RADIUS configuration

Hi,

Our network uses cisco AS2511-RJ for the RAS users to access the network.all works fine.
I am planning to install RADIUS server from option pack(IIS4.0).
While I am configuring RADIUS,it requires values for vendor-specific attributes.Can anyone pls tell me what is the vendor-specific attribute for cisco AS2511-RJ?

If possible what other configurations should I perform on the router.

Thanks