[avtext] draft-ietf-avtext-framemarking and FEC

[Bernard Aboba <[e-mail]>]

So far, discussion on framemarking has focused on conveying information
about video frames useful to an SFU.

In video forwarding scenarios, forward error correction can be used to
protect one or more layers.

Today, typically robustness (FEC or RTX) is dealt with hop-by-hop, not
end-to-end.  For example, FEC is consumed and re-generated by the SFU which
receives video frames and repairs via the received FEC if it can.The SFU
decides which video frames to forward (such as by using info in the frame
marking header), and will regenerate an FEC stream corresponding to the
forwarded stream.

My question is whether hop-by-hop robustness is expected to continue with
PERC so that the payloads of FEC packets would be available to the SFU, or
whether FEC payload would also be encrypted so that FEC would be
end-to-end.

If FEC becomes end-to-end, do those packets also need to be marked?