TELECOMMUNICATION PROCESSORS such as modems , multiplexers ,switches and routers perform a variety of support functions between the computer and other devices in a telecommunications network. A telecommunication processors includes: Modems Multiplexers Internetworked Processors . and are probably the most widely used data communications hardware in business. then to receive these signals and convert them back to digital signals. while a similar unit separates the individual transmissions at the receiving end. • Multiplexers A multiplexer is a communications processor that allows a single communications channel to carry simultaneous data transmissions from many terminals. The word "modem" is a contraction of modulate and demodulate. Typically. a multiplexer merges the transmissions of several terminals atone end of a communications channel. This process is known as modulation and demodulation.Modems: These devices are the most common type of communications processor. Functions of modems include: • Convert digital computer signals to analog signals for transmission over telephone lines. and gateways. • Hub . • Router . • Switch .a port switching communications processors. hubs. • Gateway .makes connection between telecommunications circuits in a network.Internetwork Processors: Telecommunications networks are interconnected by special-purpose communications processors called internetwork processors such as switches.connects network with different communications architecture.intelligent communications processors that interconnects network based on different protocols. . routers. Multiplexer – allows a single communication channel to carry simultaneous data transmissions from many terminals . Network Monitoring – troubleshoot and watch over the network . firewall . . traffic patterns and users’ need. Traffic Management – manage network resources and traffic to avoid congestion and optimize service levels. Security – provide authentication . auditing and enforcement. encryption . Capacity Planning – survey network resources . alerting administrators of potential problems. Star Network – ties end user computer to a central computer. Ring Network – ties local computers processors together in a ring on a relatively equal basis. Topology – the structure of the network. Bus Network – local processors share the same communications channel. . . software . . and interfaces between users and computer systems. hardware . Handshaking – the process of exchanging predetermined signals and characters Network Architecture – master plan of standard protocols . Protocol – a standard set of rules and procedures for the control of communications in a network. Each layer add functions. Transmission Control Protocol/ Internet Protocol TCP/IP A five-layer telecommunications protocol used by the internet. . Model for should messages should be transmitted between two points in a network.Open Systems Interconnection (OSI) Model A seven layer model that serves as a standard model for network architectures. . bandwidth is the width of the range (or band) of frequencies that an electronic signal uses on a given transmission medium. bandwidth is often used as a synonym for data transfer rate .the amount of data that can be carried from one point to another in a given time period (usually a second). .