Understanding Switched Networks

Another WAN alternative for moving data between different LAN sites is switched network technology. A switched network allows multiple users to take advantage of the same line. This makes the overall cost of this WAN technology cheaper than dedicated leased lines.

On a switched network, your LAN (or your multiple LANs at different locations, if your company is connecting multiple sites) is connected to the wide area network by a switched network service provider or the POTS. Data leaving your LAN through the WAN connection enters the switched network and then makes its way to the final destination. The path that the data takes, however, can be different each time. This means that many different users can take advantage of moving data on the switched network almost simultaneously .

Switched networks make it easy for companies to expand because additional remote sites can be connected to the switched network at any time. Switched networks come in two different flavors: circuit switching and packet switching.

Note

Using T-Carrier lines as a way to connect LANs at different locations requires a couple different pieces of equipment. We've already mentioned the multiplexer/demultipexer (MUX), which actually combines multiple channels into one stream of information or breaks down the data stream into the individual channels. A piece of equipment called a Channel Service Unit/Digital Service Unit (CSU/DSU) actually sits between the LAN multiplexer and the connection to the local loop.