Arista Networks Inc.v.Cisco Systems, Inc.

Patent Trial and Appeal Board

Oct 22, 2015

10087342 (P.T.A.B. Oct. 22, 2015)

Trials@uspto.gov Paper 8
571-272-7822 Entered: October 22, 2015

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

ARISTA NETWORKS, INC.,
Petitioner,

v.

CISCO SYSTEMS, INC.,
Patent Owner.
____________

Case IPR2015-01050
Patent 7,023,853 B1
____________

Before BRYAN F. MOORE, MATTHEW R. CLEMENTS, and
PETER P. CHEN, Administrative Patent Judges.

MOORE, Administrative Patent Judge.

DECISION
Denying Institution of Inter Partes Review
37 C.F.R. § 42.108

I. INTRODUCTION
Petitioner, Arista Networks, Inc., filed a Petition for inter partes
review of claims 46–52, 54, 56, and 59–63 of U.S. Patent No. 7,023,853 B1
(Ex. 1001, “the ’853 patent”). Paper 2 (“Pet.”). Patent Owner, Cisco
Systems, Inc., filed a Preliminary Response. Paper 7 (“Prelim. Resp.”).
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Institution of an inter partes review is authorized by statute when “the
information presented in the petition . . . and any response . . . shows that
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);
see 37 C.F.R. § 42.108. Upon consideration of the Petition and the
Preliminary Response, we conclude the information presented does not show
a reasonable likelihood that Petitioner would prevail in establishing the
unpatentability of any of the challenged claims of the ’853 patent.
A. Related Matters
The parties state that the ’853 patent is the subject of Cisco Systems,
Inc. v. Arista Networks, Inc., No. 4:14-cv-05343-JSW (N.D. Cal.), filed
December 5, 2014, and ITC Inv. No. 337-TA-945 (Network Devices,
Related Software and Components Thereof (II)), filed December 19, 2014).
Pet. 1; Paper 4 (Patent Owner’s Mandatory Notice). The ’853 patent is also
the subject of IPR2015-976. Petitioner has also filed petitions requesting
inter partes review of other patents owned by Patent Owner: IPR2015-
00973 (U.S. Patent No. 6,377,577), IPR2015-00974 (U.S. 7,224,668),
IPR2015-00975 (U.S. Patent No. 8,051,211), IPR2015-00976 (U.S. Patent
No. 7,023,853), IPR2015-00978 (U.S. Patent No. 7,340,597), and IPR2015-
01049 (U.S. Patent No. 6,377,577).
B. The ’853 Patent
The ’853 patent is titled, “Access Control List Processing in
Hardware,” and relates generally to a method for performing access control
list processing in hardware using an associative memory. Ex. 1001, 1:5–8.
Data packets transmitted between network devices can be restricted using a
technique known as “access control.” Id. at 1:14–20. One access control
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technique is to use access control lists or “ACLs” to determine whether to
permit or deny transmission of a packet to a particular destination. Id. at
1:23–25 (“[T]he ACL describes which selected source devices are permitted
(and which denied) to send packets to which selected destination devices.”).
The Specification provides an example of a known ACL format,
where each ACL includes “access control specifiers.” Id. at 1: 2627.
These specifiers contain information to match with incoming packets, and
then based on a match, specify a particular access result (e.g., whether
transmission of a packet is “specifically permitted or specifically denied).
Id. at 1:27–34. Figure 1 of the ’853 patent is reproduced below.

Figure 1 is a block diagram of a system for performing access control in
accordance with the ’853 patent. Ex. 1001, 3:2223, 4344. As shown in
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Figure 1, packet 130 arrives at one of the system’s packet interfaces 101. Id.
at 3:47–48. A routing element 110 then selects one or more of the output
interfaces to which the packet should be forwarded. Id. at 3:50–53. Prior to
forwarding, access control element 120 determines whether to allow
transmission of the packet. Id. at 3:53–57.
Figure 2 of the ’853 patent is reproduced below.

Figure 2 is a block diagram of an access control element which contains
access control patterns. Id. at 4:1718. When packet 130 arrives at access
control element 120, packet label 200 is created based on information
derived from packet header 133 of packet 130. Id. at 4:19–22. The packet
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label goes to access control memory 210, which attempts to match
information from the packet label to access control specifiers in memory
211. Id. at 4:54–60.
To perform this matching process, packet label 200 is compared to
label match mask 212 and label match pattern 213 of each access control
specifier 211. Id. at 4:56–58. If a match is found with a particular access
control pattern, priority encoder 200 selects the corresponding access control
specifier 211 with the highest priority and provides an indicator of that
access control specifier 211 to output port 202. Id. at 4:5–56, 5:10–14. The
indicator specifies an access control result, which specifies if the packet
should be transmitted. Id. at 5:1–9.
C. Illustrative Claim
Claims 46 and 63 of the challenged claims of the ’853 patent are
independent. Claims 46 and 63, reproduced below, are illustrative of the
claimed subject matter:
46. A system comprising:
means for maintaining a set of access control patterns in at least
one associative memory;
means for receiving a packet label responsible to a packet, said
packet label being sufficient to perform access control processing for
said packet;
means for matching matchable information, said matchable
information being responsive to said packet label, with said set of
access control patterns in parallel;
means for generating a set of matches in response thereto, each
said match having priority information associated therewith;
means for selecting at least one of said matches in response to
said priority information, and generating an access result in response
to said at least one selected match; and
means for making a routing decision in response to said access
result.
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63. A method of processing a packet comprising:
selecting an output interface to which to forward the packet;
determining forwarding permission for the packet, wherein the
determining comprises
matching one or more characteristics of said packet with
one or more access specifiers in at least one access control
element;
processing said packet based on said forwarding
permission;
wherein, the selecting step is performed in parallel with
the determining step.

D. Asserted Grounds of Unpatentability
Petitioner contends that claims 46–52, 54, 56, and 59–63 of the
’853 patent are unpatentable based on the following specific grounds (Pet.
9–60):
References Basis Challenged Claim(s)
Feldmeier
1
35 U.S.C. § 102 46–50, 59, 60, and 63
2

Feldmeier and Hendel
3
35 U.S.C. § 103 51, 54, and 56
Feldmeier and Muller
4
35 U.S.C. § 103 54, and 60–62

1
U.S. Patent No. 5,920,886, filed March 14, 1997, issued July 6, 1999 (Ex.
1005, “Feldmeier”).
2
Although claim 52 is listed in the table of grounds (Pet. 3) and heading (id.
at 33), the Petition includes no analysis of claim 52 (id. at 33–49).
3
U.S. Patent No. 6,081,522, filed June 30, 1997, issued June 27, 2000 (Ex.
1007, “Hendel”).
4
U.S. Patent No. 5,938,736, filed June 30, 1997, issued Aug. 17, 1999 (Ex.
1008, “Muller”).
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References Basis Challenged Claim(s)
Feldmeier, Muller, and
Elliot
5

35 U.S.C. § 103 56
II. DISCUSSION
A. Claim Construction
In an inter partes review, we construe claim terms in an unexpired
patent according to their broadest reasonable construction in light of the
specification of the patent in which they appear. 37 C.F.R. § 42.100(b); see
also In re Cuozzo Speed Techs., LLC, 793 F.3d 1268, 1278–79 (Fed. Cir.
2015). Consistent with the broadest reasonable construction, claim terms are
presumed to have their ordinary and customary meaning as understood by a
person of ordinary skill in the art in the context of the entire patent
disclosure. In re Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir.
2007) (quoting Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005)
(en banc)). An inventor may provide a meaning for a term that is different
from its ordinary meaning by defining the term in the specification with
reasonable clarity, deliberateness, and precision. In re Paulsen, 30 F.3d
1475, 1480 (Fed. Cir. 1994).
1. Construction of Means plus Function Limitations
Several terms of the claims for which inter partes review is sought
recite claim terms in means-plus-function format, and thus 35 U.S.C. § 112,
sixth paragraph of the pre-AIA Patent Act applies.
6
Petitioner recognizes

5
U.S. Patent No. 5,867,495, filed Nov. 18, 1996, issued Feb. 2, 1999 (Ex.
1019, “Elliot”).
6
The ’853 Patent’s filing date is before the effective date set for the AIA’s
changes to § 112. America Invents Act, sec. 4(e), 125 Stat. 284, 297 (2011).
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that issues relating to the sufficiency of a claim under Section 112 are
outside the scope of an inter partes review. Pet. 10. Nonetheless, Petitioner
asserts, without citation, that “it is appropriate for the [Patent Trial and
Appeal Board (PTAB)] to analyze the prior art for the presence of structures
corresponding to the best available disclosure of the ’853 Patent,
notwithstanding that such disclosure may be insufficient to support the
claims.” Id. This is an incorrect statement of the standard the Board uses.
As explained in BlackBerry Corp. v. MobileMedia Ideas, LLC, Case
IPR2013-00036, slip op. at 19–20 (PTAB Mar. 7, 2014) (Paper 65), the
specification must provide the necessary structure under § 112, sixth
paragraph. When the specification of the challenged patent lacks sufficient
disclosure of structure under 35 U.S.C. § 112, sixth paragraph, the scope of
the claims cannot be determined without speculation and, consequently, the
differences between the claimed invention and the prior art cannot be
ascertained. Id.
Thus, the disclosure we rely on from the specification, and not the
“best available” disclosure, must be sufficient to determine the scope of the
claim.
Therefore, if one employs means-plus-function language in a
claim, one must set forth in the specification an adequate
disclosure showing what is meant by that language. If an
applicant fails to set forth an adequate disclosure, the applicant
has in effect failed to particularly point out and distinctly claim
the invention as required by the second paragraph of section
112.

In re Donaldson Co., 16 F.3d 1189, 1195 (Fed. Cir. 1994) (en banc). “The
specification must be read as a whole to determine the structure capable of
performing the claimed function.” Budde v. Harley–Davidson, Inc., 250
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F.3d 1369, 1379 (Fed. Cir. 2001) (citations omitted). A structure disclosed
in the specification qualifies as “‘corresponding’ structure only if the
specification or prosecution history clearly links or associates that structure
to the function recited in the claim.” B. Braun Med., Inc. v. Abbott Labs.,
124 F.3d 1419, 1424 (Fed. Cir. 1997) (emphasis added). This duty to link or
associate structure to function is the quid pro quo for the convenience of
employing 35 U.S.C. § 112, sixth paragraph. See O.I. Corp. v. Tekmar Co.,
115 F.3d 1576, 1583 (Fed. Cir. 1997). While “corresponding structure need
not include all things necessary to enable the claimed invention to work,” it
“must include all structure that actually performs the recited function.”
Cardiac Pacemakers, Inc. v. St. Jude Med., Inc., 296 F.3d 1106, 1119 (Fed.
Cir. 2002) (citation omitted).
2. “means for maintaining a set of access control patterns in at least
one associative memory”

Claim 46 recites the function of “means for maintaining a set of
access control patterns in at least one associative memory.” Petitioner states
that the “best available” (yet not sufficient) corresponding structure is access
control memory 210 in access control element 120. Pet. 10 (citing Ex. 1001,
Figs. 1& 2, 4:54–56.) Patent Owner states the corresponding structure of
’853 patent includes “one or more content-addressable memory units and a
general-purpose processor, program and data memory, and mass storage,
executing operating system software.” Prelim Resp. 17 (citing Ex. 1001,
Fig. 1 “CPU,” 5:21–25, 1:33–37.) Patent Owner suggests that the algorithm
running on the general purpose computer is “performing [at least] the steps
of recording and keeping up a set of access control patterns in at least one
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associative memory, and its equivalents.” Id. (citing Ex. 1001, Fig. 2, 4:54–
63, 5:33–46, 5:55– 6:20.)
Petitioner argues that “[t]he general purpose processor identified by
[Patent Owner] does not, in the ’853 Patent, perform the function of
‘maintaining a set of access control patterns.’” Pet. 11. Petitioner further
argues that “in the ’853 Patent, the CPU is a higher-level processor element
that performs secondary software access control processing, ancillary to the
access control of the invention, as directed by the access control result.” Id.
(citing Ex. 1001, 5:17–18, 5:21–30.)
The Specification states at col. 1, lines 33 to 37, as cited by Patent
Owner (Prelim. Resp. 17), that the invention is implemented on a router,
implementing operating system software, such as the IOS operating system.
However, the Specification also suggests that an object of the invention is to
avoid “the drawback that comparing at least some incoming packets against
the ACL must be performed using software.” Ex. 1001, 2:11–14. The
Specification further states that “embodiments of the invention can be
implemented using circuits adapted to particular process steps and data
structures described herein.” Id. at 3:36–39.
The Specification discloses a “higher level processor” that includes a
general-purpose processor. Id. at 5:21–30. According to the Specification,
after access control is performed “the packet 130 [may be] forwarded to a
‘higher-level’ processor for further treatment.” Id. at 5:16–17. “The higher-
level processor includes a general-purpose processor, program and data
memory, and mass storage, executing operating system and application
software for software (rather than hardware) examination of the packet
130.” Id. at 5:21–25 (emphasis added). Therefore, the Specification
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suggests, if a packet is not forwarded to the “higher-level” processor,
“examination of the packet” is done in hardware, not in software.
The corresponding structure need not be explicitly identified but must
disclose to a person of ordinary skill in the art what structure is identified in
the specification. See Atmel Corp. v. Info. Storage Devices, Inc., 198 F.3d
1374, 1380 (Fed. Cir. 1999). It is unclear from the Specification whether the
CPU, shown in Figure 2 as part of access control element 120, is the
“higher-level processor” (Ex. 1001, 5:21–25), or some other processor
running IOS (Ex. 1001, 1:33–37). It is also unclear which part of the access
control element 120 is composed of “circuits adapted to particular process
steps and data structures” (id. at 3:36–39). Here, the patent is at best unclear
whether the claimed function is implemented in software executed on a
general purpose CPU or in hardware as a collection of circuits. See
Blackboard, Inc. v. Desire2Learn Inc., 574 F.3d 1371, 1385 (Fed. Cir. 2009)
(“That ordinarily skilled artisans could carry out the recited function in a
variety of ways is precisely why claims written in ‘means-plus-function’
form must disclose the particular structure that is used to perform the recited
function.”).
We also find that it is equally unclear whether the following means-
plus-function limitations in claim 46, which appear to involve access control
element 120, are implemented in hardware or in software structure (or some
combination of both): “means for matching matchable information, said
matchable information being responsive to said packet label, with said set of
access control patterns in parallel”; “means for making a routing decision in
response to said access result”; and “means for receiving a packet label
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responsible to a packet, said packet label being sufficient to perform access
control processing for said packet.”
Because the Specification of the challenged patent lacks sufficient
disclosure of structure under 35 U.S.C. § 112, sixth paragraph, the scope of
independent claim 46, and claims 47–52, 54, 56, and 59–62 that depend
therefrom cannot be determined without speculation and, consequently, the
differences between the claimed invention and the prior art cannot be
ascertained. Thus, we decline to institute an inter partes review as to any
ground challenging claims 46–52, 54, 56, and 59–62.
B. Asserted Anticipation by Feldmeier
Petitioner contends that claim 63 is unpatentable under 35 U.S.C.
§ 102 as anticipated by Feldmeier. Pet. 47–49. Petitioner relies on the
testimony of Dr. H. Johnathan Chao. Id. at 47, 48 (citing Ex. 1003).
1. Feldmeier (Ex. 1005)
Feldmeier describes techniques for a networking device to perform
hierarchical address translation and filtering. Ex. 1005, 1:7–10. Feldmeier
specifically describes using a content addressable memory (“CAM”) to aid
in hierarchical address translation (i.e., routing packets to the correct
network based on the hierarchical organization of network addresses). Id. at
5:32–35, 13:19–21. When a packet is received, Feldmeier describes
reviewing the packet header information and performing a lookup against
the information stored in the CAM. Id. at 13:24–27, Fig.14. Based on
performing a lookup, a decision is made about whether to pass the packet
forward, or to discard it. Id. Feldmeier also describes how to choose
between multiple matches using the relative priority of the various matched
entries in the CAM. Id. at 11:10–12.
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2. Analysis
Petitioner contends that Feldmeier discloses all the limitations of
independent claim 63. Pet. 47–49. Petitioner asserts Feldmeier discloses
processing a packet by selecting an output interface to which to forward the
packet, determining forwarding permission for the packet wherein the
determining comprises matching one or more characteristics of a packet with
one or more access control specifiers in at least one access control element,
and processing the packet based on the forwarding permission where the
selecting step is performed in parallel with the determining step. Id. at 47–
49 (citing Ex. 1003 ¶¶ 115–119).
Claim 63 recites determining forwarding permission for the packet,
“wherein the determining comprises matching one or more characteristics of
said packet with one or more access control specifiers in at least one access
control element” and “processing said packet based on said forwarding
permission” Ex. 1001, 12:20–30. Petitioner asserts Feldmeier discloses this
limitation because “Feldmeier [discloses] searching the CAM for the address
that was extracted from the packet . . . and Feldmeier states that the
‘comparand’ in the search is “the address that is being searched for in the
CAM.” Pet. 36 (citing Ex. 1005, 10:64–66.), 47. In other words, Petitioner
asserts the address matching is the claimed “matching.” Petitioner further
asserts Feldmeier discloses that a packet will either be discarded or routed
on to a destination depending on the information received following the
CAM lookup. Id. at 40 (citing Ex. 1005, 13:24–27 (“Demultiplexer 1430
routes the packet received from input packet queue 1410 to either output
packet queue 1450 or to discard line 1460 depending on the signal received
from network address lookup 1440.”); see also id. at Fig.14.
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Patent Owner argues, “Feldmeier’s packet forwarding is not the same
as determining forwarding permissions (e.g., whether a packet is restricted
from being transmitted from a selected source device to a selected
destination device.)” Prelim. Resp. 31–32. Patent Owner further argues
Feldmeier does not process a packet based on a forwarding permission. Id.
We agree. Petitioner purports to show that “matching one or more
characteristics of said packet with one or more access control specifiers,”
recited in claim 63, results in “permission” to forward a packet. Petitioner
states that “the information obtained from the CAM lookup governs the
decision of whether to route or discard the packet.” Pet. 40 citing (Ex. 1003
¶ 106).
We note that Feldmeier discloses that “[a]ddress filtering is a process
similar to address translation, except that rather than retrieving the data
associated with an address, the process simply determines whether the
address exists in a table of addresses.” Ex. 1005, 1:19–22. Feldmeier
further discloses that “[t]he term address translation, as used herein, includes
both address translation and address filtering operations.” Id. at 1:22–24.
Also, as cited by Petitioner (Pet. 40), “Demultiplexer 1430 routes the packet
. . . to either output packet queue 1450 or to discard line 1460 depending on
the signal received from network address lookup 1440.” Ex. 1005, 13:24–
27. Finally, “[n]etwork address lookup 1440 is an apparatus for performing
hierarchical address translations according to an embodiment of the
invention.” Id. at 13:19–22. These passages suggest that a translation that
yields no match (filtering) results in the packet being sent to the discard line.
In contrast, the Specification supports that a successful match leading
to a forwarding permission is contemplated by the claims. Ex. 1001, 7:1–12,
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27–39 (determining an input or output permission by, among other things,
“determining all of the successful matches”). Based on the above passages,
Petitioner has not shown evidence that an affirmative match in Feldmeier
results in a permission of packet forwarding, as required by claim 63.
For the reasons stated above, we determine Petitioner has not shown
sufficiently that Feldmeier discloses all of the limitations of independent
claim 63. Accordingly, the information presented does not show a
reasonable likelihood that Petitioner would prevail in showing that claim 63
is anticipated by Feldmeier.
III. CONCLUSION
For the foregoing reasons, we determine that the information
presented does not show that there is a reasonable likelihood that Petitioner
would prevail at trial with respect to at least one claim of the ’853 patent,
based on any grounds presented in the Petition. On this record, we deny the
petition for inter partes review of claims 46–52, 54, 56, and 59–63.
ORDER
Accordingly, it is
ORDERED that that the petition is DENIED as to all challenged
claims, and no trial is instituted.

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PETITIONER:
Walter Renner
Kevin E. Greene
David Goren
FISH & RICHARDSON P.C.
IPR40963-0004IP1@fr.com
axf@fr.com

PATENT OWNER:
Lori A. Gordon
Robert G. Sterne
Jon E. Wright
Byron L. Pickard
STERNE, KESSLER, GOLDSTEIN & FOX P.L.L.C.
lgordon-PTAB@skgf.com
rsterne-PTAB@skgf.com
jwright-PTAB@skgf.com
bpickard-PTAB@skgf.com