Cisco CISCO2650 - 2650 Router Hardware Installation Manual page 136

Channelized E1/ISDN PRI Unbalanced (75-Ohm) Network Modules
Figure 7-16 1-Port Channelized E1/ISDN PRI Network Module (Unbalanced)
cE1-U
PRI
Figure 7-17 2-Port Channelized E1/ISDN PRI Network Module (Unbalanced)
cE1-U
PRI
CE1/PRI Module Jumper Settings
Jumpers on CE1/PRI modules can be used to connect or disconnect receive shield to ground (see
Table
ground. The default setting for unbalanced, 75-ohm CE1/PRI-U modules connects receive shield to
ground. If you are experiencing ground loop problems with E1 cabling, you may want to try changing
the jumper settings for the module.
Table 7-3
CE1/PRI Module Type Default Setting Function
Balanced, 120-ohm
Unbalanced, 75-ohm 1 and 2
Cisco Network Modules Hardware Installation Guide
7-12
CTRLR 0
CE1/PRI-U port
CTRLR 1
CTRLR 0
CE1/PRI-U ports
7-3). The default setting for balanced, 120-ohm CE1/PRI-B modules disconnects receive shield to
CE1/PRI Module Jumpers
2 and 3
Chapter 7
EN
EN
Disconnects receive shield from ground
Connects receive shield to ground
Connecting ISDN PRI Network Modules
OL-2485-20