1. A telephony security system located within one or more locations of an enterprise for monitoring and/or controlling incoming and outgoing calls between a public circuit-switched network for provision of circuit-switched circuits to the public, wherein a physical circuit is temporarily established on demand and kept reserved for the user until the network receives a disconnect signal and one or more end-user stations located within an enterprise's one or more locations, said telephony security system comprising: one or more rules associated with the one or more end-user stations located within the enterprise's one or more locations, said one or more rules associated with the one or more end-user stations located within the enterprise's one or more locations designating at least one action to be performed based on at least one attribute of an incoming and outgoing call between the public circuit-switched network and the one or more end-user stations located within the enterprise's one or more locations, said at least one attribute of the incoming and outgoing call between the public circuit-switched network and the one or more end-user stations located within the enterprise's one or more locations is from a group including: the call direction, the call source, the call destination, the call type, the keyword detected in the call content, the call connect time, the call start date, the call start time, the call end date, the call end time, the call duration, the identifier for the extension or direct connect line carrying the call, the PBX trunk through which the call is processed, the channel through which the call is processed, the digits dialed prior to the base phone number, and the digits dialed after the base phone number; means for determining said at least one attribute of the incoming and outgoing call between the public circuit-switched network and the one or more end-user stations located within the enterprise's one or more locations; and means for performing said at least one action in accordance with said one or more rules associated with the one or more end-user stations located within the enterprise's one or more locations.