Receiving and Sending External Information on a LAN - Business - Small Business

Outside information comes into a home network from the Internet through a telephone line (standard or DSL), a cable connection, or from a satellite hookup. Information that originates in the LAN can also be sent out to other locations on the Internet. This outside data exchange is in addition to the data being sent and received among the various nodes on the LAN.

Communication between networks requires that they use a common protocol and that each computer or other device attached to each network have a unique address. The most common protocol currently used on LANs and to connectnetworks to one another is Transmission Control Protocol/Internet Protocol(TCP/IP). This protocol is used throughout the Internet. TCP/IP addresses each node on a LAN by a unique Internet Protocol address (IP address), which consists

of four numbers separated by periods. Each of the four numbers in an IPaddress

must consist of no more than eight bits of binary

data, which means that each number cannot be higher than 256. This keeps the addresses short and standardized for consistency.

How Data Travels on the Internet The Internet is really a vast collection of WANs, all interconnected to one another and able to communicate with each other. Data going from a node on a home LAN to a node on a distant network reaches its destination by traveling through the communication lines of other networks located between the originating point and the destination. Usually, the data can take many possible routes. Some are long and require more time for the data to arrive than others, but since all the WANs that make up the entire Internet are connected, it is possible to send data from a node on any LAN to a node on any other, provided the IP address of the destination is known and the data is directed toward that address by the Internets data management devices, or routers.

Figure 2-9 shows the Internet as a web of interconnected, but independent, networks over which data travels from source to destination by various routes. A node on the California LAN A can send data to the node on New York LAN F by manydifferent routes: router 1 to 3 to 8 to Network F, F. The Role of Routers

Routers are the hardware units responsible for directing data traffic betweeninterconnected networks. They function as intelligent switches that have theability to make decisions based on preprogrammed instructions and implement

access point vs router