3Com 5108M-TP manual Fiber Backbone, Twisted Pair To-The-Desk

Table 2-2. LAN Product Equivalent Distances (Continued)

LAN Product	Equivalent
	Distance (meters)
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

Fiber Backbone, Twisted Pair To-The-Desk

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

Designing and Expanding the Network 2 - 7