Timers

Busy timeout
- Sets the length of time after which calls that are transferred to busy destinations are disconnected.
Interdigit timeout
- Configures the interdigit timeout value for all Cisco Unified IP phones attached to the router.
Ringing timeout
- Sets the duration, in seconds, for which the Cisco Unified CME system allows ringing to continue if a call is not answered. Range is 5 to 60000. Default is 180.
Keepalive
- Sets the time interval, in seconds, between keepalive messages that are sent to the router by Cisco Unified IP phones

Configuration

telephony-service
  timeouts busy <seconds> 
  timeouts interdigit <seconds> 
  timeouts ringing <seconds> 
  keepalive <seconds>