Specifications

Setting Up the Network
How to Set Up the Network
48
Cisco Unified Survivable Remote Site Telephony Version 4.0 System Administrator Guide
Verifying That Cisco Unified SRST Is Enabled
To verify that the Cisco Unified SRST feature is enabled, perform the following steps:
Step 1 Enter the show running-config command to verify the configuration.
Step 2 Enter the show call-manager-fallback all command to verify that the Cisco Unified SRST feature is
enabled.
Step 3 Use the Settings display on the Cisco IP phones in your network to verify that the default router IP
address on the phones matches the IP address of the Cisco Unified SRST router.
Step 4 To temporarily block the TCP port 2000 Skinny Client Control Protocol (SCCP) connection for one of
the Cisco IP phones in order to force the Cisco IP phone to lose its connection to the Cisco Unified
CallManager and register with the Cisco Unified SRST router, perform the following steps:
a. Use the appropriate IP access-list command to temporarily disconnect a Cisco IP phone from the
Cisco Unified CallManager.
During a WAN connection failure, when Cisco Unified SRST is enabled, Cisco IP phones display a
message informing you that they are operating in Cisco Unified CallManager fallback mode. The
Cisco IP Phone 7960 and Cisco IP Phone 7940 display a “CM Fallback Service Operating”
message, and the Cisco IP Phone 7910 displays a “CM Fallback Service” message when operating
in Cisco Unified CallManager fallback mode. When the Cisco Unified CallManager is restored, the
message goes away and full Cisco IP phone functionality is restored.
Step 4
max-ephones max-phones
Example:
Router(config-cm-fallback)# max-ephones 24
Configures the maximum number of Cisco IP phones
that can be supported by the router. The default is 0. The
maximum number is platform dependent. See the
“Platform and Memory Support” section on page 29 for
further details.
Note You must reboot the router in order to reduce the
limit of Cisco IP phones after the maximum
allowable number is configured.
Step 5
limit-dn {7910 | 7935 | 7940 | 7960} max-lines
Example:
Router(config-cm-fallback)# limit-dn 7910 2
Limits the directory number lines on Cisco IP phones
during Cisco Unified CallManager fallback.
Note You must configure this command during initial
Cisco Unified SRST router configuration, before
any phone actually registers with the
Cisco Unified SRST router. However, you can
modify the number of lines at a later time.
The setting for maximum lines is from 1 to 6. The default
number of maximum directory lines is set to 6. If there is
any active phone with the last line number greater than
this limit, warning information is displayed for phone
reset.
Step 6
exit
Example:
Router(config-cm-fallback)# exit
Exits call-manager-fallback configuration mode.
Command or Action Purpose