RTCPeerConnection: RTCPeerConnection() constructor
The RTCPeerConnection()
constructor returns a newly-created RTCPeerConnection
, which represents
a connection between the local device and a remote peer.
Syntax
new RTCPeerConnection()
new RTCPeerConnection(configuration)
Parameters
configuration
Optional-
An object providing options to configure the new connection:
bundlePolicy
Optional-
Specifies how to handle negotiation of candidates when the remote peer is not compatible with the SDP BUNDLE standard. If the remote endpoint is BUNDLE-aware, all media tracks and data channels are bundled onto a single transport at the completion of negotiation, regardless of policy used, and any superfluous transports that were created initially are closed at that point.
In technical terms, a BUNDLE lets all media flow between two peers flow across a single 5-tuple; that is, from a single IP and port on one peer to a single IP and port on the other peer, using the same transport protocol.
This must be one of the following string values, if not
balanced
is assumed:balanced
-
The ICE agent initially creates one
RTCDtlsTransport
for each type of content added: audio, video, and data channels. If the remote endpoint is not BUNDLE-aware, then each of these DTLS transports handles all the communication for one type of data. max-compat
-
The ICE agent initially creates one
RTCDtlsTransport
per media track and a separate one for data channels. If the remote endpoint is not BUNDLE-aware, everything is negotiated on these separate DTLS transports. max-bundle
-
The ICE agent initially creates only a single
RTCDtlsTransport
to carry all of theRTCPeerConnection
's data. If the remote endpoint is not BUNDLE-aware, then only a single track will be negotiated and the rest ignored.
certificates
Optional-
An
Array
of objects of typeRTCCertificate
which are used by the connection for authentication. If this property isn't specified, a set of certificates is generated automatically for eachRTCPeerConnection
instance. Although only one certificate is used by a given connection, providing certificates for multiple algorithms may improve the odds of successfully connecting in some circumstances. See Using certificates for further information.Note: This configuration option cannot be changed after it is first specified; once the certificates have been set, this property is ignored in future calls to
RTCPeerConnection.setConfiguration()
. iceCandidatePoolSize
Optional-
An unsigned 16-bit integer value which specifies the size of the prefetched ICE candidate pool. The default value is 0 (meaning no candidate prefetching will occur). You may find in some cases that connections can be established more quickly by allowing the ICE agent to start fetching ICE candidates before you start trying to connect, so that they're already available for inspection when
RTCPeerConnection.setLocalDescription()
is called.Note: Changing the size of the ICE candidate pool may trigger the beginning of ICE gathering.
iceServers
Optional-
An array of
RTCIceServer
objects, each describing one server which may be used by the ICE agent; these are typically STUN and/or TURN servers. If this isn't specified, the connection attempt will be made with no STUN or TURN server available, which limits the connection to local peers. iceTransportPolicy
Optional-
The current ICE transport policy; if the policy isn't specified,
all
is assumed by default, allowing all candidates to be considered. Possible values are:"all"
-
All ICE candidates will be considered.
"public"
Deprecated-
Only ICE candidates with public IP addresses will be considered. Removed from the specification's May 13, 2016 working draft.
"relay"
-
Only ICE candidates whose IP addresses are being relayed, such as those being passed through a TURN server, will be considered.
peerIdentity
Optional-
A string which specifies the target peer identity for the
RTCPeerConnection
. If this value is set (it defaults tonull
), theRTCPeerConnection
will not connect to a remote peer unless it can successfully authenticate with the given name. rtcpMuxPolicy
Optional-
The RTCP mux policy to use when gathering ICE candidates, in order to support non-multiplexed RTCP. Possible values are:
negotiate
-
Instructs the ICE agent to gather both RTP and RTCP candidates. If the remote peer can multiplex RTCP, then RTCP candidates are multiplexed atop the corresponding RTP candidates. Otherwise, both the RTP and RTCP candidates are returned, separately.
require
-
Tells the ICE agent to gather ICE candidates for only RTP, and to multiplex RTCP atop them. If the remote peer doesn't support RTCP multiplexing, then session negotiation fails. This is the default value.
Return value
A newly-created RTCPeerConnection
object, configured as described by
configuration
, if specified; otherwise, configured to appropriate basic
defaults.
Using certificates
When you wish to provide your own certificates for use by an
RTCPeerConnection
instead of having the RTCPeerConnection
generate them automatically, you do so by calling the static
RTCPeerConnection.generateCertificate()
function.
The certificates
property's value cannot be changed once it's first
specified. If it's included in the configuration passed into a call to a connection's
setConfiguration()
, it is ignored.
This attribute supports providing multiple certificates because even though a given
DTLS connection uses only one certificate, providing multiple certificates allows
support for multiple encryption algorithms. The implementation of
RTCPeerConnection
will choose which certificate to use based on the
algorithms it and the remote peer support, as determined during DTLS handshake.
If you don't provide certificates, new ones are generated automatically. One obvious benefit to providing your own is identity key continuity—if you use the same certificate for subsequent calls, the remote peer can tell you're the same caller. This also avoids the cost of generating new keys.
Specifications
Specification |
---|
WebRTC: Real-Time Communication in Browsers # dom-peerconnection |
Browser compatibility
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