Signaling Protocol

The Unity Render Streaming package provides two different signaling protocols as examples.

  • HttpSignaling
  • WebSocketSignaling

In the example, the schema given to URL Signaling is used to determine which protocol to use.

Render Streaming backend

If it starts with http, HttpSignaling is used. If it starts with ws, WebSocketSignaling is used.

HttpSignaling

Signaling is handled by Http Request. The signalling server is polled at specified intervals to obtain the Offer and Candidate of the difference from the last time.

WebSocketSignaling

Signaling is handled by WebSocket. When the signaling server receives the Offer or Candidate, the server distributes it to the connected clients.

Warning

WebSocket does not work in iOS Safari on servers that use self-signed certificates. If you want to verify the behavior of WebSocket signaling in iOS Safari, use a certificate issued by a trusted certification authority. Or try signaling with Http.

Proprietary Signaling Class

Both of the signaling classes implement ISignaling. If you want to create your own signaling class, you can inherit ISignaling to use it directly from the UnityRenderStreaming class. The following is a description of each method.

void Start();
  • A method to call when starting signaling.
  • In the sample, we are establishing a session with the server for each protocol.
void Stop();

A method to call when you want to stop signaling. In the sample, we are terminating the session with the server for each protocol.

public delegate void OnOfferHandler(ISignaling signaling, DescData e);
event OnOfferHandler OnOffer;
  • This is a delegate that registers the process to be performed when a new Offer is received by signaling.
public delegate void OnAnswerHandler(ISignaling signaling, DescData e);
event OnAnswerHandler OnAnswer;
  • This is a delegate that registers the process to be performed when a new Answer is received by signaling.
  • In the current version, it is not used in Unity because it does not receive Answers.
public delegate void OnIceCandidateHandler(ISignaling signaling, CandidateData e);
event OnIceCandidateHandler OnIceCandidate;
  • This is a delegate that registers the process to be performed when it receives a new Candidate by signaling.
void SendOffer();
  • A method to call when sending an Offer in signaling.
  • In the current version, it is not implemented in the sample because it is not possible to send Offer from Unity.
void SendAnswer(string connectionId, RTCSessionDescription answer);
  • A method to call when sending an Answer in signaling.
void SendCandidate(string connectionId, RTCIceCandidate candidate);
  • A method to call when sending a Candidate in signaling.