The Service Level Threshold for the entire deployment is defined in System Information. Each call type can inherit this value, or define a new value for the Service Level Threshold.
You also have to define how abandoned calls affect the service level - there are three possibilities. Again, a system-wide value through System Information and the ability to override at the call type level.
You also want to consider the short calls setting (Abandon Call Wait Time) in System Information.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...