US 9215275

No CAFC 2026 dockets were found for US patent 9215275.

Patent Summary for US9215275

• Title: System and method to balance servers based on server load status
• Assignee: A10 Networks Inc.
• Inventors: Lalgudi Narayanan KANNAN, Ronald Wai Lun Szeto, Lee Chen, Feilong Xu, Rajkumar Jalan
• Filing Date: 2010-09-30
• Issue Date: 2015-12-15
• Abstract: A method, system, and computer program product for balancing servers based on server load status, include: receiving from a server a service response to a service request, the service response including a result from a processing of the service request and a server status indicating a computing load status of the server; obtaining the server status from the service response; receiving a next service request from a host, the next service request comprising a Uniform Resource Locator (URL); determining that the server is configured to process the URL; determining whether the server status indicates that the server is available to process the next service request; and in response to determining that the server status indicates that the server is available to process the next service request, sending the next service request to the server.

Plain-Language Overview of Independent Claims:

US Patent 9215275 has three independent claims: Claim 1 (a method claim), Claim 6 (a non-transitory computer readable storage medium claim), and Claim 11 (a system claim). Independent claims are broader in scope and do not refer to other claims.

Claim 1: Method for balancing servers by a service gateway
This claim describes a method performed by a service gateway to balance server load. It involves:

1. Receiving service responses from two different servers (first and second servers) for their respective service requests, where each request includes a URL associated with that server.
2. Receiving a new service request (third service request) from a host, which also includes a URL.
3. Identifying that the first server is the "primary" server for this third URL, and the second server is the "secondary" server for the same third URL.
4. Discovering from the first server's prior service response that it cannot currently act as the primary server for the third URL.
5. Discovering from the second server's prior service response that it can currently act as a secondary server for the third URL.
6. Sending the third service request to the second server.
7. Receiving a response from the second server for this third request.
8. Forwarding that response to the original host.

In essence, the method outlines an intelligent load balancing scheme where a service gateway considers the real-time load status of both primary and secondary servers, as communicated in their service responses, to direct new service requests to an available server, even if it's a secondary one.

Claim 6: Non-transitory computer readable storage medium
This claim covers a non-transitory computer readable storage medium storing instructions that, when executed by a processor, perform the exact same method as described in Claim 1. This means the invention can be embodied in software on a storage device.

Claim 11: System
This claim describes a system comprising a processor and memory, where the memory stores instructions that, when executed by the processor, perform the exact same method as described in Claim 1. This means the invention can be embodied in a hardware system (e.g., a server load balancer appliance) that executes the described method.

Based on the available search results, no litigation specifically involving US patent 9215275 has been found. The search of Unified Patents and general litigation information did not yield any cases for this specific patent number.

Proceedings overview

There are no PTAB proceedings on file for US patent 9215275.

Strategic summary

As of 2026-05-29, there are no AIA trial proceedings (IPR, PGR, or CBM) recorded for US patent 9215275 in the USPTO ODP API or found through web search. This means all claims of the patent (claims 1-15) are currently untested by AIA trial proceedings.

The absence of PTAB activity could be a signal that the patent has not been extensively asserted, or that prior art challenging its validity has not yet been identified or brought forth in an AIA trial. For a defendant facing assertion, this means there are no estoppel limitations under § 315(e)(2) from prior AIA trials, and all prior-art grounds remain available for potential challenges, such as in an IPR petition or district court litigation.

Recommended next steps

If facing assertion of US patent 9215275, a defendant should consider a thorough prior art search to identify potential grounds for an AIA trial challenge (e.g., an Inter Partes Review). The absence of prior PTAB challenges means this patent has not yet been "hardened" through such proceedings, potentially making an IPR a viable defensive strategy.

Inventors

• Lalgudi Narayanan KANNAN (A10 Networks Inc)
• Ronald Wai Lun Szeto (A10 Networks Inc)
• Lee Chen (A10 Networks Inc)
• Feilong Xu (A10 Networks Inc)
• Rajkumar Jalan (A10 Networks Inc)

No unusual patterns observed regarding inventor departure from the original assignee.

Original assignee

A10 Networks Inc. The company develops and sells application delivery controllers (ADCs), which are used for load balancing, application acceleration, and security. They ship products embodying the claims, specifically their AX-Series traffic managers are mentioned in the patent. A10 Networks Inc is currently operating.

Assignment timeline

• 2010-09-30 (executed) / recorded 2010-09-30 — Reel 025827/0458
  • Conveyance: Assignment
  • Assignor: CHEN, LEE, JALAN, RAJKUMAR, KANNAN, LALGUDI NARAYANAN, SZETO, RONALD WAI LUN, XU, FEILONG (inventors)
  • Assignee: A10 NETWORKS, INC.
  • Correspondent: Jeffrey C. Chang, A10 Networks, Inc., 2300 Orchard Parkway, San Jose, CA 95131
  • Context: Original assignment from inventors to company.
• 2013-08-22 (executed) / recorded 2013-09-11 — Reel 030589/0329
  • Conveyance: Assignment
  • Assignor: A10 NETWORKS, INC.
  • Assignee: A10 NETWORKS, INC.
  • Correspondent: Jeffrey C. Chang, A10 Networks, Inc., 2300 Orchard Parkway, San Jose, CA 95131. This correspondent recurs in this chain.
  • Context: Change of address/internal reorg.
• 2013-09-30 (executed) / recorded 2013-10-18 — Reel 030792/0971
  • Conveyance: Security Interest
  • Assignor: A10 NETWORKS, INC.
  • Assignee: ROYAL BANK OF CANADA, AS COLLATERAL AGENT
  • Correspondent: D. Ted Kennedy, Shearman & Sterling LLP, 525 Market St., Suite 2200, San Francisco, CA 94105
  • Context: Securitization (patent used as collateral for a loan).

Timeline diagram

timeline
    title Ownership of US 9215275
    2010 : Filed by A10 Networks Inc
    2013 : A10 Networks Inc address change
         : Security interest Royal Bank of Canada
    2015 : Issued

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The patent has remained with A10 Networks Inc., an operating company.
2. Known asserter in the chain — Not present. No known NPEs are present in the assignment chain.
3. Repeat correspondent across the chain — Present. Jeffrey C. Chang of A10 Networks, Inc. is listed as the correspondent on two assignments (Reel 025827/0458 and Reel 030589/0329).
4. Cascading transfers — Not present. There are only two assignments recorded by A10 Networks Inc itself, with a gap of approximately 3 years, not within 24 months. The third record is a security interest.
5. Pre-litigation transfer — Unclear. Without litigation data, it is not possible to determine if any assignments preceded litigation.
6. Bankruptcy fire-sale — Not present. A10 Networks Inc. is currently operating.
7. Privateering — Not present. The patent is still held by A10 Networks Inc.
8. Defensive aggregator (anti-NPE) — Not present. The patent is not currently assigned to a defensive aggregator.

Verdict

Operating-company assertion

The patent is currently owned by A10 Networks Inc., an operating company that produces products embodying the claimed invention. The assignments recorded are consistent with initial inventor assignment to the company, an internal reorganization, and a security interest for financing, not with transfers to shell entities for assertion purposes.

USPTO Assignment Center search for US9215275: https://assignmentcenter.uspto.gov/#!/patent/9215275

The United States Patent and Trademark Office (USPTO) database confirms the existence of US patent 9215275, titled "System and method to balance servers based on server load status". This patent was granted on December 15, 2015, from an application filed on September 30, 2010, and is currently active, set to expire on October 2, 2031.

Here's an analysis of the most relevant prior art cited in US patent 9215275, along with their potential anticipation of claims under 35 U.S.C. § 102:

Most Relevant Prior Art for US9215275

The following citations are presented based on their description in US9215275 and their direct relevance to the core concept of balancing server load based on real-time server status.

1. US20020194350A1 (Lu Leonard L.)

   • Full Citation: US20020194350A1, "Content-aware web switch without delayed binding and methods thereof"
   • Publication/Filing Date: Published: December 19, 2002 (Filed: June 18, 2001)
   • Brief Description: This patent application describes a content-aware web switch that directs web requests to appropriate servers without delayed binding. The system analyzes the content of a request (e.g., URL) to select a server. It focuses on efficiently routing requests based on content knowledge at the switch.
   • Potential Anticipated Claim(s) under 35 U.S.C. § 102: US20020194350A1 potentially anticipates aspects of claims related to a service gateway receiving a service request with a URL and determining a server to process that URL (e.g., portions of claim 1 where "determining the first server is a primary server associated with the third URL and the second server is a secondary server associated with the third URL"). However, US20020194350A1 does not explicitly disclose obtaining server load status from a service response to dynamically adjust server selection, which is a key distinguishing feature of US9215275.

2. US20040202182A1 (Lund Martin)

   • Full Citation: US20040202182A1, "Method and system to provide blade server load balancing using spare link bandwidth"
   • Publication/Filing Date: Published: October 14, 2004 (Filed: February 12, 2003)
   • Brief Description: This reference details a method and system for load balancing in a blade server environment by utilizing spare link bandwidth. While it addresses load balancing and server status (specifically, bandwidth), it focuses on a different metric and mechanism than US9215275's reliance on server computing load status embedded in service responses.
   • Potential Anticipated Claim(s) under 35 U.S.C. § 102: This reference might anticipate the general concept of using server-specific parameters for load balancing. However, its specific focus on "spare link bandwidth" as the load metric and its deployment in a blade server context, rather than a general computing load status obtained from a service response, would likely differentiate it from the specific claims of US9215275. It may anticipate the general idea of "discovering... the first server temporally cannot act as a primary server" if that discovery is based on network-level load rather than application-level computing load status in a service response.

3. US7076555B1 (Novell, Inc.)

   • Full Citation: US7076555B1, "System and method for transparent takeover of TCP connections between servers"
   • Publication/Filing Date: Granted: July 11, 2006 (Filed: January 23, 2002)
   • Brief Description: This patent describes a system and method for transparently taking over TCP connections between servers, primarily for fault tolerance and seamless service migration. While it involves managing server interactions and potentially implies some knowledge of server state for a seamless takeover, it doesn't explicitly teach the dynamic load balancing based on server computing load status communicated within service responses for incoming new service requests as claimed in US9215275.
   • Potential Anticipated Claim(s) under 35 U.S.C. § 102: This patent's focus on TCP connection takeover for fault tolerance is distinct from dynamically selecting a server for new requests based on its current computing load status as reported in a service response. Therefore, it is less likely to directly anticipate the core claims of US9215275, particularly those regarding the server status within a service response and its use for new request distribution.

4. US20070195792A1 (A10 Networks Inc.)

   • Full Citation: US20070195792A1, "System and method for an adaptive TCP SYN cookie with time validation"
   • Publication/Filing Date: Published: August 23, 2007 (Filed: February 21, 2006)
   • Brief Description: This patent application, assigned to the same entity (A10 Networks Inc.) as US9215275, focuses on an adaptive TCP SYN cookie mechanism for network security and efficiency, particularly in handling SYN attacks. While it relates to network traffic management and server interaction, its primary inventive concept is around TCP SYN cookie generation and validation, not the dynamic balancing of application-level service requests based on server computing load status reported in application-level service responses.
   • Potential Anticipated Claim(s) under 35 U.S.C. § 102: While from the same assignee and related to network appliances (like SLBs mentioned in US9215275's background), this reference's focus on TCP SYN cookies is distinct from the core claims of US9215275 regarding server load status in service responses for load balancing. It would not anticipate the specific method steps of US9215275.

5. US20100235880A1 (A10 Networks, Inc.)

   • Full Citation: US20100235880A1, "System and Method to Apply Network Traffic Policy to an Application Session"
   • Publication/Filing Date: Published: September 16, 2010 (Filed: October 17, 2006)
   • Brief Description: This patent application describes applying network traffic policies to application sessions. It involves inspecting application-layer information to apply policies, which hints at deeper traffic inspection. However, it does not explicitly disclose the mechanism of servers reporting their computing load status within a service response that is then used by a service gateway for dynamic load balancing decisions on subsequent requests, which is central to US9215275.
   • Potential Anticipated Claim(s) under 35 U.S.C. § 102: This reference, also from A10 Networks, Inc., relates to applying policies based on application sessions, suggesting some level of application-aware processing. However, it does not clearly teach the explicit reporting of server computing load status within a service response for the purpose of dynamically selecting servers for new requests, which is a key element of US9215275's claims.

It is important to note that a definitive assessment of anticipation would require a detailed claim-by-claim analysis against the full disclosure of each prior art reference, considering all limitations in the claims of US9215275. The descriptions above are based on the summaries provided in US9215275 and typical interpretations of patent titles and abstracts.

Obviousness Analysis of US9215275 under 35 U.S.C. § 103

This analysis evaluates whether the claims of US Patent 9215275, "System and method to balance servers based on server load status," would have been obvious to a person having ordinary skill in the art (POSITA) at the time of the invention (priority date: September 30, 2010). The analysis considers the prior art references explicitly cited within the patent.

Level of Ordinary Skill in the Art

A person having ordinary skill in the art in the field of US Patent 9215275 would be a network engineer or software developer with experience in data communications, server load balancing, distributed systems, and web services. Such an individual would be familiar with common network protocols (e.g., HTTP, FTP, SIP, XML), server architectures (e.g., web servers, application servers), and techniques for monitoring server health and distributing network traffic.

Differences Between Prior Art and Claims

The independent claims (Claim 1, 6, and 11) of US9215275 generally describe a method, computer-readable medium, and system for a service gateway to balance servers by:

1. Receiving service responses from servers, where these responses include a server status indicating the computing load status of the server.
2. Obtaining this server status from the service response.
3. Receiving a new service request with a URL.
4. Determining primary/secondary server configurations for the URL.
5. Discovering, using the server status from the service response, that a primary server temporally cannot act as primary.
6. Discovering, using the server status from the service response, that a secondary server temporally can act as secondary.
7. Directing the new service request to the available secondary server.

As noted in the prior art section, a key distinguishing feature of US9215275 is the explicit disclosure of obtaining server computing load status directly from a service response to dynamically adjust server selection for new service requests. The cited prior art references generally address aspects of load balancing or server monitoring but do not explicitly combine these elements in the same manner.

Specifically:

• US20020194350A1 (Lu Leonard L.) teaches a content-aware web switch that directs requests based on URLs, which aligns with the service gateway's function of receiving requests and routing based on URL association. However, it does not explicitly disclose servers sending their real-time computing load status within service responses.
• US20040202182A1 (Lund Martin) introduces the concept of load balancing using server parameters, specifically "spare link bandwidth" in a blade server environment. This reference anticipates the general idea of using server status to determine if a server "temporally cannot act". However, it focuses on a network-level metric (bandwidth) rather than application-level computing load status, and does not specify obtaining this status within a service response.
• US7076555B1 (Novell, Inc.), US20070195792A1 (A10 Networks Inc.), and US20100235880A1 (A10 Networks, Inc.) address TCP connection takeover, SYN cookie mechanisms, and network traffic policies, respectively. While relevant to network and server management, their inventive concepts are distinct from the specific mechanism of server load balancing based on computing load status embedded in service responses.

Motivation to Combine Prior Art References

A POSITA at the time of the invention would have been motivated to combine the teachings of the prior art and modify them to arrive at the claimed invention due to a recognized problem in existing load balancing systems. The background section of US9215275 explicitly articulates this problem: "Common methods to balance load among servers is to distribute the service requests based on the applications (HTTP, FTP, etc.), service addresses such as URL, priorities based on network interfaces or host IP addresses. SLB may distribute service requests additionally in a round robin fashion to the servers, assuming and ensuring the servers would be evenly loaded. However, different service requests have different service computing consequences. A server may be fully loaded with only a handful of service requests while another server remains mostly idle even with plenty of service requests. SLB may inappropriately send another request to a busy server, incorrectly considering the busy server being readily available, instead of sending the request to an idle server."

This statement clearly highlights the known deficiency of traditional load balancers in accurately assessing real-time server computing load status to make intelligent distribution decisions.

The motivation to combine and modify would be to enhance the accuracy and responsiveness of load balancing by providing the service gateway with a more direct and real-time measure of a server's actual computing capacity.

1. Combining Content-Aware Routing with Server Load Awareness: A POSITA would logically combine the content-aware routing capabilities of a web switch (as taught by US20020194350A1) with the general principle of using server load information for selection (as taught by US20040202182A1). While US20040202182A1 uses "spare link bandwidth," a POSITA would recognize that application-level services require knowledge of internal computing resources (CPU, memory, storage utilization, etc.) for optimal load distribution, as explicitly stated in US9215275.
2. Modifying Server Status Reporting to Use Service Responses: Given that the service gateway (load balancer) already intercepts and processes service responses (as part of its function described in US20020194350A1), it would be an obvious design choice for a POSITA to embed the server's computing load status directly within these existing communication flows. This approach is efficient, avoids the overhead of separate out-of-band monitoring or polling mechanisms, and provides context-specific load information. The patent itself suggests various common methods for embedding this status, such as in an HTTP header, HTML tag, XML tag, SIP tag, or FTP reply code. Extending existing protocols with custom tags or headers is a well-known and routine engineering practice for conveying additional metadata.
3. Applying Primary/Secondary Server Logic with Real-Time Status: The concept of configuring servers as primary or secondary for specific URLs is a common practice in load balancing for fault tolerance and optimized resource allocation, and is explicitly described in US9215275 as a known configuration. Once a more accurate, real-time computing load status is available (via embedding in service responses), it would be an obvious and natural extension for the service gateway to use this enhanced information to intelligently route traffic. If a primary server reports it is overloaded (e.g., status '2' for "very busy" as shown in FIG. 3 and discussed in the patent), a POSITA would logically redirect new requests for that URL to an available secondary server to prevent service degradation, thus addressing the problem identified in the patent's background.

Therefore, motivated by the known problem of inefficient server load balancing due to a lack of accurate, real-time computing load status, a POSITA would have been led to combine the content-aware routing of US20020194350A1 with the concept of using server-reported load from US20040202182A1, and to implement the server load reporting by embedding computing load status in application-level service responses using conventional protocol extension techniques. This combination and modification would have been made with a reasonable expectation of improving load balancing efficiency and addressing the identified problem.