Frame Relay networks provide more features and benefits than simple point-to-point WAN links, but to do that, Frame Relay protocols are more detailed. For example, Frame Relay networks are multiaccess networks, which means that more than two devices can attach to the network, similar to LANs. Unlike with LANs, you cannot send a data link layer broadcast over Frame Relay. Therefore, Frame Relay networks are called nonbroadcast multiaccess (NBMA) networks. Also, because Frame Relay is multiaccess, it requires the use of an address that identifies to which remote router each frame is addressed.
Figure 13-1 outlines the basic physical topology and related terminology in a Frame Relay network.