Normally, ICE candidates are only gathered after RTCPeerConnection.setLocalDescription is called, because this is the point at which the PeerConnection knows how many ports it needs. The iceCandidatePoolSize member of RTCConfiguration instructs the PeerConnection to gather ICE candidates before this occurs, as a performance optimization. Thus, if setting the local description is delayed (by signaling, for example), interactions with STUN/TURN servers can occur in parallel.


Working draft or equivalent

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 59
  • Chrome for Android release 59
  • Chrome for iOS release 59
  • Android WebView release 59

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • In development
  • Positive
  • Positive
  • Positive


Last updated on 2020-11-09