Panasonic KX-NS500 Features Manual page 218

2.16.1 Direct Inward System Access (DISA)
Feature Guide References
2.1.1.6 Intercept Routing
2.1.1.7 Intercept Routing—No Destination
2.3 Call Forwarding (FWD)/Do Not Disturb (DND) Features
5.1.1 Class of Service (COS)
5.5.8 Floating Extension
User Manual References
1.2.8 To Access Another Party Directly from Outside (Direct Inward System Access [DISA])
1.2.9 Setting Your Telephone from Another Extension or through DISA (Remote Setting)
218 Feature Guide