: [AVTCORE] [Technical Errata Reported] RFC4733 (3451)

Before accepting this report I would want to know the consensus view of 
the meaning of "same timestamp base". The problem was raised in the 
discussion of draft-ietf-avtext-multiple-clock-rates. My understanding 
of "timestamp base" is that it defines the time units in which the 
timestamp is expressed (usually some small fraction of a second) for all 
payloads using the same SSRC. The fact that the above-mentioned draft 
was accepted as a WG document suggests that my understanding is wrong. 
Perhaps someone else can comment.

On 11/01/2013 8:24 AM, 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=3451
>
> --------------------------------------
> Type: Technical
> Reported by: Xavier Marjou <xavier.marjou@orange.com>
>
> 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
> MUST use the same SSRC (therefore the same timing and sequence
> number space) and the same timestamp clock rate as the regular
> audio channel to simplify the generation of audio waveforms at a
> gateway.
>
> 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)
>
> Instructions:
> -------------
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>
> --------------------------------------
> 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
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