"trickle" ICE option should be provided for all media streams in the ICE description

[taylor-b]

Something noticed by @fippo: It's legal for "a=ice-option:trickle" to exist at the media-level (as opposed to session-level), and there's nothing that explicitly prevents an endpoint from using "trickle" with some media streams but not others.

The "trickle" ICE option isn't intended to have that level of granularity, so I suggest addressing this in the trickle spec by adding a sentence like:

An ICE agent compliant to this specification MUST inform the peer about the compliance using the 'trickle' ICE option, either at the session level or for every media stream at the media stream level.

This sentence is mostly copied from ICEbis talking about the "ice2" option.

[stpeter]

Although I don't trust that @fippo guy, this sounds like a reasonable suggestion. ;-)

[fippo]

https://datatracker.ietf.org/doc/draft-ietf-mmusic-ice-sip-sdp/?include_text=1 makes it session or media-level.

i stumbled over this when wondering about chrome's implementation and https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-18#section-4.1.15 -- if different values were allowed that would be very odd.

[stpeter]

I'm going to post to the ICE WG list about this.