Suddenly, for no apparent reason, no-one can CFwdALL! They can add a number (via IP Phone or CCM), and this displays on IP Phone. But if you call the DN, it just rings.
First check in eventviewer of your server if you have received any events for DBL monitor service.
For restarting, you can do so from Application>Servicability
Here go to Tools>Control Center
Choose server from left hand panel, choose service from right hand side and stop/start it
Check DBL monitor service and if possible restart it