Cabling Specifications

This appendix describes cables and cabling guidelines for the router and contains the following sections:

Note For detailed information about cables used with Cisco WICs and VICs, refer to the Cisco WAN Interface Cards Hardware Installation Guide that comes with each of the cards.

Ethernet Cables

This section describes the Ethernet cables t hat are used to connect the router to your local Ethernet network. A 10/100BaseTX router, like the Cisco 1750 router, requires Category 5 unshielded twis ted-pair (UTP) or shielded twisted-pair (STP) cable. Table B-1 describes the pinouts for a RJ-45-to-RJ-45 Ethernet cable.

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

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

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

Ethernet Network Cabling Guidelines

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

Specification	10BaseT	100BaseTX
Maximum segment length	100 meters	100 meters
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 STP

Table B-2: Ethernet Cabling Guidelines

Specification 10BaseT 100BaseTX

Maximum segment length

100 meters

100 meters

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 STP

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

Console Cable and Adapters

A console cable kit is provided with your router. Use this kit when connecting your router to a PC or terminal.

The console cable kit contains:

RJ-45-to-RJ-45 console cable (light blue)
DB-9-to-RJ-45 console adapter

Table B-2 describes the wiring for the console port, the console cable, and the included adapters. This table also includes pinouts for a DB-9-to-RJ-45 console adapter.

Table B-3: Console Cable and Adapter Pinouts
Console
(DTE) Console Port Console Cable Adapter Adapter Terminal
(DTE)

Signal RJ-45 Pin RJ-45 Pin DB-9 Pin DB-25 Pin Signal

RTS

1

8

8

5

CTS

DTR

2

7

6

6

DSR

TXD

3

6

2

3

RXD

GND

4

5

5

7

GND

GND

5

4

5

7

GND

RXD

6

3

3

2

TXD

DSR

7

2

4

20

DTR

CTS

8

1

7

4

RTS

**Table B-3: Console Cable and Adapter Pinouts**
Console (DTE)	Console Port	Console Cable	Adapter	Adapter	Terminal (DTE)
Signal	RJ-45 Pin	RJ-45 Pin	DB-9 Pin	DB-25 Pin	Signal
RTS	1	8	8	5	CTS
DTR	2	7	6	6	DSR
TXD	3	6	2	3	RXD
GND	4	5	5	7	GND
GND	5	4	5	7	GND
RXD	6	3	3	2	TXD
DSR	7	2	4	20	DTR
CTS	8	1	7	4	RTS

Figure B-1 illustrates how to identify the console cable, which is also referred to as the rollover cable.

Figure B-1: Identifying a Rollover Cable

VIC Cables and Pinouts

This section describes the VIC cables and pinouts for foreign exchange station (FXS), foreign exchange office (FXO), and E&M connectors. Use the following cables to connect the VICs to the network:

Standard RJ-11 modular telephone cable to connect FXS VIC ports (color-coded gray) to a telephone or fax machine.
Standard RJ-11 modular telephone cable to connect FXO VIC ports (color-coded pink) to the PSTN or to a PBX that does not support E&M signaling.
Standard RJ-48S connector and cable to connect E&M VIC ports (color-coded brown) to a PBX line. The cable wiring depends on the PBX type and connection. For details refer to the Cisco WAN Interface Cards Hardware Installation Guide.

Figure B-2 shows how to connect the VICs to the network.

Figure B-2: Connecting VICs to the Network

Table B-4 lists the pinouts for FXS and FXO VIC connectors.

Note Pins that are not used should not be connected.

**Table B-4: RJ-11 Pinout**
Pin	Signal
1	-
2	-
3	Ring
4	Tip
5	-
6	-

The E&M VIC pinout depends on the PBX type and connection. Table B-5 lists the pinout for this connector.

Note Pins that are not used should not be connected.

Pin	Signal	Description
1	SB	-48V signaling battery
2	M-lead	Signaling input
3	R	Ring, audio input
4	R or R1	Ring, audio input/output, or output
5	T or T1	Tip, audio input/output, or output
6	T	Tip, audio input
7	E-lead	Signaling output
8	SG	Signaling ground return

Table B-5:

Pin Signal Description

1

SB

-48V signaling battery

2

M-lead

Signaling input

3

R

Ring, audio input

4

R or R1

Ring, audio input/output, or output

5

T or T1

Tip, audio input/output, or output

6

T

Tip, audio input

7

E-lead

Signaling output

8

SG

Signaling ground return

E&M Pinouts

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