Subject: [rtcweb] Open issues for draft-ietf-rtcweb-fec

From: Justin Uberti <[email-masked]>
Date: Wed, 19 Jul 2017 23:27:15 -0700

Since there will be no WG meeting this week, here is the sole remaining
open issue for the document. Feedback on this issue is the only thing
standing between this document and WGLC.

1. https://github.com/juberti/draughts/issues/81

Currently, the document indicates that Opus' built-in FEC mechanism MUST be
implemented and SHOULD be used when needed.

However, Bernard mentioned that his experience with Opus did not show a
benefit:

[BA] While loss of a single packet is by far the most likely loss

mode, our tests do not indicate that there is much benefit from

Opus internal FEC.  For example, when we compared Opus internal

FEC against no FEC and concealment, we found little discernible

difference in MOS score. On the other hand, we did see a benefit

arising from RFC 2198 redundancy to protect against burst loss.

So based on our test results, we cannot recommend use of built-in

Opus FEC.

Does anyone else have an opinion on this matter?

Bernard, are there any specifics you can share?