3Com 3C8S5007 - SuperStack II PathBuilder S500 Switch User Manual page 87

To create a valid collision domain diameter, you must adhere to the
following maximum cable span lengths along with the collision domain
diameter guidelines in Table 15:
UTP (running TX or T4) — Maximum cable span length is 100 m.
Fiber (running FX) — Maximum cable span length is 412 m.
Figure 25 shows examples of collision domain diameters.
Figure 25 Collision Domain Diameter Examples
Collision domain
diameter 1
To determine a valid collision domain diameter, follow these steps:
1 Determine which interfaces will be used: TX, FX, or T4.
2 Add up the combined length of all cabling to be used.
3 Determine which class of repeaters, if any, are used in the collision
domain diameter.
4 Determine the maximum cable length by referring to Table 16, which
contains cabling and repeater guidelines for three scenarios shown in
Figure 26, Figure 27, and Figure 28.
DTE device
P a t h B u
i l d e r S w
i t c h
F a s t E t
F a s t E t
h e r n e t
R e p e a t
e r
Collision domain
diameter 2
DTE device
P a t h B u
i l d e r S w
i t c h
LAN Connector and Cables
Collision domain
diameter 3
DTE device
h e r n e t
R e p e a t
e r
E n d S t
a t i o n s
DTE
device
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