- From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
- Date: Tue, 11 Aug 2015 08:58:13 +0000
- To: Harald Alvestrand <harald@alvestrand.no>, "public-webrtc@w3.org" <public-webrtc@w3.org>
On 10/08/15 13:09, Harald Alvestrand wrote: > Den 24. juli 2015 15:00, skrev Stefan Håkansson LK: >> On 24/07/15 14:44, Peter Thatcher wrote: >>> Following the PR from https://github.com/w3c/webrtc-pc/pull/228, I have >>> changed RtpEncodingParameters.priority to an enum with very-low, low, >>> medium, and high. >>> >>> This is kind of what we decided a long ago about priorities. But I >>> forgot about it when I wrote the PR for RtpEncodingParameters.priority >>> and made it a double. This is an update to that. >>> >>> >>> Do we still have consensus for using an enum for priority? Look at the >>> PR to see how it looks. >> >> Which PR is it? Priority seems to be part of #234 and #241. >> >> Anyway, I have concerns with the part >> >> <dt>double priority</dt> >> + <dd> >> + <p> >> + Indicates the relative priority of this encoding, across >> + all RtpSenders of a given PeerConnection. When there is >> + limited bandwidth available to a PeerConnection, higher >> + prioirty encodings will be sent with more bandwidth, and >> + lower priority encodings will be sent with less >> + bandwidth. >> >> in combination with the upcoming "min" and "max" bitrate attributes. How >> should he UA act if they conflict (e.g. a very high "min" and a low >> priority)? >> >> #228 only points at RTCWEB-TRANSPORT and I think that document only >> talks about DSCP marking. > > Wearing my hat as editor of rtcweb-transport: > > Section 4 talks about prioritization. > Section 4.1 talks about mapping priority to DSCP. This points to > draft-ietf-dart-dscp-rtp for codepoint assignments. > Section 4.2 talks about mapping piority to local prioritization. This > talks about stuff that's congestion-controlled under a single congestion > controller. > > Both chapters assume the 4-level classification of priority at the API - > section 4 starts with: > > The WebRTC prioritization model is that the application tells the > WebRTC implementation about the priority of media and data flows > through an API. > > The priority associated with a media or data flow is classified as > "normal", "below normal", "high" or "very high". There are only four > priority levels at the API. > > The priority settings affect two pieces of behavior: Packet markings > and packet send sequence decisions. Each is described in its own > section below. This seems well aligned with PR #259 (https://github.com/w3c/webrtc-pc/pull/259).
Received on Tuesday, 11 August 2015 08:58:42 UTC