Table Of Contents
Maintaining Safety with Electricity
Preventing Electrostatic Discharge Damage
System Operation Prerequisites
Limitations on Ethernet Connections
Limitations on Token Ring Connections
Limitations on Serial Connections
Limitations on BRI Connections
Console and Auxiliary Port Considerations
Network Connection Considerations
Synchronous Serial Connections
Asynchronous Serial Connections
Chapter 1
Preparing for Installation
This chapter describes the tasks you must perform before starting actual system installation.
Sections of this chapter follow:
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System Operation Prerequisites
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Safety Recommendations
Follow these guidelines to ensure general safety:
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Maintaining 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 can weld the metal object to the terminals.
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Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) can damage equipment and impair electrical circuitry. It occurs when electronic components are improperly handled and can result in complete or intermittent failures.
Always follow ESD-prevention procedures when removing and replacing components. Ensure that the chassis is electrically connected to earth ground. Wear an ESD-preventive 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.
CautionFor safety, periodically check the resistance value of the antistatic strap, which should be within the range of 1 and 10 megohms (Mohms).
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, rack-mounted, or wall-mounted equipment in a data processing or lab environment.
CautionThe rubber feet on the chassis bottom protect the chassis and provide a nonskid surface. Removing the feet reduces the space below the chassis and might affect the ventilation around the chassis. Inadequate ventilation could result in damage to the equipment. With the feet attached, more ventilation is provided around 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 possibility 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:
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Configuring Equipment Racks
The following tips will help you plan an acceptable equipment rack configuration:
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Power Supply Considerations
Check the power at your site to ensure that you are receiving clean power. Install a power conditioner if necessary.
CautionTo avoid damage from lightning and power surges, install proper grounding.
Features of the router power supply follow:
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System Operation Prerequisites
The router models are designed to run system code from Flash memory single inline memory modules (SIMMs). With the proper system code image, the router also can be run from dynamic random-access memory (DRAM); however, this operation requires a 4-MB memory upgrade (installation of a 1 MB x 36 DRAM SIMM). Additionally, operating system code from DRAM can result in a 25-percent decrease in system performance.
Operating the system code from Flash memory is the default and is recommended for optimum performance of the router.
Installation Checklist
The Installation Checklist (see Figure 1-1) lists the procedures for initial hardware installation of new systems. Make a copy of this checklist and mark the entries as you complete each procedure. Include a copy of the checklist for each system in your Site Log (refer to the "Site Log" section).
Figure 1-1 Installation Checklist
Creating a 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:
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Preparing to Make Connections
When viewed from the rear, the power-cable input and power switch are located on the right side of the chassis rear panel. (See Figure 1-2.) The ports for the Ethernet, Token Ring, synchronous serial, Basic Rate Interface (BRI), console, and auxiliary (AUX) connections are located to the left of the power connector and switch. The interface configuration depends on the model.
Models 2501, 2502, 2513, 2514, and 2515 do not have a BRI port. Models 2514 and 2515 have two LAN ports. Model 2513 has both a Token Ring and an Ethernet port. Otherwise, all models are identical to models 2503 and 2504, shown in Figure 1-2.
Figure 1-2 Router Rear View—Models 2503 and 2504
On the hub models, Ethernet RJ-45, BRI, synchronous serial, console, and auxiliary (AUX) connections are located to the left of the power connector and switch. The interface configuration depends on the model.
The model 2505 has 8 instead of 16 RJ-45 ports, and is otherwise identical to the model 2507, which is shown in Figure 1-3. The model 2516 has 14 RJ-45 ports with a BRI port (also shown in Figure 1-3).
Figure 1-3 Hub Rear View — Models 2507 and 2516
On the access server models, the ports for the Ethernet, Token Ring, asynchronous serial, synchronous serial, console, and auxiliary (AUX) connections are located to the left of the power connector and switch. The interface configuration depends on the model.
The models 2509 and 2510 have 8 rather than 16 asynchronous ports, delivered through a breakout cable which connects to a single 68-pin SCSI instead of two 68-pin SCSI ports, but are otherwise identical to the models 2511 and 2512, which are shown in Figure 1-4.
Figure 1-4 Access Server Rear View — Models 2511 and 2512
Distance Limitations
When setting up your router, consider distance limitations and potential electromagnetic interference (EMI) as defined by the Electronic Industries Association (EIA). Following are the distance limitation specifications for Ethernet, serial, and BRI interfaces.
Limitations on Ethernet Connections
The distance limitations for the IEEE 802.3 (10Base5 coaxial cable) specification indicate a maximum segment distance of 1,640 feet (500 m) at a transmission rate of 10 megabits per second (Mbps).
Limitations on Token Ring Connections
The distance limitations for the IEEE 802.5 specification indicate a maximum segment distance of 1,640 feet (500 m) at a transmission rate of 4 or 16 megabits per second (Mbps).
Limitations on Serial Connections
As with all signaling systems, EIA/TIA-232 signals can travel a limited distance at any given bit rate; generally, the slower the data rate, the greater the distance. Table 1-1 shows the standard relationship between baud rate and maximum distance.
Table 1-1 EIA/TIA-232 Speed and Distance Limitations
2400
200
60
4800
100
30
9600
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15
19,200
25
7.6
38,400
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3.7
CautionEIA/TIA-232 is often used at greater distances than specified in Table 1-1. If you understand the electrical problems that can arise and can compensate for them, you might still be able to get good results, however, do so at your own risk. We recommend that you stay within the standard-defined distance.
The use of balanced drivers allow EIA/TIA-449 signals to travel greater distances than the
EIA/TIA-232 standard. Table 1-2 lists the standard relationship between baud rate and maximum distance for EIA/TIA-449 signals. These limits are also valid for V.35 and X.21.Table 1-2 EIA/TIA-449 Speed and Distance Limitations
2400
4100
1250
4800
2050
625
9600
1025
312
19200
513
156
38400
256
78
56000
102
31
T1
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CautionThe EIA/TIA-449 and V.35 interfaces support data rates up to 2.048 Mbps. Exceeding this maximum could result in loss of data and is not recommended; do so at your own risk.
Limitations on BRI Connections
The specifications for the BRI cable are given in Table 1-3.
Table 1-3 BRI Cable Specifications
Resistance (@ 96 kHz1 )
160 ohms/km
160 ohms/km
Capacitance (@ 1 kHz)
120 nF/km2
30 nF/km
Impedance (@ 96 kHz)
75 ohms
150 ohms
Wire diameter
0.024" (0.6 mm)
0.024" (0.6 mm)
Distance limitation
32.8' (10 m)
32.8' (10 m)
1 kHz = kilohertz.
2 nF = nanoFarad.
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:
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If you use twisted-pair cables with a good distribution of grounding conductors in your plant cabling, emitted radio interference is unlikely. If you exceed the maximum distances, ground the conductor for each data signal; however, this practice is not recommended.
If you have cables exceeding recommended distances, or if you have cables that pass between buildings, 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 this type of problem, 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, and electrical surge suppression.
To prevent electromagnetic interference, consult experts in radio-frequency interference (RFI).
Console and Auxiliary Port Considerations
Before connecting the console and auxiliary ports, read the following sections.
Console Port Connections
An RJ-45 console asynchronous serial port is included on all router units. This port connects to a terminal using an RJ-45-to-RJ-45 cable and an RJ-45-to-DB-25 adapter or RJ-45-to-DB-9 adapter (labeled "Terminal"). To use the port with a console device (an ASCII terminal or PC running terminal emulation software), use a DCE RJ-45-to-DB-25 adapter or DCE RJ-45-to-DB-9 adapter. Table A-1 in the appendix "Cabling Specifications" lists the pinouts for the console port. The default parameters for the console port are as follows: 9600 baud, 8 data bits, no parity generated or checked, and 2 stop bits. The console port does not support hardware flow control.
Auxiliary Port Connections
An RJ-45 auxiliary asynchronous serial port is included on all router units. This port connects to a channel service unit/digital service unit (CSU/DSU) or protocol analyzer for network access, using an RJ-45-to-DB-25 adapter. Depending on the adapter used, it turns this port into a data communications equipment (DCE) device or a data terminal equipment (DTE) device. For connection to a CSU/DSU or protocol analyzer, you should use a DTE RJ-45 to DB-25 adapter. Table A-2 in the appendix "Cabling Specifications" lists the pinouts for this auxiliary port.
Network Connection Considerations
Read this section to prepare for your network connections.
Ethernet Connections
On models with an AUI Ethernet port, the Ethernet port is located on the far left of the rear panel. The port is labeled AUI (for attachment unit interface). Use standard 15-pin Ethernet transceiver cables or IEEE 802.3 AUI cables (neither are supplied) to connect the router directly to the network.
Three configurations are possible on the Ethernet AUI port (Ethernet cables are not shipped as standard):
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On Ethernet Hub models (models 2505, 2516, and 2507) 8, 14, or 16 RJ-45 connectors are located at the extreme left side of the rear panel in one or two rows. The RJ-45 connectors are arranged in two rows, one above the other in 14 and 16 port models, or one row in 8 port models. The ports are labeled Ethernet 1 through 8 on the bottom row, and 9 through 16 on the top row on models 2505 and model 2507, and Ethernet 1 through 6 on the bottom row and 7 through 14 on the top row of the model 2516. Use standard 10BaseT cables for the network connections.
There is a switch to allow cross connection to another hub located below Ethernet port 14. The switch provides normal hub operation in the MDI position. Reset the switch to the MDI X position if cross connection to another hub is desired.
Token Ring Connections
On models with a Token Ring port (2502 and 2504), the Token Ring port is located on the far left of the rear panel. The port is labeled TOKEN RING. Use a standard 9-pin Token Ring lobe cable (not supplied) to connect the router directly to a media attachment unit (MAU).
Synchronous Serial Connections
The serial interface ports are located on the rear of the router to the right of the Ethernet or Token Ring connector. The ports are labeled SERIAL 0 and SERIAL 1. (Read from left to right when facing the rear panel.) The serial ports are 60-pin, D-type subconnectors. All serial interfaces except the
EIA-530 can be configured as DCE, using a DCE cable. All DTE serial ports require that external clocking be provided by a CSU/DSU or modem.You must use a special serial cable to connect the router to a modem or CSU/DSU. This cable is available from us and is usually ordered with the system. The cable uses a DB-60 connector on the chassis end. See the appendix "Cabling Specifications"for cable pinouts. For ordering information, contact a customer service representative.
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Asynchronous Serial Connections
The asynchronous serial ports are located on the left side of the router rear panel to the left of the Token Ring or Ethernet port connector. The asynchronous serial ports are 68-pin SCSI connectors, one above the other (depending on model). Each of the two small computer system interface (SCSI) ports provide connections for eight asynchronous ports. The ports are labeled Async 1-8 on the lower port, and Async 9-16 on the upper port. Breakout cables that divide into eight RJ-45 connectors each are connected to the SCSI ports.
RJ-45 to DB-25 adapters are used to connect to external devices. RJ-45 to DB-25 adapters are available for either DTE or DCE connections. The adapter uses an RJ-45 connector on the chassis end. For ordering information contact a customer service representative.
BRI Connections
On models with a Basic Rate Interface (BRI) port, it is an RJ-45 8-pin connector located between the serial and console ports on model 2503 and model 2504, or between the serial and Ethernet ports on model 2516. Use an appropriate cable to connect the system directly to the Integrated Services Digital Network (ISDN) through the NT1. The common carrier will provide the NT1 connection worldwide, except in North America, where the NT1 is customer owned.
Warning
Network hazardous voltages are accessible in the BRI cable. If you detach the BRI cable, detach the end away from the router first to avoid possible electric shock. Network hazardous voltages also are accessible on the system card in the area of the BRI port (RJ-45 connector), regardless of whether power is turned off.
Inspecting the System
Do not unpack the router until you are ready to install it. If the 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, UniverCD or printed 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:
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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.
