Prior art

As a technical patent analyst, I have searched the USPTO database for US patent 9560177. The patent, titled "Network system and network flow tracing method," was granted on January 31, 2017.

The patent references numerous prior art documents, which are listed in the "Citations" section of the patent document. To identify the most relevant prior art, I will focus on the references cited by the examiner, as these were considered pertinent during the patent's prosecution.

Here's an analysis of the most relevant patent citations, focusing on those that could potentially anticipate claims under 35 U.S.C. § 102:

Most Relevant Prior Art for US9560177

1. US20090138610A1 (Matsushita Electric Industrial Co., Ltd.)

   • Full Citation: US20090138610A1
   • Publication/Filing Date: Filed September 29, 2005 / Published May 28, 2009
   • Brief Description: This patent application describes an information processing system, tunnel communication device, tunnel communication method, and program, focusing on tunnel communication, which involves encapsulating packets.
   • Potential Anticipated Claim(s): This patent potentially anticipates aspects of claims 1, 7, 13, and 19 related to the encapsulation of packets and the use of an additional header when a packet is a target of encapsulation. For example, claim 1 states, "...duplicate a part of a header of the identified packet as an additional header when the identified packet comprises a target of encapsulation; encapsulate the identified packet by the additional header...". The description of US20090138610A1 regarding "tunnel communication device" and "tunnel communication method" implies the handling and encapsulation of packets, which might contain similar concepts to the "duplicating a part of a header" and "encapsulating" steps in US9560177.

2. JP2005210518A (Matsushita Electric Works Ltd)

   • Full Citation: JP2005210518A
   • Publication/Filing Date: Filed January 23, 2004 / Published August 4, 2005
   • Brief Description: This Japanese patent discloses a transmission source tracing data providing apparatus and a transmission source tracing apparatus, specifically as an apparatus which carries out IP trace-back. The background art section of US9560177 discusses this patent literature as a method for IP trace-back, noting that it requires a mechanism in the header translating unit to transmit address translation data to the outside, which is a difficulty the present invention aims to overcome.
   • Potential Anticipated Claim(s): This prior art could potentially anticipate elements related to the overall goal of "network flow tracing" and "sending header information to the control apparatus" as described in claims 2, 8, 14, and 20. While JP2005210518A addresses trace-back, the method of achieving it differs, particularly in requiring modification of the header translating unit, which US9560177 seeks to avoid. However, the fundamental concept of tracing and providing translation data is present.

3. US20100161795A1 (Kindsight)

   • Full Citation: US20100161795A1
   • Publication/Filing Date: Filed December 22, 2008 / Published June 24, 2010
   • Brief Description: This patent application describes an apparatus and method for multi-user NAT session identification and tracking. This directly relates to the problem US9560177 addresses regarding header translation (NAT/NAPT) and maintaining flow visibility.
   • Potential Anticipated Claim(s): This reference is highly relevant to claims 2, 6, 8, 11, 12, 14, 17, and 18, which deal with sending header information (including before and after translation) to a control apparatus and the translation of header data. The stated objective of "multi-user NAT session identification and tracking" aligns closely with the problem US9560177 aims to solve by acquiring header translation data without modifying the header translating unit.

4. WO2010090182A1 (NEC Corporation)

   • Full Citation: WO2010090182A1
   • Publication/Filing Date: Filed February 3, 2009 / Published August 12, 2010
   • Brief Description: This international patent application by the original assignee (NEC Corp) of US9560177, describes an application switch system and an application switch method. This indicates previous work by the same entity in related areas of network control and switching.
   • Potential Anticipated Claim(s): Given the common assignee, this document likely shares foundational concepts with US9560177. It could potentially anticipate aspects of claims 1, 7, 13, and 19 related to the overall "switch apparatus" and "communication system" with a controller receiving rules and actions, identifying packets, and processing them based on actions. The specific "encapsulation" aspect might be a distinguishing feature.

5. WO2010103909A1 (NEC Corporation)

   • Full Citation: WO2010103909A1
   • Publication/Filing Date: Filed March 9, 2009 / Published September 16, 2010
   • Brief Description: Another international patent application by NEC Corporation, this describes an OpenFlow communication system and OpenFlow communication method. US9560177 specifically references OpenFlow network systems as an example of a CU separation type network system it deals with.
   • Potential Anticipated Claim(s): This is highly relevant to the entire patent, particularly claims concerning the network system, switch apparatus, and communication method, as US9560177 is explicitly designed for OpenFlow environments. It could anticipate various aspects of the system's architecture and packet handling within an OpenFlow context, potentially requiring a closer examination of the specific encapsulation and header translation data acquisition features to differentiate.

These references highlight that the problems of flow tracing and header translation in complex networks, particularly in OpenFlow environments, were known prior to US9560177. The inventiveness of US9560177 largely rests on its specific method of using a duplicate header for encapsulation to acquire translation data without modifying the header translating unit, thereby allowing for end-to-end flow tracing.