Web/API/RTCIceCandidateStats/priority

The RTCIceCandidateStats dictionary's priority property is a positive integer value indicating the priority (or desirability) of the described candidate. During ICE negotiation while setting up a WebRTC peer connection, the priority values reported to the remote peer by a user agent are used to determine which candidates are considered "more desirable". The higher the value, the more desirable the candidate is.

Syntax

priority = rtcIceCandidateStats.priority;

Value

A positive integer indicating the priority of the RTCIceCandidate described by the RTCIceCandidateStats object. The value may be anywhere from 1 to 2,147,483,647.

Determining priority

The ICE specification describes how user agents and other software using WebRTC should calculate the priority. The priority of a candidate is calculated using the following variables as inputs:

The preferability of the candidate type (local, server reflexive, peer reflexive, or relayed)
The preferability of the candidate's specific IP address (for multihomed agents)
The candidate's component ID (1 for RTP, 2 for RTCP)

The candidate's priority is computed using the formula (p_type is the priority of the candidate's type and p_local is the priority of the IP address):

<math display="block">\mathit{priority} = 2^{24} \times p_{type} + 2^{8} \times p_{local} + (256 - \mathit{componentID})</math>

This is equivalent to mapping the priorities of teh candidate type, the local IP, and the component ID into various bit ranges within the 32-bit priority value.

Specifications

Specification	Status	Comment
Identifiers for WebRTC's Statistics APIThe definition of 'RTCIceCandidateStats.port' in that specification.	Candidate Recommendation	Initial specification.

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
`port`	Chrome No support No	Edge No support No	Firefox Full support 27 Alternate Name' Full support 27 Alternate Name' Alternate Name' Uses the non-standard name: `portNumber`	IE No support No	Opera ?	Safari ?	WebView Android No support No	Chrome Android No support No	Firefox Android Full support 27 Alternate Name' Full support 27 Alternate Name' Alternate Name' Uses the non-standard name: `portNumber`	Opera Android ?	Safari iOS ?	Samsung Internet Android No support No

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Uses a non-standard name.': Uses a non-standard name.