Re: [AVT] T.38 over RTP: RTP Sequence Number

[Magnus Westerlund <magnus.westerlund at ericsson.com>]

Hi,

It is the RTP payload format that specifies the definite rules of the 
RTP timestamp, which must be following the basic RFC 3550 rules. So it 
is very reasonable to specify a limitation that RTP payloads shall not 
use the same timestamp. That is for example done for T.140. If that is 
not done and instead it is actually expected that the RTP timestamp 
becomes the same for packets. Then RFC 2198 is clearly not applicable 
for the RTP payload format.

To me it seems that the T.38 defined RTP payload format specification 
needs some updates to clarify these things. It might also be appropriate 
to recommend one and only one robustness mechanism. And that being a 
mechanism that works for the payload format.

However please remember that you must stay within the ground rules of 
RTP. For example defining the marker bit strangely may not be the 
wisest. At least not as long as it is within an audio RTP session.

cheers

Magnus

PS.
Please remove parts of previous emails that you are not refering to. 
That way the email is simpler to read and waste less storage space.
DS.


--

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
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S-164 80 Stockholm, Sweden | mailto: magnus.westerlund at ericsson.com

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