Cisco Systems 78-13342-03 Ethernet Network Cabling Guidelines, RJ-45 Pin, Signal, Direction

Appendix B Cabling Specifications

Ethernet Network Cabling Guidelines

Table B-1 Straight-Through Ethernet Cable (RJ-45-to-RJ-45) Pinouts

RJ-45 Pin1	Signal	Direction		RJ-45 Pin
1	TX+	—>	1
2	TX–	—>		2
3	RX+	<—	3
6	RX–	<—		6

1.Pins 4, 5, 7, and 8 are not used for signaling but for reducing radiated cable emissions.

Ethernet Network Cabling Guidelines

Table B-2describes guidelines for creating Ethernet networks. Numbers might vary, depending on the manufacturer of the network equipment.

Table B-2 Ethernet Cabling Guidelines

Specification	10BASE-T	100BASE-TX
Maximum segment	100 meters	100 meters
length
Maximum number of	5	•	With Class I
segments per network			repeaters: 1
		•	With Class II
			repeaters: 2
Maximum hop count1	4	•	With Class I
			repeaters: none
		•	With Class II
			repeaters: 1
Maximum number of	1024	1024
nodes per segment
Cable type required	Category 3, 4, or 5	Category 5

1.Hop count = routing metric used to measure the distance between a source and a destination.

	Cisco 1760 Modular Access Router Hardware Installation Guide
B-2	78-13342-03