Subject: [rtcweb] REMB with many ssrc entries

From: Iñaki Baz Castillo <[email-masked]>
Date: Thu, 2 Mar 2017 22:07:04 +0100

Hi,

I asked a question regarding REMB with multiple SSRC entries, but got
not response:

https://mailarchive.ietf.org/arch/search/?email_list=rmcat&gbt=1&index=ZNGmTcO2LXXevzcCIxUPsL2xHcA

To summarize, the question is:

If Alice is sending Bob an audio stream (SSRC 1111) and a video stream
(SSRC 2222) and Bob sends a REMB feedback message with:
  - bitrate: 100000 (100kbits/s)
  - ssrcs: 1111, 2222

Does it mean that Alice should limit the sum of her sending audio and
video bitrates to 100kbits/s? or does it mean that Alice can send
100kbits/s of audio and 100kbits/s of video (total = 200)?

Thanks.

-- 
Iñaki Baz Castillo
<[email-masked]>

---

From: Harald Alvestrand <[email-masked]>
Date: Fri, 3 Mar 2017 15:50:59 +0100

1) REMB is abandoned at this point.
2) The way it was originally designed, it meant that the total should be
100 Kbits/sec. REMB did not take a position on how the sender chose to
allocate bits between the SSRCs, only the total amount of bits sent.

---

From: Iñaki Baz Castillo <[email-masked]>
Date: Fri, 3 Mar 2017 16:57:37 +0100

> 1) REMB is abandoned at this point.

Yes, I know. However browser do implement it and, AFAIK, there is no
other way to limit the sender whole transport bandwidth (TMMBR is per
stream).

> allocate bits between the SSRCs, only the total amount of bits sent.

Clear, thanks a lot.

-- 
Iñaki Baz Castillo
<[email-masked]>