MJL ADSL Tutorial

ADSL TUTORIAL Matthew J. Langlois, University of New Hampshire InterOperability Laboratory 121 Technology Drive, Suite 2, Durham, NH 03824 USA. Extracted from the Introduction and Chapter 1 of A G.hs Handshaking Protocol Analyzer For ADSL, a Master’s Project by Matthew J. Langlois, May 2002. INTRODUCTION The demand for high-speed data networks in the “last mile” has driven the need for robust, interoperable, and easy to use multi-vendor Digital Subscriber Line (DSL) access solutions. DSL collectively refers to a group of technologies that utilize the unused bandwidth in the existing copper access network to deliver high-speed data services from the distribution center, or central office, to the end user. DSL technology is attractive because it requires little to no upgrading of the existing copper infrastructure that connects nearly all populated locations in the world. In addition, DSL is inherently secure due to its point-to-point nature. A simple diagram of a typical DSL system is shown in Figure 1 below: DSL "the last m ile"wide areahome network(W AN)central office internet, ISP, business(CO) network, etc.businessDSL access multiplexerscampus(DSLAMs) Figure 1: Typical DSL system. There are many variations of DSL, each aimed at particular markets, all designed to accomplish the same basic goals. ADSL, or Asymmetric DSL, is aimed at the residential consumer market. ADSL provides higher data rates in the downstream ...