Scientific Telecommunications LLC v. Adtran Inc.

Filing 62

MEMORANDUM ORDER re: claim construction. Signed by Judge Sue L. Robinson on 11/21/2016. (nmfn)

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF DELAWARE

SCIENTIFIC TELECOMMUNICATIONS, LLC, )
)

Plaintiff,
v.
ADTRAN, INC.,

)
)
) Civ. No. 15-647-SLR
)
)
)

Defendant.

)

MEMORANDUM ORDER
At Wilmington this Jl."1 day of November, 2016, having heard argument on, and
having reviewed the papers submitted in connection with, the parties' proposed claim
construction;
IT IS ORDERED that the disputed claim language of U.S. Patent Nos. 6,058,429
("the '429 patent") and 7,222,188 ("the '188 patent") 1 shall be construed consistent with
the tenets of claim construction set forth by the United States Court of Appeals for the
Federal Circuit in Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005), as follows:

1

The '188 patent is a continuation of the '429 patent.

Terms Common To The '429 and '188 Patents

1. [A] switch: 2 "Circuitry and/or software that transfers data between one or
more connected components or virtual components (such as a VLAN)." Defendant
argued that applicant made various limiting statements during prosecution of the '188
patent, which is a continuation of the '429 patent. (D.I. 58 at 1-4; see also D.I. 59, ex.
D-2 at 31) Defendant asked the court for the following construction:
"Switch" is a device that does not use or participate in any routing
protocols, even on occasion, to calculate where data needs to be
transferred, and is without routing capability including the capability to
issue its own ARP requests.
(D.I. 55 at 1) (emphasis added) This is a series of negative limitations, and defendant's
argument was based upon a characterization of the prosecution history as including a
series of limiting statements; however, defendant never demonstrated that these
statements contain limitations not already discussed in the specification. For example,
in distinguishing the Bryant reference, applicant stated that "the claimed invention [is] a
switch that comprises a mechanism to send information contained within a packet

without use of a routing function (or protocol)." (D.I. 59, ex. D-2 at 80) (emphasis
added) The examiner rejected the claims under§ 112,

~

1 for lack of enablement (D.I.

59, ex. D-2 at 48) In response, applicant discussed the known art:
As the Examiner is aware, typical switches operate based on "layer two"
(L2 of the OSI model) addresses. Routers, however, not only identify the
protocol of an incoming packet and the destination of the packet
predetermined based on L3 information, but also perform operations in
accordance with a routing protocol on each incoming packet in order to
determine the most cost-effective path for data of the incoming packet.
For instance, a router operating in accordance with Open Shortest Path
First (OSPF) routing protocol generates link state routing data and obtains
link state routing data from other nodes in the network in order to calculate
the best path from a source device to a destination device. Thus, prior to

2

Found in claim 1 of the '429 patent and claims 6 and 26 of the '188 patent.

2

the claimed invention, it is Applicants' contention that switches did not rely
on L3 information to determine where to transfer information.
(D.I. 59, ex. D-2 at 31) Applicant then discussed the Bryant reference:
In contrast [to Bryant], the claimed switch does not use or participate in
any routing protocols to calculate where data needs to be transferred.
Instead, as set forth in the specification of the subject application, the
switch monitors router control messages, such as ARP messages for
example, to populate tables with the switch.
(Id.) (emphasis in original) The switch "monitors [L3] router control messages ... to

populate tables," but does not route data at Layer 3. This statement is consistent with
the specification, which includes statements such as "[b)y inspecting certain packets
that flow between the devices and the routers, the learning internetwork switch learns
the location of the devices without having to use a routing protocol." ('429 patent,
abstract) (emphasis added) The specification also discusses, beyond Layer 3, that the
switch employs Layer 2 routing, and it is not clear that applicant intended to disclaim all
forms of routing outside of Layer 3. ('429 patent, 10:62, 11 :5, figure 5, items 506 and
510) While the intrinsic evidence shows that applicant distinguished a switch from a
router, as was known in the art, there is nothing in the specification or the prosecution
history that suggests that applicant intended to use the term "switch" differently from the
plain and ordinary meaning. 3 In light of numerous similar statements in the specification
and claims, defendant has not demonstrated that any of applicant's statements are-in
fact-limiting. Since applicant's statements are consistent with the specification,
defendant has provided no basis to explain why the court should import these limitations
from the specification into the claims. Moreover, defendant has not explained why the
court should add additional limitations (e.g., "even on occasion" and "including the

3

Plaintiff provided extrinsic evidence to support the plain and ordinary meaning of
"switch." (See, e.g., D.I. 57, ex.Cat 6)

3

capability to issue its own ARP requests") to its construction. For these reasons, the
court adopts plaintiff's proposal.
2. [A] router: 4 "Circuitry and/or software that may use routing protocols to
calculate where data needs to be transferred." 5
3. Port: 6 "Circuitry and/or software that forms a point to point interface between
two components or networks." 7

The '429 Patent
4. Preamble, claim 1: Not limiting. 8

4

Found in claim 1 of the '429 patent and claims 6 and 26 of the '188 patent.

5

The parties agreed that "a router may use routing protocols to calculate where data
needs to be transferred." (D.I. 58 at 5) Defendant argued that a "router must be a
separate device external to the claimed switch." (Id.) This construction is not supported
by the specification; therefore, the court adopts plaintiff's construction.
6

Found in claim 1 of the '429 patent and claim 6 of the '188 patent.

7

Defendant proposed that a port is "[a] physical interface for connecting to an external
device or network." (D.I. 55 at 1) Defendant's extrinsic evidence, requiring that a port
include a "physical interface," was not persuasive. Meanwhile, plaintiff provided
extrinsic evidence that supports a construction not tied to a physical interface. (D.I. 56
at 6-7) For these reasons, the court adopts plaintiff's construction.

8

Defendant argued that the preamble to claim 1 of the '429 patent is limiting, because
allegedly limiting statements made by applicant during prosecution must be imputed to
the preamble. (D.I. 58 at 2-4) As discussed above, the court disagrees. "In general, a
preamble is limiting if it is necessary to give life, meaning, and vitality to the claim."
Deere & Co. v. Bush Hog, LLC, 703 F.3d 1349, 1357 (Fed. Cir. 2012) (internal citations
and quotation marks omitted). The preamble recites, "[a] learning internetwork switch
for use in a network that includes a plurality of virtual local area networks." ('429 patent,
claim 1) Here, the preamble does not provide antecedent basis for the terms in the
claim, and there is nothing in the preamble that is necessary to "give life, meaning, and
vitality" to the claim. Moreover, defendant's prosecution history argument and proposed
construction is not persuasive. For these reasons, the preamble is not limiting.

4

5. A first set of ports connecting the learning internetwork switch to a set

of virtual local area networks: 9 "A first set of ports, each of which forms a point to
point interface between the learning internetwork switch and at least one virtual local
area network in a set of virtual local area networks." 10
6. Each virtual local area network ... is locally attached to the learning

internetwork switch: 11 "Each virtual local area network is attached via a port to the
learning internetwork switch." 12

7. A second set of ports connecting the learning internetwork switch to a
router, wherein devices that belong to the virtual local area networks in the set of
virtual local area networks communicate with the router by transmitting packets

9

Found in claim 1 of the '429 patent

10

Defendant proposed "Each VLAN of the set of VLANs is connected to its own port of
the first set of ports on the learning internetwork switch." (D.I. 58 at 16-17) While the
embodiment shown in the figures and discussed in the specification demonstrates a
one-to-one correspondence between VLANs and ports, nothing in the specification
limits the invention as such. Defendant argued that the
specification is clear that for each port of the switch attached to a VLAN,
a corresponding port of the switch is attached to the router.
(D. I. 58 at 17) (emphasis added) The relevant text of the specification states that the
learning internetwork switch contains a connection to each virtual local
area network and a corresponding connection to the router.
('429 patent, 3: 19-21) (emphasis added) Defendant did not explain how "connection"
must be interpreted as "port." Plaintiff's construction matches the language of the claim,
which does not require a one-to-one relationship between ports and VLANs. ('429
patent, claim 1) Moreover, plaintiff's extrinsic evidence of VLAN trunking is a plausible
example of an architecture that does not require a one-to-one correspondence and that
meshes with the above language in the specification. (D.I. 57, ex. Fat 2) For this
reason, the court adopts plaintiff's construction.
11

Found in claim 1 of the '429 patent

12

The court adopts plaintiff's construction, because defendant's proposal followed "from
the one-to-one correspondence between a VLAN and a port of the first set of ports of
the switch." (D.I. 58 at 18) The court did not adopt defendant's construction requiring a
one-to-one correspondence between ports and VLANs. See supra note 10.

5

through the learning internetwork switch: 13 "A second set of ports, each of which
forms a point-to-point interface between the learning internetwork switch and a router,
and is configured to transmit packets from devices in the virtual local area networks to
the router. "14
8. A learning mechanism that inspects control packets sent between the

router and the devices: 15 Support is found in the specification in the form of an
algorithm described with reference to figures 3 and 4. ('429 patent, figs. 3a, 3b, steps
304, 306, 314, and 316; 5:40-7:46; figs. 4a, 4b, steps 404, 414; 8:32-39; 9:12-15)
Section 112, ~ 6 does not apply. 16 Not indefinite.17

13

Found in claim 1 of the '429 patent

14

See supra note 12.

15

Found in claim 1 of the '429 patent

16

The structure described in the '429 patent is a computer-implemented algorithm. "To
one of skill in the art, the 'structure' of computer software is understood through, for
example, an outline of an algorithm, a flowchart, or a specific set of instructions or
rules." Apple Inc. v. Motorola, Inc., 757 F.3d 1286, 1298 (Fed. Cir. 2014), overruled by
Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015). Williamson overruled
the strength of the presumption applied in Apple, but Apple remains on point for
computer-implemented inventions that do not employ means-plus-function language.
Plaintiff identified support in the specification for the algorithm. (D.I. 56 at 17)
Defendant failed to demonstrate that a person of ordinary skill in the art would not
recognize the algorithm as sufficiently definite structure. (D.I. 58 at 7) For this reason,
the disclosed algorithm is sufficiently definite structure, and § 112, ~ 6 does not apply.
See Williamson, 792 F.3d at 1349.
17

Plaintiff argued that "learning mechanism" is indefinite because the specification does
not disclose corresponding structure. (D.I. 58 at 11) As discussed above,§ 112, ~ 6
does not apply, and "corresponding structure" is only used in the test for indefiniteness
under that section. The Patent Act, § 112, ~ 2, requires "that a patent's claims, viewed
in light of the specification and prosecution history, inform those skilled in the art about
the scope of the invention with reasonable certainty." Nautilus, Inc. v. Biosig
Instruments, Inc.,_ U.S._, 134 S.Ct. 2120, 2129 (2014). Here, defendant did not
address the Nautilus factors; therefore, the claim is not indefinite.

6

9. Control packets: 18 "Parts of a network packet containing information used
for configuring or routing network communications." 19
10. The learning mechanism storing association data that indicates a
correspondence between data link layer addresses, network layer addresses, and
the first set of ports based on information contained in the control packets: 20

Support is found in the specification in the form of an algorithm described with reference
to figures 3, 4, and 6. ('429 patent, figs. 3a, 3b, steps 308, 318; 6:50-55; 7:40-42; fig.
4c, step 422; 9:43-46; fig 6, steps 608, 614; 11 :31-46) Section 112, 1J 6 does not
apply. 21 Not indefinite. 22
11. Traffic: 23 "Digital information that travels within and between points in a
network." 24

18

Found in claim 1 of the '429 patent

19

Claim 1 recites "control packets sent between the router and the devices." The
specification discusses "control information contained in the ARP query." ('429 patent,
9: 13-14) Defendant's expert stated that, while the embodiments discussed in the
specification only "disclose the use of ARP packets," there are "numerous other protocol
candidates which could be considered as 'control packets', with different packet
formats, and with L2 and L3 addresses and additional information contained within
those packets." (D.I. 58, ex. A at 1J 123) Defendant argued that "a control packet is
clearly not a data packet and is at least a packet containing an ARP request or
response." (D.I. 58 at 19) (emphasis added) The court disagrees. The term "data
packet" does not appear anywhere in the specification, and it is not apparent from
defendant's argument that the court should import this negative limitation to the "control
packet" term. Moreover, defendant's proposed construction is inconsistent with the
specification; therefore, the court adopts plaintiff's construction.
2

°Found in claim 1 of the '429 patent

21

See supra note 16.

22

See supra note 17.

23

Found in claim 1 of the '429 patent

24

Defendant argued that "claim 1 and the specification dictate that traffic are data
packets carrying messages between devices, not control packets." (D.I. 58 at 20) The
specification does not make this distinction, for example, "[a]ll traffic between the device
in the VLANs and the router must pass through the learning internetwork switch." ('429

7

12. A third set of ports on the router connect the router to the second set
of ports: 25 "A third set of ports on the router, each of which forms a point-to-point
interface between the router and one of the second set of ports on the learning
internetwork switch." 26 Not indefinite. 27
13. The learning mechanism is further configured to store data indicating a
correspondence between data link layer addresses of the third set of ports and
network layer addresses of the third set of ports based on information contained
in the control packets: 28 Support is found in the specification in the form of an
algorithm described with reference to figures 3, 4, and 6. ('429 patent, figs. 3a, 3b,

patent, 3:21-23) There is nothing in the specification or prosecution history to suggest
that applicant intended to limit "traffic" to data packets and not control packets.
25

Found in claim 2 of the '429 patent

26

See supra note 12.

27

Defendant argued that claim 2 is indefinite under IPXL, "because it defines the
claimed invention with reference [to] the structure of another device and how that device
is connected to the claimed invention, such that infringement depends on whether a
user makes a single connection of the switch to one port of a router or makes multiple
connections to a 'set of ports' (plural) on this router." (0.1. 58 at 21) A claim is indefinite
under§ 112, ~ 2 if it "recites a system and the method for using that system." IPXL
Holdings, LLC v. Amazon.com, Inc., 430 F.3d 1377, 1384 (Fed. Cir. 2005); see also
Rembrandt Data Techs., LP v. AOL, LLC, 641 F.3d 1331, 1339 (Fed. Cir. 2011 ). In
IPXL, the claim recited both "[t]he system" and "the user uses the input means." IPXL,
430 F.3d at 1384. In Rembrandt, the claim claimed "a data transmitting device ...
comprising: first buffer means ... fractional encoding means ... second buffer means .
. . and transmitting the trellis encoded frames." Rembrandt, 641 F.3d at 1339
(emphasis added). Here, claim 2 of the '429 patent recites a "learning internetwork
switch comprising: a first set of ports ... a second set of ports ... a learning
mechanism, and said ... switch using said association data to forward traffic ...
wherein a third set of ports on the router connect the router to the second set of ports;
and the learning mechanism is further configured .... " ('429 patent, claim 2)
(emphasis added) The "wherein" clause places additional limitations on the second set
of ports and the learning mechanism, but claim 2 does not recite a system and a
method for using that system. For these reasons, IPXL does not apply, and claim 2 is
not indefinite.
28

Found in claim 2 of the '429 patent

8

steps 308, 318; 6:50-55; 7:40-42; fig. 4c, step 422; 9:43-46; fig 6, steps 608, 614; 11 :3146) Section 112, ~ 6 does not apply. 29 Not indefinite. 30
The '188 Patent

14. Preamble, claim 6: Not limiting. 31
15. A plurality of ports adapted for coupling together a plurality of virtual
local area networks being at least three virtual local area networks: 32 "A plurality of

ports, each of which carries data between a set of virtual local area networks that
includes at least three virtual local area networks."33
16. At least one of the plurality of ports is directly coupled to a router so
that there are no interceding devices or local area networks between the switch
and the router: 34 "At least one of the plurality of ports is connected to a router with no

external devices or local area networks in between the switch and the router." 35 Not
indefinite. 36
17. A mechanism to (a) analyze information transferred from a source
device of a first virtual local area network to a destination device of a second

29

See supra note 16.

30

See supra note 17.

31

The preamble of claim 6 recites "[a] switch comprising." ('188 patent, claim 6) There
is nothing in this language to suggest that the preamble is limiting. See supra note 8.

32

Found in claim 6 of the '188 patent.

33

See supra note 12.

34

Found in claim 6 of the '188 patent.

35

Defendant proposed language that required "an external router." As above, the
specification does not require that the router be "external" to the switch. The court
adopts plaintiff's construction.
36

Defendant argued that this term is indefinite under IPXL. (D.I. 58 at 22) For the
reasons discussed above, /PXL does not apply. See supra note 27.

9

virtual local area network: 37 Support is found in the specification in the form of an
algorithm described with reference to figures 3, 4, and 6. ('429 patent, figs. 3a, 3b,
steps 304, 306, 314, and 316; 5:40-7:46; figs. 4a, 4b, steps 404, 414; 9:12-15)
Section 112, ~ 6 does not apply. 38 Not indefinite. 39
18. A mechanism to ... (b) store information identifying a port coupled to

the second virtual local area network, a layer two (L2) address of the destination
device and a layer three (L3) address of the destination device corresponding to

37

Found in claim 6 of the '188 patent.

When a claim uses the word "means," the presumption is that§ 112, ~ 6 applies.
Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1349 (Fed. Cir. 2015). Generic terms
may be used "in a manner that is tantamount to using the word 'means' because they
'typically do not connote sufficiently definite structure."' Id. at 1350 (citations omitted).
Defendant argued that "mechanism" follows means-plus-function format and does not
connote any structure. (D.I. 58 at 10) Simply using the term "mechanism," however,
does not automatically trigger§ 112, ~ 6. Massachusetts Inst. of Tech. & Elecs. For
Imaging, Inc. v. Abacus Software, 462 F.3d 1344, 1354 (Fed. Cir. 2006). When a
limitation lacks the term "means," a challenger may overcome the presumption against
means-plus-function treatment by showing that "the claim term fails to recite sufficiently
definite structure or else recites function without reciting sufficient structure for
performing that function." Id. at 1353 (citations omitted). For example, Williamson
articulated a two-part test, applying § 112, ~ 6 to the term "distributed learning control
module," because the court determined that: "module" was a "well-known nonce word
that can operate as a substitute for 'means,"' and the "distributed learning control" prefix
did not "provide any indication of structure." Williamson, 792 F.3d at 1350-51. An
outcome of this two-part test is that the alleged "nonce word" is interpreted to be
equivalent to the term "means," which "creates a presumption that§ 112, ~ 6 applies,"
thereby shifting the burden to the patentee. Id. at 1349. Here, defendant argued that
"mechanism does not connote any structure, because it does not have a "generally
accepted structural meaning." (D.I. 58 at 10) Defendant did not address the second
part of the Williamson test such as by discussing the language used in conjunction with
"mechanism" in the claim; therefore the burden has not shifted, and the presumption is
that§ 112, ~ 6 does not apply. (See D.I. 58 at 1O; D.I. 61 at 5).
38

Defendant argued that this term is indefinite, because§ 112, ~ 6 applies and the
specification does not recite any structure corresponding to the claimed
functions." (D.l. 58 at 11) As discussed above,§ 112, ~ 6 does not apply, and
"corresponding structure" is only used in the test for indefiniteness under that section.
Here, defendant did not address the Nautilus factors; therefore, the claim is not
indefinite.
39

10

the L2 address: 40 Support is found in the specification in the form of an algorithm
described with reference to figures 3, 4, and 6. ('429 patent, figs. 3a, 3b, steps 308,
318; 6:50-55, 7:40-42; fig. 4c, step 422; 9:43-46; fig. 6a, steps 608, 614; 11 :31-46)
Section 112, ~ 6 does not apply. 41 Not indefinite. 42
19. A mechanism to . .. (c) using the information to forward data between

the plurality of virtual local area networks: 43 Support is found in the specification in
the form of an algorithm described with reference to figures 4, 5, and 6. ('429 patent,
figs. 4a-c, 5, 6a-b; 7:50-12: 18) Section 112, ~ 6 does not apply. 44 Not indefinite. 45
20. The stored information forming a table that is populated based on prior

communications with the router: 46 "The stored information forms a table containing
information included in prior traffic directed to the router." This construction is supported
by the specification:
Learning internetwork switch 200 generates a table that reflects the
correlation between L2 and L3 addresses based on information learned
from inspecting certain packets (e.g. ARP queries and ARP responses)
sent between router 126 and the members of the various VLANs 102, 110,
and 118.
('429 patent, 4:58-62) 47

4

° Found in claim 6 of the '188 patent.

41

See supra note 38.

42

See supra note 39

43

Found in claim 6 of the '188 patent.

44

See supra note 38.

45

See supra note 39

46

Found in claim 6 of the '188 patent.

47

Defendant proposed that this term be construed as "[t]he external router populates a
table in the switch such that the switch does not control its own table population through
issuing ARP messages." (D.I. 55 at 7) This argument was based upon statements
11

21. Information/the information/the stored information: 48 "Digitally encoded
data." Not indefinite. 49
22. The information is obtained from packets configured in accordance
with an Address Resolution Protocol: 50 "Digitally encoded data." Not indefinite. 51

applicant made during prosecution. (D.I. 58 at 23) During prosecution, in response to
an obviousness rejection, applicant stated:
For instance, as an example, neither of these references, alone or in
combination, suggest a switch featuring L2/L3 tables populated by the router,
with the switch directly coupled to the router as set forth in certain claims, and
uses the populated information to perform subsequent packet transfers.
(D.I. 59, ex. D-1 at 133) The specification provides that the switch controls the table
and populates the table based upon information contained in packets sent between the
router and the VLANs. ('429 patent, 4:58-62) There is nothing in the specification to
suggest that "populated by the router" means that "the external router populates a table
in the switch." Applicant's use of the passive voice in prosecution does not suggest that
defendant may now rewrite the statement in the active voice and select the router as the
actor. For a better indication of applicant's intent, applicant amended claim 6 (which
was claim 24 during prosecution) to include the language in question at the same time
that applicant sent the reply to the USPTO. (See D.I. 59., ex. D-1at133; compare id. at
164 with id. at 124) Applicant's statement to the US PTO may not have been especially
articulate or clear, but applicant's contemporaneous claim amendment to overcome an
obviousness rejection clarified that the table "is populated based upon prior
communications with the router." (Id. at 124) For this reason, the court rejects
defendant's construction.
48

Found in claim 6 of the '188 patent.

49

Defendant argued that the limitations make it impossible to send a message to a third
VLAN, even though claim 6 requires at least three VLANs. (D.I. 58 at 25) The court
disagrees with defendant's reading of the claim. Defendant also did not address the
key question under Nautilus of claim scope as would be understood, with reasonable
certainty, by a person of ordinary skill in the art. For these reasons, the claim is not
indefinite.

° Found in claim 7 of the '188 patent.

5

51

Defendant argued that claim 7 is indefinite, "because the antecedent relationship
between 'the information' in claim 7 and the various references to 'information' in claim
6 is not reasonably certain." (D.I. 58 at 26) Defendant's argument appears to be based
upon defendant's reading of claim 6 and the specification to mean that an ARP packet
cannot be the "information" transferred at step (a); however, defendant did not
adequately explain this position. (Id.)
12

23. Packets configured in accordance with an Address Resolution
Protocol: 52 "Packets containing at least some information that was determined
according to an Address Resolution Protocol." 53
24. The mechanism uses the information by (i) determining both the L2
address of the destination device and the port coupled to the second network
based on the L3 address of the destination device supplied by the source
device: 54 Support is found in the specification in the form of an algorithm described
with reference to figures 3, 4, and 6. (See D.I. 56 at 23) Section 112,

~

6 does not

apply. 55 Not indefinite. 56
25. The mechanism uses the information by ... (ii) setting a destination of
packets of the data to the L2 address of the destination device: 57 Support is found
in the specification in the form of an algorithm described with reference to figures 5 and
6. (See D.I. 56 at 23) Section 112, ~ 6 does not apply. 58 Not indefinite. 59

52

Found in claim 7 of the '188 patent.

53

Defendant proposed "Packets that originate and are received by a device or a router
connected to the same VLAN that request or provide a layer two (L2) address of a
device or router port (gateway) on that VLAN." (D.I. 55 at 7) The specification suggests
provisions for accommodating ARP packets. (See, e.g., '429 patent, 11 :18-24)
Defendant, citing embodiments discussed in the specification, argued that ARP packets
"are not sent from a device on one VLAN to a device on another VLAN." (D.I. 58 at 24)
Other than this citation to the specification, defendant presented no evidence to support
this conclusion. Defendant's proposal requires the court to read these (and other)
limitations from the specification into the claim; therefore, the court adopts plaintiff's
construction.
54

Found in claim 26 of the '188 patent.

55

See supra note 38.

56

See supra note 39

57

Found in claim 26 of the '188 patent.

58

See supra note 38.

59

See supra note 39
13

26. Storing a layer three (L3) address and a layer two (L2) address
corresponding to the L3 address in a table accessible by a switch: 60 "Storing a

layer three (L3) address and a layer two (L2) address corresponding to the L3 address
in a table from which data can be read by a switch." 61
27. A router directly coupled to the switch with no interceding devices or
local area networks between the switch and the router: 62 "A router that is

connected to a switch with no external devices or local area networks in between the
switch and the router." Not indefinite. 63
28. Destination device: 64 "The device to which the packet is directed."65
29. The data structure: 66 "A table." Not indefinite. 67

6

° Found in claim 26 of the '188 patent.

61

Defendant proposed "an external router populates a table accessible by a switch with
layer three (L3) address and a layer two (L2) address corresponding to the L3 address."
(D.I. 55 at 8) The court adopts plaintiff's construction, because the court already
determined that the router must not be external to the switch and that the router does
not populate the table. See supra notes 5, 35, and 47.
62

Found in claim 26 of the '188 patent.

63

Defendant argued that this term is indefinite under IPXL. (D. I. 58 at 29) For the
reasons discussed above, IPXL does not apply. See supra note 27.

64

Found in claims 6 and 26 of the '188 patent.

65

The parties appear to agree as to this term. (D.I. 55 at 8-9)

66

Found in claim 26 of the '188 patent.

67

Applicant used the terms "data structure" and "table" interchangeably during
prosecution, amending the claim language between the two. For example, the
independent claims "feature a limitation of a data structure (or table) being populated
based on prior communications with the router." (D.I. 59, ex. D-1 at 132) (emphasis
added) A person having ordinary skill in the art would read the specification and claims
as "table" providing antecedent basis for "data structure" in claim 26.
14

30. The packet directed to the router: 68 "The packet 'communicat[ed] ... to a
router' in step (c)." Not indefinite. 69
31. The string of the L3 address and the corresponding L2 address is in a

table contained in the switch: 70 Not indefinite. 71
32. The court has provided a construction in quotes for the claim limitations at
issue. The parties are expected to present the claim construction consistently with any
explanation or clarification herein provided by the court, even if such language is not
included within the quotes.

unitedStatDiStriciJUdie

68

Found in claim 26 of the '188 patent.

69

The parties agreed to the meaning of this term, and defendant agreed that this term is
not indefinite. (D.I. 58 at 29)

7

° Found in claim 27 of the '188 patent.

71

A person having ordinary skill in the art would understand "string" to refer to the table
of L3 and L2 addresses in claim 26 part (a).

15