2.10 Busy Line/Busy Party Features2.10.1 Automatic Callback Busy (Camp-on)DescriptionIf the destination or line is busy when a call is made, an extension user can set the Automatic Callback Busyfeature. The PBX will monitor the status of the destination or trunk and, when it becomes available, will senda callback ringing to the calling extension to inform the user. After the extension answers the callback ringing,the previously dialled extension number is automatically redialled, or the trunk is automatically seized.Conditions• If the callback ringing is not answered within 10 seconds, the callback is cancelled.• If the extension hears a busy tone before dialling the telephone number, only the trunk or trunk group isreserved. After answering the callback ringing, the extension should dial the telephone number.• An extension can set only one Automatic Callback Busy. The last setting is effective.• Multiple extension users can set this feature to one trunk simultaneously.However, a maximum of four extension users can set this feature to one extension.Callback ringing will be sent to extensions in the order that the feature was set. In other words, the extensionthat set the feature first will receive a callback ringing first.• This feature cannot be used for calls to a VPS, the Unified Messaging system, or to an ISDN extension.PC Programming Manual References10.6.1 PBX Configuration—[2-6-1] System—Numbering Plan—Main—Features— Automatic Callback BusyCancel10.6.3 PBX Configuration—[2-6-3] System—Numbering Plan—B/NA DND Call Feature— AutomaticCallback BusyUser Manual References1.2.4 When the Dialled Line is Busy or There is No Answer140 Feature Guide2.10.1 Automatic Callback Busy (Camp-on)