Correct Transmission, LLC

Patent Trials and Appeals Board

Aug 30, 2021

IPR2021-00571 (P.T.A.B. Aug. 30, 2021)

Trials@uspto.gov Paper 10
Tel: 571-272-7822 Entered: August 30, 2021

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

JUNIPER NETWORKS, INC.,
Petitioner,

v.

CORRECT TRANSMISSION, LLC,
Patent Owner.
____________

IPR2021-00571
Patent 7,127,523 B2
____________

Before BRYAN F. MOORE, JOHN R. KENNY, and
STEPHEN E. BELISLE, Administrative Patent Judges.

BELISLE, Administrative Patent Judge.

DECISION
Denying Institution of Inter Partes Review
35 U.S.C. § 314

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I. INTRODUCTION
A. Case Posture
Juniper Networks, Inc. (“Petitioner”) filed a Petition (Paper 1, “Pet.”)
requesting an inter partes review of claims 1–6 and 10–15 (“Challenged
Claims”) of U.S. Patent No. 7,127,523 B2 (Ex. 1001, “the ’523 patent”).
Petitioner identifies itself as a real party in interest. Pet. ix. Correct
Transmission, LLC (“Patent Owner”) identifies itself as a real party in
interest (Paper 4, 1), and timely filed a Preliminary Response to the Petition
(Paper 6, “Prelim. Resp.”). In addition, with prior authorization from the
Board, the parties filed supplemental briefing concerning the Preliminary
Response. Paper 8 (“Reply”); Paper 9 (“Sur-Reply”).
We have authority to determine whether to institute an inter partes
review. 35 U.S.C. § 314(b) (2018); 37 C.F.R. § 42.4(a) (2020). We may not
institute an inter partes review “unless . . . there is a reasonable likelihood
that the petitioner would prevail with respect to at least 1 of the claims
challenged in the petition.” 35 U.S.C. § 314(a).
Applying those standards, and upon consideration of the information
presented in the Petition, Preliminary Response, and supplemental briefing,
we determine that Petitioner has not demonstrated a reasonable likelihood of
prevailing with respect to any of challenged claims 1–6 and 10–15 of the
’523 patent. See 35 U.S.C. § 314; 37 C.F.R. § 42.4(a). Accordingly,
constrained by the record before us, we deny institution of an inter partes
review of the ’523 patent.
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B. Related Proceedings
The parties indicate that the ’523 patent is involved in two U.S.
district court actions, namely, Correct Transmission, LLC v. Juniper
Networks, Inc., No. 6:20-cv-670 (W.D. Tex.); and Correct Transmission,
LLC v. Adtran, Inc., No. 6:20-cv-669 (W.D. Tex.). Pet. ix; Paper 4, 1.
Patent Owner also indicates that the following matters may affect, or
be affected by, a decision in this case: Juniper Networks, Inc. v. Correct
Transmission, LLC, IPR2021-00469 (PTAB); and Juniper Networks, Inc. v.
Correct Transmission, LLC, IPR2021-00682 (PTAB). Paper 4, 1; see Pet. ix
(Petitioner indicating that it filed a petition for inter partes review of U.S.
Patent No. 7,983,150 (IPR2021-00469)).
C. The ’523 Patent
The ’523 patent is titled “Spanning Tree Protocol Traffic in a
Transparent LAN,” and issued on October 24, 2006, from U.S. Patent
Application No. 10/057,332, filed January 25, 2002. Ex. 1001, codes (10),
(21), (22), (45), (54). The ’523 patent claims priority to U.S. Provisional
Patent Application No. 60/308,410, filed July 27, 2001. Id. at code (60).
The ’523 patent generally relates to “methods and systems for
enabling spanning tree protocol traffic over a network using label
switching.” Ex. 1001, 1:13–16. The ’523 patent summarizes the invention
as follows:
[A] spanning tree protocol (STP) is implemented in a TLS [i.e.,
“transparent LAN service”] network by sending STP signaling
along the data paths through the MPLS [i.e., “multi-protocol
label switching”] tunnels making up the network. In other words,
STP frames are sent through the same tunnels as the user traffic,
but are distinguished from the user data frames by a special STP
label. Loop removal is carried out in this way for each one of the
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TLSs, so that each TLS has its own loop-free topology. Using
this method, the TLS network operator is able to ensure that there
are no loops in the core network, irrespective of loops that users
may add when they connect their own equipment to the network.
Id. at 5:65–6:9; see id. at 3:42–45 (MPLS), 4:23–25 (TLS).
Figure 1 of the ’523 patent is reproduced below.

Figure 1 is a block diagram depicting a multi-protocol
label switching (MPLS) system configured for
transparent LAN service (TLS).
Ex. 1001, 7:52–55, Fig. 1. As shown in Figure 1 above, multi-protocol label
switching (“MPLS”) system 10 includes point-to-point transparent LAN
service (“TLS”) network 12 connecting between first user 14 and second
user 16. Id. at 8:16–23. Users 14 and 16 are connected by label switching
routers (LSRs) 18, 19, 20, 21, and 22 across label switching paths
(“LSPs”) 23, 24, 25, 26 and 27. Id. at 8:23–26. Labeled packets originating
from user 14 and destined for user 16 cross a set of the LSPs. Id. at 8:26–28.
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According to the ’523 patent, MPLS system 10 transmits “encapsulated
configuration bridge protocol data units (BPDU),” which prevent “loops” in
TLS network 12. Id. at 5:62–64, 8:16–20.
Figure 3 of the ’523 patent is reproduced below.

Figure 3 is a schematic diagram depicting encapsulation
of a configuration bridge protocol data unit (BPDU) used
in a spanning tree protocol (STP).
Ex. 1001, 7:60–62, Fig. 3. As shown in figure 3 above, MPLS frame 39
encapsulates configuration BPDU 40 used in STP with MPLS routing labels
pushed onto a label stack above BPDU 40. Id. at 8:58–62. “The first label
is a specialized BPDU identifying label 42, comprising an agreed upon value
signifying that the underlying data is a BPDU. This label will enable LSRs
in system 10 to identify frame 39 as a STP frame, rather than a normal data
frame.” Id. at 8:63–67. “A further MPLS destination label 44 is pushed
onto the label stack at each LSR, in accordance with conventional MPLS
routing procedures. This is the same label as is used for user data frames
carried between users of TLS network 12.” Id. at 8:67–9:4. “A stack flag
bit 46 is set in destination label 44 to indicate that the receiving LSR should
pop the next level label off the label stack and examine it, in order to
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discover the BPDU identifying label and perform the required STP
processing.” Id. at 9:4–8.
According to the ’523 patent, “[a]lthough the method of encapsulating
BPDU 40 in frame 39 [with BPDU identifying label 42] . . . is novel, both
[pushing MPLS routing label 44 with label stacking bit 46 onto BPDU
frame 40 and sending BPDU frame 40 to a destination] . . . are part of
normal MPLS processing, as is known in the art.” Ex. 1001, 9:20–23,
Figs. 3, 4A.
D. Illustrative Claim
The ’523 patent includes 19 claims, of which claims 1–6 and 10–15
are challenged. Claims 1 and 10 are the challenged independent claims.
Claim 1 is illustrative and reproduced below.
1. A method for communication, comprising:
defining a topology of a transparent local area network service
(TLS), comprising a system of label-switched tunnels
between label-switched routers (LSRs) through a
communication network, the TLS having at least first and
second endpoints to which first and second user equipment
is connected so that the TLS acts as a virtual bridge
between the first and second user equipment;
transmitting control frames among the LSRs in the TLS via the
label-switched tunnels, each control frame comprising a
control traffic label and a bridge protocol data unit
(BPDU) in accordance with a spanning tree protocol
(STP), the control traffic label indicating to the LSRs that
the STP is to be executed by the LSRs without
transmission of the BPDU to the user equipment; and
upon receiving the control frames at the LSRs, processing the
BPDU, responsively to the control traffic label, so as to
remove loops in the topology of the TLS irrespective of
the user equipment.
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Ex. 1001, 10:55–11:7.
E. Applied References
Petitioner relies upon the following references:
Fine et al., U.S. Patent No. 6,188,694 B1 (Ex. 1005,
“Fine”), filed December 23, 1997, issued February 13, 2001.
Rekhter et al., U.S. Patent No. 6,339,595 B1 (Ex. 1006,
“Rekhter”), filed December 23, 1997, issued January 15, 2002.
E. Rosen and Y. Rekhter, “BGP / MPLS VPNs” –
Network Working Group – Request for Comments: 2547
(March 1999) (Ex. 1007, “RFC-2547”). Petitioner submits
RFC-2547 was “published no later than March 1999,” citing,
inter alia, the Declaration of Sandy Ginoza. Pet. 2 (citing
Ex. 1034 ¶¶ 6–10, 14).
Pet. 2–3.
F. Asserted Grounds of Unpatentability
Petitioner challenges the patentability of claims 1–6 and 10–15 of the
’523 patent based on the following grounds.
Claims Challenged 35 U.S.C. § Reference(s)
1–6, 10–15 103(a)1 Fine, Rekhter
1–6, 10–15 103(a) Fine, RFC-2547
Pet. 2. Petitioner relies upon the Declaration of Yaling Yang, Ph.D.
(Ex. 1003).

1 The Leahy-Smith America Invents Act (“AIA”), Pub. L. No. 112-29,
125 Stat. 284, 287–88 (2011), amended 35 U.S.C. § 103. Because the
’523 patent was filed before March 16, 2013, the effective date of the
relevant amendment, the pre-AIA version of § 103 applies.
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II. ANALYSIS
A. Applicable Law
Petitioner challenges the patentability of claims 1–6 and 10–15 of the
’523 patent on grounds that the claims would have been obvious under
35 U.S.C. § 103 in light of various references including: Fine, Rekhter, and
RFC-2547. “In an [inter partes review], the petitioner has the burden from
the onset to show with particularity why the patent it challenges is
unpatentable.” Harmonic Inc. v. Avid Tech., Inc., 815 F.3d 1356, 1363 (Fed.
Cir. 2016) (citing 35 U.S.C. § 312(a)(3) (requiring inter partes review
petitions to identify “with particularity . . . the evidence that supports the
grounds for the challenge to each claim”)) (emphasis added). This burden
never shifts to Patent Owner. See Dynamic Drinkware, LLC v. Nat’l
Graphics, Inc., 800 F.3d 1375, 1378 (Fed. Cir. 2015) (citing Tech. Licensing
Corp. v. Videotek, Inc., 545 F.3d 1316, 1326–27 (Fed. Cir. 2008))
(discussing the burden of proof in inter partes review).
A claim is unpatentable under 35 U.S.C. § 103 if “the differences
between the subject matter sought to be patented and the prior art are such
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406
(2007). The question of obviousness is resolved on the basis of underlying
factual determinations, including (1) the scope and content of the prior art;
(2) any differences between the claimed subject matter and the prior art;
(3) the level of skill in the art; and (4) when of record, objective evidence of
obviousness or non-obviousness, i.e., secondary considerations. Graham v.
John Deere Co., 383 U.S. 1, 17–18 (1966). Secondary considerations may
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include the following: “commercial success, long felt but unsolved needs,
failure of others, etc.”2 Id. The totality of the evidence submitted may show
that the challenged claims would not have been obvious to one of ordinary
skill in the art. In re Piasecki, 745 F.2d 1468, 1471–72 (Fed. Cir. 1984).
When evaluating a combination of teachings, we must also “determine
whether there was an apparent reason to combine the known elements in the
fashion claimed by the patent at issue.” KSR, 550 U.S. at 418 (citing In re
Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).
We analyze the challenges presented in the Petition in accordance
with the above-stated principles.
B. Level of Ordinary Skill in the Art
Petitioner contends that a person of ordinary skill in the art, at the time
of the effective filing date of the ’523 patent:
would have had a bachelor’s degree in electrical engineering,
computer engineering, computer science, or a closely related
field, and one to two years of experience in the design and
development of network communication systems. Alternatively,
a POSITA would have a Master’s degree or similar post-graduate
work in electrical engineering, computer engineering, computer
science, or a closely related field, and less years of design and
development experience.
Pet. 11 (citing Ex. 1003 ¶¶ 75–79). Patent Owner does not present an
alternative definition at this stage of the proceeding. Prelim. Resp. 34.
We regard Petitioner’s proposed definition as reasonable, and
consistent with the prior art before us. See In re GPAC Inc., 57 F.3d 1573,

2 At this stage of the proceeding, Patent Owner has not presented objective
evidence of non-obviousness.
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1579 (Fed. Cir. 1995) (determining that the Board of Patent Appeals and
Interferences did not err in concluding that the level of ordinary skill in the
art was best determined by the references of record). Accordingly, we apply
the level of skill set forth above, which also is consistent with the testimony
of Dr. Yang (Ex. 1003 ¶¶ 75–79).
C. Claim Construction
Neither Petitioner nor Patent Owner proposes any claim terms for
construction. Pet. 12 (“Juniper construes each of the ’523 claim terms as
having its ordinary and customer meaning.”); Prelim. Resp. 10 (“Patent
Owner does not propose any claim term departs from its ordinary and
customary meaning.”). We do not find that the express construction of any
term is necessary for this decision. See Vivid Techs., Inc. v. Am. Sci. &
Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (“[O]nly those terms need be
construed that are in controversy, and only to the extent necessary to resolve
the controversy.”); Nidec Motor Corp. v. Zhongshan Broad Ocean Motor
Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (applying Vivid Techs. in the
context of an inter partes review).
D. Obviousness of Claims 1–6 and 10–15 over the Combination of
Fine and Rekhter (Ground 1)
Petitioner contends claims 1–6 and 10–15 are unpatentable under
35 U.S.C. § 103 as obvious over the combination of Fine (Ex. 1005) and
Rekhter (Ex. 1006). Pet. 13–55. Patent Owner opposes Petitioner’s
contentions. Prelim. Resp. 1–3, 34–51. Based on our review of the Petition
and Preliminary Response, we determine that Petitioner has not
demonstrated a reasonable likelihood that it would prevail in showing that
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claims 1–6 and 10–15 are unpatentable as obvious over the combination of
Fine and Rekhter, as discussed below. We begin with an overview of Fine.
1. Overview of Fine
Fine generally relates to “a shared spanning tree protocol for defining
a plurality of loop-free paths within a computer network.” Ex. 1005, 1:5–8.
Fine discloses:
A shared spanning tree protocol (SSTP) creates a plurality
of spanning trees (i.e., loop-free paths) which are shared among
one or more virtual local area network (VLAN) designations for
data transmission within a computer network. Each shared
spanning tree includes and is defined by a primary VLAN and
may be associated with one or more secondary VLANs. In order
to associate VLAN designation(s) with a single shared spanning
tree, network devices exchange novel shared spanning tree
protocol data units (SST-PDUs). Each SST-PDU corresponds to
a given primary VLAN and preferably includes one or more
fields which list the secondary VLAN designations associated
with the given primary VLAN. The association of VLAN
designations to shared spanning trees, moreover, preferably
depends on which path traffic is to follow as well as the
anticipated load characteristics of the various VLANs. The
association of VLAN designations to shared spanning trees thus
provides a degree of load balancing within the network. Data
messages tagged with a particular VLAN designation are then
distributed by the devices only along the shared spanning tree to
which that VLAN has been associated by SSTP.
Id., Abstract.
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Figure 3B of Fine is reproduced below.

Figure 3B is a block diagram of a tagged bridge protocol
data unit (BPDU).
Ex. 1005, 5:60–61. As shown in Figure 3B above, Fine’s bridge protocol
data unit (BPDU) 340 includes VLAN tag field 342 to form a tagged BPDU.
Id. at 10:6–9. BPDU 340 also includes, among other fields, destination and
source MAC (“Media Access Control”) address fields 344, 346. Id. at 10:9–
18, 8:55. Fine discloses that VLAN tag field 342 identifies a primary VLAN
designation, which is used to direct the tagged BPDU through each port of a
switch associated with that VLAN designation. Id. at 11:39–54.
2. Independent Claims 1 and 10: “the control traffic label
indicating to the LSRs that the STP is to be executed by the
LSRs without transmission of the BPDU to the user
equipment”
The parties dispute, inter alia, whether Petitioner’s cited evidence
adequately supports Petitioner’s contention that Fine discloses “the control
traffic label indicating to the LSRs that the STP is to be executed by the
LSRs without transmission of the BPDU to the user equipment,” as recited
in both challenged independent claims 1 and 10. See, e.g., Prelim. Resp. 41–
48; Pet. 33–35, 44; Ex. 1001, 10:67–11:3, 11:62–65.
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Petitioner contends “Fine explains its LSRs execute the tagged BPDU
and this BPDU isn’t transmitted to the user equipment,” but Petitioner does
not cite any evidentiary support for this statement, let alone direct us with
particularity to where this is explained in Fine. Pet. 33 (emphases added);
see Pet. 33–34.3 Petitioner then contends, again without citing any
evidentiary support, “[b]ecause [Fine’s] switches 118, 121 will have
executed spanning tree protocol calculations based on the tagged BPDUs,
[the skilled artisan] would have understood that Fine’s tagged BPDUs don’t
reach the entities of the LANs 102, 109.” Pet. 34 (emphasis added); see
Pet. 35. Petitioner further contends “the entities of LANs 102, 109 don’t
execute spanning tree protocol calculations or consider this information, so
[the skilled artisan] would have appreciated Fine’s switches don’t transmit
this information to entities of LANs 102, 109.” Pet. 34; see Pet. 34–35.
Patent Owner argues “Petitioner fails to address how or why Fine’s
purported ‘control traffic label,’ which Petitioner discloses as the VLAN Tag
Field, performs the required limitation of ‘indicating to the LSRs that the
STP is to be executed by the LSRs without transmission of the BDPU to the
user equipment.’” Prelim. Resp. 47. Patent Owner argues “Petitioner states
Fine’s ‘VLAN tag field 342 in combination with [the] special multicast
address in the destination address field 344 to be a disclosure of the claimed
“control traffic label,”’ but “Petitioner fails to even mention this VLAN Tag
Field or Destination Address Field in the portion of the Petition dedicated to
‘a control traffic label indicating to the LSRs.” Id. at 47–48 (citations

3 For each quote in this paragraph, Dr. Yang makes a similar statement, but
Dr. Yang’s declaration also does not cite any evidentiary support for those
statements. Ex. 1003 ¶ 135.
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omitted). Patent Owner argues “Petitioner does not even mention the term
‘indicating’ or its equivalent, not to mention any purported control traffic
label,” and “[a]s a result, Petitioner has failed to meet its burden for this
limitation under 37 C.F.R. § 42.104(b)(4).” Id. at 48. We are persuaded by
Patent Owner’s argument.
Notably, although Petitioner understands that the Examiner allowed
the Challenged Claims based on this “indicating” limitation (Pet. 33),
Petitioner fails to direct us with particularity to any disclosure or teaching in
Fine of a “control traffic label” itself “indicating” to LSRs that the STP is to
be executed by the LSRs without transmission of the BPDU to the user
equipment. See Pet. 33–35. As argued by Patent Owner (Prelim. Resp. 47–
48), Petitioner does not explain with particularity how or why Fine’s VLAN
Tag field 304 or Destination Address field 306 (or both) indicates to LSRs
that the STP is to be executed by the LSRs without transmission of the
BPDU to user equipment (or teaches such “indicating”). Instead, Petitioner
merely leaps from arguing that Fine teaches that tagged BPDUs do not reach
user equipment (Pet. 34), to averring that this constitutes or teaches the
claimed “indicating” limitation, without providing particular support and
explanation for such a leap. See Pet. 33–35; 35 U.S.C. § 312(a)(3) (The
petition must identify supporting evidence “with particularity.” (emphasis
added)); 37 C.F.R § 42.104(b)(4) (“The petition must specify where each
element of the claim is found in the prior art . . . .” (emphasis added)).
For the foregoing reasons, and constrained by the Petition, we are not
persuaded that the cited evidence adequately supports Petitioner’s contention
that Fine discloses “the control traffic label indicating to the LSRs that the
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STP is to be executed by the LSRs without transmission of the BPDU to the
user equipment,” as recited in independent claims 1 and 10.
3. Summary
For the foregoing reasons, we determine that Petitioner has not
demonstrated a reasonable likelihood of success in establishing the
unpatentability of any of independent claims 1 and 10, and claims 2–6 and
11–15, which depend therefrom, as obvious over the combination of Fine
and Rekhter.
E. Obviousness of Claims 1–6 and 10–15 over the Combination of
Fine and RFC-2547 (Ground 2)
Petitioner contends claims 1–6 and 10–15 are unpatentable under
35 U.S.C. § 103 as obvious over the combination of Fine (Ex. 1005) and
RFC-2547 (Ex. 1007). Pet. 55–74. Patent Owner opposes Petitioner’s
contentions. Prelim. Resp. 1–3, 34–51.
Petitioner again relies solely on Fine for allegedly teaching “the
control traffic label indicating to the LSRs that the STP is to be executed by
the LSRs without transmission of the BPDU to the user equipment,” as
recited in both challenged independent claims 1 and 10. See Pet. 66
(“As discussed with respect to claim element 1.4 in Ground 1 [i.e., the
“indicating” limitation], Fine discloses this claim element”), 68. Petitioner
does not offer any additional arguments under this ground directed to the
deficiencies noted above regarding Fine (see Section II.D.2, supra). See
generally Pet.
Accordingly, for the reasons set forth above in Section II.D,
we determine that Petitioner has not demonstrated a reasonable likelihood of
success in establishing the unpatentability of any of independent claims 1
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and 10, and claims 2–6 and 11–15, which depend therefrom, as obvious over
the combination of Fine and RFC-2547.
F. Discretionary Denial Under 35 U.S.C. §§ 314(a) and 325(d)
Because we deny institution upon consideration of the merits of
Petitioner’s challenges, Patent Owner’s arguments that we should exercise
our discretion under 35 U.S.C. §§ 314(a) and 325(d) to deny institution are
moot.
III. CONCLUSION
Petitioner has not demonstrated a reasonable likelihood of prevailing
with respect to any of claims 1–6 and 10–15 of the ’523 patent under either
of proffered Grounds 1 and 2.
IV. ORDER
For the reasons given, it is:
ORDERED that, pursuant to 35 U.S.C. § 314(a), an inter partes
review is not instituted for claims 1–6 and 10–15 of U.S. Patent
No. 7,127,523 B2.

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For PETITIONER:
Joseph Edell
Kyle Tsui
FISCH SIGLER LLP
joe.edell.IPR@fischllp.com
kyle.tsui@fischllp.com

For PATENT OWNER:
Bradley Liddle
Seth Lindner
Scott Breedlove
CARTER ARNETT PLLC
bliddle@carterarnett.com
sbreedlove@carterarnett.com
slindner@carterarnett.com