What is the difference? Did alertcentral replace ipmonitor?
Not really comparable products, and definitely no replacement relationship.
ipMonitor is the monitoring tool. As part of it's existence it has the capability to generate alerts. But the management of those alerts is somewhat basic.
Alert Central is exclusively an alert management engine. It allows you to take those alerts from ipMonitor (or any other product that generates email-based alerts) and manage the entire lifecycle of those alerts. It can:
and several other alert management operations.
Think of Alert Central as an enhancement to your existing capabilities with ipMonitor.
More importantly, Alert Central is FREE!