Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 1 of 38 PageID #: 6158
`
`IN THE UNITED STATES DISTRICT COURT
`FOR THE EASTERN DISTRICT OF TEXAS
`TYLER DIVISION
`
`VimetX Inc. and Science Applications International
`Corporation,
`
`Plaintiffs,
`
`v'
`
`Civil Case No. 6:1 1-cv-00018—LED
`
`Mitel Networks Corporation, Mitel Networks, Inc.,
`Siemens Enterprise Communications GmbH & Co.
`KG, Siemens Enterprise Communications, Inc.,
`and Avaya Inc.
`
`Defendants.
`
`
`
`DEFENDANTS’ RESPONSIVE CLAIM CONSTRUCTION BRIEF
`
`Page 1 of 38
`
`VIRNETX EXHIBIT 2031
`
`Mangrove V. VirnetX
`Trial |PR2015—01046
`
`
`
`
`
`
`
`
`
`VIRNETX EXHIBIT 2031
`Mangrove v. VirnetX
`Trial IPR2015-01046
`
`Page 1 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 2 of 38 PageID #: 6159
`
`TABLE OF CONTENTS
`
`I.
`
`INTRODUCTION .................................................................................................................. 1
`
`II. LEGAL STANDARDS .......................................................................................................... 2
`
`III.
`
`PATENTS-IN-SUIT ............................................................................................................ 2
`
`IV.
`
`LEVEL OF ORDINARY SKILL IN THE ART ................................................................. 2
`
`V. DISPUTED CLAIM CONSTRUCTIONS ............................................................................. 3
`
`A.
`
`Disputes Concerning Types of Communication Links .................................................... 3
`
`1.
`
`2.
`
`3.
`
`―Virtual private network‖ ............................................................................................. 3
`
`―Virtual private link‖ .................................................................................................... 9
`
`―Secure communication link‖ ..................................................................................... 10
`
`B.
`
`The ―Indicate‖ / ―Indicating‖ / ―Indication‖ Disputes ................................................... 14
`
`―An indication that the domain name service system supports establishing a secure
`1.
`communication link‖ ............................................................................................................. 14
`
`―Indicate/indicating in response to the query whether the domain name service
`2.
`system supports establishing a secure communication link‖ ................................................ 15
`
`Disputes Concerning Domain Name, Domain Name Service, Secure Domain Name,
`C.
`and Query .................................................................................................................................. 18
`
`1.
`
`2.
`
`3.
`
`4.
`
`5.
`
`―Domain name‖ .......................................................................................................... 18
`
`―Query‖ ....................................................................................................................... 23
`
`―Domain Name Service (DNS)‖................................................................................. 24
`
`―DNS proxy server‖ .................................................................................................... 25
`
`―Domain Name Service System‖ ............................................................................... 25
`
`D.
`
`Disputes Concerning Web Site, Secure Web Site, Secure Web Computer, etc. ............ 26
`
`1.
`
`2.
`
`3.
`
`―Web site‖ ................................................................................................................... 26
`
`―Secure web site‖ ........................................................................................................ 27
`
`―Secure target web site‖ ............................................................................................. 28
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`Page 2 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 3 of 38 PageID #: 6160
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`4.
`
`―Target computer‖ ...................................................................................................... 28
`
`E.
`
`The ―Between‖ Disputes ................................................................................................ 29
`
`1.
`
`2.
`
`―Between [a/the] first location and [a/the] second location‖ ...................................... 29
`
`―Between a client computer and target computer‖ ..................................................... 29
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`VI. CONCLUSION .................................................................................................................. 29
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`Page 3 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 4 of 38 PageID #: 6161
`
`CASES
`
`TABLE OF AUTHORITIES
`
`Agilent Techs., Inc. v. Affymetrix, Inc.,
`567 F.3d 1366 (Fed. Cir. 2009)................................................................................................19
`
`Amazon.com, Inc. v. Barnesandnoble.com, Inc.,
`239 F.3d 1343 (Fed. Cir. 2001)..................................................................................................6
`
`Becton, Dickinson and Co. v. Tyco Healthcare Group, LP,
`616 F.3d 1249 (Fed. Cir. 2010)................................................................................................19
`
`Bicon, Inc. v. Straumann Co.,
`441 F.3d 945 (Fed. Cir. 2006)............................................................................................19, 20
`
`CCS Fitness, Inc. v. Brunswick Corp.,
`288 F.3d 1359 (Fed. Cir. 2002)................................................................................................22
`
`In re Am. Acad. Of Sci. Tech Ctr.,
`367 F.3d 1359 (Fed. Cir. 2004)................................................................................................27
`
`In re Swanson,
`540 F.3d 1368 (Fed. Cir. 2008)................................................................................................27
`
`Micro Intern. Ltd. v. Beyond Innovation Tech. Co., Ltd.,
`521 F.3d 1351 (Fed. Cir. 2008)................................................................................................23
`
`Nystrom v. Trex Co., Inc.,
`424 F.3d 1136 (Fed. Cir. 2005)..................................................................................................9
`
`Phillips v. AWH Corp.,
`415 F.3d 1303 (Fed. Cir. 2005)................................................................................................23
`
`Takeda Pharm. Co., Ltd. v. Handa Pharms.,
`LLC, 2012 WL 1243109 (N.D. Cal. Apr. 11, 2012) ................................................................23
`
`Thorner v. Sony Comp. Entertainment America LLC,
`669 F.3d 1362 (Fed. Cir. 2012)................................................................................................22
`
`Verizon Servs. Corp. v. Vonage Holdings Corp.,
`503 F.3d 1295 (Fed.Cir.2007)..................................................................................................17
`
`OTHER AUTHORITIES
`
`Alan Freedman, Computer Desktop Encyclopedia (9th ed, 2001) ................................................24
`
`Dick Pountain, The New Penguin Dictionary of Computing (2001) .............................................24
`
`
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`Page 4 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 5 of 38 PageID #: 6162
`
`Dictionary of the Internet (2001) ...................................................................................................23
`
`McGraw- Hill Dictionary of Scientific and Technical Terms (6th ed. 2003) ................................23
`
`Phillip A. Laplante, Dictionary of Computer Science, Engineering, and Technology
`(2001) .......................................................................................................................................24
`
`S.M.H. Collin, Dictionary of Personal Computing and the Internet (3d ed, 2000) ......................24
`
`
`
`
`
`
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`Page 5 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 6 of 38 PageID #: 6163
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`I.
`
`INTRODUCTION
`
`Recognizing that the Court has already ruled on many of the disputed claim terms of the
`
`‘135, ‘504, and ‘211 Patents in the Microsoft and Cisco Cases, Defendants have focused their
`
`responsive brief on a discrete set of issues not previously before the Court. First, since the Cisco
`
`Markman hearing, VirnetX has submitted hundreds of pages of argument and expert declarations
`
`to the Patent Office in connection with reexaminations of the ‘135, ‘504, and ‘211 Patents, in an
`
`attempt to distinguish the patents from prior art (each and every claim of all three patents
`
`currently stands rejected). These statements made to distinguish prior art during reexamination
`
`must also bind VirnetX in this litigation.
`
`Second, Defendants request the Court make explicit its conclusion in the Cisco case that
`
`the claims of the ‘504 and ‘211 Patents require an indication to the user. Although the Court
`
`agreed with Cisco Defendants on that point, the Court concluded their proposed construction was
`
`too narrow because it required a visible indication to the user, whereas it would also be possible
`
`to inform the user with an audible indication. Defendants in this case have not limited the
`
`indication to any particular form, whether visible, audible, or otherwise. The critical conclusion
`
`is one the Court has already reached—that the indication is presented to the user.
`
`Finally, for a limited number of other claim terms, Defendants have proposed a different
`
`construction from the Cisco Defendants that more succinctly focuses the parties‘ dispute in a
`
`way the Court has not previously considered, while staying faithful to the claim language,
`
`specification, and prosecution history. Throughout, Defendants have sought to avoid
`
`unnecessary repetition of argument the Court has already considered in the Microsoft and Cisco
`
`Cases and, accordingly, also incorporate by reference the arguments from those briefs that apply
`
`to the claim terms at issue here.
`
`1
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`Page 6 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 7 of 38 PageID #: 6164
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`II. LEGAL STANDARDS
`
`This Court is familiar with the pertinent claim construction principles. For convenience,
`
`Defendants cite to relevant authority in the body of the brief.
`
`III. PATENTS-IN-SUIT
`
`The Court is familiar with the three Patents-in-Suit from the Cisco Case.1 All three
`
`patents are closely related. The ‘504 and ‘211 Patents are based on a continuation-in-part to the
`
`‗135 Patent, adding new material to the specification, most notably a section titled ―One-Click
`
`Secure On-Line Communications and Secure Domain Name Service‖ and related Figures 34 and
`
`35. The Patents-in-Suit have all been subject to reexamination. The Patent Office granted
`
`Microsoft‘s request for inter partes reexamination of the ‘135 Patent, but confirmed the claims
`
`after Microsoft settled with VirnetX and withdrew from the reexamination. Since that time, the
`
`Patent Office has initiated new reexaminations of the ‘135, ‘504, and ‘211 Patents and has issued
`
`Office Actions rejecting each and every claim of all three patents as invalid over the prior art.
`
`VirnetX has responded to the Office Actions, but all three patents remain rejected.
`
`IV. LEVEL OF ORDINARY SKILL IN THE ART
`
`Defendants agree that a person of ordinary skill in the art would have a Master‘s degree
`
`in computer science or computer engineering, or in a related field such as electrical engineering,
`
`as well as about two years of experience in computer networking and in some aspect of security
`
`with respect to computer networks. Defendants also agree with VirnetX that such person would
`
`have actual experience with networking protocols as well as the security of those protocols.
`
`
`1
`All three Patents-in-Suit (the ‘135, ‘504, and ‘211 Patents) are asserted in the Cisco Case.
`However, the Cisco Case also includes other patents that are not asserted here, some of which are
`also related to the ‘135, ‘504 and ‘211 Patents.
`
`2
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`Page 7 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 8 of 38 PageID #: 6165
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`V. DISPUTED CLAIM CONSTRUCTIONS2
`
`A. Disputes Concerning Types of Communication Links
`
`1. “Virtual private network”
`VirnetX’s Proposed Construction
`
`Defendants’ Proposed Construction3
`
`a network of computers which privately
`and directly communicate with each other
`by
`encrypting
`traffic
`on
`insecure
`communication
`paths
`between
`the
`computers
`
`a network of computers which privately
`and directly communicate with each other
`by
`encrypting
`traffic
`on
`insecure
`communication
`paths
`between
`the
`computers
`to accomplish both data
`security and anonymity, and in which a
`computer is able to address additional
`computers over
`the network without
`additional setup
`
`
`
`a. “In which a computer is able to address additional computers over the
`network without additional setup”
`
`Defendants agree with the Court‘s construction in the Cisco case and have adopted it
`
`insofar as it addressed issues presented in that action. However, Defendants wish to bring the
`
`Court‘s attention to statements VirnetX made during the ‘135 Patent reexamination that were not
`
`addressed in the Microsoft or Cisco briefing. These statements require the VPN to be a network
`
`―in which a computer is able to address additional computers over the network without
`
`additional setup.‖ VirnetX argued this distinction to the Patent Office to get the ‘135 Patent out
`
`of reexamination, and VirnetX must therefore be bound to this requirement for purposes of this
`
`
`2
`Defendants have agreed to drop ―DNS request‖ and ―authorized‖ from the list of terms
`requiring the Court‘s construction. Defendants further note that although ―generating from the
`client computer a Domain Name Service (DNS) request‖ was originally a disputed term, VirnetX
`has now agreed to the construction Defendants proposed and the Court reached in the Cisco
`Case. Defendants and VirnetX agree that ―automatically initiating the VPN‖ means ―initiating
`the VPN without involvement of a user.‖
`
`3
`Avaya has agreed to consolidate its position with Mitel and Siemens to narrow the issues
`for the Court.
`
`3
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`Page 8 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 9 of 38 PageID #: 6166
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`case.4 VirnetX also endorsed this requirement in the Microsoft Case, when it proposed that VPN
`
`should be construed as ―a network … which is capable of expanding to include additional
`
`computers and communication paths.‖ Microsoft Case, D.I. 194 (attached as Ex. 1) at 4-6
`
`(emphasis added). In view of VirnetX‘s prior statements to both the Patent Office and this
`
`Court, its current argument that there is ―simply no basis‖ for this requirement (D.I. 153 at 6)
`
`rings especially hollow.
`
`When reviewing the relevant prosecution history in connection with the Cisco case, the
`
`Court noted that VirnetX made three distinctions over the Aventail reference in reexamination.5
`
`The Court also observed that each distinction was ―independently present[ed] and discuss[ed]‖
`
`and that ―[e]ach of these reasons, alone, served to distinguish the claimed VPN from the Aventail
`
`reference.‖ Ex. 19 at 7. VirnetX‘s first distinction was that Aventail was not directed to a VPN
`
`because it did not disclose computers that ―communicate with each other as though they were on
`
`the same network.‖ Response to Office Action (attached as Ex. 2) at 5-7. VirnetX went on to
`
`explain this distinction:
`
`―Aventail has not been shown to demonstrate that computers
`connected via the Aventail system are able to communicate with
`each other as though they were on the same network. Aventail
`discloses establishing point-to-point SOCKS connections between
`a client computer and a SOCKS server. Aventail does not disclose
`a VPN, where data can be addressed to one or more different
`computers across the network, regardless of the location of the
`computer.‖
`
`
`
`
`
`4
`These reexamination proceedings occurred after the Court entered its Claim Construction
`order in the Microsoft Case
`
`5
`The Court and the parties to the Cisco Case focused on the third distinction VirnetX drew
`between its claims and the Aventail reference, which gave rise to the ―directly‖ requirement in
`the construction of VPN.
`
`4
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`Page 9 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 10 of 38 PageID #: 6167
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`Id. at 5-6 (emphasis added). In other words, VirnetX argued that a VPN, as claimed in the ‘135
`
`Patent, requires something more than setting up a point-to-point connection between two
`
`computers. VirnetX further clarified that the additional computers in a VPN can be addressed
`
`―without additional setup”:
`
`For example, suppose two computers, A and B, reside on a public
`network. Id. at ¶ 21. Further, suppose two computers, X and Y,
`reside on a private network. Id. If A establishes a VPN
`
`connection with X and Y's network to address data to X, and B
`separately establishes a VPN connection with X and Y's network
`to address data to Y, then A would nevertheless be able to address
`data to B, X, and Y without additional set up. Id. This is true
`because A, B, X, and Y would all be a part of the same VPN.
`
`Id. (emphasis added). VirnetX specifically distinguished this from Aventail, which discloses two
`
`devices connected directly to one another with a point-to-point connection:
`
`In contrast, suppose, according to Aventail, which only discloses
`communications at the socket layer, A establishes a SOCKS
`connection with a SOCKS server for relaying data to X, and B
`separately establishes a SOCKS connection with the SOCKS
`server for relaying data to Y. Id. at ¶ 22. In this situation, not
`only would A be unable to address data to Y without establishing
`a separate SOCKS connection (i.e. a VPN according to the Office
`Action), but A would be unable to address data to B over a secure
`connection. Id. This is one example of how the cited portions of
`Aventail fail to disclose a VPN. Id.
`
`Id. at 6 (emphasis added). Therefore, a VPN is not a point-to-point connection between computers.
`
`Rather, a VPN would allow additional computers to be addressed over the network without
`
`additional setup.
`
`
`
`Either choosing to ignore or conveniently forget this history, VirnetX makes the blanket,
`
`unsupported statement that there ―is simply no basis‖ for this limitation. D.I. 153 at 6. Yet the
`
`basis is clear—VirnetX‘s own unequivocal representations to the Patent Office. VirnetX cannot
`
`escape the consequences of these statements when making its infringement allegations in this
`
`5
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`Page 10 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 11 of 38 PageID #: 6168
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`case. See Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343, 1351 (Fed. Cir. 2001)
`
`(―A patent may not, like a ‗nose of wax‘ be twisted one way to avoid anticipation and another to
`
`find infringement.‖). In arguing that Aventail does not disclose a VPN, VirnetX has clearly
`
`defined ―virtual private networks‖ as networks within which a computer is able to address
`
`additional computers over the network without additional setup. This requirement is also
`
`consistent with VirnetX‘s position before this Court in the Microsoft Case.
`
`b. The Court’s construction in the Cisco Case
`
`Subject to incorporation of the ―additional computers‖ requirement, Defendants agree
`
`that the Court‘s construction in the Cisco Case was correct and request the Court adopt the same
`
`construction for the reasons discussed in the Microsoft briefing (Ex. 3 at 3-11 and Ex. 4 at 1-4),
`
`the Cisco briefing (Ex. 15 at 2-7) and the Court‘s Cisco Markman order (Ex. 19 at 5-8), which
`
`Defendants expressly incorporate by reference. For the Court‘s convenience, Defendants will
`
`not restate the entire analysis here. Nevertheless, because VirnetX devoted substantial argument
`
`to this term, Defendants will briefly summarize the supporting arguments below.
`
`i. Secure and anonymous
`
`The Court in the Microsoft and Cisco Cases correctly ruled that a VPN requires that the
`
`communications are both secure and anonymous.6 Ex. 19 at 5, 31; Ex. 5 at 8-9. VirnetX now
`
`
`6
` Although the Court‘s reached this conclusion in the Microsoft Case, the Court‘s
`construction did not expressly incorporate those requirements. Microsoft Case, D.I. 246
`(Attached as Ex. 5) at 8-9. As explained in detail by the Cisco Defendants, this resulted in added
`complications at trial where the parties had to rely on cross-examination to convey these
`requirements to the jury, which in turn complicated the trial and increased the risk of jury
`confusion. Ex. 15 at 3-4. To avoid similar complications a second time in the Cisco Case, the
`Court explicitly included the ―secure and anonymous‖ language in its most recent construction of
`VPN. See Cisco Case, D.I. 266, (attached as Ex. R) at 5. These requirements should be
`expressly included in the construction of VPN in this case for the reasons previously addressed
`by the Court.
`
`6
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`Page 11 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 12 of 38 PageID #: 6169
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`argues a VPN does not require anonymity. D.I. 153 at 4-6. Not only is this argument contrary to
`
`the Court‘s rulings, it also contradicts the position VirnetX previously took in the Microsoft
`
`Case.7 There, VirnetX conceded a VPN must achieve both data security and anonymity.8
`
`The intrinsic evidence supports the Court‘s conclusion that a VPN as claimed in the ‘135
`
`Patent provides both security and anonymity. First, the Background of the Invention states that
`
`the invention addresses ―two security issues . . . called data security and anonymity.‖ Ex. A
`
`(‘135 Patent) at 1:35-36 (emphasis added). The ‘135 Patent also specifically explains that
`
`anonymity involves ―prevent[ing] an eavesdropper from discovering that terminal 100 is in
`
`communication with terminal 110.‖ Id. at 1:26-27. Further, the specification repeatedly equates
`
`the word ―private‖ in ―virtual private network‖ with ―anonymity,‖ explaining that ―[a]nonymity
`
`would thus be an issue, for example, for companies that want to keep their market research
`
`interests private.‖ Id. at 1:32-33 (emphasis added). And the remainder of the specification
`
`describes ways to solve the dual security issues of data security and anonymity. Id. at 2:66-3:17,
`
`19:66-20:3, 23:11-36, 37:40-49, 37:63-38:6, 39:29-33. As the Court previously recognized in
`
`
`7
`
`See Microsoft Case, D.I. 391 (attached as Ex. 6) at 88:18-89:17, 155:8-15; Microsoft
`Case, D.I. 392 (attached as Ex. 7) at 64:1-71:12, 85:19-89:1, 93:10-15; Microsoft Case, D.I. 393
`(attached as Ex. 8) at 42:1-43:11, 62:20-65:15; Microsoft Case, D.I. 395 (attached as Ex. 9) at
`100:12-101:25, 105:1-9; Microsoft Case, D.I. 396 (attached as Ex. 10) at 19:5-32:6, 70:2-88:12,
`98:22-109:19, 118:12-121:19, 126:8-18; Microsoft Case, D.I. 397 (attached as Ex. 11) at 56:3-
`59:8; Microsoft Case, D.I. 398 (attached as Ex. 12) at 136:12-137:16.
`
`8
` After issuance of the Court‘s claim construction order, Microsoft moved to have the ―data
`security and anonymity‖ language incorporated in the Court‘s construction of VPN. Microsoft
`Case, D.I. 247. Neither Microsoft nor VirnetX disputed that a virtual private network requires
`anonymity when the Court considered the issue at the pretrial conference in that case. Microsoft
`Case, D.I. 339 (attached as Ex. 14) at 6:16-14:16. Indeed, VirnetX even assured the Court that
`its expert would not contest that ―private‖ requires both anonymity and security.‖ Id. at 12:20-
`13:2. Microsoft ultimately agreed to rely on cross examination of VirnetX‘s expert witnesses,
`rather than expressly incorporating the requirements into the construction, to convey that
`requirement at trial. Id. at 14:2-4.
`
`7
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`Page 12 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 13 of 38 PageID #: 6170
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`the Microsoft Case, because the Detailed Description of the Invention section refers back to the
`
`anonymity features disclosed earlier in the specification, the term VPN requires anonymity
`
`wherever it appears.
`
`VirnetX‘s opening brief rehashes—for a third time—a long-settled dispute from the
`
`Microsoft case about the ―purpose‖ of encapsulation. D.I. 153 at 5-6. As was true in the Cisco
`
`Case, this discussion has no bearing here for several reasons. First, encapsulation is only one of
`
`the methods the ‘135 Patent teaches for achieving anonymity. See Ex. A (‘135 Patent) at 7:49-58
`
`(describing alternate method of accomplishing anonymity by having the destination field of the
`
`IP header point to an intermediary router instead of the ultimate destination). In fact, the Court
`
`expressly acknowledged in the Microsoft Case that anonymity can be achieved with techniques
`
`other than tunneling (encapsulation). Ex. 5 at 9-10. VirnetX‘s recitation of its arguments from
`
`the Microsoft and Cisco Cases should again be rejected.
`
`ii. Directly
`
`
`
`The Court in the Cisco Case correctly found that computers in a VPN communicate
`
`―directly‖ with one another. Ex. 19 at 6-7. VirnetX stated in its opening brief that it does not
`
`object to ―directly‖ subject to the caveat that it ―refers to direct addressability and (i) is not
`
`destroyed by routers, firewalls, and similar servers that participate in typical network
`
`communication, and (ii) does not require a direct, electromechanical connection.‖ D.I. 153 at 6.
`
`Defendants agree that ―directly‖ refers to ―direct addressability‖ as set forth in the Court‘s Cisco
`
`Markman Order and, thus, for efficiency, will not rehash all of the arguments on this point here.
`
`However, Defendants expressly incorporate by reference and preserve all arguments advanced
`
`by the Cisco Defendants regarding VirnetX‘s clear statements to the Patent Office that
`
`computers in a VPN communicate ―directly‖ with each other, and that without direct
`
`communications between the computers there is no VPN. Ex. 15 at 5-7. The Court properly
`
`8
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`Page 13 of 38
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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 14 of 38 PageID #: 6171
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`included the ―directly‖ limitation in the construction of VPN in the Cisco Case because it was
`
`one of three separate distinctions VirnetX made to overcome Aventail during reexamination.
`
`2. “Virtual private link”
`VirnetX’s Proposed Construction
`
`that permits
`link
`a communication
`computers to privately communicate with
`each other by encrypting
`traffic on
`insecure communication paths between
`the computers
`
`
`
`Defendants’ Proposed Construction
`
`a virtual private network as previously
`defined9
`
`The Court in the Cisco Case agreed with Defendants‘ proposed construction. Ex. 19 at 8-
`
`10. In particular, the Court concluded it was appropriate to construe VPN and ―virtual private
`
`link‖ the same way because the ‘135 patent specification ―uses the term[s] . . . interchangeably.‖
`
`Ex. 19 at 9. Defendants expressly incorporate by reference and preserve all arguments advanced
`
`by the Cisco Defendants regarding this term. Among other reasons, the Court‘s analysis is
`
`supported by numerous examples of interchangeable usage throughout the specification10 and by
`
`applicable case law. E.g., Nystrom v. Trex Co., Inc., 424 F.3d 1136, 1143 (Fed. Cir. 2005)
`
`(―[D]ifferent terms or phrases in separate claims may be construed to cover the same subject
`
`matter where the written description and prosecution history indicate that such a reading of the
`
`terms or phrases is proper.‖).
`
`
`9
`Because Defendants‘ construction for ―virtual private link‖ mirrors their construction for
`―virtual private network,‖ Defendants will adopt the Court‘s construction from the Cisco case of
`―a virtual private network as previously defined‖ to maintain consistency.
`
`10
`For example, compare Ex. A (‘135 Patent) at 44:37-40 (―When a packet is received from
`a known user, the signaling server activates a virtual private link (VPL) between the user and the
`transport server. . . .‖), with id. at 45:10-13 (noting that the signaling server requests the transport
`server to create a hopping table for the purpose of ―creating a VPN with client 3103.‖), and id. at
`45:32-35 (―After a VPN has become inactive for a certain time period (e.g. one hour), the VPN
`can be automatically torn down by transport server 3102 or signaling server 3101.‖).
`
`9
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`Page 14 of 38
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`

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`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 15 of 38 PageID #: 6172
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`VirnetX does not respond substantively to this analysis. VirnetX merely requests that the
`
`Court reject a proposed ―anonymous‖ or ―without additional setup‖ requirement for virtual
`
`private link ―for the reasons discussed above in [the VPN section of VirnetX‘s brief].‖ D.I. 153
`
`at 7 (emphasis added). But in referring to its VPN briefing, VirnetX appears to make
`
`Defendants‘ argument for them: VPN and virtual private link should be construed consistently.
`
`The Court should construe ―virtual private link‖ as ―a virtual private network as previously
`
`defined‖ for the same reasons it reached that conclusion in the Cisco Case.
`
`3. “Secure communication link”
`VirnetX’s Proposed Construction
`Defendants’ Proposed Construction
`
`a direct communication link that provides
`data security
`
`Mitel and Siemens:
`a direct communication link that provides
`data security by encrypting data on
`insecure communications paths, and in
`which a computer is able to address
`additional
`computers
`over
`the
`communication link without additional
`setup
`
`Avaya:
`same construction as ―virtual private
`network‖
`
`
`
`a. Encryption
`
`In the Cisco Case, VirnetX argued the term ―secure communication link‖ requires
`
`encryption. The Court declined to reach that conclusion for two reasons: (i) because in stating
`
`security is ―usually‖ accomplished with encryption, the specification implies encryption is not
`
`the only means of achieving security, and (ii) because dependent claim 28 of the ‘504 Patent
`
`specifies that ―the secure communication link uses encryption.‖ Ex. 19 at 13. But after the
`
`Cisco Markman hearing, VirnetX expressly stated to the Patent Office in reexamination of the
`
`‘504 Patent that ―[o]ne of ordinary skill in the art would have understood a secure
`
`10
`
`Page 15 of 38
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`

`
`Case 6:11-cv-00018-LED Document 165 Filed 06/11/12 Page 16 of 38 PageID #: 6173
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`communication link to require encryption.‖ March 29, 2012 Resp. to Office Action (attached as
`
`Ex. 16) at 25. Defendants respectfully submit the presumptions the Court previously applied—
`
`that claims are not limited to a preferred embodiment, and that limitations in dependent claims
`
`should not be read into independent claims—must yield to the understanding of ―secure
`
`communication link‖ the patentee has clearly and expressly provided to the Patent Office in
`
`reexamination. Accordingly, the Court should adopt Defendants‘ requirement that the secure
`
`communication link provides data security ―by encrypting data.‖
`
`Defendants maintain that in addition to requiring encryption, the term ―secure
`
`communication link‖ requires (i) encrypting data ―on insecure communications paths‖ and (ii)
`
`the ability ―to address additional computers over the communication link without additional
`
`setup,‖ and (iii) ―direct‖ communications.11 These are similar to the requirements Defendants
`
`propose for VPN, and each is supported by the intrinsic evidence and VirnetX‘s own statements
`
`to the Patent Office.
`
`b. “Insecure communication paths”
`
`The fact that the link is providing data security on ―insecure communications paths‖ is
`
`supported by the inherent nature of the claimed invention. See, e.g., Ex. A (‘135 Patent) at 7:37-
`
`9:19. If the communication paths in question were already secure, there would of course be no
`
`need for a ―secure communication link‖ in the first place. For the same reasons this limitation
`
`was included in the construction of VPN, it should be included here in the construction of the
`
`term ―secure communication link.‖ Defendants incorporate the earlier briefing of the VPN term
`
`for this limitation.
`
`
`11
`Although Avaya proposes an alternative construction (i.e., that ―secure communication
`link‖ be construed the same as VPN), Avaya join