General Features
104 Features Guide
Tru nk Busy -O ut
Description
Allows the Manager and an Operator to busy out a CO line to prevent extension users from
accessing it.
[The details of Trunk Busy-out feature]
There are the following two types of trunk port relay status which is set to Trunk Busy-out.
a) Busy(LoopRelayOn):makingthelinebusybyhardware
b) Idle (Loop Relay Off): making the line busy by software
The Central Office recognizes a trunk line as shown in the table "The Specification of Trunk
Busy-out On."
TheactualbehaviorofthePBXisasfollows:
1. Idle status
a) When the PBX user makes a call:
The trunk line is recognized as busy and making a CO call is disabled.
b) When the outside caller makes a call and then the Central Office gives the incoming call
to PBX:
The Central Office recognizes the PBX as idle and the call is processed. (The outside
caller hears a ringback tone.) However, even though the PBX receives the bell signal
from the Central Office, the PBX ignores it.
2. Busy status (the status of grabbing a CO line) / during a conversation
a) When the PBX user makes a call:
The trunk line is recognized as busy and making a CO call is disabled.
b) When the outside caller makes a call and then the Central Office gives the incoming call
to PBX:
The Central Office recognizes the PBX as busy and the caller hears a busy tone.
Notes
• The default of each card is "Idle." If it were "busy," there is a possibility that the Central
Office will mistakenly believe that there is something wrong with the trunk line.
• T1 standard does not have Busy-out Status (Block).
Therefore, the default of all interfaces (Loop Start CO / Ground Start CO / DID / TIE)
is regarded as idle status.
