Exchange 2000 access with Outlook 2k3 using VPN

[wknock]

Hi,

I've got an Exchange 2000 server which clients access using Outlook 2003. I'm trying to set up a VPN connection for remote workers using SecurRemote, but for some reason Outlook wants to communicate with Exchange on ports 135 (RPC so understandable), but also ports 1182 1200 and 1268 which, from what I can find on the net, have nothing to do with Exchange and Outlook?

Any info on theses ports and why they're needed would be appreciated.

Thanks,

Will