Keep the chassis area clear and dust-free during and after installation.
Put the removed chassis cover in a safe place.
Keep tools away from walk areas where you and others could trip over them.
Do not wear loose clothing that could get caught in the chassis. Fasten your tie or scarf and sleeves.
Wear safety glasses when working under any conditions that might be hazardous to your eyes.
Do not perform any action that creates a potential hazard to people or makes the equipment unsafe.

Safety with Electricity

Follow these guidelines when working on equipment powered by electricity.

Warning Before working on equipment that is connected to power lines, remove jewelry (including rings, necklaces, and watches). Metal objects will heat up when connected to power and ground and can cause serious burns or weld the metal object to the terminals.

Locate the emergency power-off switch in the room in which you are working. Then, if an electrical accident occurs, you can act quickly to shut the power off.
Before working on the system, turn off the power and unplug the power cord.
Disconnect all power before doing the following:
- Installing or removing a chassis
- Working near power supplies
- Performing a software upgrade
Do not work alone when potentially hazardous conditions exist.
Never assume that power has been disconnected from a circuit. Always check.
Look carefully for possible hazards in your work area, such as moist floors, ungrounded power extension cables, and missing safety grounds.
If an electrical accident occurs, proceed as follows:
- Use caution; do not become a victim yourself.
- Turn off power to the system.
- If possible, send another person to get medical aid. Otherwise, assess the victim's condition and then call for help.
- Determine if the person needs rescue breathing or external cardiac compressions; then take appropriate action.

Preventing Electrostatic Discharge Damage

Electrostatic discharge (ESD) can damage equipment and impair electrical circuitry. It occurs when electronic printed circuit cards are improperly handled and can result in complete or intermittent failures.

Always follow ESD prevention procedures when removing and replacing cards. Ensure that the chassis is electrically connected to earth ground. Wear an ESD wrist strap, ensuring that it makes good skin contact. Connect the clip to an unpainted chassis frame surface to safely channel unwanted ESD voltages to ground. To properly guard against ESD damage and shocks, the wrist strap and cord must operate effectively.

If no wrist strap is available, ground yourself by touching the metal part of the chassis.

General Site Requirements

This section describes the requirements your site must meet for safe installation and operation of your system. Ensure that your site is properly prepared before beginning installation.

The router can be used as desktop or rack-mounted equipment in a data processing or lab environment. Optional rack-mount kits are available.

For desktop mounting, use the rubber feet provided. They protect the chassis and provide a nonskid surface for the chassis.

Site Environment

The location of individual chassis and the layout of your equipment rack or wiring room are extremely important for proper system operation. Equipment placed too close together, inadequate ventilation, and inaccessible panels can cause system malfunctions and shutdowns and can make system maintenance difficult.

When planning your site layout and equipment locations, use the following precautions to help avoid equipment failures and reduce the likelihood of environmentally caused shutdowns. If you are currently experiencing shutdowns or unusually high errors with your existing equipment, these precautions may help you isolate the cause of failures and prevent future problems.

Preventive Site Configuration

The following precautions will help you plan an acceptable operating environment for your router and will help you avoid environmentally caused equipment failures:

Remember that electrical equipment generates heat. Ambient air temperature might not be adequate to cool equipment to acceptable operating temperatures without adequate circulation. Ensure that the room in which you operate your system has adequate air circulation.
Always follow the ESD-prevention procedures in the section "Preventing Electrostatic Discharge Damage" to avoid damage to equipment. Damage from static discharge can cause immediate or intermittent equipment failure.
Ensure that the chassis cover is secure. The chassis is designed to allow cooling air to flow within. An open chassis allows air leaks, which may in turn interrupt and redirect the flow of cooling air across internal components.

Equipment Racks

The following tips will help you plan an acceptable equipment rack configuration:

Enclosed racks must have adequate ventilation. Ensure that the rack is not overly congested because each unit generates heat. An enclosed rack should have louvered sides and a fan to provide cooling air.
When mounting a chassis in an open rack, ensure that the rack frame does not block the intake or the exhaust ports. If the chassis is installed on slides, check the position of the chassis when it is seated all the way into the rack.
In an enclosed rack with a ventilation fan in the top, excessive heat generated by equipment near the bottom of the rack can be drawn upward and into the intake ports of the equipment above.
Baffles can help to isolate exhaust air from intake air, which also helps to draw cooling air through the chassis. The best placement of the baffles depends upon the air flow patterns in the rack, which can be found by trial-and-error.
When equipment installed in a rack fails, particularly in an enclosed rack, try operating the equipment by itself, if possible. Turn off other equipment in the rack (and in adjacent racks) to allow the unit under test a maximum of cooling air and clean power.

Power Supply Considerations

Check the power at your site to ensure that you are receiving "clean" power (free of spikes and noise). Install a power conditioner if necessary.

Install proper grounding to avoid damage from lightning and power surges.

Features of the router power supply follow:

Autoselects either 110-volt (V) or 220-V operation.
All units include a 6-foot (1.8-meter) electrical power cord. (A label near the power cord indicates the correct voltage and current draw for your unit.)

Installation Checklist

The Installation Checklist (see Figure 2-1) lists the procedures for initial hardware installation of new systems. Make a copy of this checklist and mark your entries as each procedure is completed. Include a copy of the checklist for each system in your Site Log. (See the "Site Log" section.)

Site Log

The Site Log provides a historical record of all actions relevant to the system. Keep it in a common place near the chassis where anyone who performs tasks has access to it. Use the Installation Checklist to verify steps in the installation and maintenance of your system. Site Log entries might include the following:

Installation progress--Make a copy of the Installation Checklist and insert it into the Site Log. Make entries on the checklist as each procedure is completed.
Upgrades and removal and replacement procedures--Use the Site Log as a record of ongoing system maintenance and expansion history. Each time any procedure is performed on the system, update the Site Log to reflect the following:
- Configuration changes
- Maintenance schedules and requirements
- Corrective maintenance procedures performed
- Intermittent problems
- Related comments

Tools and Equipment Required

You need the following tools and equipment to install and upgrade the router:

ESD cord and wrist strap
Screwdrivers: No. 1 and No. 2 Phillips

Preparing to Make Connections

When viewed from the rear, the power cable and power switch appear on the right side of the chassis. The ports for the system console, auxiliary (AUX), LAN (Token Ring, Ethernet, or BRI), and serial line appear to the left of the power cable and switch. The configuration depends on which model you purchase. Refer to Figures 2-2 through 2-7 for rear views of the different router configurations.

Figure 2-2: Router--Rear View with Ethernet and BRI Ports

Figure 2-3: Router--Rear View with Two Ethernet Ports

Note If the system's serial port is labeled with V2, as shown in Figure 2-4, Figure 2-5, Figure 2-6, or Figure 2-7, then for optimum performance, use the version of the cable with the part number ending in -02 (for example,72-0671-02 [DTE]).

Figure 2-4: Router--Rear View with Ethernet and Serial Ports

Figure 2-5: Router--Rear View with Serial and Token Ring Ports

Figure 2-6: Router--Rear View with One Ethernet, Two Serial, and One BRI ports

Figure 2-7: Router--Rear View with Two Serial, One Token Ring, and One BRI ports

As seen from the rear, the system console port is the top, left female RS-232 25-pin D-connector on the back of the chassis. The auxiliary port is located directly below the console port and is a male RS-232 25-pin D-connector.

RJ-45 Lock Plug

On systems with a Basic Rate Interface (BRI ) port that are not licensed for ISDN use, an RJ-45 lock plug comes installed in the BRI port. (See Figure 2-8.) Removing this plug without authorization is a violation of the software license agreement.

Figure 2-8: RJ-45 Lock Plug

RS-232 Connections

When setting up your router, consider distance limitations and potential electromagnetic interference (EMI) as defined in the Electronic Industries Association's (EIA) Recommended Standard 232-C.

Distance Limitations

As with all signaling systems, RS-232 signals can travel a limited distance at any given bit rate; generally, the slower the data rate, the greater the distance. Table 2-1 shows the standard relationship between bit rate and distance as defined in RS-232-C.

RS-232 Speed and Distance Limitations

Data Rate (Baud)	Distance (Feet)	Distance (Meters)
2400	200	60
4800	100	30
9600	50	15
19200	25	7.6
38400	12	3.7

Note RS-232 is often used in violation of these specifications. If you understand the electrical problems that can arise and can compensate for them, you might be able to get good results at distances greater than those shown in Table 2-1; however, do so at your own risk. We recommend that you stay within the standard-defined distance.

Interference Considerations

When you run cables for any significant distance in an electromagnetic field, interference can occur between the field and the signals on the cables. This fact has two implications for the construction of terminal plant cabling:

Plant cabling can emanate radio interference if it is unshielded for too long a distance.
Strong electromagnetic interference, especially as caused by lightning or radio transmitters, can destroy the RS-232 drivers and receivers in the server.

If you use twisted-pair cables in your plant cabling with a good distribution of grounding conductors, the plant cabling is unlikely to emit radio interference. When exceeding the distances listed in Table 2-1, ground the conductor for each data signal.

If you have cables exceeding the distances in Table 2-1, or if you have cables that pass between buildings, then give special consideration to the effect of lightning strikes or ground loops. The electromagnetic pulse caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If your site has experienced problems of this sort, consult experts in lightning suppression and shielding.

Most data centers cannot resolve the infrequent but potentially catastrophic problems just described without pulse meters and other special equipment. Take precautions to avoid these problems by providing a properly grounded and shielded environment, with special attention to issues of electrical surge suppression.

To predict and remedy strong electromagnetic interference, consult experts in RFI.

Console and Auxiliary Port Considerations

Before connecting the console and auxiliary ports, read the following sections.

Console Port Connections

Each router system includes a female DB-25 connector asynchronous system console port wired as a data communications equipment (DCE) device. The default parameters for the console port follow:

9600 baud
8 data bits
No parity generated or checked
One stop bit

Table A-1 in Appendix A lists the pinouts for the console port.

Auxiliary Port Connections

A male DB-25 connector auxiliary console port is included on all router units. This is a data terminal equipment (DTE) port to which you can attach an RS-232-C connector from a channel service unit/data service unit (CSU/DSU) or protocol analyzer for network access. Table A-2 lists the pinouts for this auxiliary console port.

Network Connection Considerations

Read this section in preparation to making network connections.

Ethernet Connections

On systems with an Ethernet port, the Ethernet port is located to the right of the console and auxiliary ports (as shown in Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-6). The ports are labeled on the chassis as Ethernet or as Ethernet 0 and Ethernet 1, depending on the system's configuration. Standard 15-pin Ethernet transceiver cables and IEEE 802.3 attachment unit interface (AUI) cables can be used. An 18-inch transition cable is provided for each Ethernet port. This cable provides flexibility for alternate connection configurations. Three configurations are possible:

The transition cable can be used by itself to connect the router directly to the media attachment unit (MAU) or transceiver. (See Figure 2-9.)
The transition cable can be used as a flexible extension of the router Ethernet port. An Ethernet transceiver cable with a slide-latch-type connector (802.3 AUI cable) will mate with the female end of the 18-inch transition cable. (See Figure 2-10.)
An Ethernet transceiver cable with thumbscrew connectors (not shown) can be connected directly to the router's Ethernet port without using the 18-inch transition cable (not shown).

Figure 2-9: Ethernet Transition Cable Connections

Figure 2-10: Extending the Transition Cable from the Router's Ethernet Port

Token Ring Connections

On systems with a Token Ring port, the Token Ring port is located to the right of the serial port (as shown in Figure 2-5). Use a standard 9-pin Token Ring lobe cable (not supplied) to connect the router directly to a media attachment unit (MAU). (See Figure 2-11.)

Figure 2-11: Token Ring Cable Connections

Serial Connections

The serial interface ports are located on the rear of the router. (See Figure 2-4, Figure 2-5, Figure 2-6, and Figure 2-7.) The serial ports are 50-pin, D-type subconnectors. The router is available as DTE only, except models 3104 and 3204. On models 3104 and 3204, the serial ports can be configured as DTE or DCE depending on the special serial cable being used. DTE serial ports require that clocking be provided by a CSU/DSU or modem.

If the system's serial port is labeled with V2, then for optimum performance, use the version of the cable with the part number ending in -02: for example, 72-0740-02 (DCE) or 72-0671-02 (DTE).

You must use a special serial cable to connect the router to a modem or CSU/DSU, as shown in Figure 2-12. This cable is available from us and is usually ordered with the system. See Appendix A, for cable specifications. For ordering information, contact your sales representative.

Figure 2-12: Serial Cable Connections

BRI Connections

The Basic Rate Interface (BRI) port is an RJ-45 connector located on the chassis rear to the right of the Ethernet port. (See Figure 2-2, Figure 2-6, and Figure 2-7.) Use an RJ-48 cable to connect the system directly to a the Integrated Services Digital Network (ISDN) through the NT1. The common carrier will provide the NT1 connection worldwide, except in North America.

Figure 2-13: ISDN Basic Rate Interface RJ-45 Port

Inspecting the System

Do not unpack the router until you are prepared to install it. If its final installation site will not be ready for some time, keep the chassis in its shipping container to prevent accidental damage. When you have determined where you want the router installed, proceed with the unpacking.

The router, cables, publications, and any optional equipment you ordered might be shipped in more than one container. When you unpack each shipping container, check the packing list to ensure that you received all of the following items:

Router
6-foot (1.8-meter) power cord
Rubber feet for desktop system use
Optional equipment (which might include network connection cables)
This publication and optional companion publications, as specified by the customer order

Inspect all items for shipping damage. If anything appears damaged, or if you encounter problems when installing or configuring your system, contact a customer service representative.

Table of Contents

Preparing for Installation