clarification on WAN

MrXpert

I've just started reading about WAN types such as frame relay and leased lines.Am a bit confused about these so hope someone can provide me with a better understanding how they connect together. Your help much appreciated.

My own version of the differences are that with leased lines you have a point to point connection between routers in offices and these lines are typically T1,E1,T3,E3. They give you dedicated bandwidth and these lines are referred to as T1/T3/E1/E3 CAS connections. The CAS part of it refers to the point to point connection as opposed to T1 frame relay WAN.With a leased line you have a router connected to a csu/dsu via a serial cable. In the office The CSU/DSU is then hooked up to a RJ-48 connector/T1 cable which plugs into the demark point or wall jack. The CSU/DSU is an external device but some routers have WAN INTERFACE CARDS which means the csu/dsu is intergrated into the router so no need for serial cable.I hope so far i'm close enough to what it means?

With frame relay WANs these are packet switching type networks as opposed to leased lines. Do you still need a CSU/DSU and serial cables? And does it also use T1 lines from the demarcation point to the frame relay cloud?

MrXpert

anyone know?