Re: [rtcweb] RTP Usage: Is RTP Retransmission REQUIRED or RECOMMENDED

[Magnus Westerlund <[e-mail]>]

Hi,

As Individual I like to state my position.

We have a video conference system developed by my colleagues used
internally at Ericsson that uses RTP Retransmission for video, not for
audio with great success. This is implemented such that we actually
allow the video to fall behind the audio when packet loss and
retransmission is not able to repair in a timely enough fashion. The
benefit is minimal overhead and still no loss induced degradations in
the video. Yes, we get degradation in form of frame display jittering
and short freezes. But those events that are truly visible are rare over
wired networks.

I am personally convinced that RTP Retransmission is great tool in the
toolbox when it comes to improve media quality in many use cases. Yes
there are scenarios where RTP retransmission is less efficient. Long
RTTs (over 200-400 ms) is the primary source of degradations. Compared
to FEC it so much more efficient from bandwidth consumption perspective.

I also think it is important that we have some mandatory to implement
tool for making the transport more robust now that we have a consensus
that we are not going for a FEC solution in the initial specification.

Thus my personal position is that RTP Retransmission should be REQUIRED
to implement.

Cheers

Magnus


On 2012-06-27 09:36, Magnus Westerlund wrote:
> WG,
> 
> We had a discussion at the interim if RTP Retransmission is to be
> considered REQUIRED or RECOMMENDED to implement. I would like to see if
> we can first have some discussion on this topic before moving on to see
> if we can get a consensus here on the mailing list.
> 
> Please provide your views on this topic.
> 
> Cheers
> 
> Magnus Westerlund
> (As Chair and document editor)
> 
> 
> ----------------------------------------------------------------------
> Multimedia Technologies, Ericsson Research EAB/TVM
> ----------------------------------------------------------------------
> Ericsson AB                | Phone  [phone]
> Färögatan 6                | Mobile [phone]
> SE-164 80 Stockholm, Sweden| mailto: [e-mail]
> ----------------------------------------------------------------------
> 
> 
> _______________________________________________
> rtcweb mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/rtcweb
> 
> 


-- 

Magnus Westerlund

----------------------------------------------------------------------
Multimedia Technologies, Ericsson Research EAB/TVM
----------------------------------------------------------------------
Ericsson AB                | Phone  [phone]
Färögatan 6                | Mobile [phone]
SE-164 80 Stockholm, Sweden| mailto: [e-mail]
----------------------------------------------------------------------