ry to give a clear idea of what it takes to come up with such a product. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. SYSTEMS ENGINEERING ISSUES SYSTEMS ENGINEERING ISSUES Our analysis will serve as a tentative first iteration of a potential design. In a real-life environment, many teams of people are involved in researching, documenting, discussing, and debating issues before decisions are made. Here we will discuss a design process that is slightly less elaborate than one that an entire engineering department would undertake. That process would be much more involved than the traditional back-of-the-napkin designs for which some Silicon Valley or Greater Boston-based networking companies have become famous. Task Definition Assume that our designer's task is to build a complete, scalable, heavy-duty, edge network multi- service switch/router that can handle multiple 1 Gigabit Ethernet connections downstream connect- ing four IP LANs with a 10 Gigabit Ethernet uplink connection to some centrally located server. The designer must also have the capability to switch and route traffic to and from these two realms and to and from an OC-48c realm, which can be ATM and/or POS. The desired system must be carrier-grade reliable, which implies the judicious redundancy of cards, and scalable in a typical 19-inch rack environment. This means the designer will need to con- sider choices that allow the original shelf to be upgraded eventually to a multishelf configuration with- out losing track of power consumption or the number of available slots in a chassis. The system will need to be upgradeable to potentially handle frame-relay and time-division multiplexing (TDM) traf- fic if required in the future. Multiple protocols will need to be supported and executed inside the MSR. We will also examine the most important task of eventually allocating these 