Skype crippling network performance

Another thing I've learned today: Whenever Skype runs in the "super-node" mode it will do some traffic shaping on your network.

While it does make sense for the limited DSL upstream one would have, it absolutely makes no sense to limit my 100 mbit link to the router down to ~90mbit. This would also cripple transfer from/to my NAS.

So, what can be done about that? You could try to setup some intelligent (desktop) firewall rules to prevent Skype doing NAT Traversal and becoming a Supernode. As we all know, Skype is VERY persistent when it comes to punching holes into your firewall. So this task might cost you some nerves and could potentially affect other applications you run on your desktop. So, what options do we else have? Apparently Skype does offer some hidden registry settings which will affect that behavior. Once you disabled the supernode feature using the registry snippet below your intranet network performance should return to its former glory

  1. Windows Registry Editor Version 5.00
  3. [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Skype\Phone]
  4. "DisableSupernode"=dword:00000001