4-21
Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
OL-17309-02

Chapter4 Connecting the Cisco uBR7225VXR Router to the Cable Headend

Connecting and Configuring the Upstream

Figure4-25 Calibrating Multiple “X-level” Test Points Connected to Multiple Upstream Ports

Cisco
uBR7225VXR
Downstream
271678
Upstream
0 dBmV
Downstream
(0 to +5 dBmV)
Cable
modem
LH
C
6 dB
attenuator
40 dB
attenuator
3 dB
attenuator
+13 dBmV
Cable
modems
+48 dBmV
+31 dBmV
2-way
splitter
+10 dBmV
Diplex filter
Downstream
(0 to +5 dBmV)
Cable
modem
LH
C
3 dB
attenuator
Diplex filter
Downstream
(0 to +5 dBmV)
Cable
modem
LH
C
Diplex filter
6 dB
attenuator
40 dB
attenuator
+18 dBmV
+42 dBmV
+58 dBmV
2-way
splitter
+10 dBmV
6 dB
attenuator
40 dB
attenuator
21 dB
attenuator
+31 dBmV +42 dBmV
+49 dBmV
+50 dBmV
2-way
splitter
+10 dBmV
X
X
X
Reverse optical
transmitter
Optical
receiver Fiber-optic
cable Distribution
network
+17 dBmV
Reverse optical
transmitter
Optical
receiver Fiber-optic
cable Distribution
network
+17 dBmV
Reverse optical
transmitter
Optical
receiver Fiber-optic
cable Distribution
network
+17 dBmV
Modem
transmit
levels
Modem
transmit
levels
Modem
transmit
levels