Cisco® Network Professional's: Advanced Internetworking Guide

11.3. Enterprise WAN

When you start to think about connecting your remote sites, you need to consider the different topologies that can be used. The best topology is a full mesh topology because it provides optimal routing. The full mesh topology provides a dedicated virtual circuit between any two customer edge (CE) routers in the network. The biggest problem with the full mesh solution is that with a large number of virtual links expense can get very high.

For a less expensive solution, customers may choose to use a partial mesh topology or a hub-and-spoke topology. The problem then becomes routing; it is no longer optimal. The partial mesh topology reduces the number of virtual circuits; usually this minimum number is just enough to provide ...