DCT
3:13-cv-02024
Radware Ltd v. F5 Networks Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Radware, Ltd. (Israel); Radware, Inc. (New Jersey)
- Defendant: F5 Networks, Inc. (Washington)
- Plaintiff’s Counsel: McDermott Will & Emery LLP
- Case Identification: 3:13-cv-02024, N.D. Cal., 07/09/2013
- Venue Allegations: Venue is asserted based on Defendant’s corporate residence, transaction of business, and the occurrence of a substantial part of the events giving rise to the claims within the Northern District of California, including in Santa Clara County.
- Core Dispute: Plaintiff alleges that Defendant’s BIG-IP and VIPRION product lines, which function as Application Delivery Controllers, infringe three patents related to network load balancing.
- Technical Context: The technology concerns methods for intelligently directing client traffic across multiple servers or network paths to optimize performance and availability, a critical function in modern data centers and cloud computing environments.
- Key Procedural History: The complaint alleges that Defendant had pre-suit knowledge of the asserted patents through various channels, including citations to the patents during the prosecution of Defendant's own patent applications and a press release by Plaintiff. The filing is a First Amended Complaint.
Case Timeline
| Date | Event |
|---|---|
| 1998-07-15 | Priority Date for ’702, ’319, and ’374 Patents |
| 2003-12-16 | ’702 Patent Issued |
| 2008-10-27 | F5 allegedly gained knowledge of ’702 Patent via its own patent prosecution |
| 2012-09-11 | ’319 Patent Issued |
| 2012-11-05 | Radware allegedly put F5 on notice of ’319 Patent via press release |
| 2012-12-05 | Radware allegedly put F5 on notice of ’702 and ’319 Patents via product marking |
| 2013-01-23 | ’319 Patent allegedly brought to F5's attention by USPTO examiner |
| 2013-07-09 | ’374 Patent Issued |
| 2013-07-09 | Radware allegedly notified F5 of ’374 Patent infringement |
| 2013-07-09 | First Amended Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,665,702 - "Load Balancing"
- Issued: December 16, 2003
The Invention Explained
- Problem Addressed: The patent addresses the shortcomings of conventional load balancing, where routing client requests to the geographically nearest server does not always provide the best performance due to factors like network latency or server processing capacity (U.S. Patent No. 6,665,702, col. 2:6-20).
- The Patented Solution: The invention describes a system for determining the "network proximity" of a client to multiple, geographically dispersed server farms. This is achieved by having the load balancers poll the client to measure performance metrics like latency and the number of network hops. This data is used to populate a "proximity table" that maps client subnets to the optimal server farm, allowing the system to intelligently route traffic based on real-time performance rather than just geography ('702 Patent, Abstract; col. 3:1-14; Fig. 2A).
- Technical Importance: This technology enabled a more sophisticated form of global server load balancing (GSLB) that considers actual network conditions to improve application performance and reliability for end-users ('702 Patent, col. 2:6-20).
Key Claims at a Glance
- The complaint asserts independent claim 8 (Compl. ¶24).
- Claim 8 is a system claim comprising the following essential elements:
- A network management system with a network controller and a data manager for managing a computer network connected to the Internet via multiple routes.
- The network controller receives a client request directed to a remote server.
- The data manager looks up an entry in a "proximity table" indexed by an address related to the remote server.
- The proximity table contains "ratings" for a plurality of routes between the client and remote server networks.
- The network controller selects a route based on these ratings and sets the source IP address of the client request to correspond to the selected route.
- The complaint alleges infringement of "one or more claims" of the '702 patent (Compl. ¶22).
U.S. Patent No. 8,266,319 - "Load Balancing"
- Issued: September 11, 2012
The Invention Explained
- Problem Addressed: As a divisional of the application leading to the '702 patent, this patent addresses the same problem: the limitations of conventional load balancing methods that do not adequately account for real-time network performance when routing traffic between geographically separate server farms (U.S. Patent No. 8,266,319, col. 2:1-20).
- The Patented Solution: The invention describes a device that performs load balancing by intercepting and resolving a client's Domain Name System (DNS) query. The device selects an optimal route (e.g., an ISP link in a multi-homed network) and responds to the DNS query with an IP address associated with that selected route. This directs all subsequent traffic from the client through the optimal network path from the start of the session. The system may also employ a network address translator ('319 Patent, Abstract; col. 8:23-36).
- Technical Importance: This approach integrates intelligent, performance-based route selection directly into the DNS resolution process, providing a way to optimize traffic paths for multi-homed networks before a connection is even established ('319 Patent, Abstract).
Key Claims at a Glance
- The complaint asserts independent claim 31 (Compl. ¶35).
- Claim 31 is a device claim comprising the following essential elements:
- A device for managing a network that is connected to the Internet via multiple routes with respective IP addresses.
- A network controller receives a DNS resolution query from a remote computer for a domain name.
- The controller selects one of the routes and responds to the DNS query with an IP address associated with that selected route.
- The controller also receives packets with a destination IP corresponding to one of the routes.
- The device includes a network address translator that translates the destination IP address to an IP address within the computer network.
- The complaint alleges infringement of "one or more claims" of the ’319 patent (Compl. ¶33).
U.S. Patent No. 8,484,374 - "Load Balancing"
- Issued: July 9, 2013 (Compl. ¶42)
Technology Synopsis
- As part of the same patent family, this invention concerns a device for load balancing client requests among various ISP links in a multi-homed network. The device resolves an incoming DNS query by selecting an optimal ISP link based on a load balancing criterion and returns an IP address associated with that link to the client, thereby directing the client's subsequent traffic through the chosen path (Compl. ¶46).
Asserted Claims & Accused Features
- Asserted Claims: The complaint asserts independent claim 9 (Compl. ¶46).
- Accused Features: The accused functionality is the ability of Defendant's products to perform load balancing by receiving DNS queries, selecting a server or route for the client request, and responding to the query with an IP address corresponding to the selection (Compl. ¶46).
III. The Accused Instrumentality
Product Identification
- Defendant’s BIG-IP and VIPRION product suites (Compl. ¶16).
Functionality and Market Context
- The complaint identifies the accused products as Application Delivery Controllers (ADCs) that provide load balancing and traffic management services (Compl. ¶8, ¶18). Functionally, they are alleged to monitor network connections to select routes for client requests (Compl. ¶24).
- The products are alleged to receive DNS resolution queries from remote users, select a server, and respond to the query with an IP address for that server site (Compl. ¶35, ¶46). The complaint presents a quote from an F5 configuration guide explaining that the accused system "distributes client requests to multiple servers instead of to the specified destination IP address only" (Compl. ¶35).
- The complaint alleges that the Defendant is a direct competitor to the Plaintiff in the application delivery networking market (Compl. ¶15).
IV. Analysis of Infringement Allegations
’702 Patent Infringement Allegations
| Claim Element (from Independent Claim 8) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a network management system... comprising: a network controller... and a data manager... | The accused BIG-IP and VIPRION products are alleged to be network management systems that provide traffic management and load balancing. | ¶22, ¶24 | col. 7:3-9 |
| a data manager looking up a table entry within a proximity table... the tables entries of the proximity table containing ratings for a plurality of routes... | The accused products are alleged to use a "routing table" to determine the interface through which to route traffic. This routing table is alleged to be the claimed "proximity table" containing "ratings." | ¶24 | col. 7:9-14 |
| and wherein said network controller selects one of the plurality of routes based on the ratings within the table entry looked up in the proximity tables... | The accused products' alleged function of comparing a destination address to its routing table to determine an interface is asserted to meet this limitation. | ¶24 | col. 7:12-14 |
| and wherein said network controller sets the source IP address of the client request corresponding to the selected route on the client side. | The complaint does not provide sufficient detail for analysis of this element. | col. 2:36-47 |
’319 Patent Infringement Allegations
| Claim Element (from Independent Claim 31) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A device for managing a computer network... | The accused BIG-IP and VIPRION products. | ¶33 | col. 8:23-28 |
| a network controller receiving a DNS resolution query from a remote computer for a domain name... | The accused products are alleged to be capable of receiving DNS resolution queries from a remote user. | ¶35 | col. 8:23-26 |
| said network controller selecting one of the plurality of routes... | The accused products allegedly "can select a server to direct the user to," which is asserted to be a selection of a route. | ¶35 | col. 8:26-28 |
| and said network controller responding to the DNS resolution query with an IP address associated with the selected route... | The accused products are alleged to respond to the DNS query with an IP address for the selected server site. | ¶35 | col. 8:28-31 |
| the device further comprising a network address translator translating the destination IP address to an IP address within the computer network. | The complaint does not provide sufficient detail for analysis of this element. | col. 9:35-39 |
Identified Points of Contention
- Scope Questions: For the ’702 patent, a central dispute may arise over whether the accused products' "routing table" constitutes the claimed "proximity table" containing "ratings." The patent specification describes "ratings" in terms of performance metrics like latency and hops ('702 Patent, col. 3:60-64), raising the question of whether a standard routing table meets this definition.
- Technical Questions: For the ’319 patent, the complaint does not appear to allege specific facts demonstrating that the accused products perform the functions of the claimed "network address translator." The analysis may turn on what evidence is produced to show the accused products translate a destination IP address as required by the claim.
V. Key Claim Terms for Construction
The Term: "ratings" (from '702 Patent, Claim 8)
- Context and Importance: The infringement case for the ’702 patent appears to depend heavily on this term. If "ratings" is construed narrowly to require specific performance metrics (e.g., latency, packet loss), and the accused product's "routing table" lacks such data, it may support a non-infringement argument. Practitioners may focus on this term because it distinguishes the patented invention's intelligent, metric-based selection from conventional routing.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term is not explicitly defined in the patent, which may support an argument that it should be given its plain and ordinary meaning, potentially covering any data used to make a routing decision.
- Evidence for a Narrower Interpretation: The specification repeatedly describes determining proximity by measuring factors like "latency, hops, and server processing capacity" ('702 Patent, col. 3:60-64). The detailed description explains that polling results are used to create a "total weighted value for each server farm" ('702 Patent, col. 15:13-16), and Figure 7 depicts a "Destination Table" with columns for specific metrics, suggesting "ratings" refers to such quantitative or qualitative performance data.
The Term: "network address translator" (from '319 Patent, Claim 31)
- Context and Importance: This is a required element of the asserted claim. A core question will be whether the accused products contain a component that performs the claimed function of translating a destination IP address. The absence of this feature in the accused products would preclude a finding of literal infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term "Network Address Translation" (NAT) has a well-understood meaning in the art. A party could argue the claim simply requires a device that performs this standard function in the context of the claim.
- Evidence for a Narrower Interpretation: The specification provides specific examples of NAT functionality, such as Figure 4B, which shows a "NAT Mapping Table" translating a public-facing IP address to a private server IP address ('319 Patent, Fig. 4B; col. 16:40-51). A party could argue the term should be limited to the specific translation schemes disclosed in the embodiments.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement of infringement for all three patents. The allegations are based on Defendant's promotional materials, user guides, manuals, and white papers, which allegedly "instruct, direct, and encourage" customers to use the accused products in an infringing manner (Compl. ¶18, ¶23, ¶34, ¶45).
- Willful Infringement: The complaint alleges willful infringement for all three patents. For the ’702 patent, willfulness is based on alleged pre-suit knowledge from at least October 2008, stemming from F5's citation of the patent as prior art in its own patent prosecutions (Compl. ¶26). For the ’319 patent, knowledge is alleged based on a Radware press release and an examiner's citation in an F5 patent prosecution (Compl. ¶37). For the '374 patent, knowledge is alleged as of the patent's issue date via direct notice from Plaintiff's counsel (Compl. ¶47).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "ratings", which the '702 patent specification ties to measured performance metrics like latency and hops, be construed to read on the data contained in the accused products' standard "routing table"? The outcome of this construction could be determinative for the '702 patent.
- A key evidentiary question will be one of functional presence: does Radware's complaint, which is silent on the matter, presage an inability to prove that F5's products contain a "network address translator" that performs the specific translation of a destination IP address as required by claim 31 of the '319 patent?
- A third central question will concern willfulness and damages: given the detailed allegations that F5 was aware of the '702 patent for years prior to the suit through its own patent prosecution activities, the case raises the question of whether any infringement found would be deemed willful, which could expose F5 to a risk of enhanced damages.