Getting a remote desktop client to work can be a pain. Having used OS X's default share screen option on a local network and found it good, but lacking in some respects, I typically wanted more control. Apple Remote Desktop seemed the logical extension to that.
Getting it to work in anyway with the BT Homehub 3 was far from clear, but after many attempts at trying everything possible, and asking the IT guy at work, it's now working. For my own sanity and those in the same situation it's only good to share, so here is my solution.
- Log in the home hub ( http://bthomehub.home )
- Navigate to Advanced > Port forwarding > Supported applications
Add a new 'Game or Application' with the following ports and click apply when done
- Any 5900-5900 -> 5900 -5900
- Any 3283-3283 -> 3283 -3283
- Any 5988-5988 -> 5988 -5988
- Any 22-22 -> 22 -22
- Go to Configuration
- Select your newly named 'Game or Application' and importantly for the device use the internal IP of your computer. If you use the device name it doesn't work. Go figure!
To test you need to use a device that isn't on the same network. I wasted much time and pulled out some hair by missing this step. I tested by tethering the computer that I was controlling on to my iPhone so it was vis 3G, but you can also use a VPN out your local network and back in.
If you want to make sure you can always get your computer, I would recommend using a service like no-ip.org or similar so you can just point your RDC to mymegacomputer.no-ip.org and it will take care of the external IP.
I imagine I have extra ports open that are in excess so please test and correct me.