RTCPeerConnection.signalingState

The read-only signalingState property on the RTCPeerConnection interface returns one of the string values specified by the RTCSignalingState enum; these values describe 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 signalingState isn't "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 RTCPeerConnection.setLocalDescription(). Your code will be more reliable if you watch for mismatched states like this and handle them gracefully.

This value may also be useful during debugging, for example.

In addition, when the value of this property changes, a signalingstatechange event is sent to the RTCPeerConnection instance.

Syntax

 var state = RTCPeerConnection.signalingState;

Value

The allowed values are those included in the enum RTCSignalingState.

RTCSignalingState enum

The RTCSignalingState enum specifies the possible values of RTCPeerConnection.signalingState, which indicates where in the process of signaling the exchange of offer and answer the connection currently is.

Example

var pc = new RTCPeerConnection(configuration);
var state = pc.signalingState;

Specifications

Browser compatibility

[1] Though this property is not prefixed, the interface it belongs to was until Chrome 56.

[2] Though this property is not prefixed, the RTCPeerConnection interface it's a member of was until Firefox 44.

See also

• Lifetime of a WebRTC session
• RTCPeerConnection
• signalingstatechange
• WebRTC