Dtu

To achieve Requirement 1 - If you use the Extension Lock/Unlock feature, you could setup the Alternate COS to have Inter-COS call blocking - ie stop that COS from calling all other COS's. This depends on your current setup and how many different COS's you actually use.

LICB - List Inter-COS Call Blocking
Function: To list Class-Of-Service (COS) values (00-31) which cannot call other COS values. The restriction does not apply in the other direction unless specified by configuration or by a separate RICB command.

Horizontal COS value is COS of called extension
Vertical COS value is COS of calling extension
B, at the intersection of two Classes-of-Service, denotes blocking between calling COS and called COS.


RICB - Revise Inter-COS Call Blocking
Function: To prevent (Block) extensions with specified Class-Of-Service (COS) from calling extensions with a specified Class-Of-Service, or to cancel blocking.

Parameters:
FROM COS: COS (0-31) of calling extension
TO COS: COS (0-31) of called extension
BLOCK?: Y to apply blocking
N to cancel blocking
Output:
None.