An automatic call distribution system wherein, when no agent is immediately available, and the calculated delay before an agent is likely to become available is above a predetermined threshold, a record is made of the calling number (either received as part of call set up or inputs from the caller),...http://www.google.fr/patents/US5311574?utm_source=gb-gplus-shareBrevet US5311574 - Automatic customer call back for automatic call distribution systems
Automatic customer call back for automatic call distribution systems
