2014280 - RTC.IceConnectionStateChange callbacks can be slow

Status: NEW

(Core :: WebRTC: Signaling, enhancement, P3)

Description

[Jim Mathies [:jimm]]

Reported by a stream service - 'During internet interruptions, disconnect messages take longer to receive on our servers compared to other browsers. On Chrome, it is almost immediate while on Firefox it takes about 5 seconds which causes issues for immediate reconnects. We are listening to the RTC.IceConnectionStateChange callback on the server.'

Comment 1

[Dan Baker[:dbaker]]

If there is a reliance on disconnected state the determination for signaling this is implementation dependent and the spec does not point to any faster compliant method for connectivity interruptions.

• WebRTC 1.0 spec (webrtc-pc)
“The disconnected state is intended to indicate a temporary disruption… The exact conditions under which this state is entered are implementation dependent.” 
https://www.w3.org/TR/webrtc/#dom-rtcicetransportstate-disconnected

RFC 7675 consent checks:

• MUST NOT be sent more often than once every 4 seconds
• Have a 30-second expiration timeout 
https://www.rfc-editor.org/rfc/rfc7675#section-5.1

Waiting for failed checks will result in the ~5s delay being observed. Chrome appears to detect this disconnection more aggressively, potentially in ways that are not spec compliant.

We should look into reducing the delay for signaling connectivity interruptions, but any changes should remain spec compliant and consider existing applications that may rely on Firefox’s current behavior.