The service allows you finding out who has called you, when the telephone line was busy, switched off or was outside the zone of coverage. By doing so, it ensures that an important call will not be missed.
Open Source Asterisk PBX 1.8 release within Long-Term Support (LTS) commitment
The release of the 1.8 version as an open source VoIP project targeting its own long term support (LTS) project.