Cisco Systems UBR7225VXR specifications Two-Way Data Headend Architecture

Chapter 4 Connecting the Cisco uBR7225VXR Router to the Cable Headend

Two-Way Data Headend Architecture

Two-Way Data Headend Architecture

Figure 4-1shows a typical headend configuration configured for two-way data, including digitized voice and fax.

Figure 4-1

Typical Cable Headend Configuration for Two-Way Data

Laser

Main

transmitter

Node 1

Cisco

headend feed

Broadcast

+17 dBmV

Optical

video carrier

uBR7225VXR

splitter

(typical)

8-way

Narrowcast

Node 2

tap

+7 dBmV

0 to 20 dB

Downstream

3-way

attenuator

data carrier

forward

splitter

(typical)

Downstream

(as required)

test point

Upstream

0 dBmV

Optical

Reverse optical

+10 dBmV

receiver

Fiber-optic transmitter

+31 dBmV

6 dB

X

3 dB

+13 dBmV

cable

+17 dBmV

Distribution

+48 dBmV

attenuator

attenuator

network

2-way

Diplex filter

Modem

splitter

Cable

transmit

40 dB

L H

Downstream

levels modems

attenuator

(0 to +5 dBmV)

C

Cable

modem

Optical

Reverse optical

+10 dBmV

receiver

Fiber-optic transmitter

+58 dBmV

6 dB

X

8 dB

+18 dBmV

cable

+17 dBmV

Distribution

+42 dBmV

attenuator

attenuator

network

2-way

Diplex filter

Modem

splitter

transmit

40 dB

Downstream

L H

levels

attenuator

(0 to +5 dBmV)

C

Cable

modem

Optical

Reverse optical

+50 dBmV

+10 dBmV

receiver

Fiber-optic

transmitter

+31 dBmV

+17 dBmV

+42 dBmV

6 dB

X

21 dB

cable

Distribution

attenuator

attenuator

network

2-way

Diplex filter

+49 dBmV

splitter

Modem

40 dB

Downstream

L H

transmit

attenuator

(0 to +5 dBmV)

levels

C

Cable modem

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Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide

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