Case: 19-1464   Document: 85     Page: 1   Filed: 07/16/2020




        NOTE: This disposition is nonprecedential.


   United States Court of Appeals
       for the Federal Circuit
                 ______________________

                  ALACRITECH, INC.,
                      Appellant

                            v.

 INTEL CORPORATION, CAVIUM, LLC, DELL INC.,
                 Appellees

                   UNITED STATES,
                       Intervenor
                 ______________________

                       2019-1464
                 ______________________

     Appeal from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in Nos. IPR2017-
 01393, IPR2017-01714, IPR2018-00374.
                  ______________________

                 Decided: July 16, 2020
                 ______________________

     SANFORD IAN WEISBURST, Quinn Emanuel Urquhart &
 Sullivan, LLP, New York, NY, for appellant. Also repre-
 sented by JOSEPH M. PAUNOVICH, Los Angeles, CA.

    GARLAND STEPHENS, Weil, Gotshal & Manges LLP,
 Houston, TX, for appellee Intel Corporation. Also repre-
 sented by MELISSA LARUE HOTZE; GREGORY SILBERT, New
Case: 19-1464      Document: 85    Page: 2   Filed: 07/16/2020




 2                             ALACRITECH, INC.   v. INTEL CORP.



 York, NY; AMANDA BRANCH, ANNE MARIE CAPPELLA, Red-
 wood Shores, CA.

     KARINEH KHACHATOURIAN, Rimon, P.C., Palo Alto, CA,
 for appellee Cavium, LLC. Also represented by NIKOLAUS
 A. WOLOSZCZUK.

     KIRK T. BRADLEY, Alston & Bird LLP, Charlotte, NC,
 for appellee Dell Inc. Also represented by EMILY CHAMBERS
 WELCH, Atlanta, GA; BRADY COX, Dallas, TX.

     MELISSA N. PATTERSON, Appellate Staff, Civil Division,
 United States Department of Justice, Washington, DC, for
 intervenor.    Also represented by ETHAN P. DAVIS,
 COURTNEY DIXON, SCOTT R. MCINTOSH; THOMAS W.
 KRAUSE, FARHEENA YASMEEN RASHEED, Office of the Solic-
 itor, United States Patent and Trademark Office, Alexan-
 dria, VA.
                  ______________________

         Before MOORE, CHEN, and STOLL, Circuit Judges.
 CHEN, Circuit Judge.
     Alacritech appeals from the final written decisions of
 the Patent Trial and Appeal Board (the Board) in the
 above-captioned inter partes review (IPR) proceedings
 holding claims 1, 6, 9, 12, and 15 of U.S. Patent No.
 9,055,104 invalid as obvious. 1 We affirm.




     1   Alacritech’s appeal briefing included a challenge to
 the appointment of the administrative patent judges on the
 Board under the Appointments Clause of the Constitution,
 but this challenge has since been withdrawn and waived.
 See Dkt. No. 70.
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 ALACRITECH, INC.   v. INTEL CORP.                            3



                          BACKGROUND
      The ’104 patent relates to network communications,
 and in particular to the use of a network interface device to
 offload network processing tasks from the central pro-
 cessing unit (CPU) of a host computer. ’104 patent at Ab-
 stract. To transmit data to the network, the computer
 supplies a command along with the data to the network in-
 terface, which in turn processes and transmits that data
 according to the Transmission Control Protocol (TCP) be-
 fore indicating to the computer that the data has been
 transmitted. Id. at col. 3 ll. 37–47. TCP also requires the
 recipient of the data to respond with acknowledgments
 (ACKs) indicating to the transmitting device—here, the
 network interface—which data has been successfully re-
 ceived. Id. at col. 2 ll. 10–15. The claimed invention spec-
 ifies that the network interface indicates to the
 transmitting computer that the data has been transmitted
 “prior to receiving” the ACK for all of the transmitted data.
 Claim 1 is representative:
     1. A method for communication involving a com-
     puter, a network, and a network interface device of
     the computer, the network interface device being
     coupled to the network, the method comprising:
     receiving, by the network interface device from the
     computer, a command to transmit application data
     from the computer to the network;
     sending, by the network interface device to the net-
     work, data corresponding to the command, includ-
     ing prepending a transport layer header to at least
     some of the data;
     sending, by the network interface device to the com-
     puter, a response to the command indicating that
     the data has been sent from the network interface
     device to the network, prior to receiving, by the net-
     work interface device from the network, an
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 4                            ALACRITECH, INC.   v. INTEL CORP.



     acknowledgement (ACK) that all the data corre-
     sponding to the command has been received; and
     maintaining, by the network interface device, a
     Transport Control Protocol (TCP) connection that
     the command, the data and the ACK correspond to.
 Id. at claim 1 (emphasis added).
     The Board found all of the challenged claims unpatent-
 able over U.S. Patent No. 5,937,169 (Connery) in view of
 the knowledge of a skilled artisan and, in the alternative,
 over Connery in view of PCT Patent Publication No.
 WO 00/13091. Relevant to this appeal, the Board found
 that Connery discloses the limitation of “sending, by the
 network interface device to the computer, a response to the
 command indicating that the data has been sent from the
 network interface device to the network,” and that Con-
 nery’s network interface sends this response “prior to re-
 ceiving . . . an acknowledgment (ACK) that all the data
 corresponding to the command has been received.” J.A.
 19–25; ’104 patent at claim 1.
     Alacritech appeals, and we have jurisdiction under
 28 U.S.C. § 1295(a)(4)(A).
                        DISCUSSION
     Obviousness “is a question of law based on underlying
 findings of fact.” In re Gartside, 203 F.3d 1305, 1316 (Fed.
 Cir. 2000) (citation omitted). We review the Board’s find-
 ings regarding the scope and content of the prior art for
 substantial evidence. Rambus Inc. v. Rea, 731 F.3d 1248,
 1251–52 (Fed. Cir. 2013).
     The sole dispute in this appeal relates to what Connery
 discloses, and specifically, the relative timing between a
 particular “interrupt” message sent from Connery’s net-
 work interface to the computer’s central processing unit
 (CPU) and the receipt of an ACK sent from a computer that
 received the transmitted data.
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 ALACRITECH, INC.   v. INTEL CORP.                           5



      Like the ’104 patent, Connery discloses that network
 protocol processing can be offloaded from the CPU to a net-
 work interface. Connery at col. 1 ll. 7–11. As Connery ex-
 plains, higher layer network protocols such as TCP were
 typically “handled by software drivers” and “a protocol
 stack executed in the host processor,” i.e., CPU. Id. at col.
 1 ll. 20–21, 31–33. To transmit data according to TCP, the
 CPU would first package that data into “appropriately
 sized segments.” Id. at col. 1 ll. 37–41. Separately, the
 CPU would also monitor acknowledgment (ACK) messages
 from the recipient to ensure, for reliability purposes, that
 “the amount of data sent onto the network” “does not ex-
 ceed” the advertised receiving capacity of the recipient. Id.
 at col. 1 l. 56–col. 2 l. 13. To reduce the load on the CPU,
 Connery explains that segmentation of data for transmis-
 sion can be offloaded from the CPU to the network inter-
 face. Id. at col. 7 ll. 47–49, 60–64. With the exception of
 data segmentation, Connery’s CPU continues to handle the
 remaining aspects of the TCP protocol. Id. at col. 5 ll. 51–
 53, col. 6 ll. 15–18.
       Connery’s network interface accepts a command from
 the CPU to transmit a “large datagram” and divides that
 datagram into individually transmitted segments accord-
 ing to the TCP network protocol. Id. at col. 2 ll. 46–57.
 Once the network interface transmits the data segments of
 the large datagram, Connery discloses that the network in-
 terface can send a single interrupt to the CPU. Id. at col.
 7 ll. 60–63. The parties dispute whether this interrupt sent
 by the network interface occurs before, or after, the net-
 work interface receives an ACK indicating that all of the
 transmitted data was successfully received by a destina-
 tion computer.
     The Board agreed with the petitioner that a skilled ar-
 tisan would understand Connery’s single interrupt per
 large datagram as indicating that “all generated packets
 from the large datagram have been sent from the network
 interface to the network regardless of whether any
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 6                             ALACRITECH, INC.   v. INTEL CORP.



 corresponding ACK[s] have been received.” J.A. 23. The
 Board further found that Connery’s interrupt would be
 generated by the network interface prior to receiving an
 ACK from the recipient for all of the transmitted data.
 Substantial evidence supports the Board’s fact findings.
     The Board reasonably found that the interrupt gener-
 ated by Connery’s network interface is strictly associated
 with the task given to the network interface—transmitting
 data in segments—and not other tasks, such as ACK pro-
 cessing, that the host computer has not offloaded to the net-
 work interface. As Intel’s expert, Dr. Horst, explained,
 such an interrupt to indicate that the network interface is
 done with segmenting and transmitting data “is needed be-
 cause otherwise the host would not know when the [net-
 work interface] hardware is free to accept the next large
 packet to be sent.” J.A. 1670. In contrast, the Board found
 that ACK processing is “unaffected by Connery’s alleged
 improvements to segmenting and transmitting data” on
 the network interface. J.A. 23. Thus, “an ordinarily skilled
 artisan would have presumed ACKs are processed in the
 normal processing of a TCP/IP protocol stack operable in
 the host computer.” Id. In other words, while Connery con-
 templates offloading the task of transmitting data in seg-
 ments from the CPU to its network interface, which in turn
 sends an interrupt back to the host when that task is com-
 plete, ACK processing is not affected; the ACK, as a sepa-
 rate message, continues to be sent from the recipient and
 handled by the CPU in a conventional manner. Because
 ACK processing has not been offloaded from Connery’s
 CPU to its network interface, the Board fairly concluded
 that the “interrupt” generated by the network interface in-
 dicates that the interface has completed its data transmis-
 sion assignment rather than referring to the ACK. Thus,
 like the Board, we are not persuaded by Alacritech’s argu-
 ment that Connery’s interrupt must include the ACK or de-
 pend on receipt of the ACK.
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 ALACRITECH, INC.   v. INTEL CORP.                           7



     After determining that Connery’s “interrupt for trans-
 mit complete” is sent by the network interface to the CPU
 independently of the receipt of any ACK, the Board consid-
 ered the relative timing between the transmit complete in-
 terrupt and the return of ACKs for all of the transmitted
 data. J.A. 24. We see no error in the Board’s reasoning
 that “an interrupt for transmit complete would precede”
 the ACK indicating that all data segments of the datagram
 have been transmitted “because there is substantial la-
 tency in receipt of the ACK as compared to” the interrupt.
 Id. After the network interface “transmit[s] the last packet
 of the datagram,” the transmit complete interrupt would
 be “sent immediately” and “virtually instantaneous” be-
 tween the network interface and the CPU, whereas there
 would be “substantial latency,” i.e., delay, from the trans-
 mission of the last packet of the datagram over the net-
 work, the processing of that packet at the receiving
 computer, and the return transmission of an ACK for that
 packet from the receiving computer to the transmitting
 network interface. Id.
      Alacritech alleges that, under the Board’s reading,
 Connery’s network interface must also generate a second
 interrupt “to let the CPU know that the ACKs have been
 received and the data transfer is complete,” rendering the
 initial transmit complete interrupt “meaningless.” Appel-
 lant’s Br. at 20–22. According to Alacritech, the CPU must
 wait for this alleged second interrupt indicating receipt of
 the ACKs for the first batch of data before “sending the
 next batch of data to the [network interface] for transmis-
 sion.” Id. We note that Alacritech did not make this “sec-
 ond interrupt” argument before the Board, and arguments
 not made below are generally waived. In re NuVasive, Inc.,
 842 F.3d 1376, 1380 (Fed. Cir. 2016) (“a party waives an
 argument that it ‘failed to present to the [PTAB]’ because
 it deprives the court of ‘the benefit of the [PTAB]’s informed
 judgment’”) (citing In re Watts, 354 F.3d 1362, 1367–68
 (Fed. Cir. 2004)). Although Alacritech points out that it
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 8                            ALACRITECH, INC.   v. INTEL CORP.



 argued to the Board that a skilled artisan would not depart
 from the allegedly “conventional” practice in which “the
 network interface device waits for an ACK for all the trans-
 mitted data before it sends a response indicating the com-
 mand has been completed to the local host,” that says
 nothing about a second interrupt in addition to Connery’s
 or that Connery’s CPU must wait for a second interrupt
 before supplying additional data to its network interface
 for transmission. Appellant’s Reply Br. at 1–2 (citing J.A.
 444). To the extent that Alacritech argued that Connery’s
 interrupt is dependent on the receipt of an ACK, we ex-
 plained above that substantial evidence supports the
 Board’s conclusion that Connery’s interrupt is indicative of
 transmit completion rather than ACK receipt.
      In any event, nothing in Connery or the record suggests
 that Connery’s CPU must wait for ACK confirmation be-
 fore supplying additional data to the network interface for
 transmission. Alacritech does not contend that the TCP
 protocol itself imposes such a requirement on the interac-
 tion between the CPU and the network interface. Appel-
 lant’s Reply Br. at 8–9 (acknowledging that TCP’s flow
 control mechanism, which includes ACKs, “does not specify
 the communications between the sending computer’s CPU
 and a [network interface card]”). As both parties agree, the
 TCP protocol controls the flow of data between transmit-
 ting and receiving devices based on a “window” advertised
 by the receiving device. The receiving window defines how
 much data the transmitting device can send to the receiv-
 ing device without waiting for ACKs from the receiving de-
 vice. Connery itself explains that the sending computer
 can continue to transmit data without waiting for any
 ACKs so long as the “sender controls the amount of data
 sent onto the network so that it does not exceed the size of
 the advertised window of the destination.” Connery at col.
 2 ll. 3–13. Connery further confirms that, consistent with
 TCP’s constraints on transmitting data, the CPU can
 “send[] a plurality of datagrams to the network interface
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 ALACRITECH, INC.   v. INTEL CORP.                           9



 for the same session,” and the network interface will “con-
 catenate[],” i.e., link, “data from the current datagram”
 that is sequentially aligned “with data from the following
 datagram.” Id. at col. 4 ll. 34–41. As Intel explains, such
 concatenation between datagrams would be impossible if,
 as Alacritech urges, the following datagram was not made
 available to the network interface until after the current
 datagram is transmitted and an ACK received.
     In sum, the Board’s decision finding that Connery’s in-
 terrupt represents the network interface’s completion of
 transmission of a large datagram and occurs prior to the
 receipt of an ACK for all of the data in that large datagram
 is supported by substantial evidence.
                          CONCLUSION
     We have considered Alacritech’s remaining arguments
 and find them unpersuasive. For the reasons stated above,
 we affirm the Board’s conclusion that the claims at issue
 are unpatentable.
                          AFFIRMED
