The disadvantages of Frame Relay are: Data transmission may exceed network capacity as clients use a common network, and this results in the slowing down of the network. Forward Explicit Congestion Notification (FECN): • This bit can be set by any switch to indicate that traffic is congested in the direction of travel of the frame. • The BECN bit also is a part of the address field of the frame header. An example of a simple Frame Relay network is shown in Figure 10-3. • The data size may vary up to 4096 bytes. (See Figure 1.) Sometimes called a frame relay assembler/disassembler, FRAD is a telecommunications device that enables a customer site to be connected to a frame relay service. • As per this table the packet with DLCI number 58 is forwarded to the outgoing interface-. • Frame Relay is used mostly to route Local Area Network protocols such as IPX or TCP/IP. Packets having errors are simply discarded. In the overload situations a frame may have to be discarded. •Frame relay was developed for taking the advantage of the high data rates and low error rates in the modem communication system. This saves a lot of memory space of the hosts and switches. In network communications, a transmission medium is a physical connection or an interface between the transmitter and the receiver. Frame relay switching equipment is devices that are responsible for transporting the frame relay compliant information offered by the access equipment. It supports a minimum average data rate and can handle the bursty data. If large files transferred at high speeds, the price/performance ratio is higher in X25. • Each virtual circuit is identified by a number called Data Link Connection Identifier (DLCI). ... Data Communication and Networking – SONET and SDH . 3. • The destination is informed about the congestion via this bit. If congestion occurs in the network, frame (data) is discarded within the network without re-transmission of this frame. The flow control can then be initiated or the indication may be ignored. 4. 2. • Both these are controlled by a single bit contained in the frame header of frame relay. Frame relay has considerable low overhead and its speed through the network is in part to not insuring delivery of data. • Originally there was no provision for control and management of interfaces in the frame relay because it was designed to provide PVC connection. (a) Shows four such LANs interconnected via T-lines. The reliability of frame relay is less. • The control field is not needed because flow and error control are not needed. • If the network is congested, the FECN bit is set to 1. For this each switch has a table. • Frame relay also is meant for more efficient transmission scheme than the X.25 protocol. Initially designed for transportation across an integrated services digital network infrastructure, Frame Relay pl… Data Communication and Networking – Transmission Media – Guided Media – Twisted Pair Cable / Coaxial Cable / Fiber-Optic Cable ... Data Communication and Networking – Frame Relay . • The intermediate host/switch does not keep a copy of the packet forwarded to the next host/switch. 2. Various key features of this protocol are as follows: 1. 7. A local FRAD accepts packets from a bridge, router, or other device; buffers them; frames them; and transmits them over a frame relay link to a remote FRAD that performs the process in reverse. Popular bound transmission media in use are twisted pair cable, co-axial cable and fiber optical cable. So it can be easily used in, • There are two EA locations. • This is an option offered by frame relay. • As shown in Fig. Typically you can access the Frame Relay service through Frame Relay devices, such as Frame Relay Access Devices (FRADs), frame routers, bridges, or switches. The damaged frame is simply dropped. physical layer and data link layer. Once the communication is finished, the call control signal issues a command for each node to disconnect. • Frame relay can support the Permanent Virtual Circuit (PVC) as well as Switched Virtual Circuits (SVC). FECN : Forward Explicit Congestion Notification. • The address field defines the DLCI along with some other bits required for congestion control and traffic control. Frame relay places the responsibility of ensuring data delivery on the end-point devices that are operating with multi-level protocols. This set of Data communication and Networking Multiple Choice Questions and Answers (MCQs) focuses on “Frame Relay ”. • The intermediate host/switch does not keep a copy of the packet forwarded to the next host/switch. Frame Relay Virtual Circuit: Frame Relay service provides end to end communication using connection-oriented communication. • Fig. 2. • This protocol provides management features such as : 1. Definition of Frame Relay Access Device (FRAD) in The Network Encyclopedia. • No specific protocol is defined for the physical layer. The value of the first one is fixed at 0 and the second at, • 1 is set in the DE (Discard Eligibility) for the part that can be discarded first when congestion occurs. • Each switch is a special type of computer that can forward packets based on the address contained in the packet. • The switching table for the frame relay switch is shown in Table. Transmission Media is broadly classified into the following types: 1. • It informs the sender about the congestion. X.25 was the earlier technology used in place of frame relay, but there are some demerits of using it such as low data rate, an unnecessary increase in the rate of the flow and error control. Frame relay can only detect errors (at the data link layer). Shows the frame relay network connected to. Networking and Internetworking Devices MCQs. The number of functions of a protocol at the user-network interface is reduced. • Assume that a virtual circuit has been established between computers A and C using the DLCI numbers of Fig. Layer 2 and 3 include flow control and error control. Same copper telephone wire is used. Multiple choice Questions on Transmission Media. • Frame relay can provide two types of virtual circuits. (adsbygoogle = window.adsbygoogle || []).push({}); The frame relay access device (FRAD) is a device that receives network packets from the customer’s network and encapsulates them into a format acceptable for transmission over frame relay circuits. Frame relay is a computer networking structure that allows for a quick and efficient way to transmit frames from one device to another. Extended address (Frame Relay Assembler I Disassembler) : The frame relay address has been extended from the original 2 byte address to 3 or 4 byte address, in order to increase the range of DLCIs. 5. End-points can be devices … Some of the advantages of frame relay are: 2. This frame is very similar to the HDLC frame except for the missing control field here. Frame Relay is a scalable wide area network solution which makes use of packet-mode transmission. DCE is a device which transfers data in the network. 1 The address field of a frame is 01101000 00001111. If the traffic is hefty, with a large number of small packages, its performance is more excellent than X25. • VOFR allows voice transfer on the frame relay. • So recently a protocol called LMI (local management information). there are three frame relay switches which are connected to several computers. Once the communication is finished, the call control signal issues a command for each node to disconnect. • This bit indicates whether the current byte is the final byte of the address. A layer 2 protocol, frame relay is used to create a private network through the carrier’s network. • This is an inexpensive way of sending voice over long distance. • If EA = 1 it indicates that the current byte is the final one but if EA = 0, then it tells that another address byte is going to follow. Enables data, voice and other types of traffic to travel over a medium in a digital manner previously used only for analog voice transmission. has three incoming and four outgoing interfaces. 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