I've already mentioned this point in March 18th, this year, in the
Unless I missed some key sentence, I have the feeling that this
I-D **leaves implicit** the strong requirement that there must not be any
RTP packet loss (or reordering) before reaching the Fecframe encoder,
i.e. that the RTP Sequence Numbers used to identify source symbols in
the FEC block are always in sequence.
This is a key requirement that MUST be clearly stated rather than
being left implicit.
I haven't checked carefully in draft-ietf-fecframe-raptor-05, but sections
8.2.2. and 8.2.4. in this I-D do not seem to be more explicit on this point.
This requirement, that is specific to situations where RTP source packets
are left unchanged, and some solutions to mitigate it, have already been
discussed on the list and guidelines have been added in RFC6363:
10.2. Operational and Management Recommendations
5. Management of Communication Issues before Reaching the Sending
On Oct. 20, 2011, 15:47, The IESG wrote:
The IESG has received a request from the FEC Framework WG (fecframe) to
consider the following document:
- 'RTP Payload Format for Raptor FEC'
<draft-ietf-fecframe-rtp-raptor-05.txt> as a Proposed Standard
The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf(_at_)ietf(_dot_)org mailing lists by 2011-11-03. Exceptionally, comments
sent to iesg(_at_)ietf(_dot_)org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.
This document specifies an RTP Payload Format for Forward Error
Correction repair data produced by the Raptor FEC Schemes. Raptor
FEC Schemes are specified for use with the IETF FEC Framework which
supports transport of repair data over both UDP and RTP. This
document specifies the Payload Format which is required for the use
of RTP to carry Raptor repair flows.
The file can be obtained via
IESG discussion can be tracked via
No IPR declarations have been submitted directly on this I-D.
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