Class Of Service (COS)

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Тел. : (495) 730-4022 |

Class Of Service (COS)Functional description
Each the extension and trunk subscriber can have one of 8 classes of service by day/night (From top to bottom : Class I, Class S, Class A, Class B, Class C, Class D, Class E, and Class F). This function decides whether to allow/restrict the following services by the classes.

Trunk originating digit allow/restrict service

Class I : Available to designate allowed/restricted trunk originating digit by the classes.

Class S : Available to designate allowed/restricted trunk originating digit by the classes.

Class A : Available to designate allowed/restricted trunk originating digit by the classes.

Class B : Available to designate allowed/restricted trunk originating digit by the classes.

Class C : Available to designate allowed/restricted trunk originating digit by the classes.

Class D : Available to designate allowed/restricted trunk originating digit by the classes.

Class E : Restrict all the trunk origination.

Class F : Restrict all the extension, trunk origination.

Trunk origination digit allow/restrict operation mode

Origination is restricted if the digits of a subscriber originated external trunk subscriber number match the digits designated in the restriction table of the class. If the dialed digits match the maximum digits designated in the allowance table, even when the digits match the restriction table, origination is allowed.

Example) When ‘0’ is designated in deny table, and “011”, “012”, and “019” are designated in the allowance table,

Examples of restricted originating digits : 02, 03, 010, 014, 018

Examples of allowed originating digits : 0112~, 0125~, 0198~

DID termination restriction service by classes

If the class of termination subscriber isn't higher than the class of termination allowance class of each trunk, termination of the call is restricted. In this case, the termination restricted trunk call can be processed for termination to attendant by the designated abnormal trunk I/C call process for route where the trunk is included.

Restriction on direct call between managers

Direct call is restricted when a manager subscriber calls another manager subscriber with the class higher than himself. In this case the call is terminated to the secretary of the called manager subscriber. On the contrary, if the class of the called manager subscriber is higher than or same as the calling manager subscriber, the call is directly terminated to the called manager subscriber.

Operating procedure
Service conditions

A subscriber can have one day class and one night class.

Day class or night class is applied according to the day/night mode of the system.

Attendant subscriber is not restricted of service by its class.

Data generation
Assign of day/night class of extension subscriber

[3.1 Extension Information]

Assign of day/night class for trunk subscribers

[4.1 Trunk Information ⇒ Day Class and Night Class]

Origination digit allowance/restriction table by subscriber classes for trunk origination

[3.3 Class Base OG Digit Allow/Deny]

DDI termination allowance subscriber class

[4.1 Trunk Information ⇒ IC Allow Class]

Interactions
System Speed Dial

Incase of system speed dial, restriction is designated according to the speed dial. Therefore, it is exempted from the origination digit restriction service for trunk origination. In other words, system speed dial allowed to all subscribers excluding class E and class F can be used irrespective of the designated external number.

ATD Through Dial

In case an extension subscriber originates through attendant subscriber, the subscriber’s class added by the designated ascending class is applied by the origination digit allowance/restriction function of subscriber class per route.

If the class of an extension subscriber is “D” and the class ascending step is “2”, origination restriction/allowance function of class “B” is applied.