signalingState property on the
RTCPeerConnection interface returns a string value
describing the state of the signaling process
on the local end of the connection
while connecting or reconnecting to another peer.
See Signaling in Lifetime of a WebRTC session for more details about the signaling process.
Because the signaling process is a state machine, being able to verify that your code
is in the expected state when messages arrive can help avoid unexpected and avoidable
failures. For example, if you receive an answer while the
"have-local-offer", you know that something is wrong, since you
should only receive answers after creating an offer but before an answer has been
received and passed into
code will be more reliable if you watch for mismatched states like this and handle them
This value may also be useful during debugging, for example.
The allowed string values are:
There is no ongoing exchange of offer and answer underway. This may mean that the
RTCPeerConnectionobject is new, in which case both the
null; it may also mean that negotiation is complete and a connection has been established.
The local peer has called
RTCPeerConnection.setLocalDescription(), passing in SDP representing an offer (usually created by calling
RTCPeerConnection.createOffer()), and the offer has been applied successfully.
The remote peer has created an offer and used the signaling server to deliver it to the local peer, which has set the offer as the remote description by calling
The offer sent by the remote peer has been applied and an answer has been created (usually by calling
RTCPeerConnection.createAnswer()) and applied by calling
RTCPeerConnection.setLocalDescription(). This provisional answer describes the supported media formats and so forth, but may not have a complete set of ICE candidates included. Further candidates will be delivered separately later.
A provisional answer has been received and successfully applied in response to an offer previously sent and established by calling
RTCPeerConnectionhas been closed.
var pc = new RTCPeerConnection(configuration); var state = pc.signalingState;
|WebRTC 1.0: Real-Time Communication Between Browsers |
BCD tables only load in the browser