Initiating a call

Now that we have set everything up properly, we are ready to initiate a call with a remote user. Sending the offer to another user starts all this. Once a user gets the offer, he/she will create a response and start trading ICE candidates, until he/she successfully connects. This process is exactly the same as mentioned in Chapter 3, Creating a Basic WebRTC Application, except for the fact that it is now being done remotely over our signaling server. To accomplish this, we add the following code to our script:

callButton.addEventListener("click", function () {
  var theirUsername = theirUsernameInput.value;

  if (theirUsername.length > 0) {
    startPeerConnection(theirUsername);
  }
});

function startPeerConnection(user) {
  connectedUser = user;

  // Begin the offer
  yourConnection.createOffer(function (offer) {
    send({
      type: "offer",
      offer: offer
    });
    yourConnection.setLocalDescription(offer);
  }, function (error) {
    alert("An error has...