[jitsi-dev] Transport Feedback and Video Quality on Receiver Side


#1

Hello All,

We are using the Jitsi videobridge for transmitting non-simulcasted and
non-svcd one-way streams for 1:1 calls. Since our calls are 1 way, we have
a designated sender and a designated receiver. We are also using the
following 2 properties on the jicofo server:

org.jitsi.jicofo.ENABLE_TCC = true
org.jitsi.jicofo.ENABLE_REMB=false

Our goal naturally is to enable send side bandwidth estimation by using
transport feedback packets and disable receiver side bandwidth estimation.

Reading the videobridge source code, I noticed that the videobridge sends
transport feedback to the sender of the stream independent of the receiver.
In other words, the transport feedback that the sender receives is from the
videobridge to the sender, and the sender has no knowledge how the actual
receiver is doing. If my understanding of the code is correct, then if the
receiver's downstream link becomes a bottleneck, the sender will keep
sending at its own rate (which the sender computes using feedback from the
videobridge), and the videobridge will downgrade the video quality by
dropping fps.

If the above understanding is correct, then is there a way to turn off RTCP
termination so that the sender becomes aware of the transport feedback that
the receiver is sending.

If my understanding of the code is incorrect, then please correct me :slight_smile:

Thanks,
-Ghulam


#2

Hello Ghulam,

You’re reading and interpreting the code correctly. Unfortunately, currently there’s no way to turn off RTCP termination, so my suggestion is to add a TURN server in your infrastructure to make sure the peer-to-peer connection always succeeds.

I hope this helps.

Best,
George

···

On Mar 5, 2018, at 10:07 PM, Ghulam Memon <gmemon.work@gmail.com> wrote:

Hello All,

We are using the Jitsi videobridge for transmitting non-simulcasted and non-svcd one-way streams for 1:1 calls. Since our calls are 1 way, we have a designated sender and a designated receiver. We are also using the following 2 properties on the jicofo server:

org.jitsi.jicofo.ENABLE_TCC = true
org.jitsi.jicofo.ENABLE_REMB=false

Our goal naturally is to enable send side bandwidth estimation by using transport feedback packets and disable receiver side bandwidth estimation.

Reading the videobridge source code, I noticed that the videobridge sends transport feedback to the sender of the stream independent of the receiver. In other words, the transport feedback that the sender receives is from the videobridge to the sender, and the sender has no knowledge how the actual receiver is doing. If my understanding of the code is correct, then if the receiver's downstream link becomes a bottleneck, the sender will keep sending at its own rate (which the sender computes using feedback from the videobridge), and the videobridge will downgrade the video quality by dropping fps.

If the above understanding is correct, then is there a way to turn off RTCP termination so that the sender becomes aware of the transport feedback that the receiver is sending.

If my understanding of the code is incorrect, then please correct me :slight_smile:

Thanks,
-Ghulam
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