Network Architecture Foundations
By John Stewart
There was a time when research institutions, corporate grants, and entire university programs were devoted to the task of connecting two computers across a network. Not much has changed—institutions, universities, and grants are still being used to figure out the best ways to network computers. For those without huge budgets and large numbers of researchers, the job is even more difficult.
We now face many more choices than when UCLA and SRI sent out the first login message and email. Who could know that in the year 2000 you'd have to ask, "So do I go Category 3 or 5, multimode or single-mode fiber, use Ethernet, Fast Ethernet, hubs, switches, fiber hubs, gigabit Ethernet, ATM, voice over IP, or wireless LANs?" But today, these are the exact questions that we must ask. "Connections" is about answering them. Throughout this space I'll focus on bringing computers together, not necessarily physically, but through a variety of connections and architecture practices.
It's necessary to understand some network basics before looking for answers and making decisions. When building a network, there are three options from which to choose: hubs, switches, and wireless LAN.
Hubs, Large and Small
Hubs are connecting devices that ensure two computers can communicate and "see" each other in a network topology. They accomplish this by using a shared medium methodology, kind of like a telephone conference call—all callers can hear everything on the line. From a security perspective, any host computer on the hub can see data belonging to that of another host on the same hub.
