Case: 22-1349    Document: 37     Page: 1   Filed: 03/13/2023




   United States Court of Appeals
       for the Federal Circuit
                  ______________________

                   ALTERWAN, INC.,
                    Plaintiff-Appellant

                             v.

   AMAZON.COM, INC., AMAZON WEB SERVICES,
                     INC.,
             Defendants-Appellees
            ______________________

                        2022-1349
                  ______________________

     Appeal from the United States District Court for the
 District of Delaware in No. 1:19-cv-01544-MN, Judge
 Maryellen Noreika.
                 ______________________

                 Decided: March 13, 2023
                 ______________________

     C. GRAHAM GERST, Global IP Law Group, LLC, Chi-
 cago, IL, argued for plaintiff-appellant. Also represented
 by STEVEN J. FALETTO, ALISON AUBREY RICHARDS, HAN-
 NAH L. SADLER.

    J. DAVID HADDEN, Fenwick & West LLP, Mountain
 View, CA, argued for defendants-appellees. Also repre-
 sented by JOHNSON KUNCHERIA, RAVI RAGAVENDRA RANGA-
 NATH, SAINA S. SHAMILOV; TODD RICHARD GREGORIAN, San
 Francisco, CA.
                 ______________________
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 2                         ALTERWAN, INC.   v. AMAZON.COM, INC.




         Before LOURIE, DYK, and STOLL, Circuit Judges.
 DYK, Circuit Judge.
     In this patent infringement action, the parties entered
 into a stipulation of non-infringement based on two of the
 district court’s claim construction rulings. Because the
 stipulation is ambiguous and therefore defective, we vacate
 and remand for further proceedings.
                         BACKGROUND
      Appellant AlterWAN sued appellee Amazon for in-
 fringement of claims of two patents: U.S. Patent Nos.
 8,595,478 (“the ʼ478 patent”) and 9,015,471 (“the ʼ471 pa-
 tent”). 1 AlterWAN’s patents concern improvements to im-
 plementing wide area networks (“WANs”) over the
 Internet. Both patents share a common specification. The
 specification describes two core problems with using the In-
 ternet for WANs. The first is the problem of latency (or
 delay) due to uncontrolled “hops” from one node to another
 while the data packet is en route to its destination. ’478
 patent, col. 3 ll. 32–49. The second is the lack of security
 for data transmitted over the Internet. ’478 patent, col. 3
 ll. 50–53. The patents purport to address those problems
 with a “private tunnel” that provides “preplanned high
 bandwidth, low hop-count routing paths between pairs of
 customer sites.” ’478 patent, col. 4 ll. 17–18, 34.
    At the claim construction phase, the parties disputed
 two terms relevant to this appeal: “non-blocking band-
 width” and “cooperating service provider.”




     1  There were originally six patents involved in the
 proceedings below, but only two are relevant to this appeal.
 AlterWAN voluntarily stipulated to dismissal of claims
 based on the other four patents with prejudice.
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                  I. Non-Blocking Bandwidth
     The term “non-blocking bandwidth” appears in claims
 1, 13, and 14 of the ʼ471 patent but not in the asserted
 claims of the ʼ478 patent. Claim 1 of the ʼ471 patent, which
 appears to be representative of the ʼ471 claims, uses the
 term “non-blocking bandwidth:”
    1. An apparatus, comprising:
        an interface to receive packets;
        circuitry to identify those packets of the re-
        ceived packets corresponding to a set of one
        or more predetermined addresses, to iden-
        tify a set of one or more transmission paths
        associated with the set of one or more pre-
        determined addresses, and to select a spe-
        cific transmission path from the set of one
        or more transmission paths; and
        an interface to transmit the packets corre-
        sponding to the set of one or more predeter-
        mined addresses using the specific
        transmission path;
        wherein
            each transmission path of the set of
            one or more transmission paths is
            associated with a reserved, non-
            blocking bandwidth, and
            the circuitry is to select the specific
            transmission path to be a transmis-
            sion path from the from the [sic] set
            of one or more transmission paths
            that corresponds to a minimum
            link cost relative to each other
            transmission path in the set of one
            or more transmission paths.
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 4                         ALTERWAN, INC.   v. AMAZON.COM, INC.



 ʼ471 patent, col. 15 ll. 44–63 (emphasis added). The speci-
 fication explains that “the quality of service problem that
 has plagued prior attempts is solved by providing non-
 blocking bandwidth (bandwidth that will always be availa-
 ble and will always be sufficient).” ʼ471 patent, col. 4 l. 66–
 col. 5 l. 2.
     Amazon sought the construction “bandwidth that will
 always be available and will always be sufficient,” J.A. 430,
 mirroring the language of the specification. AlterWAN ar-
 gued that no construction was necessary for “non-blocking
 bandwidth.” Alternately, AlterWAN proposed the con-
 struction “bandwidth that will always be available and will
 always be sufficient while the network is operational.” Id.
 AlterWAN urged that the language “while the network is
 operational” was necessary because “[t]here is no such
 thing as a network that can never fail.” Id. at 431. The
 district court agreed with Amazon, reasoning that the pa-
 tentee acted as its own lexicographer and that the claim
 language required that the bandwidth be available even if
 the Internet is down.
                II. Cooperating Service Provider
     The term “cooperating service provider” appears in
 claims 1, 6, 10, 18, 42, 51, and 63 of the ʼ478 patent and in
 claim 19 of the ʼ471 patent. Claim 1 of the ʼ478 patent ap-
 pears to be representative:
     1. A method of operation in a router that is part of
     a wide area network, the method comprising:
         filtering inbound data packets received on
         an input port of the router to identify data
         packets that correspond to a selected group
         of addresses relative to data packets that
         are not within the selected group of ad-
         dresses; and
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         providing priority routing for the data
         packets in the selected group of addresses,
         including
         performing a look-up into a routing table
         applicable to the selected group of ad-
         dresses to identify one or more transmis-
         sion paths that meet a minimum
         transmission requirement relative to other
         available transmission paths, and
         routing the data packets to at least one co-
         operating service provider using one of the
         identified one or more transmission paths.
 ʼ478 patent, col. 15 ll. 43–58 (emphasis added).
      AlterWAN argued that no construction was necessary
 for “cooperating service provider,” or, if construction is nec-
 essary, that the term ought to be construed as a “service
 provider whose transmission equipment is coupled to the
 path” or “third party service provider whose transmission
 equipment is coupled to the path.” J.A. 436. Amazon urged
 that the term should be construed to mean “service pro-
 vider that agrees to provide nonblocking bandwidth.” Id.
     After a Markman hearing, the district court initially
 construed “cooperating service provider” as “service pro-
 vider that agrees to provide blocked bandwidth.” 2 J.A. 40.
 The district court reasoned that the prosecution history, in
 which the patentee stated that “cooperating services pro-
 viders . . . have prearranged for blocked bandwidth[,]” sup-
 ported this construction. Id. The district court refused to



     2  Claim 2 of the ʼ471 patent includes the related
 term “cooperating third party service provider.” In its
 claim construction order, the district court assigned the
 same construction to both “cooperating service provider”
 and “cooperating third party service provider.”
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 6                        ALTERWAN, INC.   v. AMAZON.COM, INC.



 substitute “non-blocking bandwidth” for “blocked band-
 width,” as Amazon requested, because “the parties disa-
 gree[d] whether ‘blocked bandwidth’ has the same meaning
 as ‘non-blocking bandwidth,’” but the parties did not ask
 the court to construe “blocked bandwidth.” Id. The court
 noted that “[s]hould a dispute based on the meaning of
 ‘blocked bandwidth’ later arise, the parties may raise it to
 the extent necessary.” Id.
     At the summary judgment stage, AlterWAN argued
 that “blocked bandwidth” should be construed as “band-
 width reserved for a particular purpose,” while Amazon
 sought to substitute the term “non-blocking bandwidth” for
 “blocked bandwidth.” J.A. 771. At a hearing, the district
 court agreed with Amazon and changed its construction of
 “cooperating service provider” to be a “service provider that
 agrees to provide non-blocking bandwidth.” Id. at 3.
                  III. Further Proceedings
     The stipulated judgment that is appealed here was en-
 tered into after the filing of motions for summary judg-
 ment, including Amazon’s motion for summary judgment
 of non-infringement. 3 After changing the construction of



     3   The stipulation provided, in relevant part:
         [T]he parties stipulate and agree as fol-
         lows:
         1. Under the Court’s constructions of “coop-
         erating service provider” and “nonblocking
         bandwidth,” Amazon has not infringed,
         and does not infringe, the ’478 and ’471 pa-
         tents.
         2. The parties stipulate to the entry of judg-
         ment of non-infringement of the ’478 and
         ’471 patents, subject to AlterWAN’s
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 “cooperating service provider” at the summary judgment
 hearing, the district court gave AlterWAN the opportunity
 to submit a supplemental expert report to make additional
 infringement contentions based on the new construction,
 or, if the new construction meant there was no reasonable
 infringement argument that AlterWAN could make, to
 stipulate to non-infringement.
     After the summary judgment hearing, the parties filed
 a stipulation and order of non-infringement of the patents-
 in-suit. The parties stipulated to “the entry of judgment of
 non-infringement of the ʼ478 and ʼ471 patents.” J.A. 4.
 The stipulation explained, “[u]nder the Court’s construc-
 tions of ‘cooperating service provider’ and ‘non-blocking
 bandwidth,’ Amazon has not infringed, and does not in-
 fringe, the ’478 and ’471 patents.” Id. Based on the stipu-
 lation, the district court entered a final judgment.
 AlterWAN appealed.
     In its appeal, AlterWAN challenges the district court’s
 construction of “cooperating service provider” and “non-
 blocking bandwidth” as well as a third term, “routing.” Al-
 terWAN concedes that “routing,” a term that the district
 court offered guidance on at the summary judgment hear-
 ing, is not included in the stipulation, but AlterWAN ar-
 gues we should address the term to conserve judicial
 resources.     We have jurisdiction under 

(a)(1).




           forthcoming appeal of the Court’s Claim
           Construction and Summary Judgment Or-
           ders.
 J.A. 4.
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 8                         ALTERWAN, INC.   v. AMAZON.COM, INC.



                         DISCUSSION
                               I
     In past cases, we have held that stipulated judgments
 are defective if they are ambiguous in material respects.
 See Jang v. Bos. Sci. Corp., 

, 1335–36 (Fed.
 Cir. 2008). The stipulated judgment here provides that
 Amazon does not infringe under the district court’s con-
 structions of “cooperating service provider” and “non-block-
 ing bandwidth.” Under the circumstances of this case, the
 stipulation does not provide sufficient detail to allow us to
 resolve the claim construction issues presented on appeal.
      First, the stipulation does not identify which claims of
 the ’471 patent remain at issue in this appeal. We have
 vacated judgments that fail to identify which claims are
 implicated by the judgment. See Allen Eng’g Corp. v. Bar-
 tell Indus., Inc., 

 (Fed. Cir. 2002) (va-
 cating a judgment in part “[b]ecause the district court did
 not . . . identify the specific claims it held to be infringed
 under the doctrine of equivalents.”).
     More importantly, it is unclear whether the judgment
 requires the affirmance of both “cooperating service pro-
 vider” and “non-blocking bandwidth,” where the interpre-
 tation of cooperating service provider includes the term
 “non-blocking bandwidth.” 4 It is also unclear whether af-
 firmance requires the approval of all aspects of the con-
 struction of “cooperating service provider.”
     Stated differently, the parties dispute two aspects of
 the construction of the term “cooperating service provider”
 – (1) the construction of the incorporated term “non-block-
 ing bandwidth,” and (2) the meaning of the term



     4  It would appear that approval of both terms would
 be needed since some claims use one term and some use the
 other.
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 “cooperating service provider” apart from the incorporated
 term. It is unclear whether, under the stipulation, Amazon
 prevails on infringement if either construction is correct or
 only if both are correct.
     At oral argument, it became apparent that the parties
 have significant disagreements as to the effect of the stip-
 ulation—disagreements that render it impossible for this
 court to review the judgment.
      AlterWAN asserts that the judgment of non-infringe-
 ment rests solely on the district court’s construction of
 “non-blocking bandwidth,” a term which appears both in-
 dependently and in the district court’s construction of “co-
 operating service provider.” AlterWAN argues that the
 district court’s construction requires bandwidth to be avail-
 able to the customer at all times, even when the Internet is
 inoperable. Because no system can provide such a service,
 Amazon cannot infringe. At oral argument, AlterWAN
 took the position that the “sole reason” Amazon does not
 infringe under the claim constructions at issue is because
 of the exclusion of the caveat they had sought at claim con-
 struction (“while the network is operational”). This is so
 because “if the internet goes down, it doesn’t provide ser-
 vice.” Oral Arg. at 0:30–1:14; see also Oral Arg. at 31:02–
 19 (“Q: Let’s adopt your construction of non-blocking band-
 width, which doesn’t have that limitation, it only requires
 that . . . available when the internet is operable, okay? Is
 your view that they infringe under that claim construction?
 A: Yes, Your Honor.”). In AlterWAN’s view, the core issue
 on appeal is whether the district court erred by failing to
 add the qualifier “while the network is operational” to its
 construction of “non-blocking bandwidth.”
      Amazon, on the other hand, contends that the judg-
 ment of non-infringement (as to the claims incorporating
 the term “cooperating service provider”) should be affirmed
 if the construction of “cooperating service provider” is af-
 firmed, quite apart from the issue of internet availability.
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 10                        ALTERWAN, INC.   v. AMAZON.COM, INC.



 As explained at oral argument, Amazon contends that it
 allows customers to pay for different port speeds, meaning
 that the customer gets the purchased speed, not “all the
 bandwidth [they] could want.” Oral Arg. at 20:45–21:01.
 Since Amazon does not ensure that bandwidth is always
 sufficient to meet the customer’s needs, Amazon does not
 infringe. Although Amazon defends the district court’s con-
 struction of “non-blocking bandwidth” and its rejection of
 the qualifier “while the network is operational,” Amazon
 contends that any error in this respect would not affect the
 judgment of non-infringement. See Oral Arg. at 15:02–22
 (“Q: What is the basis [of infringement]? . . . A: Amazon’s
 product does not provide sufficient bandwidth to meet eve-
 rybody’s need, whether the internet is up or down.”).
     To add to the confusion, AlterWAN contends that it can
 establish infringement under the district court’s construc-
 tion of the term “cooperating service provider” once the In-
 ternet availability language is included because the plain
 and ordinary meaning of the term simply means a service
 provider that cooperates.
     We have previously warned of the dangers of stipulat-
 ing to non-infringement based on a district court’s claim
 constructions without indicating the exact basis for non-in-
 fringement. In Jang, the parties had entered into a stipu-
 lation that suffered two ambiguities. First, the stipulation
 did not identify which of the district court’s claim construc-
 tions actually affected the issue of infringement. 

. Second, the stipulation did not provide any
 factual context as to “how the disputed claim construction
 rulings relate to the accused products.” 

. We
 vacated and remanded, holding that “[a] judgment is re-
 viewable only if it is possible for the appellate court to as-
 certain the basis for the judgment challenged on appeal.”
 

 at 1334–35.
     Here, as in Jang, we cannot “ascertain the basis for the
 judgment” of non-infringement, 

 because the parties did
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 ALTERWAN, INC.   v. AMAZON.COM, INC.                       11



 not adequately explain how the claim construction rulings
 related to the accused systems. See also Superior Indus. v.
 Masaba, Inc., 

 (Fed. Cir. 2014). We
 must vacate the judgment and remand to the district court
 for further proceedings to clarify the parties’ non-infringe-
 ment positions, and to determine whether a stipulation of
 non-infringement is even possible in the circumstances of
 this case.
                               II
      Since further proceedings are required, we think it use-
 ful and appropriate to clarify the meaning of the claim term
 non-blocking bandwidth in one respect. The district court’s
 construction, which effectively requires a system to provide
 bandwidth even when the Internet is inoperable, is not a
 reasonable construction in light of the specification since it
 requires the impossible. Amazon cites Chef America for the
 proposition that “[c]ourts may not redraft claims, whether
 to make them operable or to sustain their validity.” Appel-
 lee’s Br. 20 (quoting Chef Am., Inc. v. Lamb-Weston, Inc.,
 

 (Fed. Cir. 2004)). In Chef America, the
 patentee claimed a process for making baked goods. 

. The claim limitation at issue was “heating
 the resulting batter-coated dough to a temperature in the
 range of about 400° F. to 850° F.” 

. The patentee
 contended that the temperature range of “400° F. to 850°
 F.” referred to the temperature of the oven, rather than the
 temperature of the dough. 

 at 1371–72. This court dis-
 agreed, holding that the claims were unambiguous and de-
 clining to replace the term “to” with the term “at,” even
 though the claim, as written, led to an absurd result—the
 baked good being burned.
     Chef America does not require us to depart from com-
 mon sense in claim construction. Here, the claim language
 itself does not unambiguously require bandwidth to be
 available even when the Internet is inoperable. See Ecolab,
 Inc. v. FMC Corp., 

 (Fed. Cir.),
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 12                        ALTERWAN, INC.   v. AMAZON.COM, INC.



 amended on reh’g in part, 

 (Fed. Cir. 2009).
 It is true that the specification defines “non-blocking band-
 width” as “bandwidth that will always be available and will
 always be sufficient.” ’478 patent, col. 4 l. 67–col. 5 l. 1.
 But this statement must be read in context.
      The specification states that “[t]he wide area network
 technology described herein (referred to as AlterWAN™
 network) is an alternative wide area network that uses the
 internet as a backbone.” ’478 patent, col. 3, ll. 61–63. The
 specification describes several “quality of service” problems
 that arise from using the internet as a backbone, including
 latency problems, that is, “delay on critical packets getting
 from source to destination.” ’478 patent, col. 3 ll. 20–53.
 The patent’s solution to the latency problem is to provide
 “preplanned high bandwidth, low hop-count routing paths
 between pairs of customer sites that are geographically
 separated.” ’478 patent, col. 4 ll. 17–19. The specification
 describes the preplanned routing paths as a “key charac-
 teristic that all species within the genus of the invention
 will share” and details its operation. ’478 patent, col. 4 ll.
 15–64. The specification then states: “In other words, the
 quality of service problem that has plagued prior attempts
 is solved by providing non-blocking bandwidth (bandwidth
 that will always be available and will always be sufficient)
 and predefining routes for the ‘private tunnel’ paths be-
 tween points on the internet . . . .” ’478 patent, col. 4 l. 65–
 col. 5 l. 3.
     The specification does not remotely suggest operability
 when the Internet is unavailable. Claims that are directed
 to transmission over the Internet cannot require such
 transmission when the Internet is not working. In light of
 the specification, “non-blocking bandwidth” is properly un-
 derstood to address the problem of latency, rather than
 providing for bandwidth even in the scenario where the In-
 ternet is inoperable. We do not opine on what the meaning
 of non-blocking bandwidth is, other than it does not require
 bandwidth when the Internet is down. The district court
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 on remand will make an appropriate revision to this claim
 construction.
      AlterWAN also challenges the district court’s construc-
 tion of the “routing” claim term, a term that is not included
 in the stipulation. Although it can be appropriate to decide,
 on appeal, claim constructions not implicated by the dis-
 trict court’s judgment in limited circumstances, see
 Thorner v. Sony Comput. Ent. Am. LLC, 

 (Fed. Cir. 2012), we decline to do so here.
                         CONCLUSION
     For the foregoing reasons, we vacate the stipulated
 judgment of non-infringement and remand the case for fur-
 ther proceedings consistent with this opinion.
                VACATED AND REMANDED
                             COSTS
 No costs.