Cisco CISCO2650 - 2650 Router Hardware Installation Manual page 309

Chapter 28 Connecting Cisco High-Density Extension Modules
Establishing Emergency or Power-Fail Connections
During power failures or when router power is off, emergency voice connections can be made through
power-fail ports on the EM-HDA-6FXO expansion module. The expansion module must be properly
installed on the Cisco high-density extension module. (See the
High-Density Extension Modules" section on page
To provide an emergency connection, connect an analog phone using the port information listed in
Table
There will not be a dial tone on port 15 or port 23 until the router is powered down.
Note
Table 28-3 Establishing Emergency Connections through Cisco High-Density Extension Modules
Expansion Module Slot
EM0
EM1
Analog phones connected to the power-fail ports should not be connected in parallel to a normal FXS
Caution
port on Cisco high-density extension modules. The protection circuit on the FXS port can interfere with
phone operation when router power is off.
Cisco High-Density Extension Module Cable Pinouts
Figure 28-6
and
Figure 28-6 Close-Up of the RJ-21 Connector Pinout for Cisco High-Density Extension Modules
26
1
OL-2485-20
28-3.
shows the RJ-21 connector wiring for the cable used for the high-density extension module,
Table 28-4 lists cable pinouts. Port usage depends on the type of installed expansion module.
(EVM-HD-8FXS/DID)
50
25
RJ-21 connector
28-4.)
Analog Phone Port
Port 15 Tip/Ring
Port 23 Tip/Ring
RJ-21 cable
Cisco Network Modules Hardware Installation Guide
Cisco High-Density Extension Module Cable Pinouts
"Installing Expansion Modules on Cisco
PSTN Port
Port 13 Tip/Ring
Port 21 Tip/Ring
28-9