Patent ID: 8149705
Filing Date: 2012-04-03
Classification: H04L

Abstract:
1. A packet communications unit, comprising: a plurality of network interfaces, a selective packet copying unit, and a unit control unit for controlling the plurality of network interfaces and the selective packet copying unit; a memory for holding a sampling rate of a stream to be sampled, a first stream sampling condition of the stream to be sampled in a corresponding entry of a first table, and a second stream sampling condition for identifying packets that comprise a sampling target stream in a corresponding entry of a second table, the first table including entries respectively having at least one value of a source IP address, a destination IP address, a source port number, a destination port number, and a protocol class, the second table including entries respectively having at least one of a server IP address, a client IP address, a server port number, a client port number, a protocol class, and a copy destination network interface identifier, wherein: the selective packet copying unit executes a process comprising: a step for specifying the first stream sampling condition in the corresponding entry of the first table and the sampling rate of the stream to be sampled; a step for detecting a stream start packet according to a stream-oriented protocol from a packet received by the packet communications unit based on the respective at least one value of the entry corresponding to the first stream sampling condition of the stream to be sampled held in the first table; a step for generating, based upon information in the stream start packet, the corresponding entry for the second stream sampling condition in the second table for identifying packets that comprise the sampling target stream for copying at the sampling rate; and a step for generating a copy of the identified packets that comprise the sampling target stream identified based upon the second stream sampling condition and outputting the copy of the identified packets that comprise the sampling target stream via any of the plurality of network interfaces.