| 摘要 |
A PBX having a COS for each authorization code and a method for providing an ice line service are provided to assign different COS according to each authorization code for determining whether to allow the office line service, thereby easily assigning authority to use the PBX to users. A PBX(Private Branch eXchange) having a COS(Class Of Service) for each authorization code comprises the followings: a main controller which controls switching operations of an office line interface and an extension interface in order to provide a service by the PBX; a DISA(Direct Inward System Access) database which stores extension service classes, authorization codes, and information about COS for each authorization code; and a DISA controller which controls the use of an office line by using the authorization code and the COS of the DISA database when the use of the office line is requested from extension and external telephones. |
