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Frame Relay Implementation
Frame Relay encapsulation is being used on the only link to the Internet from the District Office. Use of Frame Relay is optimal on the highly reliable T1 link because of its maximum available bandwidth. It doesn’t use windowing and much flow and error control, so provides maximum available physical bandwidth for the data flow on the expensive Internet link.
At a very basic level, this may seem similar to a leased line. However, because there is no dedicated physical circuit along the entire path, the carrier can provide bandwidth as needed, which may ultimately prove more cost effective. However, frame relay incurs additional overhead because it is a packet-switched technology.
Frame Relay is a data link-layer protocol that can handle multiple virtual circuits. Because this protocol does not do any error checking, it is much faster than the older X.25 protocol. When the PVC (permanent virtual circuit) is establish, DTE devices can begin transmitting data when they are ready. SVCs (switched virtual circuits) are used when only sporadic data communication is desired.
Traffic may reach its destination but with a large delay and significant jitter, which impacts the quality of voice or any real-time playback. As a general rule, then, avoid running real-time traffic at rates exceeding the CIR. This is pertinent because, while frame relay services may entail certain bandwidth guarantees, they do not feature any latency guarantees. This may necessitate using a different PVC for real-time and non-real-time traffic. A frame relay network can provide resilience in a cost-effective manner. For example, you could deploy backup PVCs that have a lower CIR than the equivalent primary PVC.
Frame Relay Router Commands
Sunset# configure terminal
Sunset(config)# interface s0
Sunset(config-if)# ip address 219.17.102.5
255.255.255.252
Sunset(config-if)# clockrate 56000
Sunset(config-if)# no shut
Sunset(config)# interface s0
Sunset(config-if)# encapsulation frame-relay
Sunset(config-if)# frame-relay intf-type dce
Sunset(config-if)# frame-relay map ip 219.17.102.5 100
broadcast
Sunset(config-if)# frame-relay map ip 219.17.102.6 100
broadcast