I trying to set up a Static conduit so my client can run a vpn client through a PIX running PPPoE over a DSL connection. Any ideas on how to accomplish this?

I work at a hosting facility for the DoD, and we are having an OC-12 installed. The base engineers have the OC-12 coming into our facility and branching out to our three separate organizations as OC-3's. My question is why I cannot use Ethernet inste...