DETAILED DESCRIPTION The present invention, accordingly, provides a system and method for performing security access control functions for an enterprise's telephone circuits between end-user stations and their respective circuits into the public switched telephone network (PSTN).
In the most basic configuration, inbound and outbound calls are allowed or denied (i.
e.
, blocked or "hung-up"), content monitored, recorded or redirected according to a rule-set that is managed by a security administrator.
In one aspect of the invention, the disclosed system and method combines call-progress monitoring, caller-id (CND) and/or automatic number identification (ANI) decoding, digital line protocol reception, decoding, demodulation, pulse dial detection, tone detection (DTMF and MF), and speech recognition with microprocessor control, access-control logic, and call-interrupt circuitry.
The system and method of the present invention performs centrally managed, enterprise-wide enforcement of an enterprise's telephony security policy and real-time notification in selected instances of attempted security breaches.
The system utilizes a specialized device to monitor and control access to every telephone station, fax machine, and modem line for all locations within the enterprise having telephony resources that are routed through the device.
Specific attributes identified by the telephony access control device pertaining to all inbound and outbound calls determine whether certain calls, in accordance with a predefined security policy, are allowed, denied ("hung-up"), content monitored, recorded, redirected, logged, and/or initiate additional actions such as electronic mail notification, pager alerting, console messaging, or a Simple Network Management Protocol (SNMP) trap notification.
Attributes captured by the device include, as examples: station extension; inbound caller-ID information (when available); outbound number dialed; call-type (i.
e.
, fax, modem, or voice); call content such as keywords detected via speech recognition or demodulated modem and/or fax data; time and date stamp; and call duration
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