RTCPeerConnection.setRemoteDescription() - Web APIs
syntax apromise = rtcpeerconnection.setremotedescription(sessiondescription); parameters sessiondescription an rtcsessiondescriptioninit or rtcsessiondescription which specifies the remote peer's current offer or answer.
... this value is an offer or answer received from the remote peer through your implementation of the sessiondescription parameter is technically of type rtcsessiondescriptioninit, but because rtcsessiondescription serializes to be indistinguishable from rtcsessiondescriptioninit, you can also pass in an rtcsessiondescription.
... typeerror the specified rtcsessiondescriptioninit or rtcsessiondescription object is missing the type property, or no description parameter was provided at all.

RTCSessionDescription() - Web APIs
this constructor has been deprecated because rtcpeerconnection.setlocaldescription() and other methods which take sdp as input now directly accept an object conforming to the rtcsessiondescriptioninit dictionary, so you don't have to instantiate an rtcsessiondescription yourself.
... syntax sessiondescription = new rtcsessiondescription(rtcsessiondescriptioninit); values rtcsessiondescriptioninit optional an object providing the default values for the session description; the object conforms to the rtcsessiondescriptioninit dictionary.
... this is no longer necessary, however; rtcpeerconnection.setlocaldescription() and other methods which take sdp as input now directly accept an object conforming to the rtcsessiondescriptioninit dictionary, so you don't have to instantiate an rtcsessiondescription yourself.

RTCPeerConnection.createOffer() - Web APIs
return value a promise whose fulfillment handler will receive an object conforming to the rtcsessiondescriptioninit dictionary which contains the sdp describing the generated offer.
... target: targetusername, type: "video-offer", sdp: mypeerconnection.localdescription }); }) .catch(function(reason) { // an error occurred, so handle the failure to connect }); in this code, the offer is created, and once successful, the local end of the rtcpeerconnection is configured to match by passing the offer (which is represented using an object conforming to rtcsessiondescriptioninit) into setlocaldescription().

RTCPeerConnection.setLocalDescription() - Web APIs
syntax apromise = rtcpeerconnection.setlocaldescription(sessiondescription); pc.setlocaldescription(sessiondescription, successcallback, errorcallback); parameters sessiondescription optional an rtcsessiondescriptioninit or rtcsessiondescription which specifies the configuration to be applied to the local end of the connection.
... type of the description parameter the description is of type rtcsessiondescriptioninit, which is a serialized version of a rtcsessiondescription browser object.

RTCPeerConnection.createAnswer() - Web APIs
return value a promise whose fulfillment handler is called with an object conforming to the rtcsessiondescriptioninit dictionary which contains the sdp answer to be delivered to the other peer.

RTCSessionDescription - Web APIs
the parameter is a rtcsessiondescriptioninit dictionary containing the values to assign the two properties.

RTCSessionDescriptionCallback - Web APIs
syntax rtcsessiondescriptioncallback(description); parameters description an rtcsessiondescriptioninit (or rtcsessiondescription) object describing the session being offered or being accepted.