RTCIceCandidate
The RTCIceCandidate
interface—part of the WebRTC API—represents a candidate Interactive Connectivity Establishment (ICE) configuration which may be used to establish an RTCPeerConnection
.
An ICE candidate describes the protocols and routing needed for WebRTC to be able to communicate with a remote device. When starting a WebRTC peer connection, typically a number of candidates are proposed by each end of the connection, until they mutually agree upon one which describes the connection they decide will be best. WebRTC then uses that candidate's details to initiate the connection.
For details on how the ICE process works, see Lifetime of a WebRTC session. The article WebRTC connectivity provides additional useful details.
Constructor
RTCIceCandidate()
-
Creates an
RTCIceCandidate
object to represent a single ICE candidate, optionally configured based on a configuration object.Note: For backwards compatibility, the constructor also accepts as input a string containing the value of the
candidate
property instead of the configuration object.
Instance properties
address
Read only-
A string containing the IP address of the candidate.
candidate
Read only-
A string representing the transport address for the candidate that can be used for connectivity checks. The format of this address is a
candidate-attribute
as defined in RFC 5245. This string is empty (""
) if theRTCIceCandidate
is an "end of candidates" indicator. component
Read only-
A string which indicates whether the candidate is an RTP or an RTCP candidate; its value is either
rtp
orrtcp
, and is derived from the"component-id"
field in thecandidate
a-line string. foundation
Read only-
Returns a string containing a unique identifier that is the same for any candidates of the same type, share the same base (the address from which the ICE agent sent the candidate), and come from the same STUN server. This is used to help optimize ICE performance while prioritizing and correlating candidates that appear on multiple
RTCIceTransport
objects. port
Read only-
An integer value indicating the candidate's port number.
priority
Read only-
A long integer value indicating the candidate's priority.
protocol
Read only-
A string indicating whether the candidate's protocol is
"tcp"
or"udp"
. -
If the candidate is derived from another candidate,
relatedAddress
is a string containing that host candidate's IP address. For host candidates, this value isnull
. -
For a candidate that is derived from another, such as a relay or reflexive candidate, the
relatedPort
is a number indicating the port number of the candidate from which this candidate is derived. For host candidates, therelatedPort
property isnull
. sdpMid
Read only-
A string specifying the candidate's media stream identification tag which uniquely identifies the media stream within the component with which the candidate is associated, or
null
if no such association exists. sdpMLineIndex
Read only-
If not
null
,sdpMLineIndex
indicates the zero-based index number of the media description (as defined in RFC 4566) in the SDP with which the candidate is associated. tcpType
Read only-
If
protocol
is"tcp"
,tcpType
represents the type of TCP candidate. Otherwise,tcpType
isnull
. type
Read only-
A string indicating the type of candidate as one of the strings listed on
RTCIceCandidate.type
. usernameFragment
Read only-
A string containing a randomly-generated username fragment ("ice-ufrag") which ICE uses for message integrity along with a randomly-generated password ("ice-pwd"). You can use this string to verify generations of ICE generation; each generation of the same ICE process will use the same
usernameFragment
, even across ICE restarts.
Instance methods
toJSON()
-
Returns a JSON representation of the
RTCIceCandidate
's current configuration. The format of the representation is the same as thecandidateInfo
object that can optionally be passed to theRTCIceCandidate() constructor
to configure a candidate.
Examples
For examples, see the article Signaling and video calling, which demonstrates the entire process.
Specifications
Specification |
---|
WebRTC: Real-Time Communication in Browsers # rtcicecandidate-interface |
Browser compatibility
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