xDSL
There is a whole family of Digital Subscriber Line technologies, with different telcos rolling out different versions. In general, DSL technologies all are forms of digital communication over standard copper phone lines. DSL is fairly new technology compared to ISDN or frame relay. Telephone companies have to install special equipment in their central offices in order to support the protocol, which is presumably why it's taking a long time to deploy xDSL as a product in some markets. Another key feature of DSL is that the bandwidth you pay for will be guaranteed regardless of how many people in your area sign up for the service. This technology is distance-sensitive, so people who live far away from the local phone company central office will not be able to get this product.

In the New York City area Verizon (Bell Atlantic) has been deploying ADSL neighborhood-by-neighborhood since mid-1999. See their Infospeed DSL web site for specific information about timelines and prices. The A stands for "asymmetric" which means that downstream bandwidth will be larger than upstream. In other words, you'll be able to browse very fast, but you won't be able to serve up pages to a wide audience. In fact, Verizon's version of this technology will dynamically assign an IP number to your computer, so you won't be able to assign a domain name to your machine making it almost impossible to run a commercial site from your home using the consumer version of this technology. Relately, only one computer will be able to use the connection at a time, so you won't be able to share the bandwidth amongst various computers on a LAN. It seems that Verizon is rolling out this technology in such a way that they will not really undercut their leased line business.

There is a whole other family of DSL technologies, some of which are more appropriate for running a server. SDSL is Symmetric Digital Subscriber Line, and is generally offered at either 384 or 768 KB/s which might be adequate for running a small server. A company offering SDSL in the NYC area is Media Log. Providers like Verizon also have business versions of their xDSL service where you can pay extra to get a static IP address, multiple addresses, and other features.

Cable Modems
Cable companies are also getting into the high-bandwith Internet market, but only as a consumer service at this point. First generation cable modem sytems had one-way broadband, from the head-end to the consumer. Any data that you wanted to send upstream had to go over a normal modem connection over a phone line. In the past year or two cable companies have been upgrading their systems so that data can travel both ways over the cable system. These networks have traditionally had a token ring network architecture, which means that many customers in a neighborhood share the same network segment. This is a significant difference from technologies like DSL because there is no way that the provider can guarantee a particular amount of bandwidth for any customer. The more people who sign up for the service, each user will have slightly less bandwidth available.

An upside of using cable modems is that installation is relatively easy compared to DSL. Your cable provider gives you a different box, and generally there is no installation or hardware charge. Providers offering cable modem service in the NYC area are Time Warner's Road Runner service andRCN.