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Functional Overview

Cisco uBR904 Cable Modem Installation and Configuration Guide

1-8

If you are connecting the Cisco uBR904 cable modem to a hub at the installation site (to 
provide access to the cable modem from multiple computers), you need to use a crossover 
Ethernet cable with RJ-45 connectors. 

Note

Crossover Ethernet cables are not available from Cisco Systems; they are available 

from Cisco and outside commercial cable vendors. Optionally, you can use a straight-
through Ethernet cable and connect to the uplink port on your hub (often labeled Uplink or 
MDI).

Airflow and Cooling

To keep the Cisco uBR904 cable modem operating at optimal internal temperature, keep 
the bottom, sides, and rear of the cable modem clear of obstructions and away from the 
exhaust of other equipment.

Содержание uBR904

Страница 1: ...e link that enables the transmission of two way digital data from the HFC network to the Internet is provided by the Cisco uBR7246 universal broadband router installed at the cable headend The Cisco data over cable products the Cisco uBR904 cable modem and the Cisco uBR7246 universal broadband router are based on the Multimedia Cable Network Partners Ltd MCNS Data Over Cable Service Interface Spec...

Страница 2: ...load over ISDN The same file would take approximately eight seconds to download over a data over cable system Cable Modem Terminology CATV Originally stood for Community Antenna Television Now refers to any cable coaxial fiber based system that provides television services Cable modem Any device that modulates and demodulates digital data onto a CATV plant Cable router A modular chassis based rout...

Страница 3: ...AN interface of the cable modem Host Device See Host for details MCNS Multimedia Cable Network System Partners Ltd a consortium of cable companies representing the majority of homes in the U S and Canada who have decided to drive a standard with the goal of having interoperable cable modems QAM Modulation scheme mostly used in the downstream direction QAM 64 QAM 256 QAM 16 is expected to be usable...

Страница 4: ...leshooting the Installation Figure 1 1 Cisco uBR904 Cable Modem Front View The rear of the Cisco uBR904 cable modem see Figure 1 2 provides the receptacles to connect the unit to the CATV network a console device and a personal computer Figure 1 2 Cisco uBR904 Cable Modem Rear View The Cisco uBR904 cable modem operates as a desktop device Place it on a sturdy desktop or platform near the personal ...

Страница 5: ...ree lead receptacle on the power supply end and a North American NEMA 5 15P plug on the power source end 3 AWG American Wire Gauge Power dissipation 12 to 15W Frequency 50 60 Hz4 4 Hz hertz Temperature 23 to 113 F 0 to 40 C operating 13 to 95 F 25 to 70 C nonoperating Humidity 5 to 95 noncondensing Noise level 38 dBa5 maximum at desktop 43 dBa maximum in an office 5 dBa adjusted decibels Software ...

Страница 6: ...ace the cable modem on an uneven or soft surface We recommend at least 3 inches of clearance at the rear of the cable modem See the section Site Requirements in the chapter Preparing for Installation Compliance with U S Export Laws and Regulations Regarding Encryption Cisco cable modem cards perform encryption and are regulated for export by the U S Government Following is specific information reg...

Страница 7: ...Connections The Cisco uBR904 cable modem is connected to CATV coaxial cable and to an Ethernet port on a personal computer The personal computer must have an Ethernet network card installed either an internal card installed in the computer chassis or a PCMCIA adapter card and cable installed on a laptop computer The coaxial cable connection uses standard connectors at both ends of the coaxial cabl...

Страница 8: ...onnectors Note Crossover Ethernet cables are not available from Cisco Systems they are available from Cisco and outside commercial cable vendors Optionally you can use a straight through Ethernet cable and connect to the uplink port on your hub often labeled Uplink or MDI Airflow and Cooling To keep the Cisco uBR904 cable modem operating at optimal internal temperature keep the bottom sides and re...

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