The data communication environment has changed at rapid pace and many large computing and communicating networks are now in service: coordination required for efficient use of network is complex process. Such networks may have hundreds of terminals and many small processors located at dozens of dispersed sites. These sites, in turn may be linked by different transmission channels to large host computers. The task of http://www.intellixmedia.com/index.aspx network designer is to select and coordinate the network components so that the necessary data are moved to the right place, at the right time, with a minimum of errors, and at the lowest possible cost. Communication processor: A number of communication processors are used in a network for the following purposes: Remote Concentration of Messages: The remote concentrator reduces transmission costs by receiving terminal input from many low speed lines, then concentrating and transmitting a compressed and smooth stream of data on a higher speed and more efficient transmission channel. Devices called multiplexers, equipped with micro-processor, also perform this concentration function. Message-Switching: The message switcher receives and analyses data messages from points in network, determines the destination and the proper routing, and then forwards the messages to other network location. If necessary, a message may be stored until and appropriate outgoing line is available. Packet Switching: The technique of packet switching has been specifically developed for high speed data transfer between the computers connected via broadband communication network. Data to be transferred are assembled into packets. The size of the packets is optimized for the switching system concerned, by taking into account factors such as: the capacity or transmission rate on the interconnecting circuits, the amount of store available at the switched, and the likely transmission delay time. The packets are short (64/128/256 bytes) and may be independently routed. Thus the4 system can keep the traffic flowing by sending packets which are part of different transmission consecutively down a given circuit, instead of having to keep the circuit open until a whole transmission is completed. Front-End Processing: The front-end processor is to relieve the main (host computer of a number of functions that are required for interaction with a control of the communication network. It is usually located at a central computer site. The functions of a communication processor differ from one network to another. A message packet switching processor may also function as a remote concentrator; a front-end processor may perform message/packet switching functions: and in less complex networks, the host computer may perform most or all the functions of the front-end processor.