Patent ID: 7478168

Claim:
A band control device placed between information processors connected via a network, comprising: a regulation subject detector for checking the contents of application level data sent from the information processors to detect data subject to regulation; and a regulation subject controller for, when regulation subject data has been detected by the regulation subject detector, controlling at least one of a group selected from L3 (Layer3) traffic, an L4 (Layer4) connection and an application level transaction with respect to the regulation subject data, wherein the regulation subject controller prevents traffic caused by a new application level transaction corresponding to the detected regulation subject data from passing through, refuses to establish a session for the detected regulation subject data when the termination process is being performed at the application layer level, limits the band for the L3 traffic or L4 traffic of the detected regulation subject data to a predetermined value or less, and/or adds a predetermined value of delay to the detected regulation subject data so as to increase application level processing time for the regulation subject data.