Paper No. 97
`Filed: January 6, 2020
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`––––––––––––––––––
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`––––––––––––––––––
`
`THE MANGROVE PARTNERS MASTER FUND, LTD. and APPLE INC.,
`Petitioners,
`
`v.
`
`VIRNETX INC.,
`Patent Owner.
`
`––––––––––––––––––
`
`Case No. IPR2015-010461
`U.S. Patent No. 6,502,135
`
`––––––––––––––––––
`
`PETITIONERS’ REPLY REMAND BRIEF
`
`
`
`1 Apple Inc., who filed a petition in IPR2016-00062, has been joined as a Petitioner
`in the instant proceeding.
`
`

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`IPR2015-01046
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`U.S. Patent No. 6,502,135
`
`TABLE OF CONTENTS
`
`B.
`
`Introduction....................................................................................... 1
`I.
`II. Claim Construction ............................................................................ 1
`A.
`“Client Computer” ...................................................................... 1
`1.
`The Claim Language Supports Petitioners’ Construction ......... 2
`2.
`The Specification Confirms a “Client Computer” Is Not
`Necessarily a User’s Computer ............................................ 4
`The Extrinsic Evidence Supports Petitioners’ Construction ..... 7
`3.
`“Virtual Private Network (VPN)” ................................................. 9
`B.
`III. The Claims Are Anticipated under Both of Petitioners’ Mappings ...... 15
`A.
`Petitioners’ “User Agent to Origin Server” Mapping ..................... 15
`1.
`Kiuchi Uses a Single HTTP Connection, Not Two Distinct
`Socket Connections Like Aventail ..................................... 16
`Kiuchi’s User Agent Directly Addresses the Origin Server .... 19
`2.
`Petitioners’ “Client-Side Proxy to Server-Side Proxy” Mapping...... 23
`1.
`Kiuchi’s Client-Side Proxy Meets Petitioners’ Construction of
`“Client Computer” ........................................................... 24
`Kiuchi’s Client-Side Proxy Meets Even VirnetX’s Construction
`of “Client Computer” ....................................................... 26
`C. Dr. Guerin’s Testimony is Probative and Entitled to Weight ........... 28
`IV. VirnetX’s Procedural Arguments Are Meritless ................................ 29
`A. VirnetX Concedes the Evidence Shows No § 315(b) Violation ....... 29
`B. VirnetX’s Arthrex Complaints Should Be Dismissed ..................... 33
`C. VirnetX Is Not Prejudiced by Apple’s Participation....................... 34
`V. Conclusion ....................................................................................... 35
`Exhibit List ............................................................................................... 36
`Certificate of Compliance .......................................................................... 40
`Certificate of Service ................................................................................. 41
`
`
`
`2.
`
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`

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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Abbott Labs. v. Cordis Corp.,
`710 F.3d 1318 (Fed. Cir. 2013) ................................................................ 29
`
`Amazon.com, Inc. v. Barnesandnoble.com, Inc.,
`239 F.3d 1343 (Fed. Cir. 2001) ........................................................... 13, 25
`Anchor Wall Systems, Inc. v. Rockwood Retaining Walls, Inc.,
`340 F.3d 1298 (Fed. Cir. 2003) .............................................................. 7, 9
`Applications in Internet Time, LLC v. RPX Corp.,
`897 F.3d 1336 (Fed. Cir. 2018) ................................................................ 35
`Arctic Cat Inc. v. Polaris Indus., Inc.,
`No. 19-1440, slip op. (Fed. Cir. Dec. 23, 2019) .......................................... 32
`
`Arthrex, Inc. v. Smith & Nephew, Inc.,
`941 F.3d 1320 (Fed. Cir. 2019) ................................................................ 36
`Becton, Dickinson & Co. v. Tyco Healthcare Grp., LP,
`616 F.3d 1249 (Fed. Cir. 2010) .................................................................. 4
`CAE Screenplates, Inc. v. Heinrich Fiedler GmbH & Co. KG,
`224 F.3d 1308 (Fed. Cir. 2000) .................................................................. 5
`Garmin Int’l, Inc. v. Cuozzo Speed Techs. LLC,
`IPR2012-00001, Paper 26, 6 (June 11, 2013) ............................................. 32
`
`In re Gleave,
`560 F.3d 1331 (Fed. Cir. 2009) ........................................................... 26, 27
`Liebel-Flarsheim Co. v. Medrad, Inc.,
`358 F.3d 898 (Fed. Cir. 2004) .................................................................... 6
`Nidec Motor Corporation v. Zhongshan Broad Ocean Motor Co. Ltd.
`Matal,
`868 F.3d 1013 (Fed. Cir. 2017) (Dyk, J., concurring) ............................. 36,37
`
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`Novartis AG v. Noven Pharmaceuticals,
`853 F. 3d 1289 (Fed. Cir. 2017) ............................................................... 28
`In re NuVasive, Inc.,
`841 F.3d 966 (Fed. Cir. 2016) .................................................................. 31
`Omega Eng’g, Inc, v. Raytek Corp.,
`334 F.3d 1314 (Fed. Cir. 2003) .................................................................. 3
`Phillips v. AWH Corp.,
`415 F.3d 1303 (Fed. Cir. 2005) (en banc) ................................................ 2, 7
`Power Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc.,
`843 F.3d 1315 (Fed. Cir. 2016) ................................................................ 21
`In re Rambus Inc.,
`694 F.3d 42 (Fed. Cir. 2012) ...................................................................... 3
`Teleflex, Inc. v. Ficosa N. Am. Corp.,
`299 F.3d 1313 (Fed. Cir. 2002) .................................................................. 6
`U.S. v. $671,160.00 in U.S. Currency,
`730 F.3d 1051 (9th Cir. 2013) .................................................................. 34
`Unwired Planet, LLC v. Google Inc.,
`841 F.3d 995 (Fed. Cir. 2016) .................................................................. 21
`VirnetX Inc. v. Mangrove Partners Master Fund, Ltd.,
`778 F. App’x 897 (Fed. Cir. 2019)............................................ 10, 28, 35, 37
`VirnetX, Inc. v. Cisco Sys., Inc.,
`767 F.3d 1308 (Fed. Cir. 2014) ......................................................... passim
`Statutes
`35 U.S.C. § 315(b) ........................................................................... 31, 35, 36
`35 U.S.C. § 316(a)(5) .................................................................................. 32
`Other Authorities
`37 C.F.R. § 11.18(b)(2)(iii)-(iv) .................................................................... 35
`37 C.F.R. § 42.23........................................................................................ 31
`iii
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`37 C.F.R. § 42.52........................................................................................ 33
`37 C.F.R. § 42.62........................................................................................ 35
`
`iv
`PETITIONERS’ REPLY REMAND BRIEF
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`IPR2015-01046
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`I.
`
`Introduction
`
`U.S. Patent No. 6,502,135
`
`VirnetX’s opposition (“Opp.”) strains the language of its claims, the ’135
`
`patent’s specification, and the record of these and related proceedings to contend
`
`its claims are patentable over Kiuchi. They are not—as Petitioners explained in
`
`their petition (“Pet.”), reply (“Reply”), and opening remand brief (“Br.”), Kiuchi
`
`anticipates the challenged claims.
`
`II. Claim Construction
`
`A.
`
`“Client Computer”
`
`The plain and ordinary meaning of a “client computer”—a “computer from
`
`which a data request to a server is generated”—aligns fully with the language and
`
`context of the claims in this and VirnetX’s related patents, the ’135 patent
`
`specification, and the extrinsic record. 2 Pet. 16; Br. 6-9.
`
`VirnetX contends a “client computer” can only be a user’s computer. Opp. 3.
`
`But VirnetX’s expert admitted the ’135 patent did not give “client computer” a
`
`special definition (Ex. 1036, 74:15-75:16, 95:1-5), and VirnetX identifies nothing
`
`in the prosecution history that altered its plain and ordinary meaning. Those facts
`
`doom VirnetX’s efforts to redefine this term now. The Board has thus properly
`
`
`
`2 VirnetX now represents the ’135 patent expired in 2019 (Opp. 2 n.2) but
`
`identifies no claim construction consequences of this fact. Opp. 3-11; Br. 8.
`
`1
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`rejected VirnetX’s attempts to constrict the meaning of “client computer.” E.g.,
`
`IPR2014-00403, Paper 42, 23-24; IPR2014-00404, Paper 42, 7-9; IPR2014-00481,
`
`Paper 35, 26-27; IPR2014-00482, Paper 34, 9-12.
`
`1.
`
`The Claim Language Supports Petitioners’ Construction
`
`The language and context in which “client computer” is used in the claims
`
`confirms that Petitioners’ construction is correct. Phillips v. AWH Corp., 415 F.3d
`
`1303, 1314-15 (Fed. Cir. 2005) (en banc). The claims use “client computer” to
`
`distinguish the computer that generates a “request” from the computer referenced
`
`in that request. Claim 1 recites, for example, “creating a [VPN] between a client
`
`computer and a target computer,” and “generating from the client computer a …
`
`request” for “an IP address corresponding to a domain name associated with the
`
`target computer ….”3 Those roles align with the conventional meaning of “client”
`
`in a client-server system; the “client” generates a request, while the target (e.g., a
`
`server) is identified by that request.
`
`Petitioners’ construction likewise reflects the skilled artisan’s understanding
`
`that a device in a client-server system that acts as a server in one operation can act
`
`as a client in another. Ex. 1014, 5-6. Indeed, nothing in the claims precludes a
`
`“target computer” in a first transaction from being a “client computer” in a second
`
`
`
`3 All emphasis added unless otherwise noted.
`
`2
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`transaction involving a different “target computer.” Thus, far from “do[ing]
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`violence to the claim language” (Opp. 8), Petitioners’ construction perfectly aligns
`
`with it.
`
`VirnetX’s construction, conversely, finds no support in the language or
`
`context of the claims. Critically, none of the claims contain language requiring the
`
`computer making the request to be a “user’s computer” despite the specification
`
`explicitly using that term. The claims also do not require checking a user’s status
`
`or credentials—they instead specify actions based on attributes of the request or
`
`the computer making the request. For example, claims 1 and 10, asses attributes
`
`of the domain name in the request (i.e., whether it is “requesting access to a secure
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`web site”), while claim 13 inquires whether “the request received … is from an
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`authorized client.” See also §II.A.2. And the “client,” of course, is a computer,
`
`not a person.
`
`VirnetX’s related patents likewise contradict its arguments. For example,
`
`claim 1 of U.S. Patent No. 9,386,000 recites a “client device” and then adds that
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`“the client device is a user device.”4 If “client” device already meant a “user”
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`device, the additional language in this claim would be superfluous. See Becton,
`
`Dickinson & Co. v. Tyco Healthcare Grp., LP, 616 F.3d 1249, 1257 (Fed. Cir.
`
`
`
`4 See also, e.g., U.S. Pat. App. Pub. No. 2017/0063799, claim 29.
`
`3
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`2010). VirnetX’s related patents thus confirm a “client” computer is not
`
`necessarily a “user’s” computer. Omega Eng'g, Inc, v. Raytek Corp., 334 F.3d
`
`1314, 1334 (Fed. Cir. 2003) (claim terms presumed to have the same meaning in
`
`related patents); In re Rambus Inc., 694 F.3d 42, 48 (Fed. Cir. 2012).
`
`2.
`
`The Specification Confirms a “Client Computer” Is Not
`Necessarily a User’s Computer
`
`Given the absence of support for its proposed construction in the language
`
`and context of the claims, VirnetX reads its patent specification as supposedly
`
`redefining “client computer” to mean only a user’s computer. But the specification
`
`expressly distinguishes a “client computer” from a “user’s computer,” and the
`
`passages VirnetX cites cannot justify limiting the claims as it proposes.
`
`Initially, VirnetX dismisses the ’135 patent’s distinction between a “user’s
`
`computer” and a “client computer” (Ex. 1001, 39-17-20, 39:22-29, 44:40-45),
`
`contending the terms “are described synonymously” and are “not distinguish[ed].”
`
`Opp. 9-10. But the specification refutes VirnetX’s assertions: one passage states a
`
`“user’s computer includes a conventional client (e.g., a web browser)…” (Ex.
`
`1001, 38:14-15), while another uses “client computer” without any statement or
`
`suggestion it must be a user’s device (Id., 16:16-19, Fig. 8). VirnetX ignores the
`
`latter, and implausibly asserts the former supports its construction, arguing that
`
`because a “user’s computer” has “a client” on it, the patent specification has
`
`equated a “client computer” with the “user’s computer.” Opp. 8-9. But that
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`4
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`ignores that this sentence expressly differentiates the terms “user’s computer” and
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`“client” and that its language is illustrative, not definitional—a web browser
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`running on the user’s computer is identified as an example (“e.g.,”) of a client.
`
`And while VirnetX argues the specification supports its construction because it
`
`does “not distinguish” between the terms (Opp. 9-10), that flouts the presumption
`
`that “the use of … different terms … connotes different meanings.” CAE
`
`Screenplates, Inc. v. Heinrich Fiedler GmbH & Co. KG, 224 F.3d 1308, 1317
`
`(Fed. Cir. 2000).
`
`VirnetX contends other passages discussing authorization of users compel
`
`equating “client computer” with “user’s computer.” Opp. 3-5. They do not. One,
`
`describing a single embodiment of the invention, calls for a determination that a
`
`user has sufficient security privileges, but critically, imposes no restrictions on
`
`how that determination is made, much less requires it to be made with a “user’s
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`computer.” Ex. 1001, 38:23-30. Instead, it explains a user’s authorization can be
`
`checked without a user’s credentials and can be delegated to devices other than the
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`“user’s computer.” Id., 39:6-13 (“Such a check can be made with reference to an
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`internally stored list of authorized IP addresses or can be made by communicating
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`with gatekeeper 2603 (e.g., over an “administrative” VPN 50 that is secure).” In
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`the former case, if the IP address of a proxy computer associated with a user’s
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`5
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`U.S. Patent No. 6,502,135
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`computer is on the “internally stored list” it would authorize the user in this
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`example (as in Kiuchi).
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`VirnetX also argues that, “[i]n every example” in the specification, “the
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`computer at the other end of the encrypted/secure channel from the ‘secure
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`server’—the claimed ‘client’—is the computer being operated by the user.” Opp.
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`4-5. That is incorrect (see above), and even if true, would not justify redefining
`
`“client” to mean “a user’s computer.” Liebel-Flarsheim Co. v. Medrad, Inc., 358
`
`F.3d 898, 906 (Fed. Cir. 2004) (rejecting contention that claims must be limited to
`
`a patent’s single embodiment). VirnetX also identifies no “expressions of manifest
`
`exclusion of restriction representing a clear disavowal of claim scope” (Teleflex,
`
`Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1325 (Fed. Cir. 2002)), and its expert,
`
`Dr. Monrose, conceded there were none (Ex. 1036, 74:15-75:16, 95:1-5). VirnetX
`
`simply ignores the “distinction between using the specification to interpret the
`
`meaning of a claim and importing limitations from the specification into the
`
`claim.” Phillips, 415 F.3d at 1323.
`
`VirnetX also asserts the specification “expressly distinguishes the ‘client’
`
`from proxies like Kiuchi’s client-side proxy.” Opp. 5, 8-9. But here VirnetX
`
`ignores that one computer can play multiple roles in a client-server system. And by
`
`stating “[t]he destination server sees only the [IP] address of the proxy server and
`
`not the originating client” (Ex. 1001, 1:53-55), its specification not only confirms
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`6
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`U.S. Patent No. 6,502,135
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`that multiple types of clients exist in the claimed systems but that from the
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`destination server’s perspective, the “client computer” can be the proxy server.
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`Other passages use “client computer” without any reference or context
`
`suggesting the necessity of a “user.” See, e.g., id., 6:35-36; 6:41-42; 7:33-36;
`
`16:16-17:5. VirnetX cannot simply dismiss these passages because they
`
`purportedly do not describe “the claimed VPN.” Opp. 10-12. As the Federal
`
`Circuit has held, “claim terms are normally used consistently throughout the
`
`patent,” Phillips, 451 F.3d at 1314, and a “varied use of a disputed term in the
`
`written description attests to the breadth of a term rather than providing a limiting
`
`definition,” Anchor Wall Systems, Inc. v. Rockwood Retaining Walls, Inc., 340
`
`F.3d 1298, 1308-09 (Fed. Cir. 2003).
`
`The ’135 patent’s thus uses “client computer” in its ordinary sense: a
`
`“computer from which a data request to a server is generated.”
`
`3.
`
`The Extrinsic Evidence Supports Petitioners’ Construction
`
`Petitioners’ extrinsic evidence addresses a skilled artisan’s understanding of
`
`“clients” in the same context as the claimed systems: secure communications over
`
`the Internet using “a conventional client” in a client-server system. Ex. 1001, 2:66;
`
`38:14-15. RFC 1945 defines the HTTP protocol from the late 1990s and early
`
`2000s (Ex. 1014, 1, 4), RFC 1983 concerns communications between two
`
`computers over “the Internet” (Ex. 1037, 1), and the Microsoft Computer
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`7
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`Dictionary defines “client” in “a local area network or the Internet.” Ex. 1043, 88.
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`Each describes a “client” as not being limited to a “user’s” computer, but as
`
`encompassing any “device, computer, system, or program from which a data
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`request to a server is generated.” Pet. 16; Br. 6-9; Ex. 1014, 5 (any “application
`
`program that establishes connections for the purpose of sending requests.”); Ex.
`
`1037, 11 (“A computer system or process that requests a service of another
`
`computer system or process”); Ex. 1043, 88 (“a computer that accesses shared
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`network resources provided by another computer”). Each aligns with the ’135
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`patent’s specification’s statement that a computer can include a client, and that a
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`web browser is an example of a client. Ex. 1001, 38:14-15.
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`VirnetX claims that RFC 1945 defines a “user agent” as “[t]he client which
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`initiates a request” (Opp. 6 n.3), but ignores RFC 1945’s explanation that a proxy
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`“acts as both a server and a client for the purpose of making requests on behalf of
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`other clients” and that “[a]ny given program may be capable of being both a client
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`and a server; … these terms refers only to the role being performed by the program
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`for a particular connection, rather than to the program’s capabilities in general”
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`(Ex, 1014, 5-6). See also Ex. 1037, 11 (defining “client” as a “computer system or
`
`process that requests a service of another computer system or process”); Ex. 1043,
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`88 (explaining that, in a “client/server architecture,” both client and server can be
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`personal computers).
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`8
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`VirnetX cites the Computer Desktop Encyclopedia (Ex. 2028), but this
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`supports Petitioners’ construction, explaining “client” encompasses not only a
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`“workstation or personal computer in a client/server environment” but also “[o]ne
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`end of the spectrum in a request/supply relationship between programs,” i.e., a
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`component “from which a data request to a server is generated.” Ex. 2028, 3; Pet.
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`16. Moreover, the “varied use of a disputed term … attests to the breadth of a term
`
`rather than providing a limiting definition.” Anchor Wall, 340 F.3d at 1308-09.
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`Finally, VirnetX’s criticisms of the expert testimony are unwarranted. Opp.
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`7-8. Dr. Guerin testified that Kiuchi’s client-side proxy (consistent with RFC
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`1945) “acts as a client computer in its communication with the server-side proxy
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`and as a server in its communication with the user agent.” Ex. 1003, ¶19; Ex. 1014,
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`5. Likewise, Dr. Monrose testified that a computer that makes a request of another
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`can be considered a “client computer.” Ex. 1036, 97:16-99:4.
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`B.
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`“Virtual Private Network (VPN)”
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`The Federal Circuit found that a “VPN between a client computer and a
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`target computer” requires “direct” communications between a client and a target
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`but left to the Board the task of determining whether Kiuchi discloses such “direct”
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`communications. VirnetX Inc. v. Mangrove Partners Master Fund, Ltd., 778 F.
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`App’x 897, 910 (Fed. Cir. 2019) (“[W]e leave it to the Board to assess Kiuchi’s
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`disclosure in light of the proper construction”). As Petitioners explain (Br. 18 and
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`9
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`U.S. Patent No. 6,502,135
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`below), Kiuchi’s user agent communicates “directly” with the origin server by
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`directly addressing the origin server using a single HTTP connection.
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`Central to the Federal Circuit’s construction was a disclaimer made by
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`VirnetX to distinguish its claims from the Aventail system during reexamination of
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`the ’135 patent. 778 F. App’x at 908-10; Ex. 2036, 4-8. But VirnetX nowhere in
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`its remand brief describes the details of Aventail’s system or what, precisely, it told
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`the Examiner. What those details reveal is that, while VirnetX disclaimed systems
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`that use multiple point-to-point connections at a lower (“socket layer”) level of the
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`network architecture, it did not disclaim systems like Kiuchi’s that directly address
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`a target computer using a single HTTP connection and communications sent in the
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`higher “application layer.”5
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`During the reexamination, VirnetX explained why its claimed “VPN” did not
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`encompass Aventail’s system as follows:
`
`Aventail discloses a system where a client on a public network
`transmits data to a SOCKS server via a singular, point-to-point
`
`
`
`5 On appeal, VirnetX argued it only disclaimed communications that are not
`
`“direct,”—it did not assert other distinctions raised in the reexamination that
`
`created the disclaimer. No. 2017-1368, Dkt. No. 45 at 46; Ex. 2036, 5-7.
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`10
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`SOCKS connection at the socket layer6 of the network architecture.
`The SOCKS server then relays that data to a target computer on a
`private network on which the SOCKS server also resides. All
`communications between the client and target stop and start at the
`intermediate SOCKS server. The client cannot open a connection
`with the target itself. Therefore, one skilled in the art would not have
`considered the client and target to be virtually on the same private
`network.
`
`Ex. 2036, 7 (citations omitted). VirnetX thus asserted that because Aventail’s
`
`system uses two separate socket level communications, one between the client and
`
`the SOCKS server, and a second between the SOCKS server and the target
`
`computer, the Aventail client does not communicate directly with a target
`
`computer at the socket layer (i.e., the client does not open a socket level
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`communication with the target computer). Those multiple “point-to-point”
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`connections, VirnetX contended, prevented Aventail’s client computer from being
`
`able to directly address the target computer. Id.; see id., 5-6.
`
`
`
`6 Aventail’s socket connections “operate[] between the WinSock and TCP/IP
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`layers,” and well below the application layer. Ex. 2036, 6-7 (showing WinSock
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`and Aventail below the “Windows TCP/IP application” layer). HTTP “is an
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`application-level protocol.” Ex. 1014, 1.
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`11
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`
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`Importantly, VirnetX did not distinguish Aventail’s system simply because it
`
`uses intermediary network devices such as proxy servers or firewalls. Indeed, in
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`its subsequent efforts to enforce its patents, VirnetX has consistently asserted that
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`systems that include such intermediary network devices do not prevent “direct
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`communications.”7 For example, VirnetX told the Federal Circuit in the appeal of
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`its first jury verdict against Apple that its disclaimer only excluded systems in
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`which connections started and stopped at an intermediary device—and, critically,
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`did not exclude systems in which communications are routed through intermediary
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`network devices such as Network Address Translator (NAT) routers. Br. for
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`Plaintiffs-Appellees VirnetX Inc., No. 2013-1489, Dkt. No. 54 (Fed. Cir. Dec. 9,
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`2013) (“PO 2013-CAFC Br.”), 21-22 (“NAT routers do not terminate the
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`connection” between the end devices), 27 (arguing that “NAT routers simply route
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`FaceTime calls and therefore provide direct communication”), 51 (“NAT routers
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`do not stop or terminate communications between FaceTime devices.”).
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`VirnetX likewise explained that transporting network traffic across proxy
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`servers and firewalls does not prevent direct communications. For example,
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`
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`7 VirnetX cannot construe its patent more narrowly for patentability than it did for
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`infringement. Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343, 1351
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`(Fed. Cir. 2001).
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`12
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`VirnetX argued that Apple’s VPN On Demand product infringed the ’135 patent
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`even though it transports communications from a public network to a private
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`network using proxy servers and firewalls. PO 2013-CAFC Br. 19 (“[F]or VPN On
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`Demand, the private network includes… VPN servers…, firewalls, and proxy
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`servers.”), 38-39 (“VPN On Demand…use[s]…VPN servers…proxy servers,
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`and/or firewalls, before permitting access into or out of a private network”).
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`And the Federal Circuit has relied on VirnetX’s assertions, explaining that
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`the district court’s claim construction “expressly provided that ‘routers, firewalls,
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`and similar servers ... do not impede ‘direct’ communication,’ and VirnetX
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`presented evidence that NATs operate like routers or firewalls.” VirnetX, Inc. v.
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`Cisco Sys., Inc., 767 F.3d 1308, 1320-21 (Fed. Cir. 2014).
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`Thus, when enforcing its patents, VirnetX has emphasized that “direct
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`addressability” of the target computer is the critical feature that makes a
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`communication “direct.” For example, in its litigation with Apple, VirnetX’s
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`expert testified that direct communication refers to direct addressability of the
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`target computer. Ex. 1044, 50:25-51:5 (“Q… I believe that you've told us that
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`direct communication refers to direct addressability, correct? A. That’s correct.”).
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`Then, in the appeal of that jury verdict, VirnetX told the Federal Circuit that
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`Apple’s accused FaceTime software satisfied the “direct” requirement because it
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`“allow[ed] for direct addressability” of a particular target device. PO 2013-CAFC
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`13
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`Br. 51-52. VirnetX also argued that although FaceTime communications between
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`a client and a target pass through a NAT router that modified the IP addresses of
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`the client and the target, communications were still direct because the message
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`included a transport address that mapped to the target device. Id., 21-22. 8
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`VirnetX adopted the same position in this proceeding. Its expert, Dr.
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`Monrose, testified that “direct” refers to direct addressability. Ex. 1036, 79:22-
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`80:7 (“I believe that figure 2 describes a link between the originating TARP
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`terminal and the destination TARP terminal as being direct, in that… TARP
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`terminal 110 [sic] can directly address TARP terminal 110”). He also explained
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`that messages depicted in Figure 2 of the ’135 patent were “direct” because the
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`client can address the target, even though those messages pass through many
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`intermediary network devices.
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`
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`8 While the Federal Circuit vacated the finding that FaceTime infringed related
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`patents with this “direct” requirement, it found substantial evidence supported that
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`FaceTime met the “direct” communication requirement. 767 F.3d at 1319-20.
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`14
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`Ex. 1036, 79:22-80:7.
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`
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`The use of proxy servers (such as in Kiuchi’s system) thus does not prevent
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`a communication from being “direct” in the meaning of the claims.
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`III. The Challenged Claims Are Anticipated under Both of Petitioners’
`Mappings
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`Kiuchi anticipates the challenged claims in two independent ways: (i) its
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`user agent (a “client computer”) communicates directly with the origin server via
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`HTTP (Br. 13-24) and (ii) its client-side proxy (also a “client computer”)
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`communicates directly with the server-side proxy (Br. 24-30). Under either
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`mapping, the challenged claims are unpatentable.
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`A.
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`Petitioners’ “User Agent to Origin Server” Mapping
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`There is no dispute that Kiuchi’s user agent is a “client computer,” even
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`under VirnetX’s construction. The sole issue in dispute regarding this mapping is
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`whether Kiuchi’s user agent “directly” communicates with the origin server. Br.
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`13-24. It does—Kiuchi establishes a single HTTP connection between the user
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`agent and the origin server, and the HTTP messages directly address the origin
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`server, which compel a finding of direct communications. Br. 18-19.
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`Instead of defining what “direct” communications require or explaining why
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`Kiuchi’s communications are not direct, VirnetX concocts a new theory: that the
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`Federal Circuit already found Kiuchi’s user agent communications not to be
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`“direct” because they use a “relay”-based system. Opp. 13, 15-16. But that
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`mischaracterizes both multiple Federal Circuit decisions and the record. Indeed, if
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`the Federal Circuit had resolved whether Kiuchi’s communications are direct, its
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`mandate for the Board to determine this question on remand would make no
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`sense. The evidence and VirnetX’s past admissions establish that Kiuchi’s user
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`agent directly communicates with the origin server and anticipates the claims.
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`1.
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`Kiuchi Uses a Single HTTP Connection, Not Two Distinct
`Socket Connections Like Aventail
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`Kiuchi describes communications between a user agent and origin server
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`that use a single HTTP connection. Br. 18-24. Specifically, Kiuchi’s user agent
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`sends a HTTP Get request, which is an application layer communication routed
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`through the client-side and server-side proxies and delivered to the origin server.
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`Ex. 1002, 65-66 (§2.3); Ex. 1014, 4. Kiuchi does not disclose any break in that
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`HTTP connection.
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`Kiuchi’s single HTTP connection bears no resemblance to the multiple
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`socket layer connections that VirnetX said distinguished the Aventail system from
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`16
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`IPR2015-01046
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`U.S. Patent No. 6,502,135
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`its claims—as VirnetX stated, Aventail “only discloses communications at the
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`socket layer” and uses two sets of socket layer (i.e., transport layer)
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`communications. Ex. 2036, 6. Thus, according to VirnetX, the Aventail client
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`cannot open a socket layer connection to the target device, but instead opens a
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`socket layer connection with the Aventail SOCKS server, which in turn
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`communicates with the target over a separate connection. Id., 6-7.
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`Mischaracterizing its disclaimer, VirnetX asserts its claims exclude Kiuchi’s
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`system because (i) it uses three “separate” connections: an unencrypted HTTP
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`connection between the user agent and client-side proxy, an encrypted C-HTTP
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`connection between the proxies, and another unencrypted HTTP connection
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`between the server-side proxy and the origin server, and (ii) the proxies
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`“terminate” connections when they encrypt/decrypt and wrap/unwrap the HTTP
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`messages within C-HTTP messages.9 Opp. 15-16.
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`VirnetX is wrong on both points. First, unlike Aventail’s client, Kiuchi’s
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`user agent establishes a single HTTP connection with the origin server. Second,
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`Kiuchi’s (i) encrypting and wrapping of HTTP messages within C-HTTP messages
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`for transport over a public network and (ii) decrypting and unwrapping them for
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`further transport over private networks does not break the direct HTTP
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`
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`9 Ex. 1002,