ABSTRACT
In 1992, many users deploying wide area networks (WANs) still thought in terms of 56K frame relay and fractional T1 speeds as state of the art. Some six years later, the World Wide Web (WWW) has driven most of us to deploy V.90 standard modems in the home or explore the possibilities of cable modems, ISDN, and xDSL technologies. In the enterprise network, network backbones are now primarily cell-based backbones. Long gone are shared backbones such as token ring, Ethernet, and collapsed router backbones. FDDI is still around, but nobody is getting excited about DAS and SAS. The network core within the enterprise and within the service provider (LEC, CLEC, IAP, ISP, IXC, and CIXC) networks is using a cell-based technology called ATM (asynchronous transfer mode).
