It seems like this is the only place you're sending an IAC message. If that's true, I don't think you need to give this message its own type. After all, there's only this one. What I'd do is something like this:

```
app.connect('ftu-status').then(function(ports) {
  ports.forEach(function(port) {
    port.postMessage('done');
  });
});
```

(Obviously, you'd need to add the onConnRejected function to that block too, but that doesn't need to change.)

This ties in with my other comment that `IACHandler` shouldn't name events using the `.type` member of the message object. All it ends up doing for you is requiring you to jump through an extra (small) hoop to make `IACHandler` understand your message.

While adding `message.type` to the event name does make the mediacomms code a bit simpler, now that you've added the DOM events, I'll probably put all of that code into the `handleEvent` method anyway, so I don't gain anything by having them be separate events. From what the code here looks like, you don't gain anything from it either, so let's just drop it, and have a single event type for each IAC keyword; that is, your code would listen for `'iac-ftucomms'` and mine would listen for `'iac-mediacomms'`.