UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`JUNIPER NETWORKS, INC.,
`Petitioner
`
`v.
`
`PARITY NETWORKS, LLC,
`Patent Owner
`
`Case No.: To Be Assigned
`Patent No.: 6,831,891
`Filing Date: March 6, 2001
`Issue Date: December 14, 2004
`Title: System for Fabric Packet Control
`
`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 6,831,891
`UNDER 35 U.S.C. §§ 311-319 AND 37 C.F.R. § 42.100 ET SEQ.
`
`Mail Stop Inter Partes Review
`Patent Trial and Appeal Board
`United States Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`i
`
`

`

`TABLE OF CONTENTS
`
`I.
`
`37 C.F.R. § 42.8: MANDATORY NOTICES................................................ 1
`
`A.
`
`B.
`
`C.
`
`37 C.F.R. § 42.8(b)(1): Real Party-In-Interest ..................................... 1
`
`37 C.F.R. § 42.8(b)(2): Related Matters .............................................. 1
`
`37 C.F.R. § 42.8(b)(3) and (4): Identification of Counsel and
`Service Information ............................................................................... 1
`
`II.
`
`REQUIREMENTS FOR INTER PARTES REVIEW ...................................... 2
`
`A.
`
`B.
`
`C.
`
`D.
`
`37 C.F.R. § 42.101(a)–(c): Petitioner Is Eligible to File this
`Petition for Inter Partes Review ........................................................... 2
`
`37 C.F.R. § 42.102: This Petition Is Timely ........................................ 3
`
`37 C.F.R. § 42.103 and § 42.15(a): Inter Partes Review Fee ............. 3
`
`37 C.F.R. § 42.104(a): Grounds for Standing ...................................... 3
`
`III.
`
`37 C.F.R. § 42.104(b): IDENTIFICATION OF CHALLENGE ................... 4
`
`A.
`
`B.
`
`C.
`
`D.
`
`E.
`
`37 C.F.R. § 42.104(b)(1): Claims for Which Inter Partes
`Review Is Requested ............................................................................. 4
`
`37 C.F.R. § 42.104(b)(2): Statutory Grounds and Identification
`of Prior Art ............................................................................................ 4
`
`37 C.F.R. § 42.104(b)(3): Claim Construction .................................... 4
`
`37 C.F.R. § 42.104(b)(4): How the Claims Are Unpatentable ............ 5
`
`37 C.F.R. § 42.104(b)(5): Evidence Supporting Challenge ................. 5
`
`IV. OVERVIEW OF THE ’891 PATENT ............................................................ 5
`
`A.
`
`B.
`
`C.
`
`D.
`
`Priority Date of the ’891 Patent............................................................. 5
`
`Summary of the ’891 Patent .................................................................. 6
`
`Claims of the ’891 Patent .................................................................... 12
`
`The Legal Standard for Obviousness .................................................. 15
`ii
`
`

`

`E.
`
`Person of Ordinary Skill in the Art ..................................................... 16
`
`V.
`
`IT IS MORE LIKELY THAN NOT THAT THE CHALLENGED
`CLAIMS ARE UNPATENTABLE .............................................................. 17
`
`A.
`
`B.
`
`Summary of the Grounds for Rejection .............................................. 17
`
`Summary of the Prior Art .................................................................... 17
`
`Schwartz .............................................................................................. 17
`
`Muller .................................................................................................. 22
`
`Firoiu ................................................................................................... 24
`
`C.
`
`Ground 1: Claims 1-6 Are Obvious Under § 103(a) in View of
`Schwartz and Muller ............................................................................ 25
`
`Claim 1 ................................................................................................ 25
`
`Claim 2 ................................................................................................ 41
`
`Claim 3 ................................................................................................ 41
`
`Claim 4 ................................................................................................ 43
`
`Claim 5 ................................................................................................ 43
`
`Claim 6 ................................................................................................ 47
`
`D.
`
`Claims 1-6 Are Obvious Under § 103(a) in View of Firoiu and
`Muller .................................................................................................. 47
`
`Claim 1 ................................................................................................ 47
`
`Claim 2 ................................................................................................ 56
`
`Claim 3 ................................................................................................ 56
`
`Claim 4 ................................................................................................ 58
`
`Claim 5 ................................................................................................ 58
`
`Claim 6 ................................................................................................ 60
`
`iii
`
`

`

`VI. CONCLUSION .............................................................................................. 61
`
`CONCLUSION .............................................................................................. 61
`
`VI.
`
`iv
`
`iV
`
`

`

`EXHIBIT LIST
`
`Exhibit No.
`
`Title
`
`1001
`
`U.S. Patent No. 6,831,891 to Mansharamani (“the ’891 Patent”)
`
`1002
`
`Declaration of Dr. Nicholas Bambos, (“Bambos Decl.”)
`
`1003
`
`Curriculum Vitae of Dr. Nicholas Bambos
`
`1004
`
`1005
`
`1006
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`
`PCT International Application No. WO 00/02347 A2 to Schwartz et
`al. (“Schwartz”)
`
`PCT International Application No. WO 00/52882 A2 to Muller et al.
`(“Muller”)
`
`Canadian Patent Application No. CA 2 310 531 A1 to Firoiu et al.
`(“Firoiu”)
`
`June 13, 2002 Applicant’s Response to Office Action from the
`Prosecution History of the ‘891 Patent
`
`January 6, 2003 Applicant’s Response to Office Action from the
`Prosecution History of the ‘891 Patent
`
`February 13, 2004 Applicant’s Response to Office Action from the
`Prosecution History of the ‘891 Patent
`
`“Original Complaint” (Docket Entry #1) filed in Parity Networks,
`LLC v. Juniper Networks, Inc., 6:17-cv-00495-RWS-KNM
`(E.D. Texas)
`
`Executed Summons (Docket Entry #9) filed in Parity Networks,
`LLC v. Juniper Networks, Inc., 6:17-cv-00495-RWS-KNM (E.D.
`Texas)
`
`v
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`In accordance with 37 C.F.R. § 42.100 and Section 18 of the Leahy-Smith
`
`America Invents Act (“AIA”), Juniper Networks, Inc. (“Juniper” or “Petitioner”)
`
`requests Inter Partes Review of Claims 1-6 (“the Challenged Claims”) of U.S.
`
`Patent No. 6,831,891 (“the ’891 Patent”) (Ex. 1001).
`
`I.
`
`37 C.F.R. § 42.8: MANDATORY NOTICES
`
`A.
`
`37 C.F.R. § 42.8(b)(1): Real Party-In-Interest
`
`Juniper Networks, Inc. is the real party-in-interest.
`
`B.
`
`37 C.F.R. § 42.8(b)(2): Related Matters
`
`Parity Networks, LLC (“Parity” or “the Patent Owner”) asserted the ’891
`
`Patent in Parity Networks, LLC v. Juniper Networks, Inc., 6:17-cv-00495-RWS-
`
`KNM (“the Juniper litigation”), a patent infringement action filed in the United
`
`States District Court for the Eastern District of Texas. (Order dated August 10,
`
`2018 transferring action to the United States District Court for the Northern
`
`District of California, case number yet to be assigned). The outcome of that matter
`
`may affect, or be affected by, a decision in this proceeding.
`
`C.
`
`37 C.F.R. § 42.8(b)(3) and (4): Identification of Counsel and
`Service Information
`
`Lead Counsel
`Sasha G. Rao
`Reg. No. 57,017
`srao@maynardcooper.com
`Postal and Hand-Delivery Address:
`MAYNARD, COOPER & GALE, LLP
`Transamerica Pyramid Center
`
`Back-up Counsel
`John M. Hintz
`Reg. No. 33,510
`jhintz@maynardcooper.com
`Postal and Hand-Delivery Address:
`MAYNARD, COOPER & GALE, P.C.
`The Fred F. French Building
`
` 1
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`600 Montgomery Street, Suite 2600
`San Francisco, CA 94111
`Telephone: 415.646.4702
`Fax: 415.358.5650
`
`551 Fifth Avenue, Suite 2000
`New York, NY 10176
`Telephone: 646.609.9284
`Fax: 646.609.9281
`
`John P. Hanish
`Reg. No. 75,382
`jhanish@maynardcooper.com
`Postal and Hand-Delivery Address:
`MAYNARD, COOPER & GALE, P.C.
`The Fred F. French Building
`551 Fifth Avenue, Suite 2000
`New York, NY 10176
`Telephone: 646.609.9283
`Fax: 205.714.6369
`
`Brandon H. Stroy
`Reg. No. 73,166
`bstroy@maynardcooper.com
`Postal and Hand-Delivery Address:
`MAYNARD, COOPER & GALE, LLP
`Transamerica Pyramid Center
`600 Montgomery Street, Suite 2600
`San Francisco, CA 94111
`Telephone: 415.646.4703
`Fax: 205.714.6415
`
`Petitioner submits a Power of Attorney with this Petition. 37 C.F.R.
`
`§ 42.10(b). Petitioner may be served at the offices of its counsel shown above.
`
`II.
`
`REQUIREMENTS FOR INTER PARTES REVIEW
`
`A.
`
`37 C.F.R. § 42.101(a)–(c): Petitioner Is Eligible
`to File this Petition for Inter Partes Review
`Petitioner is eligible to file this Petition for Inter Partes Review because
`
`Petitioner is not the owner of the ’891 Patent and: (a) before the date on which this
`
` 2
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`Petition for review was filed, Petitioner has not filed a civil action challenging the
`
`validity of a claim of the ’891 Patent; (b) this Petition is not being filed more than
`
`one year after the date on which Petitioner was served with a complaint alleging
`
`infringement of the ’891 Patent; and (c) Petitioner is not estopped from challenging
`
`the claims on the grounds identified in this Petition. See Ex. 1010 (“Original
`
`Complaint” filed in Parity Networks, LLC v. Juniper Networks, Inc., 6:17-cv-
`
`00495 (E.D. Tex.) (August 31, 2017)); Ex. 1011 (Service of Summons in Parity
`
`Networks, LLC v. Juniper Networks, Inc., 6:17-cv-00495 (E.D. Tex.) (indicating
`
`the date of service of the “Original Complaint” on Juniper as September 6, 2017)).
`
`B.
`
`37 C.F.R. § 42.102: This Petition Is Timely
`
`The ’891 Patent issued on December 14, 2004, and therefore this Petition is
`
`timely filed under 37 C.F.R. § 42.102(a)(2).
`
`C.
`
`37 C.F.R. § 42.103 and § 42.15(a): Inter Partes Review Fee
`
`Petitioner requests review of six (6) claims of the ’891 Patent and includes a
`
`payment of $30,500 for: (1) the $15,500 Inter Partes Review request fee for up to
`
`20 claims; and (2) the $15,000 Inter Partes Review Post-Institution fee for up to 15
`
`claims. The undersigned authorizes the Office to charge any additional fees that
`
`may be required in connection with this Petition to Deposit Account No. 504524.
`
`37 C.F.R. § 42.104(a): Grounds for Standing
`D.
`Petitioner certifies that the ’891 Patent is available for Inter Partes Review
`
`and Petitioner is not barred or estopped from requesting an Inter Partes Review
`
` 3
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`challenging the patent claims on the grounds identified in this Petition.
`
`III.
`
`37 C.F.R. § 42.104(B): IDENTIFICATION OF CHALLENGE
`
`A.
`
`37 C.F.R. § 42.104(b)(1): Claims for Which
`Inter Partes Review Is Requested
`Petitioner requests Inter Partes Review and cancellation of all of the claims
`
`(1-6) of the ’891 Patent.
`
`B.
`
`37 C.F.R. § 42.104(b)(2): Statutory Grounds
`and Identification of Prior Art
`
`Petitioner requests cancellation of Claims 1-6 of the ’891 Patent as obvious
`
`under 35 U.S.C. § 103(a) in view of Patent Cooperation Treaty (“PCT”)
`
`International Application No. WO 00/02347 A2 to Schwartz et al. (“Schwartz”)
`
`and PCT International Application No. WO 00/052882 A2 to Muller et al.
`
`(“Muller”). Petitioner requests cancellation of Claims 1-6 of the ’891 Patent as
`
`obvious under 35 U.S.C. § 103(a) in view of Canadian Patent Application No.
`
`2,310,531 A1 to Firoiu (“Firoiu”) and Muller.
`
`37 C.F.R. § 42.104(b)(3): Claim Construction
`C.
`In Inter Partes Review, a claim in an unexpired patent that will not expire
`
`before a final written decision is issued shall be given its broadest reasonable
`
`construction in light of the specification of the patent in which it appears.
`
`37 C.F.R. § 42.100(b). Claim terms are given their ordinary and customary
`
`meaning, as they would be understood by one of ordinary skill in the art in the
`
` 4
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`context of the entire disclosure. In re Translogic Tech. Inc., 504 F.3d 1249, 1257
`
`(Fed. Cir. 2007).
`
`The broadest, reasonable scope and ordinary meaning of the claim
`
`limitations of the ’891 Patent that are relevant for analysis of the specific grounds
`
`of invalidity raised in this Petition is sufficiently clear that none of the terms
`
`requires formal construction by the Board.
`
`Petitioner believes that the claims should be construed in accordance with
`
`their plain and ordinary meaning in this proceeding, but reserves the right to argue
`
`otherwise in any other proceeding such as litigation in a United States District
`
`Court.
`
`D.
`
`37 C.F.R. § 42.104(b)(4): How the Claims Are Unpatentable
`
`A detailed explanation of the reasons why the Challenged Claims are
`
`unpatentable is set forth in Section V.
`
`E.
`
`37 C.F.R. § 42.104(b)(5): Evidence Supporting Challenge
`
`An Exhibit List supports this challenge. The relevance of the evidence,
`
`including the identity of specific portions of the evidence that support this
`
`challenge, is explained in Section V.
`
`IV. OVERVIEW OF THE ’891 PATENT
`
`A.
`
`Priority Date of the ’891 Patent
`
`The ’891 Patent issued December 14, 2004 from U.S. Application Ser. No.
`
`09/800,678, filed March 6, 2001. Ex. 1001.
`
` 5
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`B.
`
`Summary of the ’891 Patent
`
`The earliest effective filing date of the ’891 Patent is March 6, 2001. The
`
`’891 Patent is entitled “System for Fabric Packet Control” and is directed to the
`
`field of routing packets through alternative paths between nodes in a routing fabric,
`
`or “flow control”, and pertains in particular to methods by which back-ups in a
`
`fabric may be avoided. Ex. 1001 (1:5-9). The ’891 Patent purports to disclose a
`
`system and method for managing data traffic in nodes in a fabric network, each
`
`node (or “switching element”) having internally-coupled ports, follows the steps of
`
`establishing a managed queuing system comprising a queue manager, one or more
`
`queues associated with each port, for managing incoming data traffic, and
`
`accepting or discarding data directed to a queue according to the quantity of data in
`
`the queue relative to queue capacity. Id. at Abstract.
`
` 6
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`Figure 1 of the ’891 Patent (reproduced above), “labeled prior art, illustrates
`
`a number of interconnected fabric nodes, labeled in this example A through J, each
`
`node of which may be fairly considered to comprise a fabric card in a switching
`
`fabric in a router.” Id. at (1:26-29). Figure 1 “illustrate[s] that there are a wide
`
`variety of alternative paths that data may take within a switching fabric. For
`
`example, transmission from node E to node J may proceed either via patent E-F-H-
`
`G-J, or alternatively via E-F-D-G-J.” Id. at (1:34-38).
`
`The ’891 Patent explains that conventional switching fabric “at the time of
`
`the present patent application fabric nodes in such a structure are implemented on
`
`fabric cards or chips that do Flow Control. Such Flow Control is very well-known
`
`in the art, and comprises a process of monitoring ports for real or potential traffic
`
` 7
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`overflow, and notifying an upstream port to stop or slow sending of further data.
`
`That is, if node G as shown in FIG. 1, becomes overloaded at a particular input
`
`port, for example, the port from D, the Flow Control at G will notify D to restrict
`
`or suspend traffic to G[.] In this example, D may receive traffic from upstream
`
`neighbors that it cannot forward to G, and it may then have to notify these
`
`neighbors to suspend sending traffic to D.” Id. at (1:43-55).
`
`A “serious problem with Flow Control as conventionally practiced is that the
`
`upstream notifications, inherent in flow control, propagate further upstream and
`
`hinder or stop traffic that there is no need to stop, partly because the
`
`interconnections of nodes may be quite complicated and the alternative paths quite
`
`numerous. Further, a node that has been informed of a downsteam overload
`
`condition cannot select to stop or divert traffic just for that particular link, but only
`
`to stop or divert all traffic. These effects, because of the complexity and
`
`interconnection of nodes in a fabric, can result in complete stultification of parts of
`
`a system, or of an entire network.” Id. at (1:64-2:8).
`
`The patent states that “[w]hat is clearly needed is a way to deal with
`
`temporary overloads at fabric nodes without resorting to problematic upstream
`
`messaging without impacting traffic that does not use the overloaded link.” Id. at
`
`(2:14-17). The patent purports to address that problem through a system of
`
`“routing packets through alternative paths between nodes in a routing fabric [and]
`
` 8
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`in particular to methods by which back-ups in a fabric may be avoided.” Id. at col.
`
`(1:6-9).
`
`In the ’891 Patent, “a preferred embodiment of the present invention [is] a
`
`method for managing data traffic at switching element in a fabric network, each
`
`node having two or more internally coupled ports is provided, comprising the steps
`
`of (a) establishing a managed queuing system comprising one or more queues
`
`associated with each port, for managing incoming data traffic; and (b) accepting or
`
`discarding data directed to a queue according to the quantity of data in the queue
`
`relative to queue capacity.” Id. at (2:20-29). “In some embodiments all data is
`
`discarded for a full queue. In some other embodiments the queue manager
`
`monitors quantity of queued data in relation to a preset threshold, and begins to
`
`discard data at a predetermined rate when the quantity of queued data reaches the
`
`threshold. In still other embodiments the queue manager increases the rate of
`
`discarding as quantity of queued data increases above the preset threshold,
`
`discarding all data traffic when the queue is full.” Id. at (2:30-38).
`
` 9
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`Figure 2 is a plan view of a fabric card 201 that has “nine queue managers
`
`209, one for each external port 205, with each queue manager isolated from its
`
`connected external port by an optical
`
`interface 207.
`
` The
`
`inter-node
`
`communication in this embodiment is by optical links. Queue managers 209
`
`interface with crossbar 203, which connects each of the nine ports with the other
`
`eight ports internally in this embodiment, although these internal connections are
`
`not shown.” Id. at (3:32-39). Each port on each card “passes through a queue
`
`management gate 209.” Id. at (3:52-53). Each “queue manager comprises a set of
`
`virtual output queues (VOQ), with individual VOQs associated with individual
`
`ones of the available outputs on a card. This VOQ queuing system manages
`
`incoming flows based on the outputs to which incoming packets are directed. Data
`
`traffic coming in on any one port, for example, is directed to a first-in-first-out
`
`(FIFO) queue associated with an output port, and the queue manager is enabled to
`
` 10
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`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`discard all traffic when the queue to which data is directed is full.” Id. at (3:54-
`
`62).
`
`The size of each queue “is set to provide adequate flow under ordinary, and
`
`to some extent extraordinary, load conditions without data loss, but under extreme
`
`conditions, when a queue is full, data is simply discarded until the situation
`
`corrects, which the inventors have found to be less conducive to data loss than the
`
`problems associated with conventional Flow Control, which uses the previously
`
`described upstream-propagated Flow Control indicators.” Id. at (3:66-4:7).
`
`In an alternative embodiment, “each queue manager on a card has an ability
`
`to begin to drop packets at a pre-determined rate at some threshold in queue
`
`capacity short of a full queue.” Id. at (4:8-11). The queue manager “may
`
`accelerate the rate of packet dropping as a queue continues to fill above the first
`
`threshold.” Id. at (4:12-14). The patent asserts that “[i]n these embodiments the
`
`incidence of dropping packets is minimized and managed, and spread over more
`
`traffic than would be the case if dropping of packets were to begin only at a full
`
`queue, wherein all packets would be dropped until the queue were to begin to
`
`empty.” Id. at (4:13-17). It declares that a “distinct advantage of the queue
`
`management scheme of the present invention is that the intelligence required is
`
`considerably lessened, and there is no addition to the traffic load by generating
`
`Flow Control indicators.” Id. at (4:18-22).
`
` 11
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`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`C.
`
`Claims of the ’891 Patent
`
`There are six (6) claims in the ’891 Patent, which are shown below with
`
`additional lettering (e.g., [A]) to designate each claim limitation:
`
`1. A method for managing data traffic at switching element nodes in a
`
`fabric network, each switching element node having a plurality of input
`
`and output ports, comprising the steps of:
`
`(a) [A] establishing at each input port, a number of virtual output queues
`
`equal to the number of output ports, each virtual output queue at each
`
`individual input port dedicated to an individual output port, storing only
`
`packets destined for the associated output port, for managing incoming
`
`data traffic; and
`
`(b) [B] Accepting or discarding data at each virtual output queue directed to
`
`a queue according to a quantity of data in the queue relative to queue
`
`capacity by providing a queue manager for monitoring quantity of
`
`queued data in relation to a preset threshold, and discarding data from
`
`each virtual output queue at a predetermined rate, when the quantity of
`
`queued data reaches or exceeds the threshold;
`
`[C] wherein in step (b), the queue manager increases the rate of
`
`discarding as quantity of queued data increases above the preset
`
`threshold,
`
` 12
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`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`[D] discarding all data traffic when the queue is full.
`
`2. The method of claim 1 wherein, in step (b), all data is discarded for a full
`
`queue.
`
`3. A switching element node for a fabric network, comprising:
`
`[A] a plurality of input an[d] output ports;
`
`[B] a number of virtual output queues at each input port equal to the
`
`number of output ports, each virtual output queue at each individual input
`
`port dedicated to an individual output port, storing only packets destined
`
`for the associated output port, for managing incoming data traffic; and
`
`[C] characterized in that a queue manager accepts or discards data
`
`directed to a queue according to a quantity of data in the queue relative to
`
`the queue capacity by monitoring quantity of queued data against a preset
`
`threshold, and discarding data from each virtual output queue at a
`
`predetermined rate, when the quantity of queued data reaches or exceeds
`
`the threshold;
`
`[D] wherein the queue manager increases the rate of discarding as
`
`quantity of queued data increases above the preset threshold.
`
`4. The switching element of claim 3 wherein all data is discarded for a full
`
`queue.
`
` 13
`
`

`

`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
`
`5. A data router having external connections to other data routers,
`
`comprising:
`
`[A] an internal fabric network; and
`
`[B] a plurality of switching element nodes in the internal fabric network,
`
`each switching element node having a plurality of input and output ports,
`
`and at each input port, a number of virtual output queues equal to the
`
`number of output ports, each virtual output queue at each individual input
`
`port dedicated to an individual output port, storing only packets destined
`
`for the associated output port, for managing incoming data traffic;
`
`[C] characterized in that a queue manager accepts or discards data
`
`directed to a queue according to a quantity of data in the queue relative to
`
`the queue capacity by monitoring the quantity of queued data against a
`
`preset threshold, and begin to discard data from each virtual output queue
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`at a predetermined rate, when the quantity of queued data reaches or
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`exceeds the threshold;
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`[D] wherein the queue manager increases the rate of discarding as
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`quantity of queued data increases above the preset threshold.
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`6. The data router of claim 5 wherein all data is discarded for a full queue.
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`Ex. 1001 at (4:34-6:17).
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`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
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`D.
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`The Legal Standard for Obviousness
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`“A patent may not be obtained though the invention is not identically
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`disclosed or described as set forth in Section 102, if the differences between the
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`subject matter sought to be patented and the prior art are such that the subject
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`matter as a whole would have been obvious at the time the invention was made to a
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`person having ordinary skill in the art to which said subject matter pertains.”
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`35 U.S.C. § 103(a) (Pre-AIA).
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`The ultimate determination whether a patent claim is invalid for obviousness
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`is a question of law based on underlying factual determinations. Kinetic Concepts,
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`Inc. v. Smith & Nephew, Inc., 688 F.3d 1342, 1360 (Fed. Cir. 2012). The initial
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`factual inquiries to determine obviousness include: (1) the scope and content of
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`the prior art; (2) the differences between the claimed invention and the prior art;
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`and (3) the level of ordinary skill in the pertinent art. Graham v. John Deere Co.,
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`383 U.S. 1, 17-18 (1966). Petitioner is not aware of any secondary considerations,
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`e.g., commercial success with a nexus to the patented invention, long-felt need or
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`failure of others, that would support a conclusion of non-obviousness.
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`A patent claim is invalid for obviousness if a person of ordinary skill in the
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`art would have recognized the problem to be solved and would have had a
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`reasonable expectation of success in making the claimed invention in view of a
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`combination of the available prior art and the knowledge of the person of ordinary
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`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
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`skill. In KSR, the Supreme Court reaffirmed that “[t]he combination of familiar
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`elements according to known methods is likely to be obvious when it does no more
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`than yield predictable results.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-16
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`(2007). A tribunal considering obviousness “need not seek out precise teachings
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`directed to the specific subject matter of the challenged claim, for [the tribunal] can
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`take account of the inferences and creative steps that a person of ordinary skill in
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`the art would employ.” Id. at 418.
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`In support of this Petition, Petitioner provides the testimony of Nicholas
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`Bambos, Ph.D., which addresses the underlying factual
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`inquiries
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`in the
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`obviousness analysis. Declaration of Dr. Nicholas Bambos, (Ex. 1002).
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`E.
`
`Person of Ordinary Skill in the Art
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`The technical field of the ’891 Patent is computer software and hardware
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`with applications to efficiently moving data-packets between routers and other
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`hardware connected in networks such as the internet and the processors and
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`circuitry, including nodes or switching elements in a routing fabric utilized for
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`such applications. A POSA in the March 6, 2001 timeframe, which is the earliest
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`claimed effective filing date of the ’891 Patent, would have had at least a
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`bachelor’s degree
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`in computer science, computer engineering, electrical
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`engineering, or a related field, and either (a) a master’s degree in computer science,
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`computer engineering, electrical engineering, or a related field or (b) two or more
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`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
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`years of work or research experience in networking and computing. Ex. 1002 at
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`¶31.
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`V.
`
`IT IS MORE LIKELY THAN NOT
`THAT THE CHALLENGED CLAIMS ARE UNPATENTABLE
`
`A.
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`Summary of the Grounds for Rejection
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`• Ground 1: Claims 1-6 of the ’891 Patent are obvious under
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`35 U.S.C. § 103(a) in view of Schwartz and Muller.
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`• Ground 2: Claims 1-6 of the ’891 Patent are obvious under
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`35 U.S.C. § 103(a) in view of Firoiu and Muller.
`
`B.
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`Summary of the Prior Art
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`Schwartz
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`PCT International Application No. WO 00/02347 A2 to Schwartz et al.
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`(“Schwartz”) (Ex. 1004) published January 13, 2000, more than one year before
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`the earliest claimed priority date of the ’963 Patent (March 6, 2001). Schwartz
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`therefore is statutory prior art to the ’963 Patent under pre-AIA 35 U.S.C. § 102(b).
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`Schwartz, titled “System and Method for Switching Packets in a Network”,
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`“relates generally to the field of digital communications, and more particularly to
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`systems and methods for switching packets of digital data in a switching node used
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`in a digital data network.” Ex. 1004 at (1:5-7). Schwartz explains that “a
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`switching node includes one or more input ports, each of which is connected to a
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`communication link to receive packets, a plurality of output ports, each of which is
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`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
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`connected to a communication link to transmit packets, and a ‘switching fabric’
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`that couples packets from the input ports to the respective outport ports for
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`transmission.” Id. at (2:1-5). After an input port receives a packet, “it will
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`typically buffer the packet, identify from the destination address the particular
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`output port that is to transmit the packet and transfer the packet to the output port
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`through the switching fabric.” Id. at (2:5-8). After the output port receives the
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`packet, it “will typically buffer the packet in a queue for transmission over the
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`communication link connected thereto.” Id. at (2:8-10).
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`Schwartz further explains that, although “buffering and scheduling by the
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`output port can provide for efficient packet transmission by the output port,
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`[because] the output port can be kept continually busy, several problems can arise
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`with output port buffering.” Id. at (2:10-12). Generally, “each output port will
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`effectively provide one queue for each input port, in which case the total number of
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`queues provided by the switching node will be on the order of N2, where ‘N’ is the
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`number of input ports, which, in turn, corresponds to the number of output ports, if
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`as is typical, each communication link provides for bi-directional transmission of
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`packets. Thus, as ‘N,” the number of input/output ports, increases, the number of
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`queues maintained by the output ports increases quadratically, at a much faster
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`rate, and so output queuing does not scale well.” Id. at (2:12-19). Schwartz
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`explains that switching nodes capable of “input queuing, in which packets are
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`Petition for Inter Partes Review of U.S. Patent No. 6,831,891
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`buffered and queued at the input ports. Only one queue is needed for each input
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`port, and so, as the number if input (and output) ports increases, the number of
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`queues increases at a linear rate, avoiding the quadratic increase with output
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`queuing.” Id. at (2:20-24). Schwartz explains, however, “input queuing results in
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`much lower efficiency of usage of the switching fabric, [because] the input ports
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`must, after buffering received packets, essentially contend and arbitrate for use of
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`the switching fabric to facilitate transfer of the packets to the respective output
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`ports for transmission.” Id. at (2:24-28).
`
`Schwartz provides a new and improved switching node that avoids “the
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`quadratic increase in packet queues, relative to increasing numbers of input/output
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`ports, that is characteristic of switching nodes that provide for output-queuing” and
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`“the relative inefficient usage of the switching fabric … that is characteristic of a
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`switching node that provides for input-queuing”. Id. at (3:1-12).
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`Schwartz provides “a swi