Web/API/RTCIceCandidate/foundation

The RTCIceCandidate interface's read-only foundation property is a string which uniquely identifies the candidate across multiple transports. As such, the foundation can be used to correlate candidates that are present on multiple RTCIceTransport objects

Syntax

var foundation = RTCIceCandidate.foundation;

Value

A DOMString which uniquely identifies the candidate across all RTCIceTransports on which it is available.

Note: If port is null — and port is supported by the user agent — passing the candidate to addIceCandidate() will fail, throwing an OperationError exception.

Usage notes

Consider this SDP attribute line (a-line) which describes an ICE candidate:

a=candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host

The field "4234997325" is the foundation.

Example

This code snippet uses the foundation of two candidates to determine if they're actually the same candidate.

if (candidate1.foundation == candidate2.foundation) {
  /* the two candidates are the same, even if they're on
     different transports */
}

Specifications

Specification	Status	Comment
WebRTC 1.0: Real-time Communication Between BrowsersThe definition of 'RTCIceCandidate.foundation' in that specification.	Candidate Recommendation	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`foundation`	Chrome Full support 74	Edge Full support ≤18	Firefox No support No	IE No support No	Opera No support No	Safari ?	WebView Android Full support 74	Chrome Android Full support 74	Firefox Android ?	Opera Android No support No	Safari iOS ?	Samsung Internet Android Full support 11.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown

RTCIceCandidate.foundation by Mozilla Contributors is licensed under CC-BY-SA 2.5.