3Com SuperStack II, NETBuilder SI manual Maximum Cable Length in Example Collision Domain Diameters

170APPENDIX D: CONNECTORS AND CABLES

Table 23 Maximum Cable Length in Example Collision Domain Diameters

	Maximum Combined Cable Length, by Interface
Scenario	TX and/or T4	FX Only	FX & TX	FX & T4
No Repeaters	100 m	412 m	not applicable	not applicable
(see Figure 22)
One Class 1 repeater*	200 m — 100 m max. on	272 m	260.8 m	231 m
(see Figure 23)	each side of the repeater		100 m max. TX	100 m max. T4
			Remaining length of FX	Remaining length of FX
One Class 2 repeater†	200 m — 100 m max. on	320 m	308.8 m	304 m‡
(see Figure 23)	each side of the repeater		100 m max. TX	100 m max. T4
			Remaining length of FX	Remaining length of FX
Two Class 2 repeaters	205 m — 100 m max. per	228 m	216.2 m	263.3 m‡
(see Figure 24)	cable span		105 m max. total TX, 100	105 m max. total T4, 100
			m max. per TX cable span	m max. per T4 cable span
			Remaining length of FX	Remaining length of FX

*A high-delay repeater as specified in IEEE 802.3 standards. A Class 1 repeater usually connects dissimilar media, for instance, UTP to fiber.

†A low-delay repeater as specified in IEEE 802.3 standards. A Class 2 repeater usually connects similar media, for instance, UTP to UTP.

‡ This scenario is unlikely, because Class 2 repeaters do not usually connect FX to T4.

WAN Connector The WAN connector can be an ISDN S/T (model 43x and 53x), ISDN U

and Cables(model 44x and 54x), 56/64 Kbps CSU/DSU (model 45x and 55x), or T1/FT1 CSU/DSU (model 46x and 56x) connector, depending on the interface module installed.

ISDN S/T Cable To connect a model 43x or model 53x bridge/router to an ISDN network, use a Category 5 shielded twisted-pair cable with an RJ-45 connector on both ends. 3Com does not supply this cable.