This chapter provides a description of basic networking concepts and modem terminology to help you better understand the key functionality of the Dual 56K LAN Modem.
What is a network? A network is a set of computers and other devices, such as printers, servers, hubs, and modems, that are connected together either directly through cabling, or indirectly through dial-up telephone or other services. The components of a network can be situated in a single room, a single building, or a contained “local” geographical area, or they can be dispersed over far distances and a wide geographical area.
What is a LAN? A LAN (Local Area Network) is a network, or a segment of a larger network, which has all its components (computers, printers, etc.) located within a contained geographical area, such as a single office building. By linking computers together and creating a LAN, users can share files and share access to devices such as printers, common servers, or, in the case of the LAN Modem, to modems for access to the Internet.
A LAN is defined in contrast to its counterpart, the WAN (Wide Area Network), and often refers to that portion of a larger network which relies only on direct cabling to connect all its devices, without crossing into the domain of the WAN, which consists of any pre-installed telephone or cable wiring, or any pre-existing public network infrastructures such as the Internet. A network as a whole can extend beyond the limits of any one LAN and can comprise limitless numbers of LANs, but where its reach is extended through the use of dial-up or leased-line services, its LAN-segment is said to end, and the network is said to cross over into the WAN space.
To link devices together to form a LAN, the type of cabling generally used is Ethernet. There are three main types of Ethernet networks: 10BASE-T, 10BASE-2 and 10BASE-5. The Dual 56K LAN Modem uses 10BASE-T Ethernet cabling.
10BASE-T Ethernet is used in small networks with only a few dozen devices located within close proximity to one another. The physical wiring used for a 10BASE-T Ethernet network is twisted pair cabling. The connector used for 10BASE-T looks similar to the connector used for your telephone connection. 10BASE-5 Ethernet is used in large networks with many devices, where transmissions occur over distant geographical areas. 10BASE-2 (Thin) Ethernet is used in smaller networks in which all devices are located relatively close together.
