Patent ID: 8089876

Claim:
A packet transmission apparatus comprising: a user identification circuit that identifies a user of an input user flow upon input of the user flow containing communication packets and maintenance packets; a maintenance packet extraction circuit that extracts the maintenance packets from the user flow of the user identified by the user identification circuit; a maintenance packet output controller that controls a transparent output of the maintenance packets extracted by the maintenance packet extraction circuit based on a set monitor rate; a processor that monitors and controls the user flow of the particular user based on the maintenance packets of the user transparently output by the maintenance packet output controller; and a monitor rate management memory that stores the monitor rate for monitor rate identification information to identify the monitor rate; a user management memory that stores the monitor rate identification information for each user; and a monitor rate setting memory that reads, upon identification of the user of the user flow by the user identification circuit, the monitor rate identification information corresponding to the identified user from the user management memory, reads the monitor rate corresponding to the read monitor rate identification information from the monitor rate management memory, and sets the read monitor rate in the maintenance packet output controller, and wherein the maintenance packet output controller controls the transparent output of the maintenance packets for the user extracted by the maintenance packet extraction circuit, based on the monitor rate for the user set by the monitor rate setting circuit.