Method and system for identifying matching packets

A system, comprising:

• a first probe to:
• receive a first plurality of packets at a first location in a network;
• and
• select a first subset of the first plurality of packets in accordance with a filter;
• a second probe to:
• receive a second plurality of packets at a second location in the network,
• the second location being different than the first location;
• and
• select a second subset of the second plurality of packets in accordance with the filter;
• and
• a packet-matching unit to:
• parse each packet in the first subset and the second subset to extract invariant header fields from an outermost interne protocol (IP) header until a set of invariant header fields is obtained, for each packet, that uniquely identifies each packet throughout the network, or until the set of invariant header fields cannot be obtained for each packet,
• the set of invariant header fields including a minimum set of invariant header fields, of each packet, that uniquely identifies each packet throughout the network within a particular time period,
• the particular time period being long enough in duration to allow each packet to traverse the network, but short enough in duration to prevent a same packet signature from being computed for different packets,
• the set of invariant header fields not being obtainable for a particular packet with a particular protocol combination,
• the particular protocol combination including no known identifier or sequence number that uniquely identifies the particular packet at the first location and the second location;
• compute a packet signature from the set of invariant header fields for each packet in the first subset and the second subset for which a set of invariant header fields is obtained;
• and
• compare packet signatures associated with the first subset and packet signatures associated with the second subset to identify matching packets with a same packet signature in the first subset and the second subset.

A device, comprising:

• one or more processors to:
• receive a first subset of a first plurality of packets,
• the first plurality of packets being associated with a first location in a network, and
• the first subset of the first plurality of packets being selected based on a filter;
• receive a second subset of a second plurality of packets,
• the second plurality of packets being associated with a second location in the network,
• the second location being different than the first location, and
• the second subset of the second plurality of packets being selected based on the filter;
• parse each packet in the first subset and the second subset to extract invariant header fields from an outermost interne protocol (IP) header until a set of invariant header fields is obtained, for each packet, that uniquely identifies each packet throughout the network, or until the set of invariant header fields cannot be obtained for each packet,
• the set of invariant header fields including a minimum set of invariant header fields, of each packet, that uniquely identifies each packet throughout the network within a particular time period,
• the particular time period being long enough in duration to allow each packet to traverse the network, but short enough in duration to prevent a same packet signature from being computed for different packets,
• the set of invariant header fields not being obtainable for a particular packet with a particular protocol combination,
• the particular protocol combination including no known identifier or sequence number that uniquely identifies the particular packet at the first location and the second location;
• compute a packet signature from the set of invariant header fields for each packet in the first subset and the second subset for which a minimal set of invariant header fields is obtained;
• and
• compare packet signatures associated with the first subset and packet signatures associated with the second subset to identify matching packets with a same packet signature in the first subset and the second subset.