Starting with the integration of faxing devices into computers via Fax modems the automated answering of voice calls by a computer went live via specific software, like e.g. TalkWorks. These systems allowed for quite elaborate voice box systems, navigated via dual-tone multi-frequency signaling, allowing a computer on a (single) telephony line to sound like a professional telephony system with hierarchical fax and message boxes with an automatic call distributor, where a caller might deposit his messages, leave his faxes behind, might listen to specific messages, or start a fax-back service.