Changing the number of times a Cisco IP Phone rings before forwarding to voice mail or another station is easily accomplished by changing a service parameter.
The parameter that needs to be changed is titled Forward No Answer Timeout. By default, it has a value of 12 seconds. A typical ring cycle is approximately 4 seconds.
Note: This is a global parameter, so changing this value will affect the behavior of all phones. When changing this value be sure to do so for all CallManagers in the cluster.
Cisco CallManager 4.2(3) allows you to set this parameter on a per line basis. The field name is No Answer Ring Duration.
For more details, please refer to Cisco 7900 IP Phone FAQs.
Voicemail behavior problems
Call forward no answer (CFNA)
We are on Cisco CallManager 10.5.
Is there a way to change the number of rings before Cisco IP phone forwards to voice mail on a per line basis ?
Cisco CallManager 4.2(3) allows you to set this parameter on a per line basis. The field name isNo Answer Ring Duration.
Do you want to do a customization per End user or Globally within your system ?
Per end user this can be done on the each Directory number line on " No Answer Ring Duration (seconds)".
Globally this can be set on Service Parameters, Publisher - call manager active, clusterwide parameters - redirection rig no answer reversion timer.
Let me know if this answers your question.
FYI - 4 seconds = 1 ring in the USA. so a setting of "16" is 4 rings then forward.
Great correct answer for Rel 10.5 system Big HELP and Time saver!!!