Hi, Some customers ask us about Callback feature for extensions, as it's now implemented for call queues. In their previous pbx systems, when they called other extension and that was busy, they pressed a key (6, for example) and PBX save this info and when the remote extension was available again, the system called them automatically. Example to understand better: 1. Ext A calls ext B. B is busy. 2. A press "6" to use Callback feature and hang up. 3. When B is again available, PBX calls A and B and establishes a call between them. What do you think? Thanks!