Using RADIUS for content filtering.

Dear all, I've given one assignment to create some sort of tunneling to cache server (netcache) to do some content filtering when browsing. There will be 2 cache-server. One passing all traffic & another one will do content filtering.. When user subscribe to this service (for their children maybe).. When user doing authentication, what should i include in the profile for the traffic to be diverted to cache server that do the filtering? Is it possible to use below? Or pls suggest suitable method.. Login-Service: TCP-Clear Login-IP-Host: 10.1.1.1 Service-Type: Login-User Login-TCP-Port: 80 I've heart about method L2TP tunnelling with ERX/SDX (juniper) .. But that seems costly... thanks.. --haizam