Twisted Pair Backbone, Twisted Pair To-The-Desk

In constructing a twisted pair backbone, one additional configuration rule must be considered:

There can be no more than eight 10BASE-T Modules in the path between any two transceivers due to the Ethernet four-repeater rule (each 10BASE-T Module counts as a 1/2 repeater). You must add a bridge if you have more than eight 10BASE-T Modules serially connected.

The configuration in Figure 2-2 illustrates a possible unshielded twisted pair network using 22 gauge cable.

Figure 2-2. Unshielded Twisted Pair Network

Note that when connecting two concentrators with twisted pair cable, use port 8 on one of the 10BASE-T Modules and disable crossover mode for that port. This allows a direct connection to another 10BASE-T Module without the need for an intervening adapter. (Refer to Dip Switch SW3 (Crossover Mode, Channel Select, Squelch) in Chapter 1 for information on crossover mode and the crossover mode switch setting.)

Designing and Expanding the Network 2 - 11

Page 39
Image 39
3Com 5108M-TP manual Twisted Pair Backbone, Twisted Pair To-The-Desk, Unshielded Twisted Pair Network