Subject: [AVT] Question on AMR PL-format: CRC building

From: Faerber Tobias ICM MP PO8 RD MCH83 <[email-masked]>
Date: Mon, 28 Jan 2002 10:21:11 +0100

In case there is a NO_DATA frame within a RTP payload containing several 
AMR frames, e.g. (7,7,8,15,15,7), and CRC bits are transmitted, is there 
a CRC entry for the NO_DATA frames as well? I could not find anything in 
draft-ietf-avt-rtp-amr-10.txt on this. In my opinion it would make not 
much sense to send CRC bits for NO_DATA frames, as there is nothing to 
protect and they would just have to be 0's. From the PT entries you 
would be able to associate the right CRC bits to the data containing 
frames. However, this would have to be specified clearly, since it 
cannot easily be seen from the payload contents which method has been 
used.

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 Faerber Tobias		Siemens AG
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From: Magnus Westerlund <[email-masked]>
Date: Mon, 28 Jan 2002 10:48:25 +0100

Hi Tobias

No, There shall not be a CRC entry for frames of type NO_DATA. This will be well
specified in the soon finished update.

Cheers

Magnus

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Magnus Westerlund

Audio Technology, Ericsson Research
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