This procedure applies to the Cisco Unified IP Phone (SCCP) only.
In some environments, such as military or government offices, you may need to make and receive urgent or critical calls. If you have the need for this specialized call handling, your system administrator can add Multilevel Precedence and Preemption (MLPP) to your phone.
Keep these terms in mind:
Precedence indicates the priority associated with a call.
Preemption is the process of ending an existing, lower priority call while accepting a higher priority call that is sent to your phone.
If you want to choose a priority (precedence) level for an outgoing call, contact your system administrator for a list of corresponding precedence numbers for calls.
If you want to make a priority call, enter the MLPP access number provided by your system administrator, followed by the phone number.
If you hear a special ring (faster than usual) or special call waiting tone, you are receiving a priority call.
If you want to accept a higher priority call, answer the call as usual. If necessary, end an active call first.
If you hear a continuous tone interrupting your call, you or the other party are receiving a call that must preempt the current call. Hang up immediately to allow the higher priority call to ring through.
When you make or receive an MLPP-enabled call, you hear special ringtones and call waiting tones that differ from the standard tones.
If you enter an invalid MLPP access number, a verbal announcement alerts you to the error.
An MLPP-enabled call retains its priority and preemptive status when you: