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Table of Contents

Preparing for Installation

Preparing for Installation

This chapter describes the equipment and site requirements for installing the Cisco uBR7246. The chapter contains the following sections:

Before installing your Cisco uBR7246 you should consider the power and cabling requirements that must be in place at your installation site, the equipment you will need to install the router, and the environmental conditions your installation site must meet to maintain normal operation. This chapter guides you through the process of preparing for your router installation.

Note The chapter "CATV Headend Considerations," describes important configuration information related to the setup of the analog RF signal and digital data. After installing your Cisco uBR7246 universal broadband router, use the instructions found in that chapter to fully configure the upstream and downstream signal alignment.

Safety Recommendations

The following guidelines will help to ensure your safety and protect the equipment. This list does not cover all potentially hazardous situations, so be alert.

Lifting Safely

A fully configured Cisco uBR7246 weighs approximately 100 pounds. The chassis is not intended to be moved frequently. Before you install the router, ensure that your site is properly prepared so you can avoid having to move the chassis later to accommodate power sources and network connections.

Whenever you lift the chassis or any heavy object, follow these guidelines (see Figure 2-1):


Figure 2-1: Lifting the Chassis



Safety with Electricity

The port adapters and power supplies are designed to be removed and replaced while the system is operating without presenting an electrical hazard or damage to the system. However, you must power down the system before removing or replacing the I/O controller and network processing engine.

Follow these basic guidelines when working with any electrical equipment:

In addition, use the guidelines that follow when working with any equipment that is disconnected from a power source, but still connected to telephone wiring or other network cabling.

Preventing Electrostatic Discharge Damage

Electrostatic discharge (ESD) damage, which occurs when electronic cards or components are improperly handled, can result in complete or intermittent system failures. The network processing engine, I/O controller, each cable modem card, and each port adapter consists of a printed circuit board that is fixed in a metal carrier. Electromagnetic interference (EMI) shielding, connectors, and a handle are integral components of the carrier. Although the carrier helps protect the boards, use an antistatic strap whenever handling the network processing engine, I/O controller, cable modem cards, and port adapters. Handle the carriers by the handles and the carrier edges only; never touch the boards or connector pins.

Caution  Always tighten the captive installation screws on the network processing engine, I/O controller, and cable modem cards. (See Figure 1-4 and Figure 1-6.) These screws prevent accidental removal, provide proper grounding for the system, and help ensure that the bus connectors are properly seated in the midplane.

Following are guidelines for preventing ESD damage:

Caution  For safety, periodically check the resistance value of the antistatic strap. The measurement should be between 1 and 10 megohms.

Site Requirements

The environmental monitoring functionality in the Cisco uBR7246 protects the system and components from potential damage from overvoltage and overtemperature conditions. To assure normal operation and avoid unnecessary maintenance, plan your site configuration and prepare your site before installation. After installation, make sure the site maintains an ambient temperature of 32°F through 104°F (0°C through 40°C), and keep the area around the chassis as free from dust as is practical.

The following sections address the site environment requirements for the Cisco uBR7246.

AC Power

The AC-input power supply uses a power factor corrector that allows the Cisco uBR7246 to operate on input voltage and frequency within the ranges of 100 to 240 VAC and
50/60 Hz.

Note We recommend attaching dual power supplies to independent power sources for full redundancy. We also recommend an uninterruptable power source to protect against power failures at your site. Each AC-input power supply operating at 120 VAC requires a minimum of 7A service. We recommend powering the Cisco uBR7246 from a 15A receptacle at the power source.

Refer to Table 1-1 in the chapter "Product Overview" for system power specifications, including input voltage and operating frequency ranges.

IF to RF Upconverter

Intermediate frequency (IF)-to-RF upconverter hardware must be installed in the downstream data path at your headend site. The upconverter is installed between the Cisco uBR7246 universal broadband router and the combiner (see Figure 2-2).

Note The combiner refers to all cables, amplifiers, and taps on the HFC network.

Figure 2-2: IF-to-RF Upconverter Installation at the Headend



Upconverters are available from a number of manufacturers and can be found in configurations ranging from a fixed number of ports to flexible multi-slot, multi-port models. You must install and configure enough upconverter ports to support the number of upstream cable modem card ports installed in each Cisco uBR7246. The number of upconverter units you will need to purchase will vary by manufacturer.

To configure an upconverter, adjust the IF and RF gain levels so they are approximately in the middle of the spectrum. Adjust the RF channel power on the output of the upconverter to approximately 50 dBmV. (The RF channel power setting is also known as the true QAM RF output power.) Refer to the documentation that ships with your upconverter for detailed instructions on upconverter operation and configuration.

Note You might need to add attenuation to the downstream path between the universal broadband router and the upconverter to configure the Cisco uBR7246.

You must add a minimum of 10 dB of attenuation on each upstream line, before the Cisco uBR7246, and each downstream line, after the upconverter. This attenuation will adjust for a minimum of 10 dB line loss in the upstream and 10 dB to 45 dB loss in the downstream. The downstream loss is caused by different RF tuners used in other cable modems that might be installed in your network, different upconverter settings, and other cabling in the network.

Upconverters and cables are available from the following Cisco-approved vendors: NextLevel, Wavecom, and Barco.

Note The lead times for upconverters can run from 2 to 18 weeks. Contact the upconverter manufacturers listed above for up-to-date information on lead times.

Diplex Filters

Diplex filters must be installed in the downstream RF path between the cable modems and the cable modem cards in the Cisco uBR7246 universal broadband router.

The input of the diplex filter consists of two ports: the high filter port and the low filter port. The output of the diplex filter consists of a single port that is connected to a splitter. Unused connection ports on the splitter must be terminated.

DHCP Server

A Dynamic Host Configuration Protocol (DHCP) server must be installed at the headend site to assign an IP address to each cable modem. The Cisco uBR7246 universal broadband router uses these assigned IP addresses to identify individual cable modems operating on the network.

When a DHCP server is configured in a network, the server assigns an IP address to each cable modem when a connection is made to the network. The DHCP server periodically polls the cable modem to see if network connection is still active. When the connection to the network ends, the IP address is reassigned, as needed, to other cable modems establishing a connection to the network.

DHCP servers are available as combined hardware and software solutions, or as a software package that can run on an existing computer or workstation. In either case, the DHCP server must be dedicated to DHCP services.

Headend Wiring

Following are guidelines for setting up the headend wiring and cabling at your site. When planning the location of the new system, consider the distance limitations for signaling, electromagnetic interference (EMI), and connector compatibility, as described in the following sections.

Interference Considerations

When wires are run for any significant distance in an electromagnetic field, interference can occur between the field and the signals on the wires. This fact has two implications for the construction of headend wiring:

If you use twisted-pair cable in your headend wiring with a good distribution of grounding conductors, the wiring is unlikely to emit radio interference. If you exceed the recommended distances, use a high-quality twisted-pair cable with one ground conductor for each data signal when applicable.

If wires exceed recommended distances, or if wires pass between buildings, give special consideration to the effect of a lightning strike in your vicinity. The electromagnetic pulse caused by lightning or other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic devices. If you have had problems of this sort in the past, you may want to consult experts in electrical surge suppression and shielding.

Distance Limitations and Interface Specifications

The size of your networks and the distances between connections depend on the type of signal, the signal speed, and the transmission media (the type of cabling used to transmit the signals). For example, standard coaxial cable has a greater channel capacity than twisted-pair cabling. The distance and rate limits in the following descriptions are the IEEE recommended maximum speeds and distances for signaling; however, you can usually get good results at speeds and distances far greater than these. For example, the recommended maximum rate for V.35 is 2 Mbps, but it is commonly used at 4 Mbps without any problems. If you understand the electrical problems that might arise and can compensate for them, you should get good results with rates and distances greater than those shown here; however, do so at your own risk.

Note We recommend that you do not exceed specified transmission rate and distance limits.

When preparing your site for network connections to the Cisco uBR7246, you must consider a number of factors related to each type of interface:

Before installing the Cisco uBR7246, have all additional external equipment and cables on hand. The information listed above is contained in the documentation that is shipped with each port adapter. For example, if you need Ethernet distance limitations and pinouts, refer to the document PA-8E Ethernet 10BASE-T Port Adapter Installation and Configuration (Document Number 78-3141-xx). This configuration note accompanies each 8-port Ethernet port adapter that is shipped from the factory as an installed item in a Cisco uBR7246 and as a FRU.

For ordering information, contact a customer service representative.

Coaxial Cable Quality

The coaxial cable used at the headend to connect the Cisco uBR7246 should be of the highest quality.

We recommend that you use RG-59 headend coaxial cable with the maximum braid available (60% + 40% braid), double foil, and the correct connector for this cable. The center conductor must be straight and extend 1/8 in. (3.2 mm) beyond the end of the connector, and the connector should be securely crimped to the cable.

If you use different types of coaxial cable, the following problems can appear:

Note Refer to the chapter "CATV Headend Considerations" for additional configuration and site requirement information related to the setup of the analog RF signal and digital data.

Equipment Racks

The rack-mounting hardware included with the Cisco uBR7246 is suitable for most 19-inch equipment racks and telco-type racks. To easily access field replaceable units (FRUs) while the router is installed in a rack, make certain you have access to the front and rear of the router.

Before using a particular rack, check for obstructions (such as a power strip) that could impair rack-mount installation. If a power strip does impair a rear rack-mount installation, remove the power strip before installing the Cisco uBR7246 in the rack, then replace it after the chassis is installed. As an alternative, you can mount the Cisco uBR7246 on an equipment shelf provided that the rack dimensions allow you to secure the router to the shelf, and the overall configuration permits safe installation and access. However, we recommend rack-mounting the Cisco uBR7246. Figure 2-3 shows the Cisco uBR7246 footprint and outer dimensions.

To use the rack-mounting hardware provided with the Cisco uBR7246, consider the following guidelines:


Figure 2-3: Cisco uBR7246 Footprint and Outer Dimensions



When planning your rack installation, consider the following guidelines:

In addition to the preceding guidelines, review the precautions for avoiding overtemperature conditions in the following section "Site Environment." To properly install the Cisco uBR7246 chassis in a rack, refer to the instructions in the section "Rack-Mounting Cisco uBR7246" in the chapter "Installing the Cisco uBR7246."

Caution  To prevent chassis overheating, never install the Cisco uBR7246 in an enclosed rack or room that is not properly ventilated or air conditioned. The Cisco uBR7246 will overheat if the input air temperature reaches 105°F (41°C).

Site Environment

Table 2-1 lists the operating and nonoperating environmental site requirements. The following ranges are those within which the Cisco uBR7246 will continue to operate; however, a measurement that is approaching the minimum or maximum of a range indicates a potential problem. You can maintain normal operation by anticipating and correcting environmental anomalies before they approach a maximum operating range.

To provide airflow though the Cisco uBR7246, cooling air is drawn in through the air intake vent on the right side of the chassis (when viewing the router from the front) and is exhausted through the left side of the chassis. Keep the right and left side of the chassis clear of obstructions and away from the exhaust of other equipment.


Table  2-1: Specifications for Operating and Nonoperating Environments
Specification Minimum Maximum
Temperature, ambient operating 32°F (0°C) 104°F (40°C)
Temperature, ambient nonoperating and storage -4°F (-20°C) 149°F (65°C)
Humidity, ambient (noncondensing) operating 10% 90%
Humidity, ambient (noncondensing) nonoperating and storage 5% 95%
Altitude, operating and nonoperating Sea level 10,000 ft (3,050 m)
Vibration, operating 5-200 Hz, 0.5 g (1 oct./min.) -
Vibration, nonoperating 5-200 Hz, 1 g (1 oct./min.) 200-500 Hz, 2 g (1 oct./min.) -

Preventive Site Configuration: Maintaining Normal Operation

Planning a proper location for the Cisco uBR7246 and the layout of your equipment rack or wiring closet are essential for successful system operation. Equipment placed too close together or inadequately ventilated can cause system overtemperature conditions. In addition, chassis panels made inaccessible by poor equipment placement can make system maintenance difficult. Following are precautions that can help avoid problems during installation and ongoing operation.

General Precautions

Follow these general precautions when planning your equipment locations and connections:

Power Considerations

Follow these precautions and recommendations when planning power connections to the Cisco uBR7246:

Tools for Installation

Your Cisco uBR7246 chassis is fully assembled at the factory; no assembly is required. However, you will need the following tools and equipment to install the chassis and the rack-mount and cable-management kit:

The rack-mount and cable-management kit includes the following parts:

To verify RF and data setup, you need the following equipment:

Note For important, detailed information about headend RF and data setup considerations, see the chapter "CATV Headend Considerations."

In addition, you might need the following external equipment:

Initial Configuration Information

After you install the chassis and verify that all the hardware is operating properly, you must configure the system and individual interfaces before you can connect your system to external networks. You can use the setup command facility or standard configuration commands to enter the configuration information.

Before you begin, you should be prepared with global (system-wide) parameters such as host names, passwords, and routing protocols, and with configuration information for each interface such as addresses, rates or speeds of operation, routing protocol specifics, and so on.

Following is some of the information you are likely to need, depending on your configuration:

For complete configuration instructions, refer to the Configuration Fundamentals Configuration Guide and the Configuration Fundamentals Command Reference, which are available on the Documentation CD-ROM or in print.

Cisco uBR7246 Installation Checklist

To assist you with your installation and to provide a historical record of what was done, by whom, use the Cisco uBR7246 Installation Checklist in Table 2-2. Make a copy of this checklist and indicate when each procedure or verification is completed. When the checklist is completed, place it in your site log (described at the end of this chapter) along with the other records for your new router.


Table  2-2: Cisco uBR7246 Installation Checklist
   Task  Verified by  Date
Date universal broadband router received

Date IF to RF upconverter(s) and diplex filters received

Date DHCP server hardware and/or software received

Router and all accessories unpacked

Types and numbers of interfaces verified

Safety recommendations and guidelines reviewed

Installation Checklist copied

Site log established and background information entered

Site power voltages verified

Site environmental specifications verified

Required passwords, IP addresses, device names, and so on, available

Required tools available

Network connection equipment available

Router mounted in rack (optional)

Cable-management brackets installed (optional but recommended)

AC power cable(s) connected to AC source(s) and router; retention clip secured

Captive installation screws on I/O controller and network processing engine checked

Network interface cables and devices connected

ASCII terminal attached to console port

Console port set for 9600 baud, 8 data bits, no parity, and 2 stop bits (9600 8N2)

System power turned on (DC OK LED is on)

System boot complete (I/O controller enabled LED is on)

I/O controller, network processing engine, all modem cards, and all port adapters operational (enabled LEDs on the port adapters and the I/O controller are on)

Console screen displays correct hardware configuration
   (displayed after system banner)

System ready for global and interface-specific configuration

Checking the Shipping Container Contents

Once you receive your Cisco uBR7246 universal broadband router, use the following procedure to check the contents of the shipping container. Use the Cisco uBR7246 Installation Checklist in Table 2-2 and the Cisco uBR7246 Component List in Table 2-3 to ensure you received all the components you ordered.

Note Do not discard the shipping container. You will need the container if you move or ship the Cisco uBR7246 in the future.

Step 1 Verify that the following are included in the shipping container (the accessories box might be separate):

Step 2 Check the contents of the accessories box against the Installation Checklist and the packing slip to verify that you received all listed equipment, which should include the following:

Step 3 Verify that the port adapters installed in your Cisco uBR7246 match the port adapter types on the packing list.

Step 4 Proceed to the section "Site Log" in this chapter, then to the chapter "Installing the Cisco uBR7246," to begin the installation.


Table  2-3: Cisco uBR7246 Component List
Component Description Received
Chassis Cisco uBR7246 chassis configured with a network processing engine, I/O controller, up to two AC power supplies, up to two port adapters (blank port adapters should be installed in empty port adapter slots), up to four cable modem cards (blank cable modem cards should be installed in empty cable modem card slots), and up to two Flash memory cards

Accessories:

Rack-mount and cable-management kit

Power cables
Documentation

The following accessories might arrive in separate shipping containers:

Two rack-mount brackets, one cable-management bracket, eight M4 x 6-mm Phillips flathead screws, four M4 x 6-mm Phillips panhead screws, and four 10-32 x 3/8-inch slotted binderhead screws


Up to two power cables

Router hardware and software documentation set and the Cisco Documentation CD-ROM package1


1 Titles and quantities of documents will vary. You must order the type and quantity of documentation sets when you order the hardware.

Site Log

A site log provides a historical record of all actions relevant to the Cisco uBR7246 operation and maintenance. Keep your site log in a common place near the chassis where anyone who performs tasks has access to it. Site log entries might include the following:

Table 2-4 shows a sample site log page. Make copies of the sample or design your own site log to meet the needs of your site and equipment.


Table  2-4: Site Log Example
Date Description of Action Performed or Symptom Observed Initials



























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