3com 5108M-TP User Manual
Designing and Expanding the Network 2 - 9
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Figure 2-1. Sample Configuration Distance Calculation
Use the following steps to determine whether your network configuration
is legal:
is legal:
1. Begin with 4.2 km (4200 m) since this is the maximum network
diameter for a pure fiber network (Rule 3).
2. Subtract 100 m for the signal exiting the Fiber Modules in
concentrators A and C (2 * 50) and 280 m for the signal entering the
Fiber Modules in concentrators C and B (2 * 140) as explained in Rule
4 and defined in Table 2-2.
Fiber Modules in concentrators C and B (2 * 140) as explained in Rule
4 and defined in Table 2-2.
3. Subtract 420 m of fiber equivalent distance for the signal entering the
10BASE-T Module in concentrator A and 165 m for the signal exiting
the 10BASE-T Module in concentrator B (Rule 4).
the 10BASE-T Module in concentrator B (Rule 4).
4. Subtract all cable lengths between the two transceivers and if the
result is greater than zero, the configuration is within legal Ethernet
limits (Rule 5).
limits (Rule 5).