Arista Networks, Inc.v.Cisco Systems, Inc.

Patent Trial and Appeal Board

Oct 19, 2015

10087342 (P.T.A.B. Oct. 19, 2015)

Trials@uspto.gov Paper 9
571-272-7822 Entered: October 19, 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 IPR2015-00976
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 6 (“Pet.”). Patent Owner, Cisco
Systems, Inc., filed a Preliminary Response. Paper 8 (“Prelim. Resp.”).
IPR2015-00976
Patent 7,023,853 B1
2
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
there is a reasonable likelihood that Petitioner would prevail in establishing
the unpatentability of any of claims 46–52, 54, 56, and 59–63 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 5 (Patent Owner’s Mandatory Notice). The ’853 patent is also
the subject of IPR2015-001050. 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,
Abstract. Data packets transmitted between network devices can be
IPR2015-00976
Patent 7,023,853 B1
3
restricted using a technique known as “access control.” Id. at 1:14–20. One
access control 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.” 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 1:27–37.
Figure 1 of the ’853 patent is reproduced below.

IPR2015-00976
Patent 7,023,853 B1
4
Figure 1 is a block diagram of a system for performing access control in
accordance with the ’853 patent. As shown in Figure 1, packet 130 arrives
at one of the system’s packet interfaces 101. Id. at 3:47–48. 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. When packet 130 arrives at access control element
120, a packet label 200 is created based on information derived from the
IPR2015-00976
Patent 7,023,853 B1
5
packet header 133 of packet 130. Id. at 4:19–22. The packet 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. The “access control patterns” are maintained
in the memory. Thereafter, “matchable information” from the packet label is
compared to the access control patterns to determine if there is a match.
Id. at 4:58–63. 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.
C. Illustrative Claim
Claims 46 and 63 of the challenged claims of the ’853 patent are
independent. Claims 46 and 63 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 responsive 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;
IPR2015-00976
Patent 7,023,853 B1
6
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.

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):
IPR2015-00976
Patent 7,023,853 B1
7
References Basis Challenged Claim(s)
Hendel
1
35 U.S.C. § 102
46–52, 54, 56, 59, and
63
Hendel and Muller
2
35 U.S.C. § 103 54, 56, and 60–62
Hendel and Elliot
3
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). 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
U.S. Patent No. 6,081,522, filed June 30, 1997, issued June 27, 2000 (Ex.
1007, “Hendel”).
2
U.S. Patent No. 5,938,736, filed June 30, 1997, issued Aug. 17, 1999 (Ex.
1008, “Muller”).
3
U.S. Patent No. 5,867,495, filed Nov. 18, 1996, issued Feb. 2, 1999 (Ex.
1019, “Elliot”).
IPR2015-00976
Patent 7,023,853 B1
8
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 § 112 ¶ 6 of the
pre-AIA Patent Act applies.
4
Petitioner recognizes that issues relating to the
sufficiency of a claim under Section 112 is outside the scope of an inter
partes review. Pet. 10. Nonetheless, Petitioner asserts, without citation, that
“it is appropriate for the 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 Corporation 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.
[I]f 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

4
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).
IPR2015-00976
Patent 7,023,853 B1
9
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
F.3d 1369, 1379 (Fed. Cir. 2001). 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. 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 § 112 ¶ 6.
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. See Cardiac Pacemakers, Inc. v. St. Jude
Med., Inc., 296 F.3d 1106, 1119 (Fed. Cir. 2002).
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,
Fig. 1, Fig. 2, 4:54–56.) Patent Owner states the corresponding structure is
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
IPR2015-00976
Patent 7,023,853 B1
10
purpose computer is “performing at least the step of recording and keeping
up a set of access control patterns in at least one associative memory.” 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
Cisco 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.)
We find that the Specification notes at col. 1, lines 33 to 37, as cited
by Patent Owner, 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 (access control list) must be performed using software.” Id. at
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
IPR2015-00976
Patent 7,023,853 B1
11
130.” Id. at 5:21–25 (emphasis added). Therefore, the Specification
suggests that, if a packet is not forwarded to a “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” which is described at Ex. 1001, 5:21–25, or some
other processor running IOS described at 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” as described
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; means for permitting or denying access for
IPR2015-00976
Patent 7,023,853 B1
12
said packet; and means for receiving a packet label 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 Hendel
Petitioner contends that claim 63 is unpatentable under 35 U.S.C.
§ 102 as anticipated by Hendel. Pet. 32–52. Petitioner relies on the
testimony of Dr. H. Johnathan Chao. Ex. 1003.
1. Hendel (Ex. 1007)
Hendel describes a system and method for forwarding packets using
multi-layer information in a multilayer network element that includes a
switching element comprising forwarding logic. Ex. 1007, 1:5–8, Figs. 1–3.
Hendel describes its approach using the OSI layer model for network
communications. Id. at 2:5–39. In particular, Hendel describes forwarding
logic 42 performing packet header analysis in both Layer 2 (“L2”) (i.e., “L2
Logic 62” (concerning link layer packet information)) and Layer 3 (“L3)”)
(i.e., “L3 Logic 64” (concerning network layer packet information)). Id. at
10:12–33, Fig. 4. Each of these compares L2 and L3 information for the
packet, respectively, to information stored in forwarding memory 40, which
is a content addressable memory (“CAM”). Id. at 8:55–61. Hendel
IPR2015-00976
Patent 7,023,853 B1
13
performs additional packet analysis in class logic 60. Id. at 11:49–60.
Merge logic 66 receives information relating to both layers, as well as
information from class logic 60, and determines what to do with the packet.
Id. at 10:47–52; see also Ex. 1003 ¶¶ 109–10. Hendel discusses using its
techniques for packet filtering (Ex. 1007, 9:21–25, 13:4–6), as well as for
network firewall applications. Id. at 14:8–12. It discusses that merge logic
66 may, in some circumstances, instruct that packets be discarded where
their proposed destination is inappropriate. Id. at 10:51–52. Hendel also
discusses techniques for finding the best match for a particular search
criteria among the various entries stored in the CAM. Id. at 12:51–55.

2. Analysis
Petitioner contends that Hendel discloses all the limitations of
independent claim 63. Pet. 50–52. Petitioner asserts Hendel 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. Pet. 50–52,
citing Ex. 1003 ¶¶ 129–136.
Claim 63 recites determining a 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.” Ex. 1001, 12:21–38. Petitioner asserts Hendel discloses
that “a packet may be directed to its destination or filtered; such results
IPR2015-00976
Patent 7,023,853 B1
14
comprise ‘forwarding permission’ for those packets permitted to be passed
to their destinations.” Pet. 50 (citing Ex. 1003 ¶ 131–134; Ex. 1007, 13:4–
8.)
Patent Owner argues “Hendel’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. 34. Patent Owner also argues “Hendel’s
minimal references to ‘filtering’ or ‘discarding’ packets does not concern
access control,” that Hendel’s “packets are only filtered or discarded as part
of the packet forwarding process when there is a problem with the packet,”
and thus, “Hendel refers to such filtering or discarding occurring when
packets are ‘ill-formed’ or have ‘no appropriate destination[s]’ or
‘unsupported’ headers.” Prelim Resp. 27 (citing Ex. 1007, 8:39–40, 10:51–
52, 13:9–11.) We agree.
Petitioner has not shown that Hendel’s filtering decision is determined
based on “matching one or more characteristics of said packet with one or
more access control specifiers.” Petitioner simply states that the packet is
“filtered.” Petitioner’s Declarant relies on the following text from Hendel:
“In a preferred embodiment, the merge logic 66 directs the input port 50i to
take one of the following actions on a packet: filter the packet; forward the
packet at layer 2; forward the packet at layer 2; forward the packet as a layer
3 flow; process the packet as a layer 3 route; and forward the packet as
multicast router.”) Ex. 1003 ¶ 132 (citing Ex. 1007, 13:4–8.) This citation
does not specify, however, that a characteristic of the packet was matched to
anything in order to make the filtering decision, only that the decision was
the result of “merge logic.”
IPR2015-00976
Patent 7,023,853 B1
15
Petitioner’s Declarant also relies on the following text from Hendel: “After
the forwarding logic 52 has determined what to do with the packet, it passes
that information to the input port 50i. If the input port 50i does not filter the
packet, then it [takes actions to forward the packet].” Ex. 1003 ¶ 132 (citing
Ex. 1007, 9:21–25.) However, this statement does not even say that
forwarding logic tells input port 50i to filter the packet, and certainly does
not explain how forwarding logic 52 would make a filtering decision.
Finally, Petitioner’s declarant relies on Hendel’s discussion of sending the
packet to a firewall for further processing if no match occurs
(Ex. 1003 ¶ 132 (citing Ex. 1007, 9:21–25)), but the claim does not recite
what happens if there is not a match. The specification confirms that a
successful match is contemplated by the claims. Ex. 1001, 7:1–12, 27–39
(determining an input [or output] permission by “determining all of the
successful matches”). Neither Petitioner, nor Petitioner’s Declarant, has tied
the matching in Hendel to a decision whether or not to forward a packet.
For the reasons stated above, we determine Petitioner has not shown
sufficiently that Hendel 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 Hendel.
III. CONCLUSION
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.
IPR2015-00976
Patent 7,023,853 B1
16
ORDER
Accordingly, it is
ORDERED that that the petition is DENIED as to all challenged
claims, and no trial is instituted.

IPR2015-00976
Patent 7,023,853 B1
17

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