The network (the network) is a collection of two or more computer systems are connected. There are many types of computer network: a. local-area network (LAN) computer that is connected to the place near the gografis (for instance a building). b. wide-area network (WAN) that connect the computer on which far apart and connected by phone line or radio waves. besides, the computer network can also be grouped based on the following criteria: a. topology: keterhubungan between the computer system. There are various topology such as bus, star, and ring.b. protocols: the protocol defines a set of rules and signals used by computers on the network to communicate. LAN protocol is the most popular Ethernet.
LAN protocol that is widely used IBM token-ring network.c. architecture: the network can be classified into the architecture of peer-to-peer or client / server.
Some of the computers in the company can terinterkoneksi and a local computer network or what's called the Local Area Network (LAN), in this local network users can contact each other and men'share 'resources, such as their data, software or hardware such as printers and others. To connect the LAN between the lines of communication required a greater or what's called the Wide Area Network (WAN). With this branch office WAN-branch offices can communicate and exchange data with headquarters atapun with the other branches. With an integrated system that in addition to data communication, voice communication can ditumpangkan to this communication system, so to a certain location (outside the city, overseas) cost efficiency can be improved. Various types of data communication services offered by many companies the provider of data communication, among others, Frame Relay, IP based VPN and VSAT. Products that have advantages and weaknesses. The selected products which are most suitable to the needs of the company.