The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

11.1. Applications of VLANs

In this section, we examine both some popular as well as some more exotic, emerging applications of VLAN technology. The focus here is on the benefits and capabilities provided to the network planner/administrator and to the users. At this point, we consider just the operational effects and not how the technology provides these capabilities.

11.1.1. The Software Patch Panel

In the early 1990s, 10BASE-T quickly became the LAN technology of choice. Sales and network deployment levels exploded much faster than anticipated by the market analysts and many corporate product planners. Within a few years, virtually all new Ethernet installations used 10BASE-T's star-wired twisted pair cabling scheme rather than the multidrop coaxial cable bus arrangement popular in the 1980s.

Why did everyone glom onto this new system so wholeheartedly? Contrary to popular belief, it was not because 10BASE-T was less expensive. (It wasn't.) While the twisted-pair cable itself may be less expensive per unit length than coaxial cable, the star-wired nature of 10BASE-T implies that a lot more cable is needed. Structured wiring systems provide a home-run from every workplace to the central wiring hub; a dedicated cable is provided from every user to the wiring closet. This uses a lot more cable than if all users simply tap into a single, common shared medium. In addition, 10BASE-T mandates the use of an active hub device that is not required in coaxial Ethernet, further increasing ...