Method for detecting broadband private connection based on open system interconnection (OSI) transmission layer timestamp

The invention discloses a method for detecting broadband private connection based on an open system interconnection (OSI) transmission layer timestamp. The method comprises the following steps of: 1) when a client requests a server for establishing a transmission control protocol (TCP) connection, returning synchronous confirmation message by the server, and intercepting the synchronous confirmation message, adding the timestamp and then sending the synchronous confirmation message to the client by telecom access routing equipment; 2) setting a first constant and a second constant in the telecom access routing equipment; 3) marking the system time of each received TCP message and acquiring the timestamp of each received TCP message by the telecom access routing equipment; and 4) acquiring the system time difference and the timestamp difference between the two adjacent TCP messages sent by the client of the same IP address in real time, acquiring the difference between the system time difference and the timestamp difference, and judging that the client corresponding to the IP address has broadband private connection phenomenon if the difference exceeds the first constant or the non-0 number of the difference in the preset time exceeds the second constant. The method has the advantages of high detection accuracy, low system resource occupancy, simple detection process and wide application range.