Anybody knows if it is possible to set a threshold or limit of time in a call per phone user. What my customer wants is to avoid monopolization of the PSTN lines.
Depending on the SR version of CallManager you are using, in CCMAdmin -> Service -> Service Parameters scroll to Clusterwide Parameters, Feature, General
Set the Maximum Call Duration Timer (in minutes) - the default is 720.
I do not believe there is a per user setting.
Hope that helps.