7-12
Cisco Network Modules Hardware Installation Guide
OL-2485-20
Chapter 7 Connecting ISDN PRI Network Modules
Channelized E1/ISDN PRI Unbalanced (75-Ohm) Network Modules
Figure 7-16 1-Port Channelized E1/ISDN PRI Network Module (Unbalanced)
Figure 7-17 2-Port Channelized E1/ISDN PRI Network Module (Unbalanced)
CE1/PRI Module Jumper Settings
Jumpers on CE1/PRI modules can be used to connect or disconnect receive shield to ground (see
Table 7-3
). The default setting for balanced, 120-ohm CE1/PRI-B modules disconnects receive shield to
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.
LOOPBACK
CTRLR 0
EN
cE1-U
PRI
H8499
LOCAL
ALARM
REMOTE
ALARM
CARRIER
DETECT
CE1/PRI-U port
LOOPBACK
CTRLR 0
EN
cE1-U
PRI
H8500
LOCAL
ALARM
REMOTE
ALARM
CARRIER
DETECT
LOOPBACK
CTRLR 1
LOCAL
ALARM
REMOTE
ALARM
CARRIER
DETECT
CE1/PRI-U ports
Table 7-3
CE1/PRI Module Jumpers
CE1/PRI Module Type Default Setting
Function
Balanced, 120-ohm
2 and 3
Disconnects receive shield from ground
Unbalanced, 75-ohm 1 and 2
Connects receive shield to ground