Nine Solutions for an ATM Upgrade By Joel Conover   Major backbone upgrades are no trivial concern. First, you must choose a technology to carry your corporation into the 21st century. Then, you must deal with a flood of vendors, each trying to convince you that its way is the right way. Eventually, you'll pick a vendor and build your company's future on its hardware. Choosing the right technology for your backbone can be just as difficult as choosing a vendor, and many people agree that ATM is one of the most powerful, most scalable solutions you can buy. We decided to put vendors to the test. We used our experience from the corporate and university environments to design a large hypothetical net work in need of a serious overhaul. Our model company, XYZ Electronic Widget Corp., is a large corporate site with more than 18,000 employees. XYZ's network is typical of a company that grew quickly: high-density repeaters, stackable hubs in the newer buildings, bridges scattered throughout the older bui ldings in an attempt to segment traffic, and a Cisco Systems AGS+ router providing interbuilding and WAN connectivity. We gave vendors a complete description of XYZ's network and asked them to submit a Request for Proposal (RFP) that met the following basic requirements: · The solution must include an ATM backbone. · The solution must provide an infrastructure that centralizes servers in the network operations center. · The solution should be robust and eliminate single points of failure. · The solution should increase bandwidth to the desktop and decrease congestion and collision rates. · The solution must be implemented over two years, and should yield an imm ediate return on investment after deploying the first year's equipment. · The solution must provide multimedia services to our training lab. · SNA connectivity between XYZ's mainframe and call-processing division must be maintained. The vendors took the bait; Bay Networks, Cabletron Systems, Cisco Systems, Digital Equipment Corp., FORE Systems, IBM Corp., Madge Networks, Newbridge Networks and 3Com Corp. all submitted plans for XYZ's campus, which consists of seven buildings (see "The XYZ Campus," below), and has the following infrastructure in place: · Two rings of multimode fiber encircle the campus and enter the basement of each building. Each ring consists of 12 strands of fiber. · Fiber runs from the basement of each building to the wiring closets on each floor. · All offices have been equipped from closet to desktop with Category 5 (CAT5) wiring. There are two types of buildings on the XYZ campus, each connected via 10BASE-FL to a Cisco AGS+ router in the Administration building. Scattered throughout the buildings are seven bridges to help segment traffic in congested areas. After weeks of analysis and scrutiny, we picked three vendors whose RFPs we felt provided XYZ with the best bang for the buck. Specifically, we looked at how the vendor distributed the ban dwidth it recommended, and what price XYZ had to pay for that bandwidth. In the end, these vendors made our RFP short list: FORE Systems, Newbridge and Cisco. The other solutions are presented here in random order.

View the RFP documentation and diagrams Windows NT Versus Unix: The Chase Is On by Dan Backman Updated May 12, 1997