Preparing For Installation - Cisco uBR-3x10 Hardware Installation And Cabling Manual

Rf switch

Table of Contents

Provisioning the Headend

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, and 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.

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

Caution

When preparing your site for network connections to the Cisco uBR 3x10 RF Switch, you must consider

a number of factors related to each type of interface:

•

Equipment Racks

The rack-mounting hardware included with the Cisco uBR 3x10 RF Switch is suitable for most 19-inch

equipment racks designed per EIA-310 or MIL-STD-189.

When planning your rack installation, follow these guidelines:

•

Cisco uBR-3x10 RF Switch Hardware Installation and Cabling Guide

2-8

The type of cabling required for each type of interface (fiber, thick or thin coaxial, shielded

twisted-pair, or unshielded twisted-pair cabling)

Distance limitations for each signal type

The specific cables you need to connect each interface

Any additional interface equipment you need, such as transceivers, hubs, switches, modems, CSUs,

or DSUs

Cable pinouts if you plan to build your cables

Install the Cisco uBR 3x10 RF Switch in an open rack whenever possible. If installation in an

enclosed rack is unavoidable, ensure that the rack has adequate ventilation.

If you plan to use an equipment shelf, ensure that the shelf is constructed to support the weight and

dimensions of the chassis.

Always install heavier equipment in the lower half of a rack to maintain a low center of gravity and

prevent the rack from falling.

Ensure that you have access to the front and rear of the unit.

Position the Cisco uBR 3x10 RF Switch close enough to the Cisco CMTS in which the cable

interface line cards are installed to be sure you have enough cable to reach the furthest interfaces.

Before using a specific 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 uBR 3x10 RF Switch in the rack, and replace it after the chassis is installed.

As an alternative, mount the Cisco uBR 3x10 RF Switch on an equipment shelf if 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 uBR 3x10

RF Switch.

Review the precautions for avoiding overtemperature conditions in the

on page

2-6.

To properly install the Cisco uBR 3x10 RF Switch chassis in a rack, refer to the instructions in the

"Rack-Mounting the RF Switch with the Cisco uBR10012 CMTS" section on page

Chapter 2