Exchange system for incoming calls from direct-in lines

Claim 2

An exchange system for controlling an incoming call of an external terminal unit from a direct-in line, the incoming call including a requested service and termination subaddress information, the termination subaddress information including a code and a station identifier, said system comprising: switching network means for receiving the incoming call from the external terminal unit; and control means, operatively connected to said switching network means, for receiving the incoming call from said switching network means and for controlling execution of the requested service, said control means comprising: call analyzing means for receiving the termination subaddress information of the incoming call; decision means for identifying the code from the termination subaddress information and for determining if the requested service is allowable based on the code; and execution means for executing the requested service if said decision means determines that the requested service is allowable.

Claim 3

A system as recited in claim 1, wherein the code is a security code, and wherein said decision means comprises: a security code table for identifying a class-of-service number corresponding to the security code of the incoming call; and class-of-service means, operatively connected to said security code table, for identifying allowable services based on the class-of-service number.

Claim 4

A system as recited in claim 2, wherein the incoming call includes a call set-up message having a termination address and the termination subaddress information.

Claim 5

A system as recited in claim 2, wherein the requested service is a direct inward dialing service or direct inward system access service, and wherein the incoming call comprises a first dial number containing a termination address and a second dial number containing the termination subaddress information.

Claim 6

A system as recited in claim 2, wherein the direct-in line is an integrated service digital network line.

Claim 7

A private branch exchange for controlling an incoming call from a direct-in line, the incoming call including a requested service and termination subaddress information, the termination subaddress information including a security code and a station identifier, said private branch exchange comprising: call analyzing means for receiving the termination subaddress information of the incoming call; a security code table for identifying a class-of-service number corresponding to the security code of the incoming call; a class-of-service table, operatively connected to said security code table, for identifying allowable services based on the class-of-service number; decision means, operatively connected to said security code table and said class-of-service table, for identifying the security code from the termination subaddress information and for determining if the requested service is allowable based on the security code, said security code table and said class-of-service table; and execution means for executing the requested service if said decision means determines that the requested service is allowable.

Claim 8

A private branch exchange for controlling an incoming call from a direct-in line, the incoming call including a requested service and termination subaddress information, the termination subaddress information including a security code and a station identifier, said private branch exchange comprising: call analyzing means for receiving the termination subaddress information of the incoming call; a security code table for identifying a class-of-service number corresponding to the security code of the incoming call; a class-of-service table, operatively connected to said security code table, for identifying allowable services based on the class-of-service number; decision means, operatively connected to said security code table and said class-of-service table, for identifying the security code from the termination subaddress information and for determining if the requested service is allowable based on the security code, said security code table and said class-of-service table; and execution means for executing the requested service if said decision means determines that the requested service is allowable.

Claim 9

A system as recited in claim 6, wherein the incoming call includes a call set-up message having a termination address and the termination subaddress information.

Claim 10

A system as recited in claim 6, wherein the requested service is a direct inward dialing service or direct inward system access service, and wherein the incoming call comprises a first dial number containing a termination address and a second dial number containing the termination subaddress information.

Claim 13

A method as recited in claim 9, wherein said method controls termination of incoming calls in an exchange system including a code conversion table having class-of-service numbers as entries, and wherein said determining in step (c) includes the steps of: (c1) identifying the code from the termination subaddress information; and (c2) obtaining the class-of-service number by accessing the code conversion table using the code.

Claim 14

A method as recited in claim 10, wherein the exchange system further includes a restriction class table containing information on permitted services, and wherein said determining in step (c) further includes the steps of: (c3) identifying the permitted services by accessing the restriction class table using the class-of-service number; and (c4) comparing the permitted services with the requested service.

Claim 15

A method as recited in claim 10, wherein the incoming call includes a call set-up message having a termination address, and the code is a security code.

Claim 16

A method as recited in claim 10, wherein the requested service is a direct inward dialing service or direct inward system access service.

Claim 17

A method as recited in claim 10, wherein the direct-in line is an integrated service digital network line.

Claim 18

A system as recited in claim 1, wherein the incoming call includes information on a termination address and the termination subaddress information.