Network Warrior

Frame-Relay Network Design

Frame-relay links are more flexible than point-to-point links because multiple links can be terminated at a single interface in a router. This leads to design possibilities allowing connectivity to multiple sites at a significant cost savings over point-to-point circuits.

Figure 22-5 shows three sites networked together with frame relay. On the left, Router B and Router C are both connected to Router A, but are not connected to each other. This design is often referred to as a partial mesh or hub and spoke network. In this network, Router B can communicate to Router C only through Router A.

Figure 22-5. Meshed frame-relay networks

On the right side of Figure 22-5 is an example of a fully meshed network. The difference here is that all sites are connected to all other sites. Router B can communicate directly with Router C in the fully meshed network.

Meshed networks are not strictly the domain of frame relay. As you can see in Figure 22-6, a fully meshed network can easily be created with point-to-point T1s.

Figure 22-6. Frame-relay versus point-to-point T1 meshed networks

In a frame-relay network like the one shown on the left side of Figure 22-6, each location needs a router that can support a single T1. Each one of the PVCs can be configured as a separate virtual ...