Physical Parts of Frame Relay

Physical Parts of Frame Relay

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To physically connect to a Frame Relay switch, the provider runs the physical equivalent of a leased line between the router and a nearby Frame Relay switch. The telco needs to be able to send and receive data to and from each router, and leased lines do that. Because Frame Relay doesn't define standards for Layer 1 features, such as basic physical transmission and cabling, Frame Relay relies on the same standards that point-to-point WAN links do for the physical cabling and electrical details. Frame Relay standards refer to this physical serial link between a router and a Frame Relay switch as a Frame Relay access link.

Although the cabling and CSU/DSUs are the same as with a leased line, the telco does something different in the CO: It connects the cable to a Frame Relay switch. A Frame Relay switch is any equipment that understands Frame Relay and can forward traffic based on Frame Relay protocols. The provider's collective set of Frame Relay switches, along with the other equipment between them, form that provider's Frame Relay network.