Line Load Control (LLC) is a feature that restricts a predefined set of telephone users from originating calls during a crisis or an emergency. LLC systematically reduces the number of telephones that can originate calls during high-traffic periods. This situation is sometimes called a lockdown. When the lockdown situation passes, the LLC restriction levels can be reduced or removed completely.

Users are assigned to a Line Load Control level based on the relative importance of the position of the user within the organization. When an emergency occurs, the administrator manually activates the LLC feature to restrict calls by users with positions that are of lower importance. When the emergency is over, the administrator manually disables the LLC feature.

For example, if a security emergency occurs, telephone users who are responsible for managing the crisis are unrestricted from originating calls. Other telephone users, for example, users in the accounting department, are restricted. When the crisis is over, the administrator returns the system to normal operation.

The LLC feature can be controlled at four levels. These levels determine what telephones, based on the Class of Restriction (COR), are restricted from originating calls. This feature does not restrict incoming calls, or calls that originate from an attendant console or a night telephone.

The four levels are as follows:

System level 1 is an invalid value. The LLC feature cannot restrict telephones with a COR that is assigned to LLC level 1 from originating calls.

When LLC is activated, the system restricts all telephones with a COR at that LLC level and below from originating any calls. If a restricted telephone is already active on a call when the restriction is activated, the call is neither interrupted nor disconnected. The telephone becomes restricted only after the user hangs up from the active call.

When the need for LLC has passed, the administrator can change the LLC to a less-restrictive level, or completely deactivate the feature.

The following table shows how the LLC feature can be used.

For this example, the LLC is at Level 0, and extension 2635 is active on a call.