IN THE UNITED STATES DISTRICT COURT

FOR THE WESTERN DISTRICT OF TEXAS

WACO DIVISION

WSOU INVESTMENTS, LLC d/b/a 

BRAZOS LICENSING AND 

DEVELOPMENT,

Plaintiff,

v.

DELL TECHNOLOGIES INC., DELL 

INC., AND EMC CORPORATION, 

Defendants.

Case No. 6:20-cv-00474-ADA

Case No. 6:20-cv-00475-ADA

Case No. 6:20-cv-00476-ADA

Case No. 6:20-cv-00479-ADA

JURY TRIAL DEMANDED

DEFENDANTS’ RESPONSIVE CLAIM CONSTRUCTION BRIEF REGARDING 

PATENT NOS. 7,212,536, 7,453,888, 7,565,435 & 8,402,129
i

TABLE OF CONTENTS

Page

DISPUTED TERMS FROM THE ’536 PATENT............................................................ 1

A. “bridge” (claims 1, 12).............................................................................................1

B. “channel in a connection based network” (claims 1, 12).........................................2

C. “forwarding system configured to read a priority of a data frame to be 

forwarded onto the connection-based network by way of the first one of 

the ports, identify a service interface which the map indicates corresponds 

to the read user priority and forward the data frame over the channel in the 

connection-based network associated with the identified service interface” 

(claim 1)...................................................................................................................3

D. “means for reading priorities of data frames directed by the bridge to at 

least a first one of the bridge ports” (claim 12) .......................................................4

DISPUTED TERMS FROM THE ’888 PATENT............................................................ 6

A. “stackable trunk port” (claims 1, 8, 9, 10, 11–13, 15, 19, 20)................................6

B. “backbone VLAN trunk” (claims 1, 5, 6, 7, 12, 15–20)..........................................7

C. “wherein the selection and association of at least one backbone VLAN ID 

with each one of the corresponding plurality of backbone VLAN trunks is 

undertaken irrespective of one of an in-use and a stand-by designation of 

each one of the plurality of backbone VLAN trunks and each one of the 

plurality of stackable trunk ports” (claim 1) / “wherein the association of 

the plurality of backbone VLAN IDs with the backbone VLAN trunk is 

undertaken irrespective of one of an in-use and a stand-by designation of 

the backbone VLAN trunk and the at least one stackable trunk port” 

(claim 15).................................................................................................................8

DISPUTED TERMS FROM THE ’435 PATENT.......................................................... 12

A. “setting the IPPC of one of the ports of one of said bridges within the 

MSTI to a lower IPPC when said port is part of the VLAN member set” 

(claims 1, 8, 13) .....................................................................................................12

B. “ideally” (claims 7, 11, and 18) .............................................................................13

C. “processing unit for setting the Internal Port Path Cost (IPPC) of one of 

the ports of one of said bridges within the MSTI to a high IPPC when said 

port is not part of the VLAN member set” (claim 8) / “processing unit for 

setting the IPPC of one of the ports of one of said bridges within the MSTI 
TABLE OF CONTENTS

(continued)

Page

ii

to a lower IPPC when said port is part of the VLAN member set” (claim 

8) ............................................................................................................................14

D. Entirety of claims 9–11 and 13–18 ........................................................................15

DISPUTED TERMS FROM THE ’129 PATENT.......................................................... 16

A. “rate of change” (claim 3)......................................................................................16

B. “initiating a poll of resources in the nodes of the network by the 

management station in response to reporting from the node or a time 

interval being exceeded” (claim 3) ........................................................................18
iii

TABLE OF AUTHORITIES

Page(s)

Cases

Cisco Systems, Inc. v. Ruckus Wireless, Inc.,

No. 1:13-cv-492, D.I. 69 (W.D. Tex. Mar. 3, 2015)..................................................................2

Computer Docking Station Corp. v. Dell, Inc.,

519 F.3d 1366, 1375 (Fed. Cir. 2008)........................................................................................9

ContentGuard Holdings, Inc. v. Apple Inc.,

701 F. App’x 957 (Fed. Cir. 2017) ..........................................................................................19

Digital Ally, Inc. v. Taser Int’l, Inc.,

810 F. App’x 873 (Fed. Cir. 2020) ..........................................................................................14

Dyfan LLC v. Target Corp.,

19-cv-179-ADA, 2020 WL 8617821 (W.D. Tex. Nov. 25, 2020) ..........................................15

Eon Corp. IP Holdings v. Silver Spring Networks,

815 F.3d 1314 (Fed. Cir. 2016)..............................................................................................1, 3

Exmark Mfg. Co. Inc. v. Briggs & Stratton Corp.,

830 F. App’x 305 (Fed. Cir. 2020) ..........................................................................................14

International Glass Comp. Inc. v. U.S.,

408 F.2d 395 (1969).................................................................................................................19

Markman v. Westview Instruments, Inc.,

517 U.S. 370 (1996)...............................................................................................................7, 8

MTD Prod. Inc. v. Iancu,

933 F.3d 1336 (Fed. Cir. 2019)................................................................................................15

Net MoneyIN, Inc. v. VeriSign, Inc.,

545 F.3d 1359 (Fed. Cir. 2008)..............................................................................................4, 5

Noah Sys., Inc. v. Intuit Inc.,

675 F.3d 1302 (Fed. Cir. 2012)..................................................................................................6

Panoptis Patent Mgmt., LLC v. Blackberry Ltd.,

Case No. 2:16-cv-62-JRG-RSP, 2017 WL 497571 (E.D. Tex. 2017).....................................15

Phillips v. AWH Corp.,

415 F.3d 1303 (Fed. Cir. 2005)............................................................................................2, 17
TABLE OF AUTHORITIES

(continued)

Page(s)

iv

Power Mosfet Techs., L.L.C. v. Siemens AG,

378 F.3d 1396 (Fed. Cir. 2004)................................................................................................14

Samsung Elecs. Am. v. Prisua Eng’g Corp.,

948 F.3d 1342 (Fed. Cir. 2020)................................................................................................15

Schumer v. Lab. Computer Sys.,

308 F.3d 1304 (Fed. Cir. 2002)................................................................................................16

Tech Properties Ltd. LLC v. Huawei Techs. Co.,

849 F.3d 1349 (Fed. Cir. 2017)..................................................................................................9

Twin Peaks Software Inc. v. IBM Corp.,

690 F. App’x 656 (Fed. Cir. 2017) ............................................................................................5

Williamson v. Citrix Online, LLC,

792 F.3d 1339 (Fed. Cir. 2015)................................................................................................15

WMS Gaming Inc. v. Int’l Game Tech.,

184 F.3d 1339 (Fed. Cir. 1999)................................................................................................15
v

TABLE OF EXHIBITS

Exhibit Description

20 February 1, 2021 Email from R. Loveless (“2/1/21 Email”)
vi

TABLE OF ABBREVIATIONS

Abbreviation Term/Document(s)

’129 patent U.S. Patent No. 8,402,129

’435 patent U.S. Patent No. 7,565,435

’536 patent U.S. Patent No. 7,212,536

’888 patent U.S. Patent No. 7,453,888

DefBr. Responsive Claim Construction Brief (Case No. 6:20-cv-474-ADA, 

Dkt. 85; Case No. 6:20-cv-00475-ADA, Dkt. 88; Case No. 6:20-cv00476-ADA, Dkt. 77; Case No. 6:20-cv-00479-ADA, Dkt. 85)

MPEP Manual of Patent Examining Procedure

MSTI Multiple spanning tree instance

MSTP Multiple spanning tree protocol

PlBr. Opening Claim Construction Brief (Case No. 6:20-cv-474-ADA, 

Dkt. 82; Case No. 6:20-cv-00475-ADA, Dkt. 85; Case No. 6:20-cv00476-ADA, Dkt. 74; Case No. 6:20-cv-00479-ADA, Dkt. 81)

POSA Person of skill in the art

ReplyBr. Reply Claim Construction Brief (No. 6:20-cv-474-ADA, Dkt. 87; 

Case No. 6:20-cv-00475-ADA, Dkt. 90; Case No. 6:20-cv-00476-

ADA, Dkt. 79; Case No. 6:20-cv-00479-ADA, Dkt. 87)

VLAN Virtual Local Area Network

WSOU WSOU Investments, LLC D/B/A Brazos Licensing and Development

Emphasis added unless indicated otherwise.
1

As detailed in Defendants’ responsive brief, all of Defendants’ constructions are expressly 

supported by the intrinsic record. Unable to combat this clear evidence, WSOU’s reply simply 

regurgitates conclusory assertions of “plain and ordinary meaning.” For the vast majority of the 

terms, WSOU refuses to even say what that plain and ordinary meaning is, instead launching halfhearted attacks on Defendants’ constructions, by simply calling them “vague” and “confusing.” 

And, for the few terms where WSOU actually provides a position as to “plain and ordinary 

meaning,” WSOU agrees with Defendants. Yet, despite agreeing with Defendants as to what is 

required, WSOU still argues that this Court should not provide the requisite clarity for a jury. The 

Court should adopt Defendants’ constructions, which are drawn directly from the intrinsic record

and would provide clarity to the jury.

DISPUTED TERMS FROM THE ’536 PATENT

A. “bridge” (claims 1, 12)

Defendants’ Proposal WSOU’s Proposal

“a network interface device that operates no higher 

than the data link layer”

Plain and ordinary meaning

WSOU does not dispute that “bridge” was a technical term well known to a POSA in 2001, 

and that it refers to a particular type of network device that operates at the data link layer (layer 2). 

See DefBr. 2–4; ReplyBr. 1. While Defendants’ construction would instruct a juror to what this

technical term actually means—and Defendants’ support for its construction is unrebutted—

WSOU seeks to keep the jury in the dark and insists that “no construction is necessary.” ReplyBr.

1. Construction is necessary here so that the jury is informed of the apparently undisputed meaning 

of the technical term “bridge” to a POSA in 2001. See Eon Corp. IP Holdings v. Silver Spring 

Networks, 815 F.3d 1314, 1319 (Fed. Cir. 2016) (“By determining only that the terms should be 

given their plain and ordinary meaning, the court left this question of claim scope unanswered, 
2

leaving it for the jury to decide. This was legal error.”).1

WSOU’s sole attack is asserting that Defendants’ construction is “vague and confusing” 

because the language is not pulled directly from the specification. See ReplyBr. 1. It is 

unsurprising that the specification did not define for a POSA what was a basic and well-understood 

technical term in 2001. Defendants’ construction accurately describes the undisputed distinction 

between a “bridge” (which refers to a device that operates at layer 2) and other types of network 

interface devices (which may operate at other layers) and is entirely consistent with the intrinsic 

record. See DefBr. 2–4; Phillips v. AWH Corp., 415 F.3d 1303, 1319 (Fed. Cir. 2005) (holding 

extrinsic sources “can help the court determine what a person of ordinary skill in the art would 

understand claim terms to mean”). Defendants’ construction therefore should be adopted to inform 

the jury of the technical meaning of “bridge.” 

B. “channel in a connection based network” (claims 1, 12)

Defendants’ Proposal WSOU’s Proposal

“one of the paths that has been established in a network for 

communications”

Plain and ordinary meaning

Unable to substantively respond to Defendants’ construction or find a flaw in the clear and 

unequivocal support for such construction (as set forth in DefBr. 5–7), WSOU resorts to three 

ancillary arguments, each of which is beside the point and should be rejected. First, WSOU argues 

that Defendants’ construction results in non-infringement. This is not a reason to reject the correct 

construction. Indeed, parties frequently stipulate to non-infringement after claim construction. 

See, e.g., Cisco Systems, Inc. v. Ruckus Wireless, Inc., No. 1:13-cv-492, D.I. 69 (W.D. Tex. Mar. 

3, 2015); see also DefBr. 5 n.3 (explaining court may concentrate on the aspects of the claims 

1 WSOU feigns shock at the notion that it would allege infringement of a device that no POSA 

would consider a bridge in 2001, but that is exactly what WSOU has done in this case. See DefBr., 

Ex. 4 at 5–6 (alleging infringement of devices with IP (network layer) routing).
3

related to the accused products in dispute). That the proper scope of the term means Defendants 

do not infringe is simply the unsurprising result of the technology described in the patent from 

2001 being fundamentally different from what is being accused of infringement 20 years later. 

Second, WSOU argues that Defendants’ construction is “confusing” because Defendants 

proffered a compromise to resolve one of the issues raised in WSOU’s opening brief. See DefBr. 

7. Not true. Defendants’ construction and their compromise both make clear that the claims 

require the “channel” portion of the term be: (1) established and (2) in the connection-based 

network. As already detailed, both of these requirements are mandated by the intrinsic record and 

WSOU does not substantively dispute these requirements. DefBr. 5–7. 

Finally, WSOU statesthat the specification provides examples of channels in a connectionbased network. While WSOU’s point is not clear, each of these examples fully supports (and is 

captured by) Defendants’ construction; a “connection based network” (like the plain old telephone 

network) requires a connection to be established in the network before communication may take 

place. See DefBr. 5–7; See Eon, 815 F.3d at 1319.

C. “forwarding system configured to read a priority of a data frame to be forwarded 

onto the connection-based network by way of the first one of the ports, identify a 

service interface which the map indicates corresponds to the read user priority 

and forward the data frame over the channel in the connection-based network 

associated with the identified service interface” (claim 1)

Defendants’ Proposal WSOU’s Proposal

This term is subject to 35 U.S.C. § 112, ¶ 6.

Function: read a priority of a data frame to be forwarded onto the 

connection-based network by way of the first one of the ports, identify a 

service interface which the map indicates corresponds to the read user 

priority and forward the data frame over the channel in the connectionbased network associated with the identified service interface

Structure: Indefinite

Plain and ordinary 

meaning

WSOU does not dispute that the term “forwarding system” is a nonce word that fails to 

connote a sufficiently definite structure. See DefBr. 7–8; ReplyBr. 2–4. Instead, WSOU argues 
4

that this term has structure because the claim also separately recites a “bridge having a plurality 

of bridge ports.” ReplyBr. 3. This, of course, is completely beside the point. The claim recites 

an apparatus with three separate components: a bridge, a map, and a forwarding system. The 

structure for one of these components cannot serve as the structure for another. See Net MoneyIN, 

Inc. v. VeriSign, Inc., 545 F.3d 1359, 1366 (Fed. Cir. 2008) (rejecting as “redundant and illogical” 

argument that requisite structure for “generating means” was a “bank computer” when claim itself 

recited a “bank computer” that included “generating means”). The block quotes WSOU recycles 

in its reply just reinforce that “system” in this context has no readily understandable structure in 

the field and that there is no actual structure tied to the recited function for “forwarding system.” 

See DefBr. 9. Indeed, the one structure WSOU suggests (“bridge”) is decidedly not what the claim 

is referring to by a “forwarding system,” since the claim separately recites the “bridge.” 

Because this claim term fails to connote sufficient structure, it is governed by Section 112, 

¶ 6. The required function of “read[ing] a priority of a data frame” lacks corresponding structure 

for the reasons detailed below for the term “means for reading priorities . . . .”

D. “means for reading priorities of data frames directed by the bridge to at least a 

first one of the bridge ports” (claim 12)

Defendants’ Proposal WSOU’s Proposal

This term is subject to 35 U.S.C. 

§ 112, ¶ 6.

Function: reading priorities of 

data frames directed by the 

bridge to at least a first one of 

the bridge ports

Structure: Indefinite

Subject to means-plus-function construction. 

Function: reading priorities of data frames directed by the 

bridge to at least a first one of the bridge ports

Structure: bridge, with bridging system and bridge port, 

and equivalents thereof2

Algorithm, (if required): see e.g., 4:26-37,

5:40-55, 6:4-14, 6:15-42, 7:23-44, 8:21-28,

Figs. 1, 2, 4, 5A -I, 6, and equivalents thereof.

2 WSOU changed its proposal in its brief from what it conveyed before briefing. Previously, 

WSOU merely identified “bridge, and equivalents thereof.” DefBr., Ex. 6 (Preliminary 

Constructions) at 9. WSOU’s flip-flopping on this point illustrates that there is no corresponding 

structure in the patent that actually performs this function.
5

This term completely lacks a corresponding structure including the requisite algorithm. 

The specification has no disclosure of the claimed function of “reading priorities of data frames.” 

WSOU concedes that the function is not contained in the specification, stating that the function 

instead “is fully explained by the claim language.” ReplyBr. 5. But the law requires that the 

specification link the claimed function to particular structure, and here the specification does not 

even describe the claimed function, let alone link it to structure. 

Faced with this indisputable fact, WSOU resorts to reusing the same block quotes from its 

opening brief as if the lack of relevant disclosure can be overcome by a lot of irrelevant disclosure. 

The closest disclosure in these four paragraphs simply states that “the priority of the frame is 

determined,” with no explanation of how it is determined, let alone that it is determined by reading 

something in the data frame. Even if this disclosure was related to the claimed “reading . . .” 

function, it does not “clearly link[]” the determination of priority to any specific structure and thus 

does not qualify as corresponding structure. Twin Peaks Software Inc. v. IBM Corp., 690 F. App’x 

656, 660 (Fed. Cir. 2017). WSOU insists that the claimed function is performed by the bridge, but 

that would be “redundant and illogical” in light of the fact that the claimed “means for reading” is 

claimed as a specific part of the bridge. See ’536 patent, cl. 12; Net MoneyIN, 545 F.3d at 1366. 

Because WSOU has no answer to this Federal Circuit case, it tries to pivot, arguing now that the 

bridge has multiple components like a bridging system and a bridge port. ReplyBr. 6. This 

argument only highlights that there is nothing in the specification to clearly link the claimed 

function to any of those components. Twin Peaks, 690 F. App’x at 660.

Finally, even if WSOU were correct that the specification linked the claimed function to 

the bridge—which it is not—Plaintiff’s asserted structure is still insufficient as the specification 

still lacks any corresponding algorithm. DefBr. 11–12. WSOU does not meaningfully dispute 
6

that an algorithm is required. ReplyBr. 6. Instead, WSOU pretends that the bare statement that 

“the priority of the frame is determined” is somehow sufficient disclosure of the alleged algorithm. 

It is not. See Noah Sys., Inc. v. Intuit Inc., 675 F.3d 1302, 1317 (Fed. Cir. 2012) (“This type of 

purely functional language, which simply restates the function associated with the means-plusfunction limitation, is insufficient to provide the required corresponding structure.”). WSOU also 

cites alternative embodiments, such as disabling user priorities, but those alternatives have nothing 

to do with the claimed “reading” function. Since there is no description of reading priority from a 

frame in the specification—let alone an algorithm to perform that function—this term is indefinite.

DISPUTED TERMS FROM THE ’888 PATENT

A. “stackable trunk port” (claims 1, 8, 9, 10, 11–13, 15, 19, 20)

Defendants’ Proposal WSOU’s Proposal

“trunk port supporting the Riverstone solution (i.e. the 

additional extension 802.1Q packet header)”

Plain and ordinary meaning

As addressed in Defendants’ responsive brief (at 14–15), “stackable trunk port” was 

expressly defined in the intrinsic record. The specification states that “trunk ports supporting the 

Riverstone solution are known as stackable trunk ports” (’888 patent, 8:24–25) and applicants

reaffirmed during prosecution that this exact disclosure “clearly illustrate[s] what is meant by . . . 

stackable trunk ports” (DefBr., Ex. 8, (6/9/08 Appl. Arg.) at 12). See also id. (“In view of this 

meaning of . . . stackable trunk port, the Examiner is kindly requested to fully reconsider the 

arguments . . .”). WSOU does not even attempt to address the substance of these definitional

statements, dismissing them as “an example.” See ReplyBr. 7. WSOU then repeats its

unsupported argument that the patent’s disclosures are merely exemplary. Compare id., with

PlBr. 10. This argument is plainly rebutted by the intrinsic record. See DefBr. 14–15. Moreover, 

as previously addressed, WSOU agrees that stackable trunk ports must at least “support the use of 
7

an additional VLAN header,”3 and WSOU’s citation to Figure 2 confirms that the Riverstone 

solution is an additional extended 802.1Q VLAN header. See id. 15. Thus, the Court should adopt 

Defendants’ construction which is taken directly from the applicants’ lexicography and explains 

this technical term to the jury. See id. 14–15 (citing cases); Markman v. Westview Instruments, 

Inc., 517 U.S. 370, 372 (1996).

B. “backbone VLAN trunk” (claims 1, 5, 6, 7, 12, 15–20) 

Defendants’ Proposal WSOU’s Proposal

“data transport trunk links defined between stackable 

trunk ports on core routers”

Plain and ordinary meaning

Like the prior term, the intrinsic record expressly mandates Defendants’ construction. See

DefBr. 16–17. And, again, WSOU’s reply simply ignores the evidence Defendants cite, and 

merely repeats its opening brief. Compare ReplyBr. 7–8, with PlBr. 10–11. As Defendants 

previously explained, applicants expressly defined “backbone VLAN trunk” during prosecution—

“Backbone VLANs travel over backbone VLAN trunks, which are defined between stackable 

trunk ports on core routers. . . . Claim 1 is directed to a method of provisioning a backbone VLAN. 

. . . A backbone VLAN is a path through the core of a network.” DefBr. 16 (quoting Ex. 7, 

(10/19/07 App. Arg.) at 11–13.). This definition is further supported by the claim language itself 

and the specification. See DefBr. 16–17. Even WSOU admits that “the claims themselves show” 

that “stackable trunk ports . . . correspond to a backbone VLAN trunk.” ReplyBr. 8. And, even 

the embodiment to which WSOU cites (in a failed effort to support its argument that stackable 

trunk ports are not required) states that the “managed domains” being bridged are “stackable trunk 

3 WSOU’s agreement confirms the need for a construction here; and completely undercuts 

WSOU’s request to simply say “plain and ordinary meaning.” How else would a lay juror 

understand that a “stackable truck port” requires “an additional VLAN header” (as stated by 

WSOU; ReplyBr. 7) or more correctly that a “stackable truck port” is “trunk port supporting the 

Riverstone solution (i.e. the additional extension 802.1Q packet header)” as defined in the intrinsic 

record and set forth in Defendants’ construction.
8

ports 302”:

Therefore backbone VLAN trunks 308 bridging two managed domains exist. For 

such backbone VLAN trunks, the backbone VLAN provisioning methods apply at 

least to the proximal managed corresponding stackable trunk ports 302.

’888 patent, 11:49–54; DefBr. 17. In other words, WSOU’s cite supports Defendants’ construction 

that a backbone VLAN trunk is defined between stackable trunk ports on core routers.

WSOU also repeats its incorrect argument that the term “core router” is “vague and 

unreliable” and thus should not be part of the construction. ReplyBr. 8. As previous addressed, 

the disclosure on which WSOU relies does not support its argument. See id. (quoting ’888 patent,

8:52–57). Rather, this disclosure simply states that the concept of a “core router” has expanded 

beyond a physical device to include “logical entities (such as virtual routers).”4

 WSOU cannot be 

allowed to ignore applicants’ clear lexicography in favor of plain meaning. As such, the Court 

should adopt the express definition provided by applicants, which will also help the jury 

understand what a backbone VLAN trunk means. See DefBr. 17 (citing cases); Markman, 517 

U.S. at 372.

C. “wherein the selection and association of at least one backbone VLAN ID with 

each one of the corresponding plurality of backbone VLAN trunks is 

undertaken irrespective of one of an in-use and a stand-by designation of each 

one of the plurality of backbone VLAN trunks and each one of the plurality of 

stackable trunk ports” (claim 1) / “wherein the association of the plurality of 

backbone VLAN IDs with the backbone VLAN trunk is undertaken irrespective 

of one of an in-use and a stand-by designation of the backbone VLAN trunk and 

the at least one stackable trunk port” (claim 15)

Defendants’ Proposal WSOU’s Proposal

“wherein the provisioning method ignores the designation of a backbone 

VLAN trunk as in-use or stand-by when associating the backbone 

VLAN ID with the backbone VLAN trunks (as opposed to, during 

association of VLANs with trunks, explicitly designating physical 

VLANs associated with a logical VLAN as in-use and explicitly 

Plain and ordinary 

meaning

4 Again, if this concept is “vague” (as WSOU asserts) then the claims are indefinite since applicants 

defined backbone VLAN trunk as links between stackable trunk ports on “core routers.” See 

DefBr. 17.
9

designating other physical VLANs associated with the logical VLAN as 

back-up)”

As detailed in Defendants’ responsive brief, applicants expressly: (1) argued that “the 

provisioning methods of the present claims ignore [in-use and standby] designations when 

associating the backbone VLAN IDs with the backbone VLAN trunks” and (2) disclaimed 

methods that “during association of VLANs with trunks explicitly designates one of the physical 

VLANs associated with a logical VLAN as in-use and explicitly designates one or more other 

physical VLANs associated with the logical VLAN as back-up.” DefBr. 19 (quoting Ex. 8, (6/9/08 

App. Arg.) at 11). The prosecution history of the ’888 patent is clear and unmistakable, and the 

“irrespective” limitation must be construed in accordance with these express disclaimers. See

DefBr. 18–20.5

WSOU’s attempts to distract from these clear statements are unavailing.6 For example, 

WSOU incorrectly states that applicants’ disclaimer was limited to the association of backbone 

VLAN IDs with “backbone VLAN trunks, not ports as Defendants are contending.” ReplyBr. 9. 

This argument is nonsensical because backbone VLAN trunks are simply the links between 

stackable trunk ports—thus association of backbone VLAN trunks necessitates the association of 

stackable trunk ports. See ’888 patent, cl. 1 (“associating each of the backbone VLAN ID with 

each one of the plurality of backbone VLAN trunks by: . . . associating the backbone VLAN ID 

with each one of the plurality of stackable trunk ports”); id., Abstract (“The method includes . . . 

provisioning backbone VLAN support on every backbone data transport trunk and by extension

5 WSOU wrongly asserts that Defendants’ construction rewrites the claim language. ReplyBr. 9. 

Defendants’ construction is copied directly from the applicants’ disclaimer and is thus dispositive. 

See Tech Properties Ltd. LLC v. Huawei Techs. Co., 849 F.3d 1349, 1357 (Fed. Cir. 2017).

6 WSOU’s citation to Computer Docking is inapposite. ReplyBr. 9 (citing Computer Docking 

Station Corp. v. Dell, Inc., 519 F.3d 1366, 1375 (Fed. Cir. 2008)). As addressed in Defendants’ 

responsive brief, and here, applicants’ disclaimers are clear and unambiguous. See DefBr. 18–20. 
10

of every stackable data trunk port[.]”); id., 8:24–27 (“[T]runk ports supporting the Riverstone 

solution are known as stackable trunk ports and the data transport trunk links associated therewith

are known as backbone trunks.”). Nonetheless, the “irrespective limitation” discussed during 

prosecution is the same as the one in the claims,7 namely the “association of the at least one 

backbone VLAN ID with each one of the corresponding plurality of backbone VLAN trunks is 

undertaken irrespective of one of an in-use and a stand-by designation . . . .”8 Id., cl. 1; see also 

id., cl. 15. 

WSOU also wrongly asserts that Defendants’ construction “omits entire concepts such as 

‘selection and association’ and ‘stackable trunk ports.’” ReplyBr. 9. To the contrary, neither of 

Defendants’ proposed constructions—for claims 1 and 15 respectively—remove those concepts 

from the claims. They are already recited earlier in the claim language. Defendants’ construction 

of the “wherein” clause is copied verbatim from applicants’ statements during prosecution 

explaining what is meant by that very phrase. In any event, associating a backbone VLAN ID with 

the backbone VLAN trunks necessarily requires the selection and association of backbone VLAN 

IDs with stackable trunk ports. See, e.g., ’888 patent, 10:19–24 (“The association 414 of the 

backbone VLAN identifier with all trunk links 308 is typically implemented via backbone VLAN 

identifier associations with the corresponding stackable trunk ports 302. All of the corresponding 

stackable trunk ports 302 are determined, step 426, and the backbone VLAN identifier is

7 Compare ’888 patent, cls. 1, 15, with DefBr., Ex. 8, (6/9/08 App. Arg.) at 2, 4.

8 WSOU partially quotes applicants’ statement that that “backbone VLAN trunks may each already 

have a designation of in-use or standby, but the provisioning methods of the present claims ignore 

those designations when associating the backbone VLAN IDs with the backbone VLAN trunks.” 

ReplyBr. 9 (quoting DefBr., Ex. 8, (6/9/08 App. Arg.) at 12). It is unclear how WSOU believes 

this statement supports its arguments. Defendants’ construction is copied from this statement and 

the statement makes clear that the claims require the association of a backbone VLAN ID with 

backbone VLAN trunks in a way that ignores spanning tree in-use and stand-by designations.
11

associated (428) therewith.”); id., Abstract, 16:8–11, 17:1–6, cls. 1, 15 & Fig. 4.

WSOU’s assertion that “patentee’s argument had nothing to do with the number ‘one’; 

[and instead] it had to do with the performance of ‘explicitly designates’ during association” is 

also totally contrary to what applicants said during prosecution. ReplyBr. 10. Applicants

expressly distinguished Gai based on its association of a backbone VLAN ID with a single in-use 

backbone VLAN trunk: 

This is completely contrary to the backup method taught by Gai, which during 

association of VLANs with trunks explicitly designates one of the physical VLANs

associated with a logical VLAN as in-use and explicitly designates one or more 

other physical VLANs associated with the logical VLAN as back-up.

* * *

Claim 1 also includes the limitation that the selection and association of the 

backbone VLAN IDs with the backbone VLAN trunks is undertaken irrespective 

of an in-use and a stand-by designation of the backbone VLAN trunks. This is a 

limitation not taught by Gai. The Examiner states that “each physical VLAN is 

designated as ACTIVE, STAND-BY, and UNUSABLE. This implies that the 

trunks in the physical VLANs associated with each logical VLAN are undertaken 

irrespective of a one in-use and/or stand-by designation.” As argued previously, 

this is actually contrary to the limitation of claim 1. Because each logical VLAN

(which the Examiner has equated with a backbone VLAN by equating the ID RED 

with a backbone VLAN ID) of Gai deliberately has one active physical VLAN 

associated with it and a number of stand-by physical VLANs, the association 

cannot be said to be irrespective of whether the trunk is in-use or stand-by.

DefBr., Ex. 8, (6/9/08 App. Arg.) at 12–13. Thus, applicants explicitly disclaimed methods, like 

the one in Gai, that designate for a particular VLAN ID a single (i.e., one) in-use trunk and 

designates other trunks as standby. See DefBr. 18–20 & Ex. 12 (Gai) Fig. 5C (annotations added).

WSOU’s assertion that applicants’ statements were limited to teaching regarding VLANs 

and not backbone VLANs (see ReplyBr. 9–10) is also belied by applicants’ statement limiting the 

claims to methods that “ignore those designations when associating the backbone VLAN IDs with 

the backbone VLAN trunks” (DefBr., Ex. 8, (6/9/08 App. Arg.) at 11). Indeed, Gai was expressly 

dealing with how to associate backbone VLAN IDs with backbone VLAN trunks. DefBr., Ex. 12 

(Gai) 6:15–17 & 7:6–47.
12

Thus, the “irrespective” clause should be construed to mean what applicants said it means. 

Namely, it requires ignoring whether a trunk is in-use or stand-by when associating the VLAN ID, 

and it cannot include designating a single VLAN trunk as active and others as backup. Moreover, 

because WSOU acknowledged this as a claim construction dispute; resolution now is appropriate. 

See DefBr. 20.

DISPUTED TERMS FROM THE ’435 PATENT

A. “setting the IPPC of one of the ports of one of said bridges within the MSTI to 

a lower IPPC when said port is part of the VLAN member set” (claims 1, 8, 

13)

Defendants’ Proposal WSOU’s Proposal

order of steps

The setting of the IPPC to a lower IPPC must occur after the 

creation and configuration of the Multiple Spanning Tree Instances 

step and after the creation of the VLAN member sets step

Plain and ordinary 

meaning

WSOU’s reply concedes that the claims require an order. ReplyBr. 10–12. WSOU also 

admits that an order of steps can apply to the system and apparatus claims. Id. Thus, at a minimum

the Court should rule as a matter of claim construction that steps 1[a] and 1[b] must begin before 

step 1[d] begins. The only remaining dispute appears to be whether steps 1[a] and 1[b] must be 

completed before step 1[d] occurs.9 As previously explained, they must. DefBr. 22–24. Step 1[b] 

refers to “the appropriate one of the MSTIs.” It expressly references “the MSTIs” referring back 

to the “plurality of Multiple Spanning Tree Instances (MSTIs)” created in step 1[a]. Thus, step 

1[b] must occur after step 1[a] is completed; after the “plurality of [MSTIs]” are created in step 

1[a], an “appropriate one” can then be determined in step 1[b]. 

WSOU also unsuccessfully tries to evade the fact that all embodiments in the specification 

9

 The bracketed notations refer to the claim limitations as identified on page 22 of Defendants’ 

Responsive brief.
13

specifically require step 1[d] to occur after steps 1[a] and 1[b] are completed. DefBr. 23–24 (citing 

’435 patent, 4:6–5:5, 6:37–7:9 (“After the VLAN member sets are created and the VLANs are 

mapped onto and associated with an appropriate MSTI, then the first feature of the present 

invention is performed [discussing limitations 1[c] and 1[d]]”).). According to WSOU, 

Defendants’ arguments are “merely an excerpt from an exemplary embodiment.” ReplyBr. 11, 

n.2 (quoting ’435 patent, 4:6–6). But there is no suggestion—in an embodiment or anywhere 

else—that the invention somehow encompasses beginning to set port costs before creating and 

mapping the member sets of VLANs. 

WSOU’s specification citation does not relate to whether 1[d] must occur after 1[a] and 

1[b], but actually relates to the “various scenarios” that can occur during step 1[b]. ’435 patent, 

4:6–8 (“Referring to FIGS. 4A-4D, there are shown various scenarios that can occur when VLAN 

1 and VLAN 2 are mapped onto and associated with MSTI 1 and MSTI 2.”). Indeed, the paragraph 

referred to by WSOU actually further underscores why step 1[a] must be completed before step 

1[b] begins. As discussed in that paragraph, there are many possible ways a VLAN can be 

associated with an MSTI. If 1[b] occurs before 1[a] is completed, a VLAN may be associated with 

an inappropriate MSTI. See id., 4:11–13 (“However as shown in FIG. 4B, VLAN 2 should not be 

mapped onto nor associated with MSTI 1[.]”). Thus, creating the MSTIs (1[a]) must be completed 

before VLAN member sets are created and associated with those MSTIs (1[b]) so that the VLAN 

is associated with the appropriate one of the MSTIs, and both must be completed before port costs 

are set (1[d]), consistent with the claim language and specification.

B. “ideally” (claims 7, 11, and 18)

Defendants’ Proposal WSOU’s Proposal

Indefinite Plain and ordinary meaning

WSOU refuses to acknowledge, much less address, the multiple potential meanings of 
14

“ideally” identified by Defendants. DefBr. 26–27. WSOU fails to explain why a POSA would 

understand with reasonable certainty whether “ideally” means “near” (and if so, how close), 

“required to be,” or “not required to be.” Instead, WSOU unilaterally picks one meaning. 

ReplyBr. 12 (essentially arguing “ideally” means required to be). But WSOU’s chosen meaning 

renders “ideally” superfluous. DefBr. 27–28. The Federal Circuit has repeatedly rejected 

constructions resulting in superfluous claim language. DefBr. 27; see also Exmark Mfg. Co. Inc. 

v. Briggs & Stratton Corp., 830 F. App’x 305, 310 (Fed. Cir. 2020) (rejecting construction that 

would render word “meaningless”); Digital Ally, Inc. v. Taser Int’l, Inc., 810 F. App’x 873, 876 

(Fed. Cir. 2020) (rejecting construction “render[ing] claim language superfluous”).10

C. “processing unit for setting the Internal Port Path Cost (IPPC) of one of the 

ports of one of said bridges within the MSTI to a high IPPC when said port is 

not part of the VLAN member set” (claim 8) / “processing unit for setting the 

IPPC of one of the ports of one of said bridges within the MSTI to a lower 

IPPC when said port is part of the VLAN member set” (claim 8)

Defendants’ Proposal11 WSOU’s Proposal

This is subject to 35 U.S.C. § 112, ¶ 6.

Function: setting the Internal Port Path Cost (IPPC) of one of the ports 

of one of said bridges within the MSTI [to a high IPPC when said port 

is not part of the VLAN member set / to a lower IPPC when said port is 

part of the VLAN member set]

Structure: Indefinite

Plain and ordinary 

meaning

WSOU’s reply all but concedes that the claims do not recite sufficient structure. ReplyBr. 

13–14 (arguing only that structure is disclosed in the specification). Faced with this undeniable 

proposition, WSOU argues that Section 112, ¶ 6 can be avoided by looking to the specification to 

10 WSOU’s citation to Power Mosfet Techs., L.L.C. v. Siemens AG, 378 F.3d 1396, 1410 (Fed. 

Cir. 2004) does not compel a different result. In Power Mosfet, the Federal Circuit determined 

“contact . . . directly” means the same as “contact” because in the context of the claim and patent, 

the adverb “directly” did not impose any additional restriction on contact. Id. Here, the patent 

and claims do not provide any information relating to how “ideally” relates to the setting of costs.

11 WSOU again lists the wrong construction under Defendants’ proposal. DefBr. 28 n.17. 
15

find structure in the claims. The Federal Circuit has squarely rejected this approach. DefBr. 29 

(discussing MTD Prod. Inc. v. Iancu, 933 F.3d 1336, 1344 (Fed. Cir. 2019)). WSOU has no 

response to MTD, failing to address it in its briefing.12

Alternatively, for the first time, WSOU argues that if this term is subject to 112, ¶ 6, then 

the corresponding structure is “processor.” ReplyBr. 14. But as Defendants stated, Section 112, 

¶ 6 requires disclosure of more than a general purpose computer or microprocessor. DefBr. 30 

(citing Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1352 (Fed. Cir. 2015)); see also WMS 

Gaming Inc. v. Int’l Game Tech., 184 F.3d 1339, 1349 (Fed. Cir. 1999); Dyfan LLC v. Target 

Corp., 19-cv-179-ADA, 2020 WL 8617821, at *7 (W.D. Tex. Nov. 25, 2020). Tellingly, WSOU 

does not address any of these cases.

 Perhaps recognizing its proposed structure is inadequate as a matter of law, WSOU argues 

that “to the extent an algorithm is necessary” it is “recited in the claim language and in the above 

recited portions of the specification.” ReplyBr. 14. WSOU’s citations, however, merely repeat 

the functionality of the claim, or describe setting a method for “fully- or semi-automatically 

configuring IPPCs” but do not provide an algorithm for fully- or semi-automatically setting port 

costs—which is the actual recited function. Thus, the specification does not disclose an algorithm.

D. Entirety of claims 9–11 and 13–18

Defendants’ Proposal WSOU’s Proposal

Indefinite Plain and ordinary meaning

12 WSOU again cites to Samsung Elecs. Am. v. Prisua Eng’g Corp., 948 F.3d 1342, 1353 (Fed. 

Cir. 2020). Br., 16, 18; ReplyBr. 13–14, but ignores that, in Samsung, the party seeking to invoke 

Section 112, ¶ 6 admitted that the claimed “digital processing unit” had structure. DefBr. 30. 

WSOU also relies upon Panoptis Patent Mgmt., LLC v. Blackberry Ltd., Case No. 2:16-cv-62-

JRG-RSP, 2017 WL 497571, *18–19 (E.D. Tex. 2017). But in Panoptis, the court relied upon 

extrinsic evidence, id. at *18 (discussing three different dictionaries), and determined that the 

“[s]urrounding claim language recites more than merely” functional language, id. at *19. WSOU 

does not argue that the claim language here imparts any structure to the claim.
16

WSOU does not address, let alone meaningfully discuss, the specific claim language of 

claims 9–11 and 13–18, which require actions not mere capabilities.13 DefBr. 31–32. As just one 

example, WSOU refuses to explain, beyond conclusory attorney argument, how claim 9 and 16’s 

requirement that the bridge “operates at layer 2” does not require actual performance. DefBr. 31–

32 (discussing why the specific language used in claims 9–11 and 13–18 shows that these claims 

recite method steps within non-method claims). Instead, WSOU recycles the same two cases and 

arguments from its opening brief—these were fully addressed in Defendants’ response. Id. 32–

33. Thus, claims 9–11 and 13–18 are indefinite under IPXL.

DISPUTED TERMS FROM THE ’129 PATENT

A. “rate of change” (claim 3)

Defendants’ Proposal WSOU’s Proposal

Plain and ordinary meaning; not an instantaneous 

value measured at a fixed point in time 

Plain and ordinary meaning

Applicants could not have been clearer during prosecution: “An instantaneous value 

measured at a fixed point in time . . . is simply not a rate of change.” DefBr., Ex. 16, (5/2/07 App. 

Arg.) at 11; DefBr. 36. WSOU’s arguments in response to this textbook disavowal amount to 

nothing more than verbal and mathematical gymnastics in a failed effort to avoid this unequivocal 

disclaimer during prosecution, as well as the clear differentiation set forth in the specification 

between monitoring a “rate of change” as required by the claim and monitoring a “value.” Nothing 

13 WSOU objects to counting the IPXL issue for these claims as one term, citing Schumer v. Lab. 

Computer Sys., 308 F.3d 1304, 1316 (Fed. Cir. 2002). But Schumer addresses whether a party 

addresses each claim at issue, not whether similar claim terms and issues can be grouped together 

for counting purposes under a court’s governing procedures. WSOU does not contend that 

Defendants did not address each claim. WSOU further protests that it did not treat claims 9–11 

and 13–18 as “one term” for counting purposes. Yet, the spreadsheet, prepared by WSOU, 

described WSOU’s counting of Defendants’ terms. DefBr., Ex. 14, at 5–6. And, WSOU’s counsel 

specifically stated that: “[W]e also will attach the spreadsheet reflecting WSOU’s accounting on 

the claim terms.” Ex. 20 (2/1/21 Email)
17

could be more telling than the fact that in two briefs, WSOU still fails to even cite—let alone try 

to substantively address—this damning disclaimer in the prosecution history. 

As an initial matter, rather than address the intrinsic evidence, WSOU starts its reply brief 

by faulting Defendants for not using extrinsic evidence to support its construction. ReplyBr. 16 

n.5. The law is quite clear that where, as here, the intrinsic evidence is clear, extrinsic evidence is 

unnecessary. See Phillips, 415 F.3d at 1317. Here, Defendant’s construction—while consistent 

with the plain meaning and relevant extrinsic evidence—is mandated by the intrinsic evidence, 

because applicants unequivocally stated what the claimed rate of change is, and is not. 

WSOU’s theoretical discussion of “rate of change” is completely divorced from the claim 

language and the rest of the intrinsic record. WSOU incorrectly argues—in the abstract—that

while one way to determine the rate of change is to examine a variable at two different times, “rate 

of change could be calculated using different method.” ReplyBr. 17. As an initial matter, WSOU 

does not offer any alternative for the fundamental mathematical concept—which is explicitly set 

forth in the specification and distinguished from measuring an instantaneous value—that 

determining the rate of change of a variable requires measuring the variable at two times. DefBr. 

34–35. More importantly, the claim language itself is explicit on this point. Claim 3 of the ’129 

patent unequivocally requires: (1) “monitoring usage of a resource”; to (2) “determine when a 

rate of change of the usage exceeds a first predetermined threshold.” ’129 patent, Cl. 3. Thus, 

the claim explicitly requires that the method monitor a particular thing—the usage of a resource—

and determine whether the rate of change of that thing exceeds a threshold. That language 

unambiguously requires determining the rate of change of the “usage” by examining the “usage” 

over time. WSOU quotes this claim language and inexplicably concludes that “the claim does not 

recite monitoring a variable and then calculating rate of change based on change of that variable.” 
18

ReplyBr. 17. But that is exactly what the claim language requires, where the variable is the “usage 

of a resource.” 

To the extent that the claim language would allow WSOU’s theoretical notion of 

determining a rate of change of a variable without examining that variable at different times, the 

file history unambiguously precludes such a reading. Applicants stated—without reservation or 

qualification—that “an instantaneous value measured at a fixed point in time” is “simply not a rate 

of change.” DefBr., Ex. 16, (5/2/07 App. Arg.) at 11. Thus, WSOU’s academic argument that 

rate of change can theoretically be measured in some way other than measuring a value over time—

which WSOU is unable to identify—is a hand-waving attempt to distract from the prosecution 

history’s explicit disclaimer. ReplyBr. 18. 

Defendants’ construction—mandated by the claim language and the prosecution history—

is also fully consistent with the specification. Figure 4 illustrates that the rate of change is 

calculated by determining the difference of the value of the monitored variable at a current time 

and a prior time. DefBr. 34–35. Consideration of the claim language, the specification, and the 

prosecution history unequivocally mandates Defendants’ construction—echoing applicants—that 

a rate of change cannot include an instantaneous value measured at a fixed point in time. 

B. “initiating a poll of resources in the nodes of the network by the management 

station in response to reporting from the node or a time interval being exceeded” 

(claim 3)

Defendants’ Proposal WSOU’s Proposal

Both of these events trigger a poll Plain and ordinary meaning

Contrary to WSOU’s protestations, Defendants’ construction is not a simple rephrasing of 

the claim language. ReplyBr. 19. Without clarity, this term could be improperly interpreted by a 

lay juror to have multiple different meanings. Specifically, if left unconstrued, it is unclear whether 

the management station of the system need be capable of initiating a poll in response to both a 
19

“reporting from a node” and “a time interval being exceeded” or rather, if the management station 

of the system need only be capable of initiating a poll in response to one of these two events. 

DefBr. 38–39. The parties now agree that both is required. PlBr. 22; DefBr. 38; ReplyBr. 18–

19.14 Despite agreeing with Defendants as to what is required, WSOU still argues that this Court 

should not provide the requisite clarity for a jury. ReplyBr. 18–19. The court should reject 

WSOU’s efforts to avoid explaining the parties’ agreement to the jury. See ContentGuard 

Holdings, Inc. v. Apple Inc., 701 F. App’x 957, 963 (Fed. Cir. 2017) (affirming district court’s 

claim construction decision because it “avoided possible jury confusion”).15

As stated in its responsive brief, Defendants’ concern is less with the exact language used 

to inform the jury of the “both” requirement, but rather that the jury is so informed. Thus, 

Defendants suggest either their original construction, (or its alternative compromise proposal);16

both provide the requisite jury clarity on the term. DefBr. 39. Because even WSOU could not 

make up its mind regarding the “plain and ordinary meaning” until its opening brief, the jury 

should be instructed as to that meaning. Tellingly, WSOU offered no reason not to provide clarity.

14 Unfortunately, WSOU put the parties through the process of briefing the term by refusing to 

explain what it understood the “plain and ordinary meaning” to be for this term prior to its opening 

brief; yet curiously states it was not required to so explain. ReplyBr. 18 n.7. Defendants asked 

WSOU to clarify its position, but WSOU refused. 

15 Construction will also help avoid a dispute later should WSOU improperly try to argue for the 

broader interpretation for infringement and the narrower for invalidity, this term requires 

construction. See International Glass Comp. Inc. v. U.S., 408 F.2d 395, 405 (1969) (“Plaintiff 

cannot have it both ways. Claims cannot be broadly construed to make out infringement and 

narrowly construed to avoid invalidity.”). 

16 Defendants would be satisfied with a construction that “management station” be construed as “a 

management station that is capable of initiating a poll in response to both reporting from the node 

and a time interval being exceeded.” DefBr. 39; ReplyBr. 19.
20

Dated: April 14, 2021 By: Barry K. Shelton

Barry K. Shelton

Texas State Bar No. 24055029

bshelton@sheltoncoburn.com

SHELTON COBURN LLP

311 RR 620, Suite 205

Austin, TX 78734-4775 

Telephone: 512.263.2165

Facsimile: 512.263.2166 

Benjamin Hershkowitz

bhershkowitz@gibsondunn.com

Brian A. Rosenthal

brosenthal@gibsondunn.com 

Allen Kathir

akathir@gibsondunn.com

Kyanna Sabanoglu

ksabanoglu@gibsondunn.com

GIBSON, DUNN & CRUTCHER LLP

200 Park Avenue

New York, NY 10166-0193 

Telephone: 212.351.4000

Facsimile: 212.351.4035 

Y. Ernest Hsin

ehsin@gibsondunn.com

Jaysen S. Chung

jschung@gibsondunn.com

GIBSON, DUNN & CRUTCHER LLP

555 Mission Street, Suite 3000

San Francisco, CA 94105-0921

Telephone: 415.393.8200

Facsimile: 415.393.8306

Ryan K. Iwahashi

riwahashi@gibsondunn.com

GIBSON, DUNN & CRUTCHER LLP

1881 Page Mill Road

Palo Alto, CA 94304-1211

Telephone: 650.849.5300

Facsimile: 650.849.5333

Attorneys for Defendants
CERTIFICATE OF SERVICE

The undersigned certifies that on April 14, 2021, all counsel of record who are deemed to 

have consented to electronic service are being served with a copy of this document through the 

Court’s CM/ECF system under Local Rule CV-5(b)(1). 

/s/ Barry K. Shelton

Barry K. Shelton