NO: 443232US
`
`
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`__________________
`
`GOOGLE INC.,
`Petitioner,
`
`v.
`
`ROCKSTAR CONSORTIUM US LP,
`Patent Owner.
`__________________
`
`Case IPR2015-_____
`Patent U.S. 6,128,298
`__________________
`
`
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 6,128,298
`UNDER 35 U.S.C. § 312 AND 37 C.F.R. § 42.104
`
`
`
`Mail Stop PATENT BOARD
`Patent Trial and Appeal Board
`US Patent and Trademark Office
`PO Box 1450
`Alexandria, Virginia 22313-1450
`
`
`
`
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`TABLE OF CONTENTS
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` Page
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`
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`I.
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`II.
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`MANDATORY NOTICES PURSUANT TO 37 C.F.R. § 42.8 ..................... 1
`
`CERTIFICATION OF GROUNDS FOR STANDING .................................. 2
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED .................... 2
`
`A.
`
`B.
`
`Prior Art Patents and Printed Publications ............................................ 2
`
`Grounds for Challenge .......................................................................... 5
`
`IV. BACKGROUND OF THE ’298 PATENT ..................................................... 5
`
`A. Overview of the ’298 Patent .................................................................. 5
`
`B.
`
`Prosecution History of the ’298 Patent ................................................. 6
`
`V.
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`CLAIM CONSTRUCTION ............................................................................ 7
`
`A.
`
`“ignoring” .............................................................................................. 9
`
`VI.
`
`IDENTIFICATION OF HOW CHALLENGED CLAIM 23 IS
`UNPATENTABLE ........................................................................................ 10
`
`A.
`
`B.
`
`C.
`
`D.
`
`E.
`
`F.
`
`G.
`
`Claim 23 is anticipated by Kim ........................................................... 10
`
`Claim 23 is rendered obvious by Kim in view of Mayes .................... 16
`
`Claim 23 is rendered obvious by Kim in view of Feigen ................... 21
`
`Claim 23 is rendered obvious by Yeom in view of Mayes
`and Shwed ........................................................................................... 28
`
`Claim 23 is rendered obvious by Yeom in view of Feigen
`and Shwed ........................................................................................... 39
`
`Claim 23 is rendered obvious by Attanasio in view of
`Mayes and Shwed ................................................................................ 45
`
`Claim 23 is rendered obvious by Attanasio in view of
`Feigen and Shwed ............................................................................... 55
`
`VII. CONCLUSION .............................................................................................. 60
`
`
`
`i
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`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`
`
`TABLE OF AUTHORITIES
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`Page
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`
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`Cases
`
`In re Trans Texas Holdings Corp.,
`
`498 F.3d 1290 (Fed. Cir. 2007) ....................................................................... 8
`
`Phillips v. AWH Corp.,
`
`415 F.3d 1303 (Fed. Cir. 2005) ...................................................................8, 9
`
`Statutes
`
`35 U.S.C. § 102(a) ............................................................................................... 3
`
`35 U.S.C. § 102(b) ........................................................................................... 3, 4
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`35 U.S.C. § 102(e) ........................................................................................... 3, 4
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`35 U.S.C. § 314(a) ............................................................................................... 5
`
`35 U.S.C. § 315(a) ............................................................................................... 1
`
`Rules
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`37 C.F.R. § 42.8 ................................................................................................... 1
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`37 C.F.R. § 42.22 ................................................................................................. 2
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`37 C.F.R. § 42.100 ............................................................................................... 7
`
`37 C.F.R. § 42.104 ........................................................................................ 2, 10
`
`
`
`ii
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`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`I. MANDATORY NOTICES PURSUANT TO 37 C.F.R. § 42.8
`
`Real Party-in-Interest: Google Inc. (“Petitioner”)
`
`Related Matters: U.S. Patent No. 6,128,298 (the “’298 patent”) is asserted in
`
`the following cases: (1) consolidated case Rockstar Consortium US LP et al v.
`
`ASUSTeK Computer, Inc. et al., Consolidated Case No. 2:13-cv-00894 (E.D. Tex.),
`
`which consolidated six different cases filed by Rockstar Consortium US LP; (2)
`
`Arris Group, Inc. et al. v. Constellation Techs. LLC et al., Case No. 14-CV-114 (D.
`
`Del.); (3) Bockstar Techs. LLC v. Cisco Sys. Inc., Case No. 13-CV-2020 (D. Del.).
`
`The ’298 patent is also asserted in Google Inc. v. Rockstar Consortium US LP et
`
`al., Case No. 4:13-cv-05933-CW (N.D. Cal.). In that case, Google requested a
`
`declaration of non-infringement on the ’298 patent; Rockstar counterclaimed for
`
`infringement of the ’298 patent; and Google then pled the affirmative defense of
`
`invalidity with respect to the ’298 Patent. Google’s affirmative defense does not
`
`trigger the statutory bar against filing an inter partes review petition. 35 U.S.C.
`
`§ 315(a)(3). There are no patents or applications that claim the benefit of the filing
`
`date of the ’298 patent.
`
`Petitioner is also filing petitions for inter partes review challenging claims
`
`11–19, 22, and 24–32 of the ’298 patent. Petitioner recommends assigning all
`
`proceedings to the same panel.
`
`Counsel:
`
`Lead Counsel:
`
`Scott A. McKeown (Reg. No. 42,866)
`
`
`
`1
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`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Backup Counsel: Greg Gardella (Reg. No. 46,045)
`
`Service Information : Email : CPDocketMcKeown@oblon.com
`
`CPDocketGardella@oblon.com
`
`Post: Oblon Spivak, 1940 Duke St., Alexandria, VA 22314
`
`Telephone: 703-412-6297
`
`Facsimile: 703-413-2220
`
`II. CERTIFICATION OF GROUNDS FOR STANDING
`
`Petitioner certifies pursuant to Rule 42.104(a) that the patent for which
`
`review is sought is available for inter partes review and that Petitioner is not
`
`barred or estopped from requesting an inter partes review challenging the patent
`
`claims on the grounds identified in this Petition.
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED
`
`Pursuant to Rules 42.22(a)(1) and 42.104(b)(1)–(2), Petitioner challenges
`
`claim 23 of the ’298 patent. The ’298 patent claims priority to Provisional U.S.
`
`Patent Application No. 60/015,945, which was filed on Apr. 24, 1996 . (Ex. 1501,
`
`the ’298 patent.)
`
`A.
`
`Prior Art Patents and Printed Publications
`
`Petitioner relies upon the following patents and printed publications:
`
`Exhibit 1503 – “IP Address Reuse Through Transparent Port-Address
`
`Translator,” by Il Hwan Kim et al. (“Kim”) was published by The Journal of Korea
`
`Information and Communications Society in December 1995, which is prior to the
`
`
`
`2
`
`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`earliest filing date claimed by the ’298 patent (April 24, 1996). Kim is therefore
`
`available as prior art under at least pre-AIA 35 U.S.C. § 102(a). Kim was not
`
`considered during the original prosecution of the ’298 patent and is not cumulative
`
`of any prior art considered by the examiner(s).
`
`Exhibit 1505 – U.S. Patent No. 5,793,763 to John C. Mayes et al. (“Mayes”)
`
`issued on August 11, 1998, based on Application Serial No. 08/552,807, filed
`
`November 3, 1995, which is prior art to the earliest filing date claimed by the ’298
`
`patent (April 24, 1996). Mayes is therefore available as prior art under at least
`
`pre-AIA 35 U.S.C. § 102(e). Mayes was considered during the original
`
`prosecution of the ’298 patent, but is presented in a new light when considered in
`
`combination with Kim and the expert declaration of Professor Vijay K. Madisetti,
`
`PhD.
`
`Exhibit 1506 – “A Transparent TCP/IP Gateway to Connect Private
`
`Networks to the Internet,” by Heon Yeom et al. (“Yeom”). As shown by the
`
`Declaration of Bob Kummerfeld (Ex. 1528), Yeom was publicly posted to the
`
`Internet on January 30, 1995 and, therefore, was publicly available prior to the
`
`earliest filing date claimed by the ’298 patent (April 24, 1996). See MPEP 2128
`
`II.B (“Prior art disclosures on the Internet or on an on-line database are considered
`
`to be publicly available as of the date the item was publicly posted.”) Yeom is
`
`therefore available as prior art under at least pre-AIA 35 U.S.C. § 102(b). Yeom
`
`
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`3
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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`was not considered during the original prosecution of the ’298 patent and is not
`
`cumulative of any prior art considered by the examiner(s).
`
`Exhibit 1510 – U.S. Patent No. 5,606,668 to Shwed (“Shwed”) issued on
`
`February 25, 1997, based on Application Serial No. 08/168,041, filed December
`
`15, 1993, which is prior to the earliest filing date claimed by the ’298 patent (April
`
`24, 1996). Shwed is therefore available as prior art under pre-AIA 35 U.S.C. §
`
`102(e). Shwed was not considered during the original prosecution of the ’298
`
`patent and is not cumulative of any prior art considered by the examiner(s).
`
`Exhibit 1523 – U.S. Patent No. 5,371,852 to Attanasio et al. (“Attanasio”)
`
`issued on December 6, 1994, which is at least one year prior to the earliest filing
`
`date claimed by the ’298 patent (April 24, 1996). Attanasio is therefore available
`
`as prior art under at least pre-AIA 35 U.S.C. § 102(b). Attanasio was not
`
`considered during the original prosecution of the ’298 patent and is not cumulative
`
`of any prior art considered by the examiner(s).
`
`Exhibit 1524 – U.S. Patent No. 5,699,513 to Feigen et al. (“Feigen”) issued
`
`on December 16, 1997, based on Application Serial No. 08/414,823, filed March
`
`31, 1995, which is prior to the earliest filing date claimed by the ’298 patent (April
`
`24, 1996). Feigen is therefore available as prior art under at least pre-AIA 35
`
`U.S.C. § 102(e). Feigen was not considered during the original prosecution of the
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`’298 patent and is not cumulative of any prior art considered by the examiner(s).
`
`
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`4
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`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`B. Grounds for Challenge
`
`Petitioner requests cancellation of challenged claim 23 under the following
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`statutory grounds:
`
`i. Claim 23 is anticipated by Kim;
`
`ii. Claim 23 is rendered obvious by Kim in view of Mayes;
`
`iii. Claim 23 is rendered obvious by Kim in view of Feigen;
`
`iv. Claim 23 is rendered obvious by Yeom in view of Mayes and Shwed;
`
`v. Claim 23 is rendered obvious by Yeom in view of Feigen and Shwed;
`
`vi. Claim 23 is rendered obvious by Attanasio in view of Mayes and Shwed; and
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`vii. Claim 23 is rendered obvious by Attanasio in view of Feigen and Shwed.
`
`Section VI below demonstrates, for each of the statutory grounds, that there
`
`is a reasonable likelihood that Petitioner will prevail. See 35 U.S.C. § 314(a).
`
`Additional explanation and support for each ground of rejection is set forth in the
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`Expert Declaration of Professor Vijay K. Madisetti, PhD (Exhibit 1509).
`
`IV. BACKGROUND OF THE ’298 PATENT
`
`A. Overview of the ’298 Patent
`
`The ’298 patent is directed to the basic and well-known concept of network
`
`address translation using an IP filter. (Ex. 1501, Abstract.) A source node in the
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`first network with a private IP address and port (pIP, pPort) sends an outgoing data
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`packet to an IP address and Port (iIP, iPort) corresponding to a destination node in
`
`
`
`5
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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`a second network. (Id. at 5:55–60.) An IP filter intercepts the outgoing data
`
`packet and replaces the source node’s IP address/port number combination with an
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`IP address and port number of the IP filter (frIP, frPort) before sending the
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`outgoing data packet to the destination node in the second network. (Id. at 5:65–
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`6:4.) The IP filter also maintains a translation table, which stores, inter alia, the
`
`source and destination node IP address and port numbers. (Id. at 5:40–50.) The IP
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`filter uses its own port number (frPort) plus an offset value to establish an index
`
`into the translation table. (Id. at 6:2–4.) When the IP filter receives an incoming
`
`data packet from the second network, the IP filter uses its port number with the
`
`known offset as an index into the translation table. The IP filter replaces the IP
`
`filter’s IP address/port number (frIP, frPort) in the incoming packet with the first
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`network’s IP address/port number (pIP, pPort), and then routes the packet to the
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`correct node in the first network. (Id. at 6:5–14.)
`
`B.
`
`Prosecution History of the ’298 Patent
`
`The application that matured into the ’298 patent, U.S. Patent Application
`
`No. 08/842,328 (“the ’328 application”), was filed on April 24, 1997. The ’328
`
`application claims priority to Provisional U.S. Application No. 60/015,945, which
`
`was filed on April 24, 1996.
`
`In a non-final office action mailed on April 27, 1999, the examiner rejected
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`claims 1-5, 9, 11, 14–18, 22, 24, and 27–31 of the ’328 application over U.S.
`
`
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`6
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`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Patent No. 5,781,550 (“Templin”). (Ex. 1502, pp. 57–64.)
`
`In a response dated July 27, 1999, the applicants submitted a declaration
`
`under Rule 131 “including facts showing a completion of the invention claimed in
`
`the present application before the filing date of the Templin reference (February 2,
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`1996).” (Ex. 1502, pp. 67–93.)
`
`In a non-final office action dated October 12, 1999, the examiner rejected all
`
`claims 1–5, 9, 11–18, and 22–32 of the ’328 application as being obvious in view
`
`of U.S. Patent No. 5,793,763 (“Mayes”). (Ex. 1502, pp. 96–101.)
`
` In a response dated February 25, 2000, the applicants amended claims 6,
`
`10, 19, and 23 to rewrite them in independent form. Furthermore, applicants
`
`argued that “Mayes does not disclose such a lookup table for stored source
`
`information, indexed by the filter node port number.” (Ex. 1502, pp. 106–15.)
`
`The ’298 patent issued on October 3, 2000.
`
`V. CLAIM CONSTRUCTION
`
`In an inter partes review, claim terms in an unexpired patent are interpreted
`
`according to their broadest reasonable interpretation (“BRI”) in view of the
`
`specification in which they appear. 37 C.F.R. § 42.100(b); Office Patent Trial
`
`Practice Guide, 77 Fed. Reg. 48,756, 48,766 (Aug. 14, 2012). The USPTO uses BRI
`
`because, among other reasons, the patentee has the opportunity to amend its claims in
`
`this proceeding. See, e.g., Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756,
`
`
`
`7
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`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`48,764 (Aug. 14, 2012) (“Since patent owners have the opportunity to amend their
`
`claims during IPR, PGR, and CBM trials, unlike in district court proceedings, they
`
`are able to resolve ambiguities and overbreadth through this interpretive approach,
`
`producing clear and defensible patents at the lowest cost point in the system.”).
`
`Thus, as required by the applicable rules, this Petition uses the BRI standard. The
`
`BRI of claim terms here may be different from the construction that those same terms
`
`may receive following claim construction proceedings in district court. See, e.g., In
`
`re Trans Texas Holdings Corp., 498 F.3d 1290, 1297 (Fed. Cir. 2007). Thus the
`
`claim constructions presented in this Petition, including where Petitioner does not
`
`propose an express construction, do not necessarily reflect the claim constructions
`
`that Petitioner believes should be adopted by a district court under Phillips v. AWH
`
`Corp., 415 F.3d 1303 (Fed. Cir. 2005). In presenting this Petition, unless otherwise
`
`stated, the grounds set forth herein are based on (1) the proposed claim
`
`construction offered by the Patent Owner in Google Inc. v. Rockstar Consortium
`
`US LP, et al., Case No. 13-5933 (N.D. Cal.) (Ex. 1526), or (2) for terms where
`
`Patent Owner has not explicitly offered a claim construction, on petitioner’s
`
`understanding of Patent Owner’s infringement contentions in Google Inc. v.
`
`Rockstar Consortium US LP, et al., Case No. 13-5933 (N.D. Cal.). (Ex. 1527.) In
`
`presenting the grounds set forth in this Petition, petitioner does not concede that
`
`any claim constructions impliedly or expressly proposed by Patent Owner are
`
`
`
`8
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`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`appropriate for the district court litigation, where a different legal standard applies
`
`to the construction of the asserted claim terms. Petitioner does not believe that
`
`many of the Patent Owner’s implied or express proposed constructions are
`
`appropriate under Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005). Instead,
`
`petitioner presents these proposed constructions to the Board for consideration in
`
`determining the BRI because Patent Owner considers these constructions correct
`
`under Phillips, and therefore necessarily also considers them within the appropriate
`
`scope of the BRI. Petitioner further submits these constructions under 35 U.S.C. §
`
`301(a)(2), which encourages submission of claim construction materials to prevent
`
`patentees from arguing broad constructions under Phillips while simultaneously
`
`arguing narrow constructions as the BRI.
`
`A.
`
`“ignoring”
`
`Claim 23 recites the “ignoring” term. The specification teaches that packets
`
`are ignored in two situations. First, packets are ignored if they are not TCP, UDP,
`
`or ICMP packets. (Ex. 1501, 2:56–57.) Second, packets are ignored if they “do
`
`not have entries in the lookup table corresponding to the IP filter port.” (Ex. 1501,
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`3:22–24.) When a packet “does not match the corresponding entries in the table,”
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`an “unauthorized access is logged and the packet dropped.” (Ex. 1501, 6:21–23.)
`
`Thus, the “ignoring” function of the IP filter is designed to prevent “unauthorized
`
`access” to the private network nodes, thereby enhancing security—the IP filter
`
`
`
`9
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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`takes no further action to process a packet because it is not recognized by the IP
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`filter. (Ex. 1509, ¶ 58.) Accordingly, a person of ordinary skill in the art would
`
`consider the broadest reasonable interpretation in light of the specification and
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`prosecution history of “ignoring” to be “dropping.” (Id.)
`
`VI.
`
`IDENTIFICATION OF HOW CHALLENGED CLAIM 23 IS
`UNPATENTABLE
`
`Pursuant to Rule 42.104(b)(4)–(5), this section demonstrates that the
`
`challenged claims are unpatentable.
`
`A. Claim 23 is anticipated by Kim
`
`Kim (Ex. 1504)
`“[C]onnections to external networks by multiple local
`nodes by using one global address can be provided by
`translating many local sockets to one global address
`and unused port number.” (Ex. 1504, p. 39.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 60.)
`
`“From this point on, the sockets in each node will be
`marked as (IP address, TCP port number), and all TCP
`packets will be expressed as (srcIP, srcPORT, dstIP,
`dstPORT).” (Ex. 1504, p. 39.)
`
` A
`
` packet is received with a source address of the
`inner network and a destination address in the
`outer network :
`
`
`(Ex. 1504, p. 44.)
`
`
`
`
`Claim 23.
`[23A] A method of
`operating a filter node
`for interfacing first and
`second data
`communications
`networks, comprising
`the steps of:
`[23B] receiving from
`the first network, an
`outgoing data packet
`having destination
`information, which
`includes a destination
`address and a destination
`port, corresponding to a
`node in the second
`network and having
`source information,
`which includes a source
`address and a source
`port, corresponding to a
`node in the first
`
`
`
`10
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`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`network:
`
`[23C] maintaining the
`source information taken
`from the outgoing data
`packet in correlation
`with a unique value
`representing a port of
`the filter node;
`
`Kim (Ex. 1504)
`“[Y]ou’ll see that the packet going from (S, 1000) to
`(D, 23) is relayed by G, changed to (G, 3000), and then
`sent to (D, 23) and that the packet sent from (D, 23) to
`(G, 3000) is relayed to (S, 1000) by G so that a one-to-
`one connection can be made between S and D.” (Ex.
`1504, p. 40.)
`
`See also Madisetti Expert Declaration (Ex. 1509,
`¶¶ 61–62.)
`“Take a look at Table 1. This table shows the sockets
`(IPaddr, PORT) created from the Node 1 (inner nodes)
`of the stub B class network with the address of
`172.16.0.0 being corresponded with the port number of
`G (Gateway node) with a global address.” (Ex. 1504,
`p. 40.)
`
`
`
`
`
`(Ex. 1504, p. 40.)
`
` A
`
` table entry with source address and port is
`allocated for a packet establishing a new
`connection:
`
`(Ex. 1504, p. 44.)
`
` A
`
` port table maintains the IP address and port of
`inner network nodes correlated with the gateway
`port value:
`
`
`
`11
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`

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`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`
`Kim (Ex. 1504)
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 62.)
`“The transmitter header of an outbound packet is
`revised from (I. Addr. I. PORT) to (G. Addr. G. PORT)
`in accordance with the port-address translation table
`and then relayed to an external global network. In
`addition, the receiver header of a packet, received by G
`from outside, is revised from (G. Addr. G. PORT) to (I.
`Addr. I. PORT) and delivered to an internal local area
`network.”
`(Ex. 1504, p. 40.)
`The packet’s source IP address and port are
`replaced with a source IP address and port of the
`gateway node:
`
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 63.)
`“The transmitter header of an outbound packet is
`revised from (I. Addr. I. PORT) to (G. Addr. G. PORT)
`in accordance with the port-address translation table
`and then relayed to an external global network. In
`addition, the receiver header of a packet, received by G
`from outside, is revised from (G. Addr. G. PORT) to (I.
`Addr. I. PORT) and delivered to an internal local area
`
`[23D] replacing in the
`outgoing data packet the
`source address with an
`address of the filter node
`and the source port with
`the filter node port
`value;
`
`[23E] sending to the
`second network the
`outgoing data packet
`having the replaced
`source information,
`whereby that packet is
`routed according to its
`
`
`
`12
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`destination information
`to the corresponding
`second network node;
`
`[23F] receiving from
`the second network, an
`incoming data packet
`having the address of the
`filter node as the
`destination address;
`[23G] correlating the
`destination port of the
`destination information
`in the incoming data
`packet to particular
`source information
`being maintained;
`
`Kim (Ex. 1504)
`
`network.”
`(Ex. 1504, p. 40.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 63–
`64.)
`“The receiver header of a packet, received by G, is
`revised from (G. Addr, G. PORT) to (I. Addr, I. PORT)
`and delivered to an internal area network.” (Ex. 1504,
`p. 40.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 65.)
`“Take a look at Table 1. This table shows the sockets
`(IPaddr, PORT) created from the Node 1 (inner nodes)
`of the stub B class network with the address of
`172.16.0.0 being corresponded with the port number of
`G (Gateway node) with a global address.” (Ex. 1504,
`p. 40.)
`
`
`
`(Ex. 1504, p. 40.)
`
`The return packet is correlated to an inner node
`address and port:
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 65.)
`“The receiver header of a packet, received by G, is
`revised from (G. Addr, G. PORT) to (I. Addr, I. PORT)
`and delivered to an internal local area network.” (Ex.
`1504, p. 40.)
`
`The return packet’s destination IP address and port
`are changed to the destination IP address and port
`of the inner node:
`
`[23H] replacing, in the
`incoming data packet,
`the destination
`information with the
`particular source
`information;
`
`
`
`13
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`
`Kim (Ex. 1504)
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 65.)
`“The receiver header of a packet, received by G, is
`revised from (G. Addr, G. PORT) to (I. Addr, I. PORT)
`and delivered to an internal local area network.” (Ex.
`1504, p. 40.)
`
`(Ex. 1504, p. 44.)
`
`The return packet is routed to the inner node:
`
`
`
`[23I] sending to the first
`network the incoming
`data packet having the
`replaced destination
`information, whereby
`that packet is routed
`according to its
`destination information
`to the corresponding
`first network node; and
`
`(Ex. 1504, p. 44.)
`
`
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 66.)
`“By fundamentally controlling inbound requests, a
`security effect that is provided by the firewall system
`can be obtained.” (Ex. 1504, p. 43.)
`
`Incoming data packets for which no entry exists in
`the table are ignored:
`
`
`[23J] ignoring the
`incoming data packet
`received from the
`second network, if the
`destination port of the
`destination information
`in that data packet can
`not be correlated to the
`maintained source
`information,
`
`(Ex. 1504, p. 44.)
`
`
`14
`
`
`
`
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`
`Kim (Ex. 1504)
`See also Madisetti Expert Declaration (Ex. 1509,
`¶¶ 67–69.)
`“Take a look at Table 1. This table shows the sockets
`(IPaddr, PORT) created from the Node 1 (inner nodes)
`of the stub B class network with the address of
`172.16.0.0 being corresponded with the port number of
`G (Gateway node) with a global address.” (Ex. 1504,
`p. 40.)
`
`[23K] wherein
`maintaining the source
`information includes
`storing the source
`information from the
`outgoing data packet as
`an entry in a lookup
`table, and the filter node
`port value correlating to
`the source information
`constitutes an index into
`the table for that entry;
`
`(Ex. 1504, p. 40.)
`
`The destination port is used as an index to search
`the port table:
`
`
`
`
`
`
`
`(Ex. 1504, p. 44.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 62.)
`“Relaying UDP applications is possible by
`implementing a suitable time based algorithm.” (Ex.
`1504, p. 43.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 69.)
`
`
`[23L] wherein the
`outgoing and incoming
`data packets include
`packets in accordance
`with a user datagram
`protocol (UDP) over an
`
`
`
`15
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Claim 23.
`internet protocol (IP);
`and
`[23M] receiving a UDP
`data packet from the
`first network, and
`adding the source
`information and the
`destination information
`from the UDP packet
`together with an interval
`indication for an
`expiration timer as a
`new entry in the lookup
`table.
`
`
`Kim (Ex. 1504)
`
`“Relaying UDP application is possible by
`implementing a suitable time based algorithm.” (Ex.
`1504, p. 43.)
`
`“The current prototype port-address translator uses an
`idle time threshold based algorithm with the threshold
`fixed at 2 minutes.” (Ex. 1504, p. 42.)
`
`See also Madisetti Expert Declaration (Ex. 1509, ¶ 69.)
`
`B. Claim 23 is rendered obvious by Kim in view of Mayes
`
`1. Obviousness Arguments
`
`Claim 23 recites, in relevant part, “ignoring the incoming data packet
`
`received from the second network, if the destination port of the destination
`
`information in that data packet can not be correlated to the maintained source
`
`information . . . .” Claim 23 claims a packet filtering function that was well known
`
`prior to April 1995. In fact, such packet filtering was an important feature of prior
`
`art address translation systems, as shown by the Mayes reference cited in the
`
`prosecution history and described below.
`
`It would have been obvious to a person of ordinary skill in the art at the time
`
`of invention of the ‘298 patent to combine Kim with the teaching of Mayes, which
`
`discloses the packet filtering functionality of claim 16. (Ex. 1509, ¶¶ 74–77.) Like
`
`
`
`16
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`Kim, Mayes describes a system “for translating local IP addresses to globally
`
`unique IP addresses.” (Ex. 1505, Abstract.) Mayes “employs NAT [network
`
`address translation] in conjunction with an adaptive security algorithm to keep
`
`unwanted packets from external sources out of a private network.” (Id. at 2:16–
`
`18.) Mayes teaches a “table of allocated translation slots.” (Id. at 5:5:49–50.)
`
`Each slot tracks an active connection, and includes “the local host’s IP address and
`
`a global IP address selected from the pool of available addresses.” (Id. at 6:20–
`
`22.) In order to evaluate an inbound packet Mayes
`
`determines whether the port and IP source and destination addresses
`of the inbound packet match those of any connection object of the
`static translation slot. If no such match is found, it can again be
`assumed that the internal host did not initiate a connection requesting
`the inbound packet. Thus, if decision step 290 is answered in the
`negative, the process is concluded at 296 with the packet being
`dropped and logged.
`(Id. at 12:32–39.)
`
`Because Mayes and Kim are directed to the very same technology – address
`
`translation enabling communication with private data networks – one of ordinary
`
`skill would have looked to Mayes for beneficial teachings relevant to Kim’s port-
`
`address translator. (Ex. 1509, ¶¶ 74-77.) The motivation for such a combination is
`
`clear and compelling – private network security. Kim itself teaches that the Kim
`
`address-translator has a security function: “[b]y fundamentally controlling
`
`
`
`17
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`inbound requests, a security effect that is provided by the firewall system can be
`
`obtained.” (Ex. 1504, p. 43.) This would have motivated one of skill in the art to
`
`improve upon the system by adding features that enhance security. (Ex. 1509,
`
`¶¶ 75–76.) In fact, Mayes teaches that its packet filtering security features are a
`
`“must have” feature in any NAT system:
`
`To implement a NAT, a translation system must be provided between
`the enterprise private network and the Internet. By virtue of this
`location, the translation must act as a firewall to protect the local
`private network from unwanted Internet packets. In view of this
`requirement, it would be desirable to have a system which employs
`NAT and provides a secure firewall.
`(Ex. 1505, 2:6–12.) In addition, one of skill in the art would recognize the security
`
`benefits of packet filtering based on firewall and security principles that were well
`
`known at the time of alleged conception, including as described in Mayes. (Ex.
`
`1509, ¶¶ 75–76.)
`
`One of ordinary skill would further understand that the inclusion of Mayes’
`
`packet filtering techniques in Kim’s port-address translator would be well within
`
`the technical skill of one of ordinary skill in the art. Kim already includes a table
`
`tracking active connections similar to Mayes’ translation slot table; the addition of
`
`rules for ignoring unwanted packets would be a trivial modification to Kim. (Ex.
`
`1509, ¶ 77.) Such a modification would present no great technical challenges, and
`
`would not negatively impact the functionality of Kim’s port-address translator.
`
`
`
`18
`
`

`
`U.S. Patent 6,128,298
`Petition for Inter Partes Review
`2. Claims Charts
`
`Claim 23.
`[23A] A method of operating a
`filter node for interfacing first and
`second data communications
`networks, comprising the steps of:
`[23B] receiving from the first
`network, an outgoing data packet
`having destination information,
`which includes a destination
`address and a destination port,
`corresponding to a node in the
`second network and having source
`information, which includes a
`source address and a source port,
`corresponding to a node in the
`first network:
`[23C] maintaining the source
`information taken from the
`outgoing data packet in correlation
`with a unique value representing a
`port of the filter node;
`[23D] replacing in the outgoing
`data packet the source address
`with an address of the filter node
`and the source port with the filter
`node port value;
`[23E] sending to the second
`network the outgoing data packet
`having the replaced source
`in