Subject: [AVT] Question on RTP sequence number in RFC2833 and bis-02

From: Eric Cheung <[email-masked]>
Date: Wed, 26 Feb 2003 07:22:19 -0500

Hi Henning, Scott

Want to clarify a fine point.

In RFC2833:

    If there has been no new event
    in the last interval, the event SHOULD be retransmitted three times
    or until the next event is recognized.

Q1: For a device conforming to RFC2833, should the RTP sequence number 
in the 3 packets be incremented, or should they be the same?

In RFC2833bis-02, this seems to be clarified:

    If an event has ended and
    there has been no new event in the last interval, the event SHOULD be
    retransmitted three times at the interval used by the source for
    updates.

    In all cases, the RTP sequence number MUST be incremented by one in
    each RTP packet.

Q2: Can you confirm that if a device conforms to bis-02, the sequence 
number in the 3 packets will be monotonically increasing?

Q3: In writing this, I realize that I am not sure whether there should 
be 4 packets (1 original transmission + 3 retransmission) or 3 packets. 
  Can you clarify this?

Sorry for the nit-picking, but when testing it seems many devices do 
many different things when it comes to 2833.

Thanks
Eric

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