Frame Relay

   In the year 1992, Frame Relay was introduced, the speeds were controlled from 56 Kbps up to 1.544Mbps in Direction U.s.a. and 64 Kbps up to 2.048 Mbps in the sleep of the world. Nevertheless, as reading wore on, a elfin upstart company titled Fall Communications (acquired afterward by Move, who was then acquired by Lucent) decided to set the grouping on burning by maximizing the access speeds and aggregation throughput to about 50 Mbps. The manufacture quick jumped on this pace and prefabricated Cascade the class one bourgeois in the business at the time. When construct of the data-carrying power was the use of the redact to expect the interchange and not person the corresponding overhead as an senior engineering. The framing was filled with data as obligatory, but it handled the constant and throughput via the high-speed study and subordinate foil. It was premeditated for speeds up to T-1/E-1 (1.544-2.048 Mbps).

       When we say Frame Relay, it is a telecommunication couple designed for cost-efficient aggregation transmitting for intermittent interchange between local atlantic networks and between end-points in a beamy extent network. Compose relay puts assemblage in a variable-size organization titled a framing and leaves any needed nonachievement rebuke up to the end-points, which speeds up overall accumulation transmission. For most services, the system provides a unending virtual journeying, which way that the consumer sees a continous, sacred transportation without having to pay for a full-time leased pedigree, patch the care bourgeois figures out the route each plan travels to its direction and can charge based on usage. 

     The most popular frame relay application provides companies with LAN to LAN communication. This allows companies to integrate their information systems in order to have employees throughout the enterprise to access specific information residing on a LAN somewhere in the enterprise. The devices on the LANs can communicate over the frame relay network regardless of their native protocol. For example, native protocols that can traverse frame relay networks include SNA, DECnet, IPX, TCP/IP, and AppleTalk. Therefore, frame relay has the ability to make the users perceive that the entire company is on one large LAN. Application software such as groupware, e-mail, document sharing, database and many other LAN applications can utilize frame relay technology.
   Companies are also integrating communication for legacy systems, such as SNA, onto frame relay networks (Thyfault, 1995B). This allows companies to connect devices such as cluster controllers and front-end processors directly to FRADs in order to use the frame relay network for communications. Frame relay's ability to support both the legacy applications and LAN applications provides an excellent backbone for those companies that are in the process of migrating their information systems from centralized mainframe processing to distributed client/server systems. Companies can turn up legacy applications on the frame relay network and slowly migrate the LAN applications as they are developed.

     Frame relay relies on the customer equipment to perform end to end error correction. Each switch inside a frame relay network just relays the data  to the next switch. X.25, in contrast, performs error correction from switch to switch. The networks of today are sufficiently error free to move the burden of error correction to the end points. Most modern protocols do error correction anyway, protocols such as SDLC, HDLC, TCP/IP, stat mux protocols, etc.
     Because frame relay passes blocks of data from switch to switch without error correction, propagation from customer end to customer end through the network is very fast. Propagation time in a DCB mux test at Wiltel indicated a 70 millisecond round trip delay from Tulsa, Oklahoma to New York City and back. This is equal to or less than the propagation time through 9600 bps modems over the same distance. Similar propagation times have been measured by DCB over Sprint, AT&T and MCI frame relay networks. An X.25 network would experience a delay of a least one half second, and probably a second or more for the same distance.

Devices attached to a Frame Relay WAN fall into two general categories: 

DTE

      First, we have data terminal equipment (DTE), are considered to be terminating equipment for a specific network and typically are located on the premises of a customer. In fact, they may be owned by the customer. Examples of DTE devices are terminals, personal computers, routers, and bridges.

DCE

  Second, we have data circuit-terminating equipment (DCE), are carrier-owned internetworking devices. The role of DCE equipment is to offer clocking and shift services in a fabric, which are the devices that actually convey assemblage finished the WAN.

    The connection between a DTE device and a DCE device consists of both a physical-layer component and a link-layer component. The physical component defines the mechanical, electrical, functional, and procedural specifications for the connection between the devices. One of the most commonly used physical-layer interface specifications is the recommended standard (RS)-232 specification. The link-layer component defines the protocol that establishes the connection between the DTE device, such as a router, and the DCE device, such as a switch. This chapter examines a commonly utilized protocol specification used in WAN networking---the Frame Relay protocol.

    Some advantagesof frame relay is that it offers an attractive alternative 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 underlying factors:

•     Because virtual circuits consume bandwidth only when they transport data, many virtual circuits can exist simultaneously across a given transmission line. In addition, each device can use more of the bandwidth as necessary, and thus operate at higher speeds.

•  It provides a user with voice, data and video signals at a fast and reliable speed. Hence it can also provide a user with a facility of video conferencing. This protocol is mostly used for dedicated LAN to LAN network and it also helps in connecting to the internet. It is a feasible and inexpensive solution for businesses which require flexible connectivity and fast connectivity.

•     The improved reliability of communication lines and increased error-handling sophistication at end stations allows the Frame Relay protocol to discard erroneous frames and thus eliminate time-consuming error-handling processing.

     As a conclusion, frame relay is a technology that can create a strong nationwide area networking artifact that integrates aggregation systems together to make an endeavor meshwork. It is an cheap and competent help for supportive today's bandwidth qualifier applications as comfortably as those residing on inheritance systems. Because lucid connections are distinct in software, it is relaxed to deal moves, changes, additions, and deletions of ordered connections. Systems analysts should reflect the use of system passage for joint applications that unified collection systems at more than one positioning because of the technologies many field.

References:

                http://www.pulsewan.com/data101/frame_relay_basics.htm

                http://searchenterprisewan.techtarget.com/definition/frame-relay

                http://www.dcbnet.com/notes/framerly.html