Re: [payload] Alexey Melnikov's No Objection on draft-ietf-payload-melpe-05: (with COMMENT)

["Victor Demjanenko, Ph.D." <[e-mail]>]

Hi Alexey,

Thanks, with your clue, I followed an example in RFC 5391 and added the
following:

"   Optional parameters:

      ptime:  the recommended length of time (in milliseconds)
         represented by the media in a packet.  It SHALL use the nearest
         rounded-up ms integer packet duration.  For MELPe, this
         corresponds to the values: 23, 45, 68, 90, 112, 135, 156, and
         180.  Larger values can be used as long as they are properly
         rounded.  See Section 6 of RFC 4566 [RFC4566].  

      maxptime:  the maximum length of time (in milliseconds) that can
         be encapsulated in a packet.  It SHALL use the nearest rounded-
         up ms integer packet duration.  For MELPe, this corresponds to
         the values: 23, 45, 68, 90, 112, 135, 156, and 180.  Larger
         values can be used as long as they are properly rounded.  See
         Section 6 of RFC 4566 [RFC4566].

      bitrate:  specifies the MELPe coder bit rates supported.  
         Possible values are a comma-separated list of rates from the
         set: 2400, 1200, 600.  The modes are listed in order of
         preference; first is preferred.  If "bitrate" is not present,
         the fixed coder bit rate of 2400 MUST be used.  The alternate
         encoding names, "MELP2400", "MELP1200", and "MELP600" directly
         specify the MELPe coder bit rate of 2400, 1200, and 600
         respectively and MUST NOT specify a "bitrate" parameter.  "

Then in section 4.2, the bulleted list is now (adding ptime and maxptime as
well as simplifying bitrate):

"        o The media type ("audio") goes in SDP "m=" as the media name. 
        o The media subtype (payload format name) goes in SDP "a=rtpmap"
   as the encoding name. 
        o The parameter "bitrate" goes in the SDP "a=fmtp" attribute by
   copying it as a "bitrate=<value>" string. 
        o  The parameters "ptime" and "maxptime" go in the SDP "a=ptime"
   and "a=maxptime" attributes, respectively."

And the last paragraph in section 4.2 describing ptime and maxptime was
deleted as its contents was fully conveyed in section 4.1.

Now there are two other paragraphs related to bitrate in section 4.2 that
have I not changed.  It's possible that these can be eliminated and/or
reduced.  Perhaps I delete all but the last sentence of the second
paragraph?  Any opinions?

"   If the encoding name "MELP" is received without a "bitrate"
   parameter, the fixed coder bit rate of 2400 MUST be used.  The
   alternate encoding names, "MELP2400", "MELP1200", and "MELP600"
   directly specify the MELPe coder bit rate of 2400, 1200, and 600
   respectively and MUST NOT specify a "bitrate" parameter.

   The optional media type parameter, "bitrate", when present, MUST be
   included in the "a=fmtp" attribute in the SDP, expressed as a media
   type string in the form of a semicolon-separated list of
   parameter=value pairs.  The string, "value", can be one or more of
   2400, 1200, and 600 separated by commas (where each bit-rate value
   indicates the corresponding MELPe coder).  An example of the media
   representation in SDP for describing MELPe when all three coder bit
   rates are supported might be:"

If the above is considered acceptable as is, I can post a new draft upon
request.  Please let me know what and when to do this.  (Roni, Ben, thanks
for your help with this as well.)

Thanks,

Victor

-----Original Message-----
From: Alexey Melnikov [mailto:[e-mail]] 
Sent: Friday, February 3, 2017 4:16 AM
To: Victor Demjanenko, Ph.D.
Cc: The IESG; [e-mail]; [e-mail];
[e-mail]; [e-mail]; Dave Satterlee (Vocal)
Subject: Re: [payload] Alexey Melnikov's No Objection on
draft-ietf-payload-melpe-05: (with COMMENT)

Hi Victor,

> On 2 Feb 2017, at 21:12, Victor Demjanenko, Ph.D.
<[e-mail]> wrote:
> 
>   Optional parameters:
> 
>      ptime, maxptime, bitrate

You either need full definition of these optional parameters or references
where they are defined.

Best Regards,
Alexey