SNMP communication requirements

DME reports on device status by polling for SNMP status changes. Therefore, only SNMP-enabled printers and devices can be monitored by DME. DME continually polls for these status change messages, and for any status faults that match the Alert Rules you applied to one or more devices.

When DME intercepts a status change message, it performs the following tasks in order:

1. Logs the start time of the fault and updates the device status in its database.
2. References the list of Alert Rules.
3. Applies all rules whose criteria matches the device and fault condition.
4. When the status changes again, DME logs the end time of the fault and once again updates the device status.
5. Sends device status information to CAS to use for reporting purposes.

DME maintains the list of status changes in its database, including the start and end time of each fault. The end time remains NULL until the status of the device changes. When the end time is set, the fault is considered "closed". Only closed faults are forwarded to CAS, so reports reflect device faults that have been resolved only. DME also holds faults that were closed within the last 7 days in its local database.