Showing posts with label Frame Relay. Show all posts
Showing posts with label Frame Relay. Show all posts

FRAME RELAY

FRAME RELAY

In the context of computer networking, frame relay (also found written as "frame-relay") consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. Network providers commonly implement frame relay for voice and data as an encapsulation technique, used between local area networks (LANs) over a wide area network (WAN). Each end-user gets a private line (or leased line) to a frame-relay node. The frame-relay network handles the transmission over a frequently-changing path transparent to all end-users.

As of 2006 native IP-based networks have gradually begun to displace frame relay. With the advent of MPLS, VPN and dedicated broadband services such as cable modem and DSL, the end may loom for the frame relay protocol and encapsulation. There remain, however, many rural areas lacking DSL and cable modem services, and in such cases the least expensive type of "always-on" connection remains a 128-kilobit frame-relay line. Thus a retail chain, for instance, may use frame relay for connecting rural stores into their corporate WAN.

Frame relay has its technical base in the older X.25 packet-switching, designed for transmitting analog data such as voice conversations. Unlike X.25, whose designers expected analog signals, frame relay offers a fast packet technology, which means that the protocol does not attempt to correct errors. When a frame relay network detects an error in a frame, it simply "drops" that frame. The end points have the responsibility for detecting and retransmitting dropped frames. (However, digital networks offer an incidence of error extraordinarily small relative to that of analog networks.)

Frame relay often serves to connect local area networks (LANs) with major backbones as well as on public wide-area networks (WANs) and also in private network environments with leased lines over T-1 lines. It requires a dedicated connection during the transmission period. Frame relay does not provide an ideal path for voice or video transmission, both of which require a steady flow of transmissions. However, under certain circumstances, voice and video transmission do use frame relay.

Frame Relay

Frame Relay

This LAN internetworking protocol standard is a fast and efficient method of transmitting information from a user device to LAN bridges and routers. Though structured similar to that of LAPD, the frame header is replaced by a 2-byte Frame. The Frame Relay header contains the congestion and status signals which the network sends to the user and also the user-specified DLCI field, which is the destination address of the frame. Frame Relay forms a good substitue to both dedicated lines and X.25 networks for connecting LANs to bridges and routers. The success of the Frame Relay protocol is based on the following two factors.

a. virtual circuits can exist simultaneously across a given transmission line as they consume bandwidth only when they transport data and each device could operate at higher speeds by using more bandwidth.

b. With the advent of improved reliability of communication lines and increased error-handling sophistication at end stations, Frame Relay protocol could discard erroneous frames and eliminate time-consuming error-handling processing.

These factors make Frame Relay a favorite choice for data transmission, but its also necessary to test and determine that the system works properly and that data is not lost.