Compaq Netelligent 1224 User Manual

Netelligent 1224

10Base-T/100Base-TX Repeater

User Guide

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NOTICE

The information in this publication is subject to change without notice.
COMPAQ COMPUTER CORPORATION SHALL NOT BE LIABLE FOR TECHNICAL OR

EDITORIAL ERRORS OR OMISSIONS CONTAINED HEREIN, NOR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES RESULTING FROM THE FURNISHING, PERFORMANCE, OR
USE OF THIS MATERIAL.

This publication contains information protected by copyright. No part of this publication may be
photocopied or reproduced in any form without prior written consent from Compaq Computer
Corporation.

The software described in this guide is furnished under a license agreement or non disclosure
agreement.

The software may be used or copied only in accordance with the terms of the agreement.
Product names mentioned herein may be trademarks and/or registered trademarks of their respective

companies.

iii

 1996 Compaq Computer Corporation.

All rights reserved. Printed in the U.S.A.

Compaq

Registered United States Patent and Trademark Office.

Netelligent is a trademark of Compaq Computer Corporation.

Compaq Netelligent 1224 10Base-T/100Base-TX Repeater

User Guide

Second Edition (April 1996)

Part Number 185812-002

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Federal Communications Commission Notice

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant
to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. This equipment generates, uses
and can radiate radio frequency energy and, if not installed and used in accordance with the instructions in
this manual, may cause interference to radio communications. Operation of this equipment in a residential
area is likely to cause harmful interference in which case the user will be required to correct the
interference at his own expense.

Class A devices bear a label indicating the interference potential of the device as well as additional
operating instructions for the user, such as the following: This device complies with Part 15 of the Federal
Communications Commission (FCC) Rules. Operation is subject to the following two conditions: (1) This
device may not cause harmful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.

v

Canadian Department of Communications

Radio Frequency Statement

This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus
set out in the Radio Interference Regulations of the Canadian Department of Communications.

Le présent appareil numérique n'émet pas de bruits radioélectriques dépassant les limites applicables aux
appareils numriques de la classe A prescrites dans le Règlement sur le brouillage radioélectrique édicté par
le ministères des Communications du Canada.

Modifications

The FCC requires the user to be notified that any changes or modifications made to this device that are not
expressly approved by Compaq Computer Corporation may void the user’s authority to operate the
equipment.

Emissions

This equipment complies with EMC directive 89/336/EEC (ITE), which includes EN50081-1 CLASS 1:
1992 (EN55022/CISPR 22 for Class A ITE). It also complies with FCC Class A.

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vi

European Union Notice

Products with the CE (Community European) Marking comply with both the EMC Directive (89/336/EEC)
and the Low Voltage Directive (73/23/EEC) issued by the Commission of the European Community.

Compliance with these directives implies conformity to the following European Norms:

■ EN55022 (CISPR 22) - Electromagnetic Interference

■ EN50082-1 (IEC801-2, IEC801-3, IEC801-4) - Electromagnetic Immunity

■ EN60950 (IEC950) - Product Safety

Safety

This equipment complies with UL 1950, Second Edition; CAN/CSA C22.2 No. 950-93, 73/23/EEC Low
Voltage Directive; TUV Rheinland EN60950, 1988; A1/1990, 1993; and A2/1992, 1992, 1993.

Immunity

This equipment complies with EMC directive 89/336/EEC (ITE), which includes EN 50082-1:

■ IEC 801-2 (Electrostatic Discharge)

■ IEC 801-3 (Radiated Immunity)

■ IEC 801-4 (Electrical Fast Transient/Burst)

■ EN55101-4 (Conducted Immunity) (not currently required)

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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vii

Contents

Preface

Intended reader.........................................................................................................ix

Organization of Contents ..........................................................................................ix

Chapter 1

Overview

Features..................................................................................................................1-1

Package Contents....................................................................................................1-2

Operational Overview.............................................................................................1-4

LED Indicators.................................................................................................1-5

10 ONLY -10/100 Switch.................................................................................1-5

RJ-45 Ports.......................................................................................................1-7

Uplink Switches...............................................................................................1-7

Display Mode Button.......................................................................................1-8

Automatic Speed Detection.....................................................................................1-9

Chapter 2

Planning Repeater Installation

Installation Requirements........................................................................................2-1

Environmental Requirements...........................................................................2-1

Electrical Requirements...................................................................................2-1

Spatial Requirements .......................................................................................2-2

Twisted-Pair (UTP) Wire Requirements...........................................................2-2

Installing New Wire.........................................................................................2-3

System Planning Charts ..........................................................................................2-5

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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viii

Chapter 3

Installing the Repeater

Mounting the Repeater............................................................................................3-1

Attaching Rubber Feet .....................................................................................3-1

Rack-Mounting the Repeater............................................................................ 3-1

Connecting Twisted-Pair Cable............................................................................... 3-3

Setting the Uplink Switches....................................................................................3-3

Interconnecting Repeaters.......................................................................................3-5

Connecting Power...................................................................................................3-6

Disconnecting Power........................................................................................3-7

Replacing the Power Supply.............................................................................3-7

Installing a Redundant Power Supply......................................................................3-8

Chapter 4

LED Status Chart

Selecting an LED Display Mode.............................................................................4-1

Appendix A

Specifications

Electrical Specifications.........................................................................................A-1

Physical Specifications ..........................................................................................A-2

Environmental Specifications.................................................................................A-2

Glossary

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ix

Preface

This guide includes information about how to install and operate the Compaq
Netelligent 1224 10Base-T/100-Base-TX Repeater. We recommend that you
read all chapters in this guide to become familiar with all of the repeater's
features and to ensure a successful installation.

Intended Reader

This guide is written for network administrators and technicians responsible
for hardware installation.

Organization of Contents

The contents of this guide are organized as follows:
Chapter 1  Provides an operational overview of the repeater and describes

its components and features.
Chapter 2  Discusses special requirements for operating the repeater and

provides charts that can help you plan the installation of the repeater.
Chapter 3  Provides instructions for mounting the repeater, connecting

cable, interconnecting the repeater to another repeater, and connecting power
to the repeater. Also included are instructions for installing a redundant power
supply module.

Chapter 4  Describes the repeater's LED operation and display.
Appendix A  Includes the repeater's electrical, physical, and environmental

specifications.
Glossary  Provides terms related to the repeater, as well as general

networking terms.

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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1-1

Chapter 1

Overview

The Compaq Netelligent 1224 10Base-T/100Base-TX Repeater provides a
new standard in flexibility for networks that employ both 10 Mb/s and 100
Mb/s functionality. Each of the 24 RJ-45 ports on the repeater accepts either a
10Base-T or 100Base-TX connection. The repeater's speed detection circuitry
automatically detects the connection's wire speed and routes transmissions to
the proper repeater core inside the repeater. The repeater also features two
uplink ports that let you interconnect the repeater to another repeater or to a
single-speed repeater (10 Mb/s or 100 Mb/s). The repeater's front panel makes
it easy to view the current operating status.

Features

The repeater includes these features:

■ 24 shielded RJ-45 ports that support 100Base-TX or 10Base-T

connections

■ Automatic speed detection at each port to detect the current wire speed

■ Uplink ports that enable bridging to 10Base-T or 100Base-TX

topologies

■ LEDs that indicate power supply status (A and B), 10 Mb/s and 100

Mb/s collisions, port link/activity/partition status, and the current LED
display mode (100 Mb/s/10, Mb/s, or Alternating)

■ Modular power supply design for easy removal and replacement

■ Auto-sensing power supply operates within the range of a 100 to 240

VAC, 50 to 60 Hz power source

■ Optional dual-redundant power supply for backup power

■ Class II support for internal 100Base-TX repeater core

■ Chassis that can stand alone or be mounted in a standard, EIA 19-inch

rack

■ Compatible with the IEEE 802.3u 100Base-TX and IEEE 802.3

10Base-T repeater specifications

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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1-2 Introduction

Package Contents

Before you start to install the repeater, verify that this package contains the
following items:

■ 1224 10Base-T/100Base-TX Repeater

■ AC power cord

■ Rack-mounting kit (two mounting brackets, eight 3/8-inch bracket

screws, and four 1/2-inch rack-mount screws)

■ Four adhesive-backed rubber feet

■ Compaq Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

■ Warranty card

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1-3

24

PWR A
PWR B

MDI

10 ONLY 10/100

10 COL

Power Cord

Rubber Feet (4)

Dual-Speed Repeater

1132143154165176187198209211022112312

MDI-X

MDI-X

Rack-Mounting Brackets

10/100 Mb/s

User Guide

100 MBPS

MDIMDI-X MDI-X

10 MBPS

ALTERNATING100 COL

DISPLAY MODE

1/2-inch Rack Mount Screws (4)

3/8-inch Bracket Screws (8)

Limited Warranty

User Guide

Figure 1-1. Package Contents

Limited Warranty

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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1-4 Introduction

Operational Overview

This section provides an overview of the repeater's components, which include
the LED indicators, RJ-45 ports, and uplink ports, and discusses the basic
functionality of the repeater. Figures 1-2 and 1-3 show the repeater's front and
back panels.

(24) RJ-45 UTP Ports

(for 10Base-T or 100Base-TX)

PWR A
PWR B

100 COL

10 COL

Power Supply, 10Base-T,

100Base-T Collision

Status Indicators

10Base-T/Dual-Speed

10 ONLY 10/100

Selection Switch

MDI

MDI-X

(for Port 1)

1132143154

Uplink Switch

Figure 1-2. Repeater Front Panel

PWR B

(for Port 1)

16

MDI-X

51761871982092110

MDI-X

22

112312

24

MDI

MDI-X

Uplink Switch

(for Port 12)

PWR A

100 MBPS

10 MBPS

ALTERNATING

Display Mode

Indicators

DISPLAY MODE

Display Mode

Selection Switch

Figure 1-3. Repeater Back Panel

Power Supply B

(Backup)

Power Supply A

(Pre-installed)

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1-5

LED Indicators

The repeater features several LED indicators that help you monitor the
repeater's status.

■ The LEDs on the left side of the front panel show the status of the

power supplies as well as the 10Base-T and 100Base-TX collision
statuses.

■ The LEDs above the RJ-45 ports indicate the link, activity, and

partition status for each of the ports.

■ The LEDs on the right side of the front panel indicate which RJ-45

LED indicators will light. For example, when the 100 MPS LED is on,
the LEDs for the RJ-45 ports with 100Base-TX connections display
their port statuses. The other two LEDs (10MBPS and
ALTERNATING) show 10 Mb/s status and Alternating status.

Figure 1-4 shows the LED arrangement for the repeater.

PWR A
PWR B

10 ONLY 10/100

100 COL

10 COL

Power Supply, 10Base-T,

100Base-T Collision

Status Indicators

Figure 1-4. LED Indicators

See Chapter 4, “LED Operation,” for more information.

10 ONLY-10/100 Switch

The 10 ONLY-10/100 switch lets you set Port 1 for either 10 Mb/s or 10/100
Mb/s (automatic speed detection).

MDI

MDI-X

1132143154

16

MDI-X

51761871982092110

MDI-X

RJ-45 Link/Partition/Activity

LED Indicators

22

24

112312

MDI

MDI-X

100 MBPS

10 MBPS

ALTERNATING

Display Mode

Indicators

DISPLAY MODE

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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1-6 Introduction

16

MDI

MDI-X

1132143154

PWR A
PWR B

100 COL

10 COL

10 ONLY 10/100

10Base-T/Dual Speed (10/100)

Selection Switch

Figure 1-5. 10 ONLY/Dual Speed (10/100) Switch

The settings have the following meaning:

■ 10/100 setting (default)  Lets the port automatically detect the

incoming wire speed like the other ports

■ The 10 ONLY  Forces the port to function as a 10Base-T port. This

setting is useful if you have a server that contains a dual-speed (10
Mb/s/100 Mb/s) Network Interface Card (NIC) that must communicate
with a 10 Mb/s segment.

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1-7

RJ-45 Ports

The repeater has 24 RJ-45 ports that let you connect UTP cabling to
workstations and servers in a 10Base-T/100Base-TX network.

Figure 1-6. Twenty-four RJ-45 UTP Ports for 10 Base-T or 100 Base-TX

Uplink Switches

The uplink switches let you convert the 1st and 12th ports on the repeater to
uplinkable OUT RJ-45 ports. This lets you interconnect the repeater to another
dual-speed repeater or to a 10Base-T or 100Base-TX repeater.

IN ports use an internal crossover of the receive and transmit lines, enabling
the port to connect to a network interface card using standard 8-wire UTP
cable. OUT ports use a straight-through (uncrossed) connection, enabling the
port to connect to any IN port of a second repeater or another repeater. This
allows the two repeaters to be on the same segment.

NOTE: IEEE specifications allow only one 100 Mb/s uplink connection per collision
domain. Therefore, you cannot uplink to two 100 Mb/s repeaters. However, you
can use both uplink ports for 10 Mb/s uplink connections.

16

MDI-X

51761871982092110

MDI-X

PWR A
PWR B

10 ONLY 10/100

100 COL
10 COL

MDI

MDI-X

1132143154

22

24

112312

MDI

MDI-X

100 MBPS

10 MBPS

ALTERNATING

DISPLAY MODE

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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1-8 Introduction

Figure 1-7. Uplink Switches

Display Mode Button

The DISPLAY MODE button lets you set the repeater to display port activity
in any of three LED display modes: 100 Mb/s, 10 Mb/s, or alternating
between 100 Mb/s and 10 Mb/s.

To select a specific display mode, press and release the DISPLAY MODE
button on the right side of the repeater.

16

MDI-X

51761871982092110

MDI-X

MDI MDI-X

PWR A
PWR B

10 ONLY 10/100

100 COL

10 COL

MDI-X

MDI

1132143154

Uplinkable

"OUT" Port

22

24

112312

MDI

MDI-X

Standard

"IN" Repeater Port

(Default)

100 MBPS

ALTERNATING

10 MBPS

DISPLAY MODE

Figure 1-8. DISPLAY MODE Button

■ The 100 Mb/s display mode shows port status for 100Base-TX

connections.

■ The 10 Mb/s display mode shows port status for 10Base-T

connections.

100 MBPS

10 MBPS

ALTERNATING

DISPLAY MODE

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1-9

■ The ALTERNATING (default) display mode alternates every 2 to 3

seconds between displaying 10Base-T and 100Base-TX port activity.

NOTE: If you select the 100 Mb/s or 10 Mb/s display mode, the mode is active for
approximately 5 minutes, at which time the repeater returns to the default
alternating mode.

Automatic Speed Detection

The repeater automatically detects the incoming wire speed of a transmission
and adjusts the repeater's operation accordingly.

The repeater immediately adjusts to 100 Mb/s wire speeds. However, the
repeater requires slightly longer (approximately 8 seconds) to adjust to 10
Mb/s wire speeds.

If you change the NIC wire speed from 10 Mb/s to 100 Mb/s, you must
momentarily disconnect the link for the automatic speed detection function to
work correctly.

During automatic speed detection, 10 Mb/s data on the detecting port will be
invalid (error packets).

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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2-1

Chapter 2

Planning Repeater Installation

This chapter contains installation requirements and system planning charts
that will help you prepare for installing the repeater.

Installation Requirements

To help ensure a correct installation, read this section to determine the
environmental, electrical, spatial, and cable requirements.

Environmental Requirements

Be sure the operating environment for the repeater is within the following
ranges:

■ Temperature: 32° to 122° F (0° to 50° C)

■ Humidity: 5% to 95% (non-condensing)

■ Altitude: 0 to 10,000 feet (0 to 3 km)

■ Clearance: minimum of 2 inches (5.1 centimeters) on each side of the

repeater (for proper ventilation)

Electrical Requirements

The electrical requirements for a repeater are as follows:

■ 100 to 240 VAC

■ 1.5 to 0.75 Amps (1.5 @ 100 VAC to 0.75 @ 240 VAC)

■ 50 to 60 Hz

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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2

-2 Planning Repeater Installation

CAUTION: The power outlet must be a non-switched, three-pronged,

grounded outlet. Do not use a three-to-two pronged adapter at the outlet.
Doing so may result in electrical shock and/or damage to the repeater and
will void your warranty.

NOTE: If the supplied power cord is lost or damaged, replace it with a power cord
of the same type, equal current rating, and required regulatory approvals to ensure
emissions compliance.

Spatial Requirements

The repeater's dimensions are 2.75 x 16.95x 14 inches, 7 x 43 x 35.5 cm
(HxWxD).

You can interconnect two repeaters. If there is not enough space to mount the
repeaters in a single rack or stack them on a single shelf, or if you want to
place the repeaters in different locations, you can place them on separate
shelves or in separate racks. See “Twisted-Pair (UTP) Wire Requirements” in
this chapter for more information.

Be sure to allow at least 2 inches (5.1 centimeters) on each side of the repeater
for proper air circulation and cable connections.

Twisted-Pair (UTP) Wire Requirements

The twisted-pair wiring you use to connect the repeater's RJ-45 ports must
meet the following minimum specifications and requirements to ensure long­term reliability.

■ The wiring must be unshielded twisted-pair (UTP), Category 5 for

100Base-TX and Category 3, 4 or 5 for 10Base-T ports.

■ Two pairs of the four-pair wiring are used for signaling.

■ All eight wires in the RJ-45 jack must be connected to the pins for 100

Mb/s operation.

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2-3

■ Depending on building codes, different insulation materials may be

required. Plenum-rated or TEFLON-coated wiring may be required in
some areas.

■ The wire gauge should be between 18 and 26 AWG. (Most telephone

installations use 24-gauge wiring.)

■ Solid copper

Installing New Wire

If you are installing the repeater where no wiring is present, or if existing
wiring does not meet the above specifications, install new wiring. The new
wiring should conform to national and local electrical wiring code
requirements and meet the above specifications. When installing wire, it is a
good idea to install extra pairs of wire for future expansion.

If you are unfamiliar with wiring installation or the applicable local electrical
wiring code or the 10Base-T/100Base-TX specification, you should have a
professional, licensed (if applicable) installer perform the installation.

Straight-through twisted-pair cable is typically used to connect a repeater to a
server or workstation. In a straight-through connection, Pin 1 at the repeater
connects to Pin 1 at the server, Pin 2 at the repeater connects to Pin 2 at the
server, and so on. Figure 2-1 shows the locations of pins on a standard RJ-45
plug on a twisted-pair cable.

Twisted-Pair Cable

1

2

3

6

RJ-45 Plug

Pins

Figure 2-1. RJ-45 Plug Pin Locations

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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2

Pin

Number

➔

➔

1

2

➔

➔

3

6

Pin

Number

➔

➔

3

6

➔

➔

1

2

-4 Planning Repeater Installation

Tables 2-1 and 2-2 show the wiring in a straight-through and crossover
twisted-pair cable. (Pins 4, 5, 7, and 8 are not used, but must be terminated
[connected to wires] for 100 Mb/s operation.)

Table 2-1

Straight-Through Twisted-Pair Wiring

Twisted Pair Number Pin

Number

11

2

23

6

Crossover Twisted-Pair Wiring

Twisted Pair Number Pin

Number

11

2

23

6

Signal

Description

TD+

TD-

RD+

RD-

Table 2-2

Signal

Description

TD+

TD-

RD+

RD-

To

To

Signal

Description

TD+

TD-

RD+

RD-

Signal

Description

RD+

RD-

TD+

TD-

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2-5

System Planning Charts

The charts in Figures 2-2 and 2-3 provide a convenient way of planning the
connections for your repeater.

10/100 Mb/s Repeater Setup and Cabling Chart

Date

Unit Number
Building
Location

Rack Mount
Table

Port 1 Uplink Switch Setting

MDI-X (default)
MDI (uplinkable)

Port 12 Uplink Switch Setting

MDI-X (default)
MDI (uplinkable)

Port 1
Speed Selection Switch Setting

10 ONLY
10/100 (default)

Port Connects To

1

2
3
4
5
6
7
8

9
10
11

12

13
14
15
16
17
18
19
20
21
22
23
24

Figure 2-2. Repeater Setup and Cabling Chart

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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2

-6 Planning Repeater Installation

Rack Inventory Chart

Use this chart to record the components installed in a particular rack.

Wiring Closet Number
Rack Number
Installer

Date

Figure 2-3. Rack Inventory Chart

Example

10/100 Mb/s Repeater

10/100 Mb/s Repeater

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3-1

Chapter 3

Installing the Repeater

This chapter explains how to mount the repeater, attach cables, and
interconnect the repeater to a second repeater.

Mounting the Repeater

You can place the repeater on a level surface (table top or shelf, for example)
or mount it in a standard EIA 19-inch rack.

Attaching the Rubber Feet

If you will place the repeater on a table top or shelf, attach the supplied
adhesive-backed rubber feet, as described in the following steps.

1. Turn the repeater over so that its bottom side faces up.

2. Remove the four rubber feet from their packaging.

3. Peel the protective paper backing off the rubber feet. Then position the
feet in the recessed areas near the corners of the repeater and press the
feet into place.

4. Turn the repeater to its upright position and place it on the mounting
surface.

NOTE: Be sure you allow at least 2 inches (5 cm) on each side of the repeater for
proper air flow.

Rack-Mounting the Repeater

The repeater occupies two slots in a standard, 19-inch rack. To mount the
repeater in a rack, use the supplied installation kit. This kit includes two side
mounting brackets, eight bracket screws, and four larger rack-mount screws.

To attach the brackets, follow these steps:

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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3-2 Installing the Repeater

1. Remove the two screws from the left and right side of the repeater.
(These screws are extras and are not needed to install the mounting
brackets.)

2. Position the bracket as shown in Figure 3-1 and secure it with the
smaller bracket screws. Then attach the remaining bracket to the other
side of the repeater.

Bracket Screws

22

24

112312

92110

MDI MDI-X

100 MBPS

10 MBPS

ALTERNATING

DISPLAY MODE

Figure 3-1. Attaching the Mounting Brackets

3. After you attach both mounting brackets, position the bracket slots over

the desired holes on the rack (Figure 3-2). Then insert and tighten the
supplied rack-mount screws.

16

PWR A
PWR B

COL

1132143154

MDI-X

51761871982092110

MDI-X

Rack-mount Screws

Figure 3-2. Positioning the Repeater in a Rack

22

24

112312

MDI MDI-X

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3-3

Connecting Twisted-Pair Cable

Each RJ-45 port on the repeater can accept a standard 8-wire twisted-pair
(UTP) cable that ends with an RJ-45 connector. These ports can support cable
lengths up to 100 meters (328 feet).

To attach twisted-pair cable, plug one of the RJ-45 connectors into the
selected port on the repeater. Connect the other RJ-45 connector into a
100Base-TX or 10Base-T workstation.

PWR A
PWR B

100 COL

1132143154

Figure 3-3. Connecting Twisted-Pair Cable

Setting the Uplink Switches

The uplink switches enable the 1st and 12th ports on the repeater to function
as either standard IN RJ-45 ports or uplinkable OUT RJ-45 ports. IN ports use
an internal crossover of the receive and transmit lines, enabling the port to
connect to a network interface card using standard 8-wire UTP cable. OUT
ports let you interconnect the repeater and another repeater without the need
for special crossover cables and allows the two repeaters to be on the same
segment.

16

MDI-X

51761871982092110

MDI-X

22

24

112312

MDI MDI-X

100Base-TX Workstation

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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3-4 Installing the Repeater

The default setting for the uplink switches is MDI-X (Media Dependent
Interface-Reversed, that is, standard IN repeater port). To convert Port 1 or
Port 12 to an uplinkable, OUT port, use a small, slotted screwdriver, or a
similar tool, to set the switch to the MDI position (Figure 3-4).

NOTE: IEEE specifications allow only one 100 Mb/s uplink connection per collision
domain. Therefore, you cannot uplink to two 100 Mb/s repeaters. However, you
can use both uplink ports for 10 Mb/s uplink connections.

100 COL

16

MDI-X

51761871982092110

MDI-X

MDI MDI-X

PWR A
PWR B

10 ONLY 10/100

10 COL

MDI-X

MDI

1132143154

Uplinkable

"OUT" Port

22

24

112312

MDI

MDI-X

Standard

"IN" Repeater Port

(Default)

100 MBPS

10 MBPS

ALTERNATING

DISPLAY MODE

Figure 3-4. Uplink Switches (Default Setting)

If you need to connect a dual-speed (10/100 Mb/s) device to the repeater and
the device must operate at 10 Mb/s, set the Port 1 speed selection switch to 10
ONLY. This forces the port to function as a 10Base-T port. When the speed
selection switch is set to its default position (10/100), Port 1 automatically
detects the incoming wire speed like the other ports.

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3-5

Figure 3-5 shows an example configuration in which two repeaters combine to
form an extended 10 Mb/s segment and a 100 Mb/s segment.

Server

Two 10/100 NICs

Port 1

10 Mb/s Uplink

10/100 Mb/s Repeater 10/100 Mb/s Repeater

(5 Meters Max.)

Set to 10/100 Set to 10 ONLY

Figure 3-5. 10 Mb/s and 100 Mb/s Uplink Configuration

Interconnecting Repeaters

You can interconnect two repeaters, providing up to 48 ports in the same
collision domain (segment). You can also connect the repeater to a single­speed repeater (10 Mb/s or 100 Mb/s).

To connect the repeater to another repeater, set the appropriate uplink switch
as described under “Setting the Uplink Switches” in this chapter and connect
the repeaters as shown in Figure 3-6.

NOTE: At 100 Mb/s, the maximum cable distance between two repeaters is 16.4
feet (5 meters) while still allowing a maximum distance of 328 feet (100 meters)
for repeater to workstation/server connections. At 10 Mb/s, the distance between
two repeaters can be up to 328 feet (100 meters).

Port 12

100 Mb/s Uplink

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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3-6 Installing the Repeater

13

14

15

16

17

18

19

20

23

21

22

24

Figure 3-6. Interconnecting Repeaters

Connecting Power

Follow these steps to connect the repeater to power:

1

2

PWR A
PWR B

10 ONLY 10/100

MDI

10 ONLY 10/100

MDI-X

MDI

MDI-X

100 COL

10 COL

PWR A
PWR B

100 COL
10 COL

3

13

14

15

1

2

3

MDI-X

4

5

6

7

8

MDI-X

16

17

18

19

20

MDI-X

4

5

6

7

8

MDI-X

11

9

21

9

12

10

MDI

MDI-X

23

22

24

11

12

10

MDI

MDI-X

MDI

MDI-X

100 MBPS

ALTERNATING

100 MBPS

ALTERNATING

10 MBPS

DISPLAY MODE

10 MBPS

DISPLAY MODE

1. Plug the power cord into the power connector on the back of the
repeater.

2. Insert the three-pronged plug on the power cord into a non-switched,
grounded power outlet on a wall, a power strip, or a grounded
extension cord.

NOTE: The power outlet should be near the repeater and easily accessible.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-7

Figure 3-7. Connecting the Power Cord

When you plug in the power cable, the PWR A LED lights steady green.

Disconnecting Power

PWR B

PWR A

To power down the repeater, disconnect the power cord from the non­switched, grounded power outlet on the wall, power strip, or grounded
extension cord. Do not power down the repeater by disconnecting the power
cord from the back of the repeater.

Replacing the Power Supply

The power supply's modular design makes the supply easy to replace. If power
supply replacement is necessary, follow the instructions under “Installing a
Redundant Power Supply Module” in the next section.

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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3-8 Installing the Repeater

Installing a Redundant Power
Supply Module

The repeater comes with a pre-installed, 90-watt power supply module (PWR
A). You can install an optional redundant power supply module (PWR B) for

backup power. Contact your authorized Compaq reseller for information about
ordering an additional power supply module.

Follow these steps to install a redundant or replacement power supply module.

NOTE: You can install the redundant power supply module while the main power
supply module is powered on.

1. Remove the two screws from the PWR B cover plate and remove the
plate. Be sure you keep the cover plate and screws in case you need
them for future use.

2. Carefully insert the power supply module into the opening until its 10­pin connector engages with the internal power connector and the face
of the module is flush with the repeater's back panel.

3. Secure the power supply by tightening its two spring screws.

PWR B PWR A

Redundant Power Supply Module

Spring Screws

Figure 3-8. Installing a Redundant Power Module

4. Plug the power cord into the connector on the new power supply

module.

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3-9

5. Insert the power cord’s three-pronged plug into a non-switched,

grounded power outlet on a wall, a power strip, or a grounded extension
cord. When you connect power, the PWR B LED indicator lights green
to indicate that the power supply module is installed and functioning
correctly.

NOTE: If the power supply module does not have power or is not functioning
correctly, the PWR B LED indicator lights yellow.

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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4-1

Chapter 4

LED Status Chart

Table 4-1 describes LED status.

Table 4-1

LED Status Chart

LED Condition Description

Steady Green The power supply is currently functioning and providing power to the

repeater.

PWR A and

PWR B

100 COL

10 COL Flashing yellow The repeater detects a 10 Mb/s collision.

RJ-45 Steady yellow The port is disabled (autopartitioned).

10 Mb/s Steady Green The RJ-45 port LEDs are displaying the status of 10BASE-T connections.
100 Mb/s Steady Green The RJ-45 port LEDs are displaying the status of 100BASE-TX connections.

Off No power is supplied to the repeater by the specified power supply.

Steady yellow The power supply is installed but not powered on or is defective.
Flashing yellow The repeater detects a 100 Mb/s collision.
Off No collisions are occurring.

Off No collisions are occurring
Steady green A link condition is present.

Flashing green There is activity at the port.
Off No link condition is present at the port or there is no connection at the port.

ALTERNATING Steady Green The RJ-45 port LEDs alternate between displaying 10BASE-T and 100BASE-

NOTE: LEDs listed as

TX status. The 10Mb/s and 100Mb/s LEDs alternate to show which status is
being displayed.

yellow

might appear orange on the repeater's front panel.

Netelligent 1224 10Base-T/100Base-T Repeater User Guide

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4-2 LED Operation

Selecting an LED Display Mode

The repeater has a display mode selection button on the front panel that lets
you select a specific LED display mode for the repeater.

16

MDI-X

51761871982092110

MDI-X

PWR A
PWR B

10 ONLY 10/100

100 COL

10 COL

MDI

MDI-X

1132143154

22

24

112312

MDI

MDI-X

Current Display

Mode Indicator

Figure 4-1. LED Display Mode Selection Button

To view a specific LED display mode, press and release the display mode
selection button until the LED for the desired mode lights. After about 5
minutes of button inactivity, the repeater returns to the alternating mode
(default). The following LED display modes are available:

10 Mb/s

In the 10 Mb/s mode, the repeater displays the status of the 10 Mb/s
ports and turns off the LEDs for the 100 Mb/s ports.

100 MBPS

10 MBPS

ALTERNATING

DISPLAY MODE

Display Mode

Selection Switch

100 Mb/s

In the 100 Mb/s mode, the repeater displays the status of the 100 Mb/s
ports and turns off the LEDs for the 10 Mb/s ports.

ALTERNATING (default)

In the alternating mode, the repeater alternates every 2 to 3 seconds
between displaying 10 Mb/s and 100 Mb/s port status.

NOTE: If there are only 100 Mb/s connections or only 10 Mb/s connections, the
alternating mode continuously displays the port status for that wire speed.

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A-1

Appendix A

Specifications

Electrical Specifications

Ports and Connectors

■ 24 shielded RJ-45 repeater ports with automatic speed detection for 10

Base-T/100 Base-TX domains

❏ Port 1  Automatic speed detection or dedicated 10Base-T port

with MDI/MDI-X option

❏ Port 12  Automatic speed detection port with MDI/MDI-X

option

LED Indicators

■ Power (PWR A and PWR B), 100 Mb/s Collisions (100 COL), and 10

■ 24 RJ-45 port LEDs to indicate 10 Mb/s or 100 Mb/s activity and link

Controls

■ Two 2-position (MDI/MDI-X) uplink switches for uplink ports

■ Pushbutton switch for three modes of LED display:

Mb/s Collisions (10 COL) 10 Mb/s Mode (10 Mb/s), 100 Mb/s Mode
(100 Mb/s), and Alternating Mode (ALTERNATING)

status

❏ 10 Mb/s only
❏ 100 Mb/s only
❏ Alternating (alternating between 10 Mb/s and 100 Mb/s display

modes)

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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A

-2 Specifications

Power Requirements

■ Voltage: 100 to 240 VAC

■ Power: 1.5 to 0.75 amps (1.5A @ 100 VAC to 0.75A @ 240 VAC)

■ Frequency: 50 to 60 Hz

Power Consumption

■ Maximum: 60 W

■ Power cord (USA)

■ 1.8 mm (6 feet), 10 Amps

Power Supply

■ 90 W redundant power supply
❏ +5 VDC at 14 A; +12 VDC at 2 A (no minimum load required)

Physical Specifications

Dimensions

■ 2.75 x 16.95 x 14 inches, 7 x 43 x 35.5 cm (HxWxD)

Weight

■ 9.9 pounds (4.5 kg)

Environmental Specifications

Operating Environment

■ 32° to 122° F (0° to 50° C)

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A-3

■ 15% to 95% humidity at 50° C (non-condensing)

■ 0 to 10,000 feet (0 to 3 km)

Storage Environment

■ 32° to 151° F (0° to 66° C)

■ 15% to 95% humidity at 50° C (non-condensing)

■ 0 to 30,000 feet altitude (0 to 9 kilometers)

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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G-1

Glossary

This section defines technical terms related to communications wiring
environments, local area networks, and the repeater.

10Base-T

An IEEE standard (802.3) for unshielded twisted-pair (UTP) wiring.
Stations are connected using a star topology. The maximum UTP cable
length is 100 meters (328 feet).

100Base-TX

An IEEE standard (802.3u) for high-speed Ethernet.

802.3

An IEEE standard that governs Carrier Sense Multiple
Access/Collision Detect (CSMA/CD) networks. 802.3, referred to as
Ethernet, operates on different cable types (e.g., UTP, coax, fiber).

Auto-negotiation

The algorithm that allows two devices at either end of a link segment
to negotiate common features and functions.

Category 3 Balanced Cable

Balanced 100 ohms and 120 ohms cables and associated connected
hardware whose transmission characteristics are specified up to 16
MHz commonly used by 10Base-T installations. Requirements are
outlined in ISO/IEC 11801 and clause 23 of the IEEE 802.3 standard.

Category 4 Balanced Cable

Balanced 100 ohms aand 120 ohms cables and associated connected
hardware whose transmission characteristics are specified up to 20
MHz as per ISO/IEC 11801 and clause 23 of the IEEE 802.3 standard.

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G-2 Glossary

Category 5 Balanced Cable

Balanced 100 ohms aand 120 ohms cables and associated connected
hardware whose transmission characteristics are specified up to 100
MHz as per ISO/IEC 11801 and clause 23 of the IEEE 802.3 standard.

Class I Repeater

A type of 100Base-T repeater with internal delay such that only one
repeater set may exist between any two DTEs within a single collision
domain.

Class II Repeater

A type of 100Base-T repeater with internal delay such that only two or
fewer such repeater sets may exist between any two DTEs within a
single collision domain.

Collision

A collision occurs when two or more nodes try to transmit
simultaneously. Large numbers of collisions may indicate a high
network load.

Collision Domain

A single CSMA/CD network. If two or more Media Access Controllers
(MAC) are within the same collision domain and both transmit at the
same time, a collision will occur. MACs that are separated by a
repeater are in the same collision domain. MACs that are separated by
a bridge are within different collision domains.

DTE

Data Terminal Equipment. A DTE can be a source or destination
communications device (typically a computer) that sends or receives
network transmissions.

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G-3

EIA

Electronic Industries Association. The EIA is an organization that sets
electrical and electronic interface standards.

Hot-Swappable

The ability of a device (such as a redundant power supply) to be added
to or removed from a repeater without powering down the repeater.

Hub

A device used to provide connectivity between DTEs. Hubs perform
basic functions such as restoration of signal amplitude and timing,
collision detection and notification, and signal broadcast to lower level
repeaters and DTEs.

IEC

International Electrotechnical Commission. The IEC, an organization
comprised of committees from several different countries, sets
international electrical and electronic standards.

Institute of Electrical and Electronic
Engineers (IEEE)

The IEEE, a membership organization made up of people in electronics
related fields, is involved with setting standards for communications
and computers.

Impedance

A measurement of the resistance to the flow of alternating current in an
electrical circuit.

Inter-Repeater Link (IRL)

A mechanism for connecting two and only two repeater sets.

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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G-4 Glossary

Inter-Packet Gap (IPG)

A delay or time gap between CSMA/CD packets intended to provide
interface recovery time for other CSMA/CD sublayers and for the
Physical Medium. For 10Base-T, the IPG is 9.6 us (96 bit times). For
100Base-T, the IPG is 0.96 us (96 bit times).

Jabbering

Continuous transmission from a node, generally as a result of a
hardware or firmware failure.

Latency

The length of time from the point at which the first bit of a packet
enters a port to the point at which the first bit of the packet exits
another port.

LED

Light Emitting Diode, typically used to indicate the operating status of
a repeater or module.

Link Pulse

A communication mechanism used in 10Base-T networks to indicate
link status and, in auto-negotiation equipped devices, to communicate
information about abilities and negotiate communication methods.
10Base-T uses Normal Link Pulses (NLPs) which indicate link status
only. 10Base-T and 100Base-T nodes equipped with auto-negotiation
exchange information using a Fast Link Pulse (FLP) mechanism which
is compatible with NLP.

Manageable

A module is manageable if it contains an SNMP agent and there is a
data communication path to that agent from an SNMP manager.

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G-5

Media Independent Interface (MII)

A transparent signal interface between the MAC or repeater and the
media transceiver device.

Network Interface Card (NIC)

A NIC is a plug-in expansion board that enables nodes to send and
receive data over the network.

Partition

The electrical disconnecting of a node from a LAN at its point of
connection to a repeater. The node remains physically attached. A node
can be autopartitioned by the hardware when 30 consecutive frame
errors occur. The reception of one good frame re-enables the
autopartitioned port.

Protocol Data Unit (PDU)

A packet that contains control information and optional data.

Port

An external connector used to connect PCs and other node devices to
the network.

Repeater Set

A repeater unit plus its associated physical layer interfaces (MAUs or
PHYs).

RJ-45

An 8-wire modular connector used for 10Base-T Ethernet, 100Base-T
Ethernet, and some telephones.

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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G-6 Glossary

Segment

A single collision domain. Each Ethernet segment supports either a 10
Mb/s or 100 Mb/s band . A multiple segment implementation increases
the band of a Local Area Network.

Stack

A stack is a group of interconnected repeaters.

Twisted Pair Wire

Two insulated copper wires twisted together. The twists vary in length
to reduce the potential for signal interference between pairs. In cables
greater than 25 pairs, the twisted pairs are grouped and bound together
in a common cable sheath. Twisted pair cable is the most common type
of transmission media.

Uplink

The connection from one repeater to another, usually done to expand a
network segment.

Unshielded Twisted Pair (UTP)

Cable that is usually connected using RJ-45 connectors.

Wiring Environment

Any building communications wiring system.

Wiring Closet

A room, closet or cabinet where station cable is terminated on
crossconnect blocks and where the building communications system
can be administered.

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I-1

Index

10 Mb/s mode 4-2
10 ONLY switch 1-5, 1-6
10/100 switch 1-5, 1-6
100 Mb/s repeaters

uplinking 1-7
100 Mbps mode 4-2
10MBPS 1-5

A

ALTERNATING 1-5
Alternating button 1-9
Alternating mode 4-3
Automatic speed detection 1-9

B

Back panel 1-4

I

IEEE specifications 1-7
IN ports 1-7, 3-3
Installing repeater 3-1

L

LED Status Chart 4-1
LEDs 1-1, 1-5

display mode, selecting 4-2

M

MDI 3-4
MDI-X 3-4
Media Dependent Interface-Reversed

See MDI-X

N

NIC 1-6

C

Cable length 3-3
Collision domain 1-7, 3-4
Crossover 1-7

D

Default mode 4-2
Dimensions 2-2
Display mode button 1-8

E

Electrical requirements 2-1
Environmental requirements 2-1

F

Front panel 1-4

O

OUT ports 1-7, 3-3
Overview 1-4

P

Package contents 1-2
Power

connecting 3-6

disconnecting 3-7
Power cord 1-2
Power outlet 2-2

Power supply 1-1

redundant 3-8

replacing 3-7

Netelligent 1224 10Base-T/100Base-TX Repeater User Guide

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-2 Index

R

Redundant power supply 3-8
Repeater

attaching rubber feet 3-1
features 1-1
interconnecting 3-5
mounting 3-1
rack mounting 3-1
steps for mounting 3-2

Repeaters

interconnecting 2-2

RJ-45 ports 1-7, 3-3

S

Status LEDs 1-5

T

Twisted-pair cable 3-3

U

Uplink

default setting 3-4

Uplink switch

setting 3-3

Uplink switches 1-7

W

Wire speed 1-9