AT&T 555-230-223 manual Task 4 Verify Components Connectivity

Task 4: Verify Components and

Connectivity

Study Figure 2-2that follows to gain a general understanding of how the system assembly is to be connected. Some customer-furnished LAN equipment is included within the dotted lines in this figure. Helpful definitions for this equipment are as follows.

Balun (balanced/unbalanced) — An impedance matching transformer. Baluns are small, passive devices that convert the impedance of coaxial cable so that its signal can run on twisted-pair wiring. They are used often so that IBM 3270-type terminals, which traditionally require coaxial cable connection to their host computer, can run off twisted-pair. Baluns work for some types of protocols and not for others. There is often some performance degradation with baluns, and the signal cannot run as far on twisted wire as it can on coaxial cable.

10BaseT Hub — An Ethernet LAN that works on twisted pair wiring which looks and feels like telephone cabling. 10BaseT Ethernet LANs work on home runs in which the wire from each workstation snakes directly to the 10BaseT hub (like the wiring of a phone system). The advantages are twofold — first, if one machine crashes, it doesn’t bring down the whole network, and second, 10BaseT hubs often come with sophisicated management software.

2-4Issue 1 January 1996