3Com 5124M-TPCL manual Unshielded Twisted Pair Network Using 24-Port Modules

Figure 2-4. Unshielded Twisted Pair Network Using 24-Port Modules

The equivalent fiber distance can be calculated as follows:

Total link distance: 100 m + 100 m + 100 m + 50 m + 20 m = 370 m

Total equivalent distance of the 24-Port Modules:

4 * 420 m + 4 * 165 m = 2340 m

(signal externally enters 4 Twisted Pair Modules: 4 * 420 m)

(signal internally enters 4 Twisted Pair Modules from the backplane: 4 * 165 m)

Note: All 3Com 10BASE-T modules (8-Port 10BASE-T Module, 50-Pin 10BASE-T Module, or the 24-Port 10BASE-T Modules) fall under these same rules.

Total equivalent distance: 370 m + 2340 m = 2710 m

Because the total equivalent distance (2710 m) is less than 4200 meters, this configuration is legal.

Designing and Expanding the Network 2 - 13