Panasonic KX-TDA100D

Feature Guide References
1.17.6 Direct Inward System Access (DISA)
2.2.1 Class of Service (COS)
User Manual References
1.2.7 Calling without Restrictions
1.2.9 Setting Your Telephone from Another Extension or through DISA (Remote Setting)
Feature Guide 139
1.9.5 Walking COS