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The digital subscriber line access multiplexer, more commonly referred to as DSLAM, is a piece of networking equipment that makes it possible to process multiple customer Internet connections simultaneously. The device broadens the service area where an Internet Service Provider can offer high-speed Internet connectivity, while maintaining the integrity of the connections. While the equipment is normally co-located at the local telephone exchange, it is also possible to establish a network of remote multiplexers as a means of expanding a coverage area or accommodating new customer connections in the current service area.
In actual practice, a DSLAM functions as a conduit that allows a number of customers to establish a high-speed gateway to the Internet using a single connection. This is accomplished by each of the customers dialing into the local telephone switch to connect with the multiplexer. From there, the device connects to the Internet through its own high-speed capability. As the users connected to the device use any type of online services, the signals are processed, sometimes compressed, and routed through the multiplexer and to the point of termination. In like manner, the multiplexer receives the return signal from the web sites accessed and acknowledges the completion of the interchange, a process known in telephony as a handshake.
To the end user, this process appears to take place instantly. Once the connection is established, the user is able to browse the Internet at high speed, based on the capability and condition of the user’s computer equipment and the amount of bandwidth that the provider devotes to its DSL services. As long as the connection between the DSLAM and the user remains intact, it is possible to quickly manage tasks like checking email, shopping with online retailers, blogging, and doing any of the many functions that are handled in an online environment today.
Some businesses also use this equipment as a means of making their use of the Internet more efficient. Municipalities often follow this pattern with buildings that house government departments. Hotels also tend to make use of one as part of their in-house communications network, as well as a way of creating access to the local phone switch for voice as well as Internet connectivity.
For residential DSL service in metropolitan areas, end users may actually route through more than one DSLAM. Remote multiplexers can be placed strategically around the city, usually at telephone switching stations that serve different sections of the business and residential districts, creating a multiplexing network. This approach makes it possible for service providers to incrementally add another multiplexer to the network as the population increases or outlying areas are developed for commercial purposes.