SRST call-forwarding for busy and no answer can be set system wide
call-forward busy <number>
call-forward noan <number> timeout 10
SRST vs CCM Callforwarding
Call-forward-all settings under regular Callmanager mode, is not retained by the phones when they go into SRST mode.
Call forward number transformations
You can also transform the extension number for call forwarding by using wild cards.
call-forward busy 40..
If a user calls 5010 and the user is busy, then the call will be forwarded to 4010.
Call forwarding on individual lines
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.
This feature can be used to create a basic hunt group setup using Callforwarding logic.