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Re: [AVT] RE: Working group last call: draft-ietf-avt-ulp-14.txt



Thanks Mark,

The WGLC of this document has conclude and there is a need for addressing these comments and an update. A one week WGLC will held on these updates at that time the new version is addressed.

I also have a comment on the feedback:


Mark Watson wrote:
C.5) Section 7.3: Timestamp: it is not clear to me what purpose it serves to timestamp the FEC packet with the time it was sent, since there are many strategies for timing the sending of the FEC packets relative to the original stream. It might be more useful to timestamp it with the same time as the last packet protected by this FEC packet, since that is the time in the stream playout after which the FEC packet is useless. However, this would not result in monotonically increasing timestamps.

There is one good reason for timestamping with transmission time. It makes the RTCP reports on the FEC traffic very accurate and can be used to measure traffic characteristics better than for example a stream of video packets. To me there is no need to indicate the protected streams media TS corresponding to the last directly protected packet. That information is in most cases available from the buffer by looking into the payload of the received FEC packet. However it will provide information is some cases that is not directly available. So this would be a definite trade-off but probably not worth changing in this update to RFC 2733.


Cheers

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
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