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Cisco 10000 Series Routers

Ethernet 100BaseTX and 10BaseT Cables: Guidelines and Specifications

Document ID: 46792



Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Which Cable Do I Need?
Ethernet Cabling Guidelines
Ethernet Version 2 and IEEE 802.3 Physical Characteristics
Fast Ethernet Connector Pinouts RJ-45
      100BaseTX RJ-45 Connector
      Specifications and Connection Limits for 100-Mbps Transmission
      IEEE 802.3u Physical Characteristics
Ethernet 10BaseT: RJ-45
      Cable Specifications for 10-Mbps 10BaseT
      10BaseT Port Pinouts
      Straight-Through 10BaseT Cable (RJ-45 to RJ-45)
      RJ-45 Straight-Through (Ethernet) Cable Pinouts
      RJ-45 Crossover (Ethernet) Cable Pinouts
      RJ-45 Rolled (Console) Cable Pinouts
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Introduction

This document provides guidelines and specifications for Ethernet 100BaseTX and 10BaseT cables.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on the software and hardware versions:

  • Ethernet 100BaseTX and 10BaseT cables

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Which Cable Do I Need?

The table below helps you determine which type of cable you need for your setup.

 

Hub

Switch

Router

Workstation

Hub

Crossover

Crossover

Straight

Straight

Switch

Crossover

Crossover

Straight

Straight

Router

Straight

Straight

Crossover

Crossover

Workstation

Straight

Straight

Crossover

Crossover

Ethernet Cabling Guidelines

The table below lists the Ethernet cabling guidelines for 10BaseT and 100BaseTX cables.

Specifications

10BaseT

100BaseTX

Maximum number of segments per network

5

  • With Class I repeaters: 1

  • With Class II repeaters: 2

Maximum hop count1

4

  • With Class I repeaters: none

  • With Class II repeaters: 1

Maximum number of nodes per segment

1024

1024

Cable type required

UTP, category 3, 4, or 5

UTP category 5 or Shielded twisted pair (STP)

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

Ethernet Version 2 and IEEE 802.3 Physical Characteristics

The table below lists the Ethernet version 2 and IEEE 802.3 physical characteristics of the different Ethernet cables.

 

Ethernet

IEEE 802.3

10Base5

10Base2

10BaseT

Data rate (Mbps)

10

10

10

10

Signaling method

Baseband

Baseband

Baseband

Baseband

Maximum segment length (m)

500

500

185

100 (Unshielded twisted pair - UTP)

Media

50-ohm coax (thick)

50-ohm coax (thick)

50-ohm coax (thin)

Unshielded twisted pair (UTP)

Topology

Bus

Bus

Bus

Star

Fast Ethernet Connector Pinouts RJ-45

100BaseTX RJ-45 Connector

The Fast Ethernet RJ-45 port actively terminates wire pair 4 and 5 and wire pair 7 and 8. Common-mode termination reduces electromagnetic interference (EMI) and susceptibility to common-mode sources.

The table below shows the pin and corresponding signal for the RJ-45 connector pinouts.

RJ-45 Connector Pinout

Pin

Signal

1

TX+

2

TX-

3

RX+

6

RX-

Specifications and Connection Limits for 100-Mbps Transmission

The table below lists cable specifications and connection limits for 100-Mbps transmission.

Parameter

RJ-45

MII

SC-type

Cable specification

Category 52, UTP3, 22 to 24 AWG4

Category 3, r, or 5, 150-ohm UTP or STP, or multimode optical fiber

62.5/125 multimode optical fiber

Maximum cable length

-

0.5 m (1.64 ft.) (MII-to-MII cable5)

-

Maximum segment length

100m (328 ft.) for 100BaseTX

1 m (3.28 ft.)6 or 400 m (1312 ft.) for 100BaseFX

100 m (328 ft.)

Maximum network length

200 m (656 ft.)6 (with one repeater)

-

200 m (656 ft.)6 (with one repeater)

2 EIA/TIA-568 or EIA-TIA-568 TSB-36 compliant.

3 Cisco Systems does not supply Category 5 UTP RJ-45 or 150-ohm STP MII cables. Both are available commercially.

4 AWG = American Wire Gauge. This gauge is specified by the EIA/TIA-568 standard.

5 This is the cable between the MII port on the port adapter and the appropriate transceiver.

6 This length is specifically between any two stations on a repeated segment.

IEEE 802.3u Physical Characteristics

The table below lists the IEEE 802.3u physical characteristics for the Ethernet 100BaseT cable.

Parameter

100BaseT

Data rate (Mbps)

100

Signaling method

Baseband

Maximum segment length (in meters)

100 m between DTE7 and repeaters

Media

RJ-45: Category 5 UTP MII: Category 3, 4, or 5, 150-ohm UTP or STP, with appropriate transceiver

Topology

Star/Hub

7 DTE = data terminal equipment.

Ethernet 10BaseT: RJ-45

This section discusses the cable specifications for the 10-Mbps 10BaseT cable, and describes the different 10BaseT port pinouts.

Cable Specifications for 10-Mbps 10BaseT

The table below lists for cable specifications for the 10-Mbps 10BaseT cable.

Parameter

RJ-45

Cable specificataion

Category 3 or Category 5 UTP with 22 to 24 AWG

Maximum segment length

100 m (328 ft.) for 10BaseT

Maximum network length

2,800 m (9,186 ft.) (with four repeaters)

10BaseT Port Pinouts

The table below lists the 10BaseT port pinouts.

8 pin8

Description

1

TX+

2

TX-

3

RX+

6

RX-

8Pins 4, 5, 7, and 8 are not used.

Straight-Through 10BaseT Cable (RJ-45 to RJ-45)

eth_strt_cable_hub.gif

The table below lists the port pinouts for the straight-through 10BaseT cable.

RJ-45 Pin

Signal

Direction

RJ-45 Pin

1

TX+

--->

1

2

TX-

--->

2

3

RX+

<---

3

4

-

-

4

5

-

-

5

6

RX-

<---

6

7

-

-

7

8

-

-

8

Examine the sequence of colored wires to determine the type of RJ-45 cable, as follows:

  • Straight-through - the colored wires are in the same sequence at both ends of the cable.

  • Crossover - the first (far left) colored wire at one end of the cable is the third colored wire at the other end of the cable.

  • Rolled - the colored wires at one end of the cable are in the reverse sequence of the colored wires at the other end of the cable.

RJ-45 Straight-Through (Ethernet) Cable Pinouts

The table below lists the cable pinouts for the Ethernet RJ-45 straight-through cable.

Signal

Pin

Pin

Signal

TX+

1

1

TX+

TX-

2

2

TX-

RX+

3

3

RX+

-

4

4

-

-

5

5

-

RX-

6

6

RX-

-

7

7

-

-

8

8

-

RJ-45 Crossover (Ethernet) Cable Pinouts

eth_cross_cable_pin_hub.gif

The table below lists the pinouts for the Ethernet RJ-45 crossover cable.

Signal

Pin

Pin

Signal

TX+

1

3

RX+

TX-

2

6

RX-

RX+

3

1

TX+

-

4

4

-

-

5

5

-

RX-

6

2

TX-

-

7

7

-

-

8

8

-

RJ-45 Rolled (Console) Cable Pinouts

The table below shows the pinouts for the RJ-45 rolled console cable.

Signal

Pin

Pin

Signal

RTS

1

8

CTS

DTR

2

7

DSR

TxD

3

6

RxD

GND

4

5

GND

GND

5

4

GND

RxD

6

3

TxD

DSR

7

2

DTR

CTS

8

1

RTS

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Updated: Aug 01, 2006Document ID: 46792