Cabletron Systems 2H28-08R Connecting a UTP Segment to the FE-100TX, FE-100TX Crossover Switch

Connecting to the Network

3.5.2Connecting a UTP Segment to the FE-100TX

NOTE

To ensure proper operation, use only Category 5 Unshielded Twisted Pair (UTP) cabling that has an impedance of 85 to 111 ohms.

An FE-100TX installed in port 7 and/or 8 has an internal crossover switch. When connecting a workstation, use a straight-through cable and set the Fast Ethernet Interface Module crossover switch shown in Figure 3-7to the crossed over position marked with X. When connecting networking devices, such as another bridge, repeater, or router, use a straight-through cable and set the Fast Ethernet Interface Module crossover switch shown in Figure 3-7to the straight-through position (not crossed over), marked with =.

Position X (crossed over)

1.RX+ 5. NC

2.RX- 6. TX-

3.TX+ 7. NC

4.NC 8. NC

x =

10

100

FE-100TX

Position =

(not crossed over)

1.TX+ 5. NC

2.TX- 6. RX-

3.RX+ 7. NC

4.NC 8. NC

16651_05

Figure 3-7 FE-100TX Crossover Switch

A schematic of a crossover cable is shown in Figure 3-8. If a cross over is required, but a crossover cable is not available, use the switch on the FE-100TX to internally cross over the RJ45 port.

NOTE:

RX+/RX– and TX+/TX– must share a common color pair. For example, the RX+/RX- pair may use the bw/wb pair, and the TX+/TX- may use the ow/wo pair.

TO

RJ45 Port

RX+ 1

RX– 2

TX+ 3

TX– 6

	TO
10BASE-T Device Port
		RX+
	1
	2	RX–
	3	TX+
	6	TX–

RJ45 to RJ45

2251-31

Figure 3-8 Cable Pinouts - RJ45 Crossover Cable

2H28-08R SmartSwitch 2208 User’s Guide 3-11