Cisco CP-7911G-CH1 System Administrator Manual page 130

How to Configure Cisco Unified SCCP SRST
The configured alternate-number must be a specific E.164 phone number or extension that belongs to
an IP phone registered on the Cisco Unified SRST router. When an IP phone registers with a number that
matches an alternate-number, an additional POTS dial peer is created. The destination pattern is set to
the initial configured number-pattern, and the POTS dial peer voice port is set to match the voice port
associated with the alternate-number.
If other IP phones register with specific phone numbers within the range of the initial number-pattern,
the call is routed back to the IP phone rather than to the alternate-number (according to normal dial-peer
longest-match, preference, and huntstop rules).
Call Forward Destination
The cfw keyword allows you to configure a call forward destination for calls that are busy or not
answered. Call forward no answer is defined as when the phone rings for a user configurable amount of
time, the call is not answered, and is forwarded to the configured destination. Call forward busy and call
forward no answer can be configured to a set string and override globally configured call forward
settings.
Note Globally configured settings are selected under call-manager-fallback and apply to all phones that
register for SRST service.
You can also create a specific call forwarding path for a particular number. The benefit of using the cfw
keyword is that during SRST, you can reroute calls from otherwise unreachable numbers onto phones
that are available. Basic hunt groups can be established with call-forwarding rules so that if the first
SRST phone is busy, you can forward the call to a second SRST phone.
The cfw keyword also allows you to alias a phone number to itself, permitting setting of per-phone
number forwarding. An example of aliasing a number to itself follows. If a phone registers with
extension 1001, a dial peer that routes calls to the phone is automatically created for 1001. If the
call-manager-fallback dial-peer preference (set with the max-dn command) for this initial dial peer is
set to 2, the dial peer uses 2 as its preference setting.
Then, use the alias command to alias the phone number to itself:
alias 1 1001 to 1001 preference 1 cfw 2001 timeout 20
In this example, you have created a second dial peer for 1001 to route calls to 1001, but that has
preference 1 and call forwarding to 2001. Because the preference on the dial peer created by the alias
command is now a lower numeric value than the preference that the dial peer first created, all calls come
initially to the dial peer created by the alias command. In that way, they are subject to the forward as set
by the alias command, instead of any call forwarding that may have been set globally.
Huntstop on an Individual Alias
The alias huntstop keyword is relevant only if you have also set the global no huntstop command under
call-manager-fallback. Also, you may need to set the global no huntstop if you have multiple alias
commands with the same number-pattern and you want to enable hunting on busy between the aliases.
That is, one alias for number-pattern is tried, and then if that phone is busy, the second alias for
number-pattern is tried.
The alias huntstop keyword allows you to turn huntstop behavior back on for an individual alias, if
huntstop is turned off globally by the no huntstop command. Setting the huntstop keyword on an
individual alias stops hunting at the alias, making the alias the final member of the hunt sequence.
Cisco Unified SCCP and SIP SRST System Administrator Guide
130
Configuring Call Handling
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