NETWORK SYSTEM AND NETWORK FLOW TRACING METHOD

• US 20130315248A1
• Filed: 12/08/2011
• Published: 11/28/2013
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: Cloud BYTE LLC
• Original Assignee: NEC Corporation
• Inventors: Morimoto, Masaharu
• Granted Patent: US 9,313,128 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 43/026 using flow identification
• CPC Class Codes: H04L 43/20 the monitoring system or the monitored elements being virtualised, abstracted or software-defined entities, e.g. SDN or NFV
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

In a flow-based network such as an open flow network system, even when a network appliance such as NAT and NAPT for translating a packet header is passed through, a correspondence relation of two flows before and after the passing can be grasped to make it possible to trace the flow in end-to-end.

Specifically, a packet is encapsulated in a switch (or in a controller requested from the switch). By encapsulating by using the same header as a current header, two kinds of headers before the translation and after the translation are attached to the packet after the packet phases through the network appliance.

Claims

1. A network system comprising:

a switch having a function to process a reception packet based on a set entry of a flow table;

a controller having a function to receive an inquiry of the packet from said switch, and to set the entry defining a rule and an operation to uniformly control packets to said flow table of said switch; and

an encapsulating module having a function to receive the packet from at least one of said switch and said controller and to encapsulate the packet by using a same header as a header of the packet.

2. The network system according to claim 1, further comprising:

a header translating unit having a function to translate header data at a head of the reception packet to transfer to another switch, when receiving the packet from said switch,

wherein said encapsulating module has a function to receive a packet to which a header before translation and a header after the translation are given, when the encapsulated packet is transferred through said header translating unit, and to notify a set of the header before the translation and the header after the translation to said controller.

3. The network system according to claim 1, wherein said encapsulating module has:

a function to check whether or not a packet received by said switch is an encapsulated packet;

a function to duplicate header data of the packet in case of not being the encapsulated packet, and to give the duplicated header data to the reception packet to encapsulate and to hand to said switch;

a function to notify a set of header data at a head of the encapsulated packet and header data of an original packet to said controller as header translation data, in case of being the encapsulated packet; and

a function to translate the encapsulated packet to a packet to which only the header data at the head is given, and to hand to said switch.

4. A computer which has a function as an encapsulating module, comprising:

means for receiving a packet from at least one of a switch which has a function to process a reception packet based on a set entry of a flow table, and a controller which has a function to receive an inquiry of the packet from said switch, and to set the entry defining a rule and an operation to uniformly control packets to said flow table of said switch; and

means for encapsulating the packet by using a same header as a header of the packet.

5. The computer according to claim 4, further comprising:

means for receiving a packet to which a header before translation and a header after the translation are given, when the encapsulated packet is transferred through a header translating unit which has a function to translate header data at a head of the reception packet to transfer to another switch, when receiving the packet from said switch, and referring to the header before the translation and the header after the translation.

6. The computer according to claim 4, wherein said computer comprises:

means for checking whether or not the reception packet is an encapsulated packet;

means for duplicating header data of the packet in case of not being the encapsulated packet;

means for giving the duplicated header data to the reception packet to encapsulate;

means for generating header translation data based on a set of header data at a head of the encapsulated packet and header data of an original packet, in case of being the encapsulated packet; and

means for translating the encapsulated packet to a packet to which only the header data at the head is given.

7. A network flow tracing method comprising:

processing a reception packet based on a set entry of a flow table in a switch;

receiving an inquiry of the packet from said switch, and setting the entry defining a rule and an operation to uniformly control packets to said flow table of said switch, in a controller; and

receiving the packet from at least one of said switch and said controller and encapsulating the packet by using a same header as a header of the packet, in an encapsulating module.

8. A storage medium which stores a program for making a computer which has a function as an encapsulating module, executing:

a step of receiving a packet from at least one of a switch which has a function to process a reception packet based on a set entry of a flow table, and a controller which has a function to receive an inquiry of the packet from said switch, and to set the entry defining a rule and an operation to uniformly control packets to said flow table of said switch; and

a step of encapsulating the packet by using a same header as a header of the packet.