Frame relay is one of the industry standards that utilize packet switching method in a Wide Area Network to specify the Physical and Logical Link Layers of the digitized communication.
In Frame Relay, is most preferred in the modern telecommunication and can be used to transmit voice and is implemented as VoFR or Frame Relay for Voice and can be applied to both local area network and even over a Wide Area Network. This essentially makes this applicable in our organization because of its diversity. In this industry standard, each of the users that are attached to both ends of a communication line is provided with a Private Line or Leased Line to a node of Frame Relay. It is the frame relay network that handles the transmission over the transparent path. It is very cheap compared to other methods like X.25 and ATM or the Asynchronous Transfer Mode.
Data is sent through packets called HDLC packets and are commonly referred to as Frames. All the circuits are permanently assigned sometimes known as PVC’s or Permanent Virtual Circuits. The circuits are logical circuits that are connected between the end users. The virtual circuits are setup and maintained throughout to ensure reliability. It is very fast because it does not perform error correction and therefore best for video conferencing and voice calls. It is also good for Polling Protocols and is easy to implement.
In addition to this standard, there is a FRAD which is a Frame Relay Assembler/ Disassembler which is network equipment that simply does what its name suggests to the frames as they arrive. An example of such is the DCB SR and SRX series that can play this role in a real communication circuit. A DLCI is a Data Link Connection Identifier usually a number for the virtual circuit that is used to pass these data frames from one network to another.
The protocols that are applied in exchange of information between the FRAD and the frame relay equipment for the network include the famous LMI that uses DLCI 1023, Annex D that uses DLCI 1 and finally the Annex A that is almost similar to Annex D and find most application in Europe.
Frame relay has the ability to give the administrator the ground to inquire the status of the network after every x seconds. One has the privilege of adjusting this from 2 to 30 seconds. The network can also perform full status inquiry so that it can have full report. The Link Integrity Verification Timer performs the role of indicating how frequently the FRAD initiates a status inquiry message. The Simple Network Management Protocol (SNMP) collects and forms Management Information Base (MIB) by use an Agent.
With all these features of the frame relay, I think it will be wise to implement our network using the frame relay standard to save on cost and also increase the reliability of our network for long service to our organization.
There are two types of sub interfaces on the frame relay. The first is point to point and the second is the multipoint that connects to a star of virtual circuits. As an example to configure a subinterface on a Cisco router named Deta with an IP address 192.168.10.2 for point to point frame relay, use the following code.