Metropolitana Area Network (MAN) is basically a LAN version is larger and usually use the same technology as LAN. MAN can include corporate offices are adjacent and can be used for private purposes (private) or the public. MAN usually mamapu support data and voice, and can even be associated with the cable television network. MAN only have one or two buiah cable and do not have a switching element, which serves to set the packet through multiple output cable. The existence of switching elements make rancangan be simpler.

The main reason separating MAN as a special category is already-determined standard for MAN, and these standards are now being implemented. Standard is called DQDB (Distributed Queue Dual Bus) or according to the standard IEEE 802.6. DQDB consists of two unidirectional kabela where all the computers are connected, as shown in Figure 1.2. Each bus has a headâ € "end, the device to start the transmission activity. Traffic to the computer that is located on the right sender using the bus top. Traffic to the left using a bus that is under.

Wide Area Network (WAN) covers a wide geographical area, sertingkali includes a state or benua. WAN consists of a collection of machines that aims to carry out the application programs.

We will follow traditional usage and call

these machines as hosts. Term End System is sometimes also digunakan in the literature. The hosts are connected by a communication subnet, or simply called subnets. Subnet task is to bring a message from the host to the other, as well as the telephone system that brings the conversation contents of the speaker to the listener. By separating the pure communication aspects of a network (subnet) of the aspects of the application (host), a complete network design becomes much simpler.

In most of the WAN, the subnet consists of two components, namely cable transmission and switching elements. Transmission cable (also disebut circuit, channel, or trunk) memindahkan bits from one machine to another.

Switching element is a special computer that is used to connect two or more transmission cables. When the data cable to the receiver, the switching element must choose a wired sender to forward these messages. Unfortunately there is no standard terminology in this seperti computer name. His name is highly variable called packet switching nodes, intermidiate systems, data switching exchange and so on.

As a generic term for computer switching, we will use the term router. But need to know in advance that there is no consensus in the use of this terminology. In this model, as shown in Figure 1.4 each host is connected to the LAN where there is a router, although in certain circumstances a host can be connected directly to a router. Set of communication channels and routers (but not the host) will form a subnet.

The term subnet is very important, once the subnet means a collection of routers and set-channel communication Sakuran move packets from the host destination host. Will tatapi, beberpa years later subnet get more meaning in connection with a network addressing.

In most of the WAN, the network consists of a number of many cable or telephone lines that connect a pair of routers. When two routers that do not contain the same cable will communicate, both must communicate indirectly through other routers. when a packet is sent from a router to another router through an intermediary router or more, then the packet is received by a router in a complete state, is stored until the output channel to be free, and then forwarded.