Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-5_13-cv-02024/USCOURTS-cand-5_13-cv-02024-31/pdf.json

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

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13-cv-02024-RMW 

ORDER DENYING MOTION FOR SUMMARY JUDGMENT OF NON-INFRINGEMENT 

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United States District Court

Northern District of California

UNITED STATES DISTRICT COURT 

NORTHERN DISTRICT OF CALIFORNIA 

RADWARE, LTD., et al.,

Plaintiffs and Counterclaim 

Defendants,

v.

F5 NETWORKS, INC.,

Defendant and Counterclaim 

Plaintiff.

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

ORDER DENYING MOTION FOR 

SUMMARY JUDGMENT OF NONINFRINGEMENT

F5 Networks, Inc. alleges infringement of U.S. Patent Nos. 6,437,802 (“’802 patent”); 

7,831,712 (“’712 patent”); 8,103,770 (“’770 patent”); and 8,392,563 (“’563 patent”) against 

plaintiffs and counterclaim-defendants Radware, Inc. and Radware Ltd. On August 10, 2015, 

Radware filed a motion for summary judgment of non-infringement of the F5 patents. Dkt. No. 

240. F5 opposed the motion, and Radware replied. Dkt. Nos. 244, 248-2. F5 then filed a motion 

for leave to file a surreply. Dkt. No. 250, 251. F5’s motion for leave to file a surreply is granted. 

For the reasons set forth below, Radware’s motion for summary judgment is denied.

I. BACKGROUND 

The F5 asserted patents1relate to load balancing between servers on a network. An HTTP 

 

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F5 alleges that Radware infringes claims 33, 42, 43, and 51 the ’802 patent; claims 1, 5-7, 10, 12, 

and 14-25 of the ’712 patent; claims 1, 4, 6, 7, and 9-13 of the’770 patent; and claims 1-3, 5-6, 17-

19, and 21-22 the ’563 patent.

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ORDER DENYING MOTION FOR SUMMARY JUDGMENT OF NON-INFRINGEMENT

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cookie is used “for the purpose of persistently directing HTTP connections to the same 

destination.” ’802 patent, col.5, ll.46-47. 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 

returning 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 

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. 

All four F5 patents share substantially the same specification, and the specifications 

disclose four distinct modes of operation—associative, passive, insert, and rewrite. These four 

modes are significant because the parties agree that Radware is licensed to practice two of the four 

modes described in the patent specifications—the associative mode and the passive mode. See

Dkt. No. 240 at 3; Dkt. No. 244 at 4-5. F5 asserts infringement of the unlicensed insert and rewrite 

modes. Dkt. No. 51-1 at 4-5.

In associative mode, illustrated in Figures 3A and 3B of the asserted patents, the server 

array controller inserts a cookie with information uniquely identifying the client into the HTTP 

response’s header. ’802 patent col.9 ll.39-42. Alternatively, the selected node server may include a 

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cookie command in the HTTP response’s header that contains blank information, after which the 

server array controller will rewrite this blank information with information that uniquely identifies 

the client. Id. col.9 ll.44-49. The server array controller maps the identified client and the address 

of the selected node server into a table that is stored in the memory of the controller. Id. col.9 

ll.50-53. The other modes do not employ a mapping table that maps client identifiers to selected 

servers.

Unlike the associative mode, the passive, rewrite, and insert modes generate cookies 

containing server identifiers, not client identifiers. In passive mode, illustrated in Figures 4A and 

4B of the asserted patents, the selected node server generates an HTTP response that includes 

cookie information identifying the selected node server. Id. col. 10 ll.59-62. The server array 

controller provides this HTTP response to the client. Id. col.10 ll.65-66. In rewrite mode, 

illustrated in Figures 5A and 5B of the asserted patents, the selected node server generates an 

HTTP response that includes a cookie with a blank field without information identifying the 

selected node server. Id. col.11 ll.55-59. The server array controller then rewrites the blank cookie 

information to identify the node server and passes the HTTP response with the rewritten cookie 

information to the client. Id. col.11 ll.61-66. In insert mode, illustrated in Figures 6A and 6B of the 

asserted patents, the selected node server does not write a cookie. Instead, after the node server 

provides an HTTP response to the server array controller, the server array controller inserts cookie 

information identifying the selected node server into the HTTP response and passes it to the client. 

Id. col.12 l.60–col.13 l.4. In the insert mode, all of the load for inserting and examining cookie 

information and rewriting data packets is placed on the server array controller, and none is placed 

on the node servers. Id. col.13 ll.39-43.

The parties agree that there is only one accused product—the version of Radware’s Alteon 

product charted in F5’s February 28, 2014 infringement contentions. See Dkt. No. 240 at 12; 244

at 1, n.1. The parties also agree that each cookie in the accused product contains four pieces of 

information: 

 CIP (client IP address) — 8 bytes for IPv4, 32 bytes for IPv6

 VIP (virtual server IP address) or NAT IP — 8 bytes for IPv4, 32 bytes for IPv6

 randomid — 8 bytes

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ORDER DENYING MOTION FOR SUMMARY JUDGMENT OF NON-INFRINGEMENT

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 RPORT — 4 bytes

Dkt. No. 239-4 at 18-19 (citing F5’s infringement contentions). F5’s infringement contentions 

state that Alteon “selects the randomid in a manner ensuring that the hash of the randomid (using 

the one_way_hash_cookie() function) is the rindex that identifies the destination real server for the 

session.” Id. Radware argues that it is entitled to summary judgment of non-infringement because 

Alteon “does not include a Cookie with Server ID information” and therefore “does not perform 

the unlicensed insert or rewrite modes, but, at best, performs the licensed associative mode.” 2 Dkt.

No. 240 at 20, 17.

II. ANALYSIS

Summary judgment is proper where the pleadings, discovery, and affidavits demonstrate 

that there is “no genuine dispute as to any material fact and the movant is entitled to judgment as a 

matter of law.” Fed. R. Civ. P. 56(c); see also Celotex Corp. v. Catrett, 477 U.S. 317, 322 (1986). 

At the summary judgment stage, the Court “does not assess credibility or weigh the evidence, but 

simply determines whether there is a genuine factual issue for trial.” House v. Bell, 547 U.S. 518, 

559–60 (2006). Material facts are those which may affect the outcome of the case. Anderson v. 

Liberty Lobby, Inc., 477 U.S. 242, 248 (1986). A dispute as to a material fact is genuine if there is 

sufficient evidence for a reasonable jury to return a verdict for the nonmoving party. Id.

In this case, there is no dispute that the cookie information in the associative mode

“uniquely identifies the client,” while the cookie information in the insert and rewrite modes

“identifies the selected node server.” See ’802 patent, col. 9 ll. 47-48; col. 10 ll. 30-31; col. 12 ll. 

 

2 Radware’s motion also includes the argument that, under Radware’s proposed constructions, the 

asserted claims “read on the licensed ‘associative’ mode,” and that therefore Radware’s license 

covers the claims. Dkt. No. 240 at 13-15. F5 admits that “some of the claims cover multiple modes 

of operations, some of which are licensed by Radware,” but F5 maintains that Radware’s use of 

either the insert or rewrite mode could still infringe the asserted claims. Dkt. No. 244 at 5-6. At the 

October 27, 2015 claim construction hearing, the parties stipulated to F5’s constructions for most

terms, and Radware does not assert that any asserted claim covers only the associative mode. The

court finds no basis to conclude that Radware could not infringe the unlicensed modes by 

practicing claims that cover both the associative mode as well as other, unlicensed modes. See 

Gen. Talking Pictures Corp. v. W. Elec. Co., 305 U.S. 124, 126 (1938) (“Any use beyond the valid 

terms of a license is, of course, an infringement of a patent.”). To the extent Radware’s motion 

rests on a theory that Radware cannot infringe any claim that covers both a licensed as well as 

unlicensed mode, summary judgment is denied.

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21-22; col. 12 ll. 64-66. There is, however, a material dispute about whether the randomid value of

Alteon’s cookies necessarily implicates the associative mode. There is a similar dispute as to 

whether Atleon’s cookies contain the server identification information required by the claims.

Therefore, summary judgment is not appropriate.

A. Whether Alteon Operates in Associative Mode

Radware asserts that the randomid of the Alteon cookie uniquely identifies the client, and 

that the Alteon uses this value to look up the associated server in a table. Dkt. No. 240 at 3. 

Specifically, Radware argues that the randomid is “analogous to the ‘CustID’ described in Figure 

7E of the patents-in-suit . . . used in the licensed ‘associative’ mode,” and that the randomid is 

hashed to generate a rindex, which in turn “points the server array controller to look in a table (the 

‘Real Address Table’ or ‘RAT’) to locate the IP address of the previously selected node server.” 

Dkt. No. 239-6 ¶ 36; Dkt. No. 248-3 at 7. F5 and its expert Dr. Alexander, however, disagree with 

this view, asserting that the randomid “does not uniquely identify a client, so it is not the client 

information required by the associative mode” and that the “RAT is not associative because it does 

not map unique client identifiers to selected servers.” Dkt. No. 243-6 ¶ 14; Dkt. No. 249-6 at 3.

The court finds that Radware has not shown a lack of dispute about whether Alteon uses a table to 

map a unique client identifier to a destination server. 

In its motion, Radware argues that F5’s infringement contentions “identify an Alteon 

cookie that utilizes a hash function to lookup the real server ID in a table.” Dkt. No. 239-4 at 19. 

F5 responds that “nothing in the claims or the specification of the F5 cookie patents excludes the 

use of a table with the server identifier in insert and rewrite mode implementations,” and F5 points 

out that the specification references the use of hash values—which may be used in conjunction 

with tables to represent destination server information—without limiting their use to any particular 

mode or modes:

Additionally, it is envisioned that a unique identification of a client 

or a destination may be represented as encoded information in the 

Cookie. The result of an equation or a hash value ... may be used to 

encode the destination uniquely identified in the Cookie. A hash 

value (or simply hash) is a number generated from a string of text. . . 

. A hash provides a quickly determinable value in the Cookie for 

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identifying a relationship between the client and the destination.

Dkt. No. 244 at 8-9 (quoting ’802 patent, col.16 ll. 4-20). 

In Radware’s reply, Radware and Dr. Rubin clarify their position that although a hash 

function may be used in all four modes, “if the result of the hash is an index to an external table” 

for determining the IP address of the destination server, then the associative mode is implicated. 

Dkt. No. 248-2 at 6-7. Radware identifies the Real Address Table (“RAT”) in Alteon as the 

external table used to map the hashed randomid value, or rindex, to the server’s real IP address. 

Dkt. No. 248-3 at 9. Although F5 concedes “there is no mapping between particular clients and 

servers” in the unlicensed modes, F5 maintains that “there could be mapping, including a table 

that correlates a particular server identifier with the actual address of the corresponding server on 

the network” in either the insert or rewrite mode. Dkt. No. 243-3 at 3. F5’s expert, Dr. Alexander, 

declared that the RAT “would not make the implementation associative mode, because among 

other reasons, the table does not use client information to identify the destination server.” Dkt. 

243-6 ¶ 17; see also Dkt. No. 243-3 at 8. F5’s view is that the “RAT is a table mapping two forms 

of server identification information, the hashed randomid (or rindex) of the server and the server’s 

real ID.” Dkt. No. 249-6 at 3. Therefore, crux of the dispute is whether the randomid uniquely 

identifies a client. 

Radware relies on a reference from F5’s infringement contentions describing randomid as 

“an 8-byte random client ID value.” Dkt. No. 248-3 at 3, 12 (emphasis added). However, the 

Alteon documentation also describes rewriting the cookie value so that it “represents the 

responding server,” either as a “value that can be used for hashing into a real server ID” or the 

“real server IP address.” Dkt. No. 243-3 at 9 (emphasis added); see also Dkt. No. 239-7 at 19 

(“Alteon device rewrites the cookie to contain a server ID for hashing on subsequent requests.”). 

And F5’s infringement contentions contain source code analysis suggesting that the randomid

identifies a server. Dkt. No. 249-6 at 2; Dkt. No. 239-7 at 21 (“A generated ‘cookie’ (randomid 

value) therefore identifies an associated real server, which is the server identified by the rindex 

produced by passing the ‘cookie’ (randomid value) through the one_way_hash_cookie() 

function.”). 

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The court finds nothing in the insert and rewrite mode disclosures of the specification that 

precludes the use of a table for a purpose other than mapping a unique client identifier to a 

destination server. The experts disagree about whether randomid uniquely identifies the client, and 

the product documentation cited in F5’s infringement contentions is ambiguous. Therefore, a

material dispute remains about whether Alteon operates in the associative mode.

B. Whether Alteon’s Cookie Contains Server Identification Information 

Radware also argues that the accused product cannot infringe because it does not store 

‘server information’ in its cookie. Dkt. No. 240 at 3, 12. Radware contends that the accused 

product cannot infringe any of the asserted claims because each asserted claim requires similar 

server identification information. Dkt. No. 240 at 22.

F5, on the other hand, contends that the “accused version of Alteon practices the insert and 

rewrite modes by utilizing cookies with ‘server identification information,’” Dkt. No. 244 at 1; see 

also Dkt. No. 243-3 at 8-9 (citing Dkt. No. 243-6, Alexander Decl.). The court is not persuaded by 

F5’s argument that the terms “insert” and “rewrite” as recited in the Alteon manual necessarily 

implicate the modes disclosed in the patent, but, as explained above, F5 cites to portions of the

Alteon manual suggesting that the cookie value “represents the responding server.” Dkt. No. 243-

3 at 9; see also Dkt. No. 239-7 at 19 (“Alteon device rewrites the cookie to contain a server ID”). 

Furthermore, F5’s source code analysis suggests that that the randomid identifies a server. Dkt. 

No. 249-6 at 2; Dkt. No. 239-7 at 21). F5’s opposition is supported by Dr. Alexander’s opinion

that the randomid that hashes to the rindex that “identifies the selected real server.”

3 Dkt. No. 243-

6 ¶ 17. 

F5 also argues that the “virtual server IP address” value in the Alteon cookie may meet the 

server identification information claim limitations. Dkt. No. 243-3 at 7; Dkt. No. 249-6 at 3. 

Radware does not address the virtual IP address in its briefing, but Dr. Rubin opines in his 

 

3 Radware argues that Dr. Alexander’s opinions are unreliable because he did not conduct source 

code review. Dkt. No. 248-3 at 8, 14. Radware cites no authority requiring Dr. Alexander to 

analyze source code. Furthermore, Dr. Rubin cites Alteon documentation that describes the

randomid value as identifying the server, and F5’s infringement contentions include source code 

analysis reaching the same conclusion. 

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