Re: [payload] WGLC on draft-ietf-avt-rtp-isac-02

["Pascal Huart (phuart)" <[e-mail]>]

Hi Roni,
I just noticed the emails, I'll follow up.
Thanks,
Pascal

From: Roni Even <[e-mail]<mailto:[e-mail]>>
Date: Wednesday, December 26, 2012 1:42 PM
To: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Cc: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: RE: WGLC on draft-ietf-avt-rtp-isac-02
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Resent-To: <[e-mail]<mailto:[e-mail]>>, <[e-mail]<mailto:[e-mail]>>, Cisco Employee <[e-mail]<mailto:[e-mail]>>, <[e-mail]<mailto:[e-mail]>>, <[e-mail]<mailto:[e-mail]>>
Resent-Date: Wednesday, December 26, 2012 1:45 PM

Hi,
I reviewed the draft and have some questions and comments


1.       In section 2 there is a mention of target bit rate. It is not clear how is it calculated and what does average during peaks mean? How is this parameter related to the ibitrate parameter defined in the IANA section.

2.       In section 2 “The  available bandwidth is continuously estimated at the receiving iSAC and signaled in-band in the iSAC bit stream”. How does it work?

3.       In section 3 second paragraph please discuss using dynamic payload type number maybe add “The assignment of an RTP payload type for the format defined in this  memo is outside the scope of this document.  The RTP profiles in use  currently mandate binding the payload type dynamically for this  payload format.”

4.       In section 3.2  what are the BEI and FL values  and how many bits each one uses.

5.       In section 3.3 what is bandwidth probe, how does it work. Is it specified elsewhere, in which case provide a reference.

6.       In section 3.3 “The user can choose to lower the maximum allowed payload length “. Who is the user(sender / receiver) and how is it done.

7.       In section 3.4 how does a receiver know if he receives a wideband or super-wideband payload in order to decode correctly.

8.       In section 3.5 “signaled inband”. What is inband, any reference?

9.       Looking at figure 6 I am not clear from the text how does the receiver know that there is padding and not payload?

10.  In section 4 change the beginning to “This RTP payload format is identified using the media type audio/isac, which is registered in accordance with [RFC4855<http://tools.ietf.org/html/rfc4855>] and uses the  template of [RFC4288<http://tools.ietf.org/html/rfc4288>].”

11.  Please verify that the registration follows the template. Currently the order is not correct and there are missing subscetions.

12.  Since ibitrate and maxbitrate are optional parameters what are the default values if not specified. I saw 20000 for ibitrate for channel adaptive mode in section 2.

13.  What are the units for ibitrate and maxbitrate

14.   In section 4 the change controller should be the payload working group.

15.  In section 5 what is the clock rate in rtpmap.

16.  Can you switch from wideband to super wideband without any signaling using the same payload type number. Can you use a 32000 clock rate also for the wideband.

17.   The document should have a congestion control section seehttp://tools.ietf.org/html/draft-ietf-payload-rtp-howto-02

18.   The security section need to be expanded see for example section 10 of RFC 5404.
Thanks
Roni Even



From: Roni Even [mailto:[e-mail]]
Sent: 13 December, 2012 8:35 AM
To: '[e-mail]<mailto:'[e-mail]>'
Cc: '[e-mail]<mailto:'[e-mail]>'
Subject: WGLC on draft-ietf-avt-rtp-isac-02

Hi,

I would like to start a WGLC on  http://tools.ietf.org/html/draft-ietf-avt-rtp-isac-02 , RTP Payload Format for the iSAC Codec




The WGLC will end on January 2nd, 2013

Please review the draft and send comments to the list.


For the draft authors;  Are you aware of any IPR that applies to draft-ietf-avt-rtp-isac-02? If so,

has this IPR been disclosed in compliance with IETF IPR rules (see RFCs 3979, 4879, 3669 and 5378 for more details)?

The above question is needed for the document write-up when sent to publication.


Thanks

Roni Even
Payload  co-chair




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