Frame Relay
Frame relay is a high performance WAN protocol which operates at the physical and data link layers of the OSI reference model. Frame Relay does not involve the error correction and network flow control operations. It has the digital transmission capabilities, such as fiber optic cable and ISDN. Frame Relay is an example of packet-switched technology. Packet-switched networks enable the end stations to dynamically use the network medium and the available bandwidth. Packet-switching technology uses the following two techniques:
Variable-length packets — Enables more efficient and flexible data transfer. These packets are routed through the various intermediate nodes in the network to reach the destination.
Statistical multiplexing — Controls the network access in a packet-switched network. This technique enables a flexible and efficient use of bandwidth for transmission.
Frame Relay supports windowing and retransmission of previous data. A computer user can work with several programs at the same time using windowing. Frame Relay is a Layer 2 protocol suite and provides no service at Layer 3. It gives higher performance and transmission efficiency than X.25. Hence, Frame Relay is suitable for the WAN applications.
Features of Frame Relay
a.Frame Relay operates at a higher speed (44.3 Mbps).
b. It operates only in physical and data link layers.
c. It is less expensive than other WAN connection.
d. Frame relay has error detection at the data link layer only. There is no retransmission policy if a frame is damaged. In this way it provides faster transmission for more reliable media and for those protocols that have flow and error control at the higher layers.
Frame Relay Network Implementation
A private frame relay network implementation is to provide a Ti multiplexer with Frame relay and non-frame relay interfaces. Ti multiplexer combines digital input signals into one high speed output signal. The Frame Relay traffic is forwarded out of the frame relay interface and onto the data network. The non-Frame Relay traffic is forwarded to the appropriate service or application such as, telephone service or video-teleconferencing application.
The Frame Relay networks provide services to the customers which is called the public Frame Relay service. Frame Relay is implemented to provide service for private enterprise networks and is implemented in public carrier-provided networks and private enterprise networks.