Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-5_13-cv-02024/USCOURTS-cand-5_13-cv-02024-28/pdf.json

Nature of Suit Code: 830
Nature of Suit: Patent
Cause of Action: 35:271 Patent Infringement

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5:13-cv-02024-RMW

ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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United States District Court

Northern District of California

UNITED STATES DISTRICT COURT

NORTHERN DISTRICT OF CALIFORNIA

SAN JOSE DIVISION

RADWARE, LTD., et al.,

Plaintiffs and Counterclaim 

Defendants,

v.

F5 NETWORKS, INC.,

Defendant and Counterclaim 

Plaintiff.

Case No. 5:13-cv-02024-RMW 

ORDER CONSTRUING CLAIMS OF 

U.S. PATENT NOS. 6,473,802; 7,831,712; 

8,103,770; AND 8,392,563

On October 27, 2015, the court held a claim construction hearing for the purpose of 

construing the meaning of certain terms in four F5 patents. While the parties initially requested 

that the court construe seven disputed terms, the parties submitted a written stipulation construing 

two of the terms,1and at the hearing on this matter, the parties reached agreement regarding the 

construction of all but one remaining term. This order adopts the parties’ agreed constructions and 

rules on the remaining disputed term, namely, “unspecific regarding.”

I. BACKGROUND

This is the second order construing claim language in this case. The first order, issued on 

April 18, 2014, construed certain language in patents that Radware has asserted against F5. Dkt. 

 

1 Dkt. No. 259.

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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No. 122. This order construes certain terms of four patents that F5 asserts against Radware. F5 

alleges that Radware infringes claims 33, 42, 43, and 51 of U.S. Patent No. 6,473,802 (’802 

patent); claims 1, 5-7, 10, 12, and 14-25 of U.S. Patent No. 7,831,712 (’712 patent); claims 1, 4, 6, 

7, and 9-13 of U.S. Patent No. 8,103,770 (’770 patent); and claims 1-3, 5-6, 17-19, and 21-22 of 

U.S. Patent No. 8,392,563 (’563 patent). F5’s asserted patents generally relate to enabling a device 

on a computer network to direct subsequent requests from a given client computer to a given 

destination server.

The ’712 patent, the ’770 patent, and the ’563 patent all claim priority to the ’802 patent by 

way of one or more continuations. The specifications of F5’s asserted patents are substantially the 

same, and the ’712 patent, the ’770 patent, and the ’563 patent incorporate the specification of the 

’802 patent by reference. See ’802 patent; ʼ712 patent col.1 ll.6-19; ’770 patent col.1 ll.6-20; and 

’563 patent col.1 ll.6-25.

The technology at issue in F5’s patents relates to maintaining persistent communication 

between at least one client and a plurality of servers in a computer network such as the Internet. 

Many data transmissions use HTTP, an application level protocol for transferring resources across 

the Internet. ’802 patent col.5 ll.52-54. A server, when sending a web page or other HTTP object 

to a client, may also send a piece of “state” information that the client’s web browser may store.

Id. col.6 ll.1-3. This state object is called a “cookie,” for no compelling reason. Id. col.6 ll.8-9. A 

cookie may be used, for example, to send back registration information so that a user does not 

have to retype a user ID number or indicate specific preferences each time the user connects to a 

website or service. Id. col.6 ll.10-18. 

To meet user demand, some content providers host copies of content and applications on 

multiple servers. A device such as a “server array controller,” in the language of F5’s patents, 

might then balance the load among the servers. See ’802 patent col.l ll.26-34. In some cases, 

however, the saved state of the relationship between a client and server may create a load 

balancing problem. Id. col.6 ll.39-41. For example, each server that is managed by a server array 

controller may not share the same state relationship with a given client. Id. col.6 ll.41-44. In that 

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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case, the controller must persistently send a repeated client HTTP request to the same node server 

because it is difficult to recreate the same state relationship in another server during the HTTP 

request/response session. Id. col.6 ll.44-47. The claimed inventions allow a network device to 

balance load and route clients to the proper server based on information in a cookie. Figure 1A of 

the asserted patents illustrates the major components described above:

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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Figures 2A and 2B of the asserted patents illustrate the basic cookie mechanism for load 

balancing and persistence. See, e.g., ’802 patent Figs. 2A and 2B. Figure 2A describes how a 

client issues an HTTP request without a cookie, and the request is routed to a server selected by 

the server array controller. The client receives a response from the server, along with a cookie that 

includes information that can be used by the server array controller to identify the server that it 

selected for the client. See, e.g., id. col.8 ll.2-36. Figure 2B describes how subsequent requests 

from the client are sent along with a copy of the cookie. When requests including the cookie are 

received, they are routed to the server identified by the cookie. See id. col.8 l.36 – col.9 l.13.

F5’s asserted patents describe four different “modes” of employing a cookie to persistently 

direct HTTP connections or other requests to a server: associative, passive, rewrite, and insert. 

’802 patent, Abstract. These four modes are significant because F5 granted a license for Radware 

to sell products practicing the associative and passive modes as part of a settlement of prior 

litigation. Dkt. No. 240 at 3; Dkt. No. 60-2. The main differences among the modes are (1) what 

content is stored in the cookie and (2) which component in the system inserts the cookie into the 

HTTP response. 

Representative claim 33 of the ’802 patent describes one possible method of achieving 

persistency between a client and a server:

33. A method for load balancing access to requests from at least one 

client to a plurality of servers, comprising: 

(a) receiving a Hypertext Transfer Protocol (HTTP) request from a 

client, the HTTP request comprising a request for access to a 

resource provided by at least one of the plurality of servers; 

(b) determining whether the HTTP request includes a Cookie 

comprising information associated with a destination server of 

the plurality of servers; 

(c) if the HTTP request does not include said Cookie, selecting, by a 

server array controller, a server of the at least one of the plurality 

of servers based on a load balancing algorithm and forwarding 

the HTTP request to the selected server; 

(d) receiving, by the server array controller, an HTTP reply from the 

selected server, the HTTP reply comprising Cookie information 

and a command to create a Cookie; 

(e) writing, by the server array controller, in the Cookie information, 

identification data for identifying the selected server; 

(f) sending the HTTP reply with the identification data to the client; 

and 

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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(g) if the determining of step (b) determines that the HTTP request 

includes said Cookie, forwarding the HTTP request to the 

destination server. 

II. LEGAL STANDARD

Claim construction is exclusively within the province of the court. Markman v. Westview 

Instruments, Inc., 517 U.S. 370, 387 (1996). “It is a ‘bedrock principle’ of patent law that ‘the 

claims of a patent define the invention to which the patentee is entitled the right to exclude.’”

Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc) (internal citation omitted).

Claim terms “are generally given their ordinary and customary meaning,” defined as “the meaning 

. . . the term would have to a person of ordinary skill in the art in question . . . as of the effective 

filing date of the patent application.” Id. at 1313 (internal citation omitted). The skilled artisan 

reads the claim term “in the context of the entire patent . . . including the specification.” Id.; see 

also Multiform Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1477 (Fed. Cir. 1998). In 

determining the meaning of a disputed claim limitation, the intrinsic evidence, including the claim 

language, written description, and prosecution history, is the most significant. Phillips, 415 F.3d at 

1315-17. The court reads claims in light of the specification, which is “the single best guide to the 

meaning of a disputed term.” Id. at 1315. Furthermore, “the interpretation to be given a term can 

only be determined and confirmed with a full understanding of what the inventors actually 

invented and intended to envelop with the claim.” Id. at 1316 (quoting Renishaw PLC v. Marposs 

Societa’ per Azioni, 158 F.3d 1243, 1250 (Fed. Cir. 1998)). The words of the claims must be 

understood as the inventor used them as revealed by the patent and prosecution history. Id.

Although extrinsic evidence is less significant than the intrinsic record, the court may also 

reference extrinsic evidence to “shed useful light on the relevant art.” Id. at 1317 (quoting C.R. 

Bard, Inc. v. U.S. Surgical Corp., 388 F.3d 858, 862 (Fed. Cir. 2004)). “[T]echnical dictionaries 

may provide [help] to a court ‘to better understand the underlying technology’ and the way in 

which one of skill in the art might use the claim terms. . . . Such evidence . . . may be considered if 

the court deems it helpful in determining ‘the true meaning of language used in the patent 

claims.’” Id. at 1318 (internal citations omitted).

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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The patent statute requires claims to be definite by “particularly pointing out and distinctly 

claiming the subject matter” that the inventor regards as the invention. 35 U.S.C. §112 ¶ 2. The 

definiteness standard under Section 112 is met when a patent’s “claims, read in light of the 

patent’s specification and prosecution history, ... inform, with reasonable certainty, those skilled 

in the art about the scope of the invention.” Nautilus, Inc. v. Biosig Instruments, Inc., ---- U.S. ----, 

134 S.Ct. 2120 (2014).

III. CLAIM CONSTRUCTION

A. Terms with Stipulated Constructions

On October 23, 2015, the parties filed a joint statement indicating that they had agreed on 

constructions of the terms “application level” and “server array controller.” Dkt. No. 259.

1. “Application level”

Stipulated Construction

“application level”: application layer (including HTTP)

This term appears in asserted claims 1, 9 and 11 of the ’770 patent; asserted claims 1, 17 

and 18 of the ’563 patent; and asserted claims 1, 7, 15 and 16 of the ’712 patent. The court adopts 

the parties’ stipulated construction.

2. “Server Array Controller”

Stipulated Construction

“server array controller”: hardware, or hardware with software, that distributes network traffic to 

server computers

This disputed term appears in asserted claims 33 and 42 of the ’802 Patent; claim 12 of the 

’770 Patent; and claim 19 of the ’712 Patent. The court adopts the parties’ stipulated construction.

B. Identification and Persistence Terms

At the October 27, 2015 claim construction hearing, the parties agreed that for purposes of 

evaluating the validity of F5’s asserted patents, the parties would adopt F5’s proposed 

constructions of the terms listed below that specify what information is stored in a cookie in the 

context of the claimed inventions. The court notes that for the three “identification” phrases listed 

below, F5 has proposed (and Radware has agreed) that the court assign the terms their “plain and 

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ORDER CONSTRUING CLAIMS OF U.S. PATENT NOS. 6,473,802; 7,831,712; 8,103,770; AND 8,392,563

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ordinary meaning.” At the claim construction hearing, the court expressed concern that the parties’ 

experts may have different interpretations of the plain and ordinary meanings of these terms. The 

court’s adoption of plain and ordinary meaning constructions is premised on the parties’ 

agreement that the terms are non-technical terms that can be readily understood and will not 

require specialized explanations from experts at trial.

The parties also agreed at the claim construction hearing that the issue of whether Radware 

has breached its license agreement with F5 depends upon an interpretation of the license 

agreement as applied to Radware’s products. Interpretation of the parties’ license agreement is 

beyond the scope of this claim construction order.

1. “Identification data for identifying the selected server”

Agreed Construction

“identification data for identifying the selected server”: (plain and ordinary meaning)

The phrase “identification data for identifying the selected server” appears in claim 33 of 

the’802 patent. The court adopts the parties’ agreement that this language has its plain and 

ordinary, non-technical meaning and will not require specialized explanation at trial. 

2. “Identification data comprises a server identifier”

Agreed Construction

“identification data comprises a server identifier”: (plain and ordinary meaning)

The phrase “identification data comprises a server identifier” appears in claim 43 of the 

’802 patent. The court adopts the parties’ agreement that this language has its plain and ordinary, 

non-technical meaning and will not require specialized explanation at trial.

3. “Information indicating the one of the plurality of [destination] 

servers”

Agreed Construction

“information indicating the one of the plurality of [destination] servers”: (plain and ordinary 

meaning)

The language above appears in claim 1 of the ’770 patent and in claim 7 of the ’712 patent.

The court adopts the parties’ agreement that this language has its plain and ordinary, non-technical 

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meaning and will not require specialized explanation at trial.

4. “Persistence information”

Agreed Construction

“persistence information”: information that indicates a relationship between a previously selected 

destination and a client’s request

The term “persistence information” appears in asserted claim 51 of the ’802 patent and 

claims 23-25 of the ’712 patent. The court adopts the parties’ agreed construction. 

C. “Unspecific regarding”

F5’s Proposed Construction Radware’s Proposed 

Construction

Court’s Construction

“unspecific regarding”: does 

not contain information 

identifying

“unspecific regarding”: (term 

is indefinite under 35 U.S.C. § 

112 or construe as “unspecific 

regarding”)

“unspecific regarding”: 

unspecific regarding

This term—the only remaining term in dispute—appears in asserted claims 1 and 9 of the 

’770 patent; claims 1, 9 and 17 of the ’563 patent; and asserted claims 1, 7, 15, and 23 of the ’712 

patent. For example, Claims 1, 7, 15, and 23 of the ’712 patent recite that the client’s “request is 

unspecific regarding the [at least] one destination server that provides access to the network 

domain resource.” Claims 1 and 9 of the ’770 patent recite that the client’s “request is unspecific 

regarding the at least one server.” Similarly, claims 1, 9, and 17 of the ’563 patent recite that a 

client device’s “request is unspecific regarding the at least one server device.”

Radware argues that the disputed term is indefinite. Dkt. No. 245 at 18-23. Radware raises 

two principal arguments. First, Radware argues that the term introduces a negative limitation 

without support in the specification. This argument is without merit because the specification has 

abundant support for the “unspecific regarding” limitation. As the specification explains, a request 

from a client, such as the initial request, may not include persistence information that can be used 

to identify a specific destination server. See, e.g., ’770 patent at Figs. 1A, 2A, 3A, 4A, 5A, and 

6A.

Second, Radware argues that “unspecific regarding” is a term of degree that lacks objective 

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bounds. This argument also misses the mark. “Unspecific regarding,” in the context of the asserted 

patents, is not a term of degree. Either a request has a cookie with information about a particular 

server, or it does not. Further, under Nautilus, a claim need only provide “reasonable clarity.” 

Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120, 2129 (2014). “Absolute precision is 

unattainable.” Id. Even if “unspecific regarding” were a term of degree, the Federal Circuit does 

not require absolute precision.

This court finds that in the context of F5’s asserted patents, a person of ordinary skill in the 

art would readily understand that a request that is “unspecific regarding” the destination server is 

simply a request that does not contain persistence information directing it at a particular 

destination server within a group of servers.

Radware argues that aside from the issue of indefiniteness, F5’s proposed construction is 

inconsistent with the specification because even a request made without persistence information in 

a cookie must contain some information identifying the server to which the request is directed “in 

the form of the domain name or the IP address of the destination server.” Dkt. No. 245 at 21. 

While Radware’s brief does not fully develop this argument, Radware is apparently drawing a 

distinction between not having any information identifying a destination server, as F5’s proposed 

construction suggests, and not having specific information about the destination server, as 

“unspecific” requires. The underlying rationale for Radware’s argument appears to be that it 

would be impossible even to send a request to a server if the request contains no information about 

the destination server (such as the server’s domain name or IP address) either in the form of a 

cookie or elsewhere within the request. Radware concedes that a request for content from a 

website might really be a request directed to “the virtual IP address of a load balancing device that 

routes the request to the optimal destination server.” Id. Such a request would not be specific to a 

particular server, but, to a person of ordinary skill in the art, the request would seem to fit within 

the context of the claims in which the disputed term appears. Accordingly, Radware’s criticism is 

not a reason for finding claims that recite the term “unspecific regarding” indefinite.

Nevertheless, Radware’s concern that F5’s proposed construction might cause confusion 

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between a complete lack of information and a lack of specific information is well-taken. 

Accordingly, the court construes “unspecific regarding” simply as “unspecific regarding.” At the 

claim construction hearing, F5 indicated that it does not object to this proposed alternative

construction.

IV. ORDER

For the reasons set forth above, the court construes the claims as follows:

Claim Language Construction

Application level Application layer (including HTTP)

Server Array Controller Hardware, or hardware with software, that 

distributes network traffic to server computers

Identification data for identifying the selected 

server

(Plain and ordinary meaning)

Identification data comprises a server identifier (Plain and ordinary meaning)

Information indicating the one of the plurality 

of [destination] servers

(Plain and ordinary meaning)

Persistence Information Information that indicates a relationship 

between a previously selected destination and a 

client’s request

Unspecific regarding Unspecific regarding

IT IS SO ORDERED.

Dated: November 6, 2015

______________________________________

Ronald M. Whyte

United States District Judge

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