3com 5108M-TP User Manual

When you configure a network with unshielded or shielded twisted pair 
cabling to-the-desk and fiber for the backbone, there are only three 
additional rules you need to be aware of:

❑

There can be no more than eight 10BASE-T Modules (5108M-TP) in 
the path between any two transceivers due to Ethernet's 
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.

❑

There is an equivalent fiber distance for the ONline Fiber Modules 
(see Rule 4). The equivalent is:

–

140 meters for signals that externally enter a Fiber Module 
port

–

50 meters for signals that internally enter a Fiber Module 
via the ONline Concentrator backplane

ONline Ethernet BNC Module 

900

Incoming signal to BNC port

450

Outgoing signal from BNC port

450

ONline Ethernet Repeater Module 

800

Incoming signal to AUI port

600

Outgoing signal from AUI port

200

IEEE Repeater

800