Description of problem:

The calltime metrics collect the durations of "calls" to destination as well as the number of calls in certain time intervals (basically the number of calls encountered between 2 metric collections).

In RHQ4 we currently only support alerting on the durations - we can alert when the duration (its min,max,avg) exceeds certain threshold or if the duration (min,max,avg) delta between collections.

It would be good to add alerting capability on the "count" aspect of the calltime data as well:

- total number of calls
- calls per minute
- number of calls delta (alert me when there's a DoS attack happening)