You most likely will obtain your high-bit-rate digital subscriber line (HDSL) modem from your digital subscriber line (DSL) provider, the company through which you receive access to the Internet. Instead of HDSL, your provider might refer to it as HDSL-2, a symmetrical high-bit-rate digital subscriber line (SDHSL) or a global standard high-bit-rate digital subscriber line (G.SHDSL). These variations might differ in upload and download speeds or in the types or number of lines that are used. To choose the best HDSL modem, you will have to consider the length of the cable you need,, if any; the modem's reliability; its longevity; and the software interface that comes with it. You also might consider initial or monthly costs and the level of customer support offered.
There has been a trend toward wireless modems, which allow more than one computer to connect to the modem, and thereby to the Internet easier than running physical wires throughout the house in support of a wired local area network (LAN). Additionally, a LAN switch is not required with a wireless ADSL modem. If a computer does not support wireless connections, a transmitter/receiver device might need to be installed. This can be done easily by using a USB device.
An HDSL modem is generally used in business settings and especially for building out cellular telephone services. Most vendors have gone with the G.SHDSL standard to provide the higher data rates and greater flexibility, because asymmetrical speeds can be set up as well. Asymmetrical speeds have crosstalk at only one end of the line, which decreases the data error rates and thereby increases throughput for the same bandwidth.
Maximum cable lengths should be considered carefully. If connecting two buildings, each with an HDSL modem, the entire length of the cable needs to be considered, not just the distance between buildings. Running a cable down several floors and then up several more floors will add significant length to the overall cable.
Besides the reliability and longevity of the HDSL modem, the software interface should be examined. Diagnostics software should be part of the modem, along with tuning capabilities. Make sure you know about any initial or monthly charges for the HDSL modem as what level of customer service is offered. This knowledge can help you choose the best HDSL modem.