Ex Parte 7,558,195 et al

Patent Trial and Appeal Board

Nov 21, 2013

90011771 (P.T.A.B. Nov. 21, 2013)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
90/011,771 06/27/2011 7,558,195 11517.0011-00000 3191
87916 7590 11/22/2013
2nd Reexam Group - Novak Druce + Quigg LLP
1000 Louisiana Street
Fifty-Third Floor
Houston, TX 77002
EXAMINER
STEELMAN, MARY J
ART UNIT PAPER NUMBER
3992
MAIL DATE DELIVERY MODE
11/22/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
______________

Ex parte BROCADE COMMUNICATIONS SYSTEMS, INC.
______________

Appeal 2013-009039
Reexamination Control No. 90/011,771
Patent 7,558,195 B11
Technology Center 3900
______________

Before JOHN C. MARTIN, HOWARD B. BLANKENSHIP,
and MAHSHID D. SAADAT, Administrative Patent Judges.

MARTIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(b) from the Examiner’s
rejection of original claim 1 of Patent 7,558,195 B1 (hereinafter “’195
patent”), the sole claim subject to this ex parte reexamination proceeding.

1 Issued July 7, 2009, based on Application 11/695,458, filed April 2, 2007,
as a continuation of Application 10/124,449 (now Patent 7,209,435 B1),
filed April 16, 2002.
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Final Office Action mailed July 19, 2012 (hereinafter “Final Action”) at l,
Part II, l. 1a.
We have jurisdiction under 35 U.S.C. §§ 6(b) and 306.
We AFFIRM.

I. STATEMENT OF THE CASE
A. This Ex Parte Reexamination Proceeding
This ex parte reexamination proceeding was initiated by a
“REQUEST FOR EX PARTE REEXAMINATION” filed on June 27, 2011,
by Third-Party Requester A10 Networks, Inc. (hereinafter “A10 Networks”).

The Examiner has rejected claim 1 under 35 U.S.C. § 102(e) for
anticipation by Guess.2 Answer 2; Non-Final Office Action mailed
November 18, 2011 (hereinafter “Non-final Action”) 6.3

B. Related Appeals and Litigation
The ’195 patent is the subject of litigation styled: Brocade
Communications Systems, Inc. v. A10 Networks, Inc., Case No. 10-CV-
03428-LHK (N.D. Cal.). APPELLANT’S APPEAL BRIEF PURSUANT
TO 37 C.F.R. § 41.37 (hereinafter “Brief”) at 3.

2 Guess, et al., US 2003/0048501 A1, published March 13, 2003.
3 The description of the rejection in the Non-final Action is implicitly
incorporated by reference in the Final Action.
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Appellant has identified twelve ex parte reexamination proceedings
and thirteen inter partes reexamination proceedings that “may be related to,
directly affect, be directly affected by, or have a bearing on the Board’s
decision in the pending appeal.” Brief 2-3. The only one of these other
proceedings that involves the ’195 patent is Inter Partes Reexamination
Proceeding 95/001,815 (hereinafter “the inter partes proceeding”) (Br. 3,
item 1), which USPTO records show was initiated by a “REQUEST FOR
INTER PARTES REEXAMINATION” filed by A10 Networks on
November 10, 2011. A Right of Appeal Notice (RAN) mailed in the inter
partes proceeding on May 24, 2013, includes a rejection of original claims 2,
4, 5, and 14-17 under 35 U.S.C. § 102(e) for anticipation by Guess. RAN 4,
para. 1. A petition4 by Patent Owner to terminate the inter partes
proceeding based on a final decision in the above-identified litigation was
dismissed in a USPTO decision mailed August 30, 2013.5

C. The Invention Described in the ’195 Patent
The ’195 patent characterizes the invention described therein as
addressing “a need for a system and method that provides a robust

4 PATENT OWNER’S PETITION UNDER 37 C.F.R. § 1.182 TO
TERMINATE THE REEXAMINATION PROCEEDINGS, filed July 10,
2013.
5 DECISION DISMISSING PETITION TO TERMINATE INTER PARTES
REEXAMINATION PROCEEDING.
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redundancy mechanism for providing failover among Layer 2 and
Layer 2/Layer 3 devices that improves on the shortcomings of presently
available solutions.” ’195 patent 3:34-37.6 The ’195 patent identifies one of
these presently available solutions as “Extreme Networks’ Extreme Standby
Router Protocol (ESRP), which provides both a Layer 3 default router and
Layer 2 loop redundancy mechanisms.” Id. at 3:19-23. The rejection before
us is based on the use of ESRP in Guess.
The ’195 patent states that “[i]n accordance with the present
invention, systems and methods are described for providing route
redundancy to Layer 2 networks.” Id. at 3:41-43. The system includes: (i) a
loop free Layer 2 network having a plurality of switching devices; (ii) and a
virtual switch that is coupled to the loop free Layer 2 network and includes
two or more switches configured to transition between master and backup
modes. Id. at 3:50-55. These switches communicate their status to each
other using redundancy control packets, and the system includes means for
allowing the redundancy control packets to be “flooded through the Layer 2
network.” Id. at 3:56-59.

6 Layer 2 (L2) refers to the data-link layer, which provides synchronization
for the physical level and furnishes transmission protocol knowledge and
management. ’195 patent 3:11-14. Layer 3 (L3), the network layer, handles
the routing of the data, e.g., sending it in the right direction to the right
destination on outgoing transmissions and receiving incoming transmissions
at the packet level. Id. at 3:14-17.
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As noted by Appellant, claim 1 (reproduced blow) is specifically
directed to a switch for use in the virtual switch. See Br. 4 (“Independent
claim 1 is directed to a switch for use in a virtual switch that provides route
redundancy for a Layer 2 network by flooding redundancy control packets
(i.e. hello packets) throughout a Layer 2 network.”).
Claim 1 reads as follows:
1. A switch for use in a system of switches, the system of
switches acting as a virtual switch, the switch comprising:
a memory; and
a plurality of ports, each for communicatively coupling
the switch to a Layer 2 network,
wherein the switch is configured to act in concert with
one or more other switches in the system of switches to
provide route redundancy for the Layer 2 network, and
wherein the switch is configured to communicate its
status to the one or more other switches by
transmitting, via at least one of the plurality of ports,
redundancy control packets for flooding throughout
the Layer 2 network.
’195 patent col. 21.7 One of the issues before us is how to interpret the last
paragraph of the claim. Appellant, as explained below, cites figures of the
’195 as support for Appellant’s claim interpretation.

7 Claim 1 as reproduced in the Claim Appendix (Br. 17) does not have the
same paragraph structure that it has in the ’195 patent.
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Figure 1 of the ’195 patent is reproduced below.

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Figure 1 is a block diagram of a configuration of VSRP (Virtual
Switch Redundancy Protocol) devices and “VSRP aware” devices according
to one embodiment of the invention. Id. at 4:37-39. VSRP aware switches
108, 110, 112, 122, 124, 126, which perform Layer 2 aggregation and
switching functionality, are aware of VSRP and may thus properly operate
with the failover functionality provided by the invention. Id. at 5:34-41.
The VSRP aware switches are connected to a network core 114, labeled
“WAN” (Wide Area Network8), by VSRP switches 104, 106, 118, and 120,
which provide L2 switching functionality and preferably also L3
functionality. Id. at 5:61-66. As shown in Figure 1, VSRP switches 104 and
106 constitute a first virtual switch X (102), while VSRP switches 118 and
120 constitute a second virtual switch Y (116). As explained in the
description of Figure 2, the function of each virtual switch is to provide
redundant paths for its associated VSRP aware switches. Id. at 6:50-52.
Referring to the “southern” region of the Figure 1 topology, switches
104 and 106 in virtual switch 102 are labeled “VSRP master switch C” and
“VSRP backup switch D,” respectively. The connections to VSRP master
switch C (104) are shown in bold typeface to indicate that normal network
traffic is being passed, i.e., the ports at both ends of the connection between
104 and 108 are forwarding data. Id. at 6:13-18. The interconnections to

8 ’195 patent 1:44.
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VSRP backup switch D (106) are shown in normal typeface to indicate that
traffic is being blocked. Id. at 6:18-20.
The description of Figure 1 in the ’195 patent does not mention
flooding, which instead is specifically addressed in the descriptions of
Figures 5 and 11, reproduced and discussed infra.
Figure 2 is reproduced below.
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Figure 2 is a block diagram showing a configuration of VSRP and VSRP
aware devices according to another embodiment. Id. at 4:40-42. In contrast
to virtual switch X (102) in the “southern” region of the Figure 1
embodiment, which consists of a VSRP master switch (104) and a single
VSRP backup switch (106), virtual switch 202 in the Figure 2 embodiment
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consists of a VSRP master switch (204) and two VSRP backup switches
(206, 208).
The ’195 patent in describing the Figure 2 embodiment explains that
the connections between the VSRP switches and the VSRP aware switches
are “symmetrical”:
Specific attention is directed to the symmetrical manner
in which the VSRP switches 204, 206 and 208 comprising the
virtual switch 202 are connected to the VSRP aware switches
210, 212, 214 for which the virtual switch 202 is providing
redundancy. For example, VSRP aware switch T 210 is
symmetrically connected to VSRP master switch Q 204, VSRP
backup switch R 206 and VSRP backup switch S 208, all three
of which comprise the virtual switch 202. . . . It should also be
noted that, in addition to the VSRP aware switches 210, 212,
214 being symmetrically connected to the virtual switch 202, it
is axiomatic that each VSRP switch 204, 206, 208 [of virtual
switch 202] must in turn be symmetrically connected to each
VSRP aware switch 210, 212, 214 that the virtual switch 202 is
providing redundancy for.
Id. at 6:49-7:3. The ‘195 patent’s discussion of Figure 5 (addressed below)
relies on “the symmetrical configuration of the connection topology” when
describing flooding of the hello packets. Id. at 10:17-21.
The ’195 patent explains that a priority value is used to determine
whether a VSRP device operates in master mode or backup mode. Id.
at 7:6-8. One of the factors in determining priority value is “the number of
connections the VSRP device has vis-á-vis other VSRP devices comprising
the same virtual switch.” Id. at 7:8-10.
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Figure 3 is reproduced below.

Figure 3 is a block diagram a depicting a situation where the VSRP device
(i.e., switch) 304 that is currently in master mode has lost communication
(at 314) with a VSRP aware switch 310 located on the far side of an
intermediate hub 308, which is an unmanaged device. Id. at 4:43-45; 7:10-
14. In order to determine the number of “live” connections, each of VSRP
switches 304 and 306 broadcasts L2 (Layer 2) “health check” packets.
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These “health check” packets are described (id. at 7:30-32) as independent
of the VSRP hello packets, which, as noted above, correspond to the claimed
“redundancy control packets.” In the situation depicted in Figure 3, the L2
health check performed by VSRP switches 304 and 306 results in VSRP
switch D (306) determining that it has two live connections, while VSRP
switch C (304), the current master switch for the virtual switch 302,
determines that it has only one connection. Id. at 7:57-61.
Figure 4 is reproduced below.
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Figure 4 is a block diagram presenting a VSRP aware device utilizing
multiple VLANs (Virtual Local Area Networks9) connected to master and
backup VSRP devices according to an embodiment of the invention. Id. at
4:46-49. VSRP aware switch 408 assigns individual ports on the switch
membership in different VLANs 414 and 416. Id. at 8:8-11. Traffic
destined for either of the VLANs on VSRP aware switch 408 is forwarded
by the VSRP master switch 406 over the forwarding link 418. Id. at 8:18-
22. The link between VSRP aware switch 408 and VSRP backup switch 404
is set to blocking 420 so as to prevent a network loop until such time as
VSRP backup switch 404 is required to transition into master mode. Id. at
8:22-26.
Figure 5, whose description in the ’195 patent Appellant (Br. 13-14)
relies on to explain what is required by the last paragraph of the claim, is
reproduced below.

9 ’195 patent 1:41-42; 8:5.
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Figure 5 is a block diagram presenting multiple VSRP aware devices, each
utilizing multiple VLANs, connected to a virtual switch according to one
embodiment of the invention. Id. at 4:50-53. Each of VSRP aware switches

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508, 510, and 512 has partitioned its ports between VLAN 1 and VLAN 2.
Id. at 9:1-3.
VSRP backup switch 506 uses received hello packets 514 to
determine whether it should be in master mode (ports forwarding), blocking
mode (ports blocking), or an intermediary “master confirm” mode (ports
blocking to traffic but transmitting hello packets). Id. at 9:41-47.10 The
hello packets are transmitted to the VSRP backup switch from the VSRP
master switch via a flooding technique. Specifically:
Once the virtual switch has reached a stable
configuration, the VSRP master switch sets its ports to
forwarding and continues to send out hello packets. . . . The
connected VSRP aware switches 508, 510 and 512 receive the
hello packets 514 and 516. Each VSRP aware switch 508, 510
and 512, floods the hello packet upon receipt, which is received
by other VSRP switches 504 and 506 in the virtual switch 502
due to the symmetrical nature of the connection topology. As
understood by those skilled in the art, flooding generally occurs
when a packet is forwarded to all devices other than the device
from which it was received, and is generally performed when
the packet has no routing address.
Id. at 10:9-24 (emphasis added). Appellant describes this symmetrical
switch configuration as “facilitat[ing] flooding redundancy control packets
through the entire Layer 2 network.” Reply Br. 10.

10 The hello packets are also identified as “514 and 516” in column 10,
line 17, reproduced below.
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Comparing claim 1 to Figure 5, the recited “virtual switch”
corresponds to virtual switch 502, which includes VSRP master switch A
(504) and VSRP backup switch B (506). The recited “Layer 2 network”
corresponds to VSRP aware switches 508, 510, and 512, which respond to
the hello packets (the recited “redundancy control packets”) received from
VSRP master switch A (504) by “flooding” the hello packets to VSRP
backup switch B (506).
Figure 11, whose description in the ’195 patent is also relied on by
Appellant (Br. 14) to explain what is required by the last paragraph of the
claim,” is reproduced below.
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Figure 11 is a block diagram presenting two VSRP devices acting as two
virtual switches providing failover to different VLANs. Id. at 5:3-6. This
embodiment likewise employs flooding to transmit hello packets:
Each VSRP switch 1104 and 1106 broadcasts hello
packets 1122 and 1124 for the virtual switches that it is a VSRP
master for over its connected interfaces; hello packets are
permitted transmission over blocked ports on a VSRP backup
switch. Each VSRP aware switch 1108, 1110 and 1112
receives the hello packets. Each VSRP aware switch 1108,
1110 and 1112, floods the hello packet upon receipt, which is
received by other VSRP switches due to the symmetrical nature
of the topology. The VSRP switches act on the hello messages
as is appropriate for each virtual switch. Alternatively, a direct
link may be provided between VSRP devices 1104 and 1106 as
a primary channel for transmission of hello packets to reduce
extraneous administrative traffic on the network.
Id. at 17:21-33 (emphasis added).

D. The Rejection
As already noted, claim 1 stands rejected under 35 U.S.C. § 102(e) for
anticipation by Guess.

II. DISCUSSION
A. The Issues and Claim Interpretation
Appellant argues that Guess fails to satisfy the last clause of claim 1
for two reasons. The first reason is that “Guess fails to expressly or
inherently disclose redundancy control packets that communicate switch
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status to other switches in a virtual switch.” Br. 8 (emphasis added). The
second reason is that “Guess fails to expressly or inherently disclose
flooding redundancy control packets throughout a Layer 2 network.” Id. at
11 (emphasis added). This second reason incorrectly assumes that the claim
requires flooding. The claim does not require the presence of a Layer 2
network, actual connection of any ports of the recited “a switch” to a Layer 2
network, or actual flooding of redundancy control packets in a Layer 2
network. The claim merely requires that the recited “a switch”: (i) have a
plurality of ports that are capable of being used to communicatively couple
the switch to a Layer 2 network”; and (ii) be configured to communicate its
status to the one or more other switches by transmitting, via at least one of
the plurality of ports, redundancy control packets that are capable of being
used “for flooding throughout the Layer 2 network.”11 We therefore will
consider whether the arguments offered as support for the second reason
demonstrate that Guess fails to describe redundancy control packets that are
capable (expressly or inherently) of such use. See In re Schreiber, 128 F.3d
1473, 1477 (Fed. Cir. 1997) (“To anticipate a claim, a prior art reference

11 “During reexamination, as with original examination, the PTO must give
claims their broadest reasonable construction consistent with the
specification.” In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1379
(Fed. Cir. 2007) (citing In re Am. Acad. of Sci. Tech Ctr., 367 F.3d 1359,
1364 (Fed. Cir. 2004)).

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must disclose every limitation of the claimed invention, either explicitly or
inherently.”).

B. The Guess Disclosure
Guess describes a system and method for deploying and operating a
metropolitan area local access distribution network. Guess para. 0001. The
local services network (e.g., Ethernet) according to the preferred
embodiment of Guess’s invention comprises a dual overlay ring topology
within the core, as shown in Figure 4. Id. at para. 0075.
Figure 4 of Guess is reproduced below.
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Figure 4 is a schematic diagram of a dual overlay ring topology within the
core. Id. The dual overlay ring topology is a physical topology in which
two complete physical paths are disposed to ensure that two data channels
are available during normal periods of use so that at least one is available to
communicate information in the event the other becomes unavailable. Id.
Figure 5 is reproduced below.
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Figure 5 is a schematic diagram of a working path and a protection path
across the core connecting a subscriber’s Layer 3 (L3) switch to its
carrier/ISP. Id. at para. 0015. As shown in this figure, the two-ring physical
topology allows the creation of a working path 50 and a protection path 52
across the network “connecting each subscriber (L3 Switch 54) to their
carrier/ISP (L3 Switches 56, 58).” Id. at para. 0076.
Figure 6, on which the Examiner principally bases the rejection, is
reproduced below.
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Figure 6 is a simplified drawing of the logical topology indicating how
Guess uses Extreme Networks’ Extreme Standby Router Protocol (ESRP) in
the distribution network design. Id. at paras. 0078, 0091. This figure
depicts ESRP as “enabled in the switches (62, 63) directly attached to the
subscriber 60.” Id.
Guess describes the functions of the ESRP master and ESRP standby
switches as follows:
[0081] ESRP is configured on a per-VLAN basis on each
switch. This system utilizes ESRP in a two switch
configuration, one master and one standby. . . . Only one
switch can actively provide Layer 2 switching for each VLAN.
The switch performing the forwarding for a particular VLAN is
considered the “master” for that VLAN. The other participating
switch for the VLAN is in [“]standby[”] mode.
(Emphasis added.) Furthermore, Guess uses ESRP packets to exchange
information in both directions between the ESRP master switch and the
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ESRP standby switch. See id. at para. 0085 (“the [master] switch exchanges
ESRP packets with other switches that are in standby mode”); and para.
0087 (“If a switch is in standby mode, it exchanges ESRP packets with other
switches on that same VLAN.”).
The Examiner, without objection by Appellant, reads the claimed “the
system of switches acting as a virtual switch,” which includes the recited “a
switch,” on ESRP master and standby switches 62 and 63. See Non-Final
Action 7 (“[B]oth of switches 62 and 63 would have the same IP address and
thus together act as a single ‘virtual switch.’”). The Examiner reads the
claimed “Layer 2 network” on Guess’s “L2 NETWORK” (presumably
minus switches 62 and 63). See id. at 8 (“Fig. 6 shows that switches 62 and
63 are connected to an ‘L2’ or Layer 2 network (communicatively coupling
the switch to a Layer 2 network).”).

C. Issue 1: Whether Guess Describes a Virtual Switch Including a Switch
That Communicates Its Status to Another Switch of the Virtual Switch by
Transmitting Redundancy Control Packets
Appellant argues that “Guess fails to expressly or inherently disclose
redundancy control packets that communicate switch status to other switches
in a virtual switch.”). Br. 8 (emphasis added). The Examiner correctly
concludes that “[the] claim language is not specific as to what information is
required by the term ‘status.’” Answer 12. The Examiner further finds that
Guess communicates switch status information of three different types
between the ESRP master and standby switches: (1) ESRP keep-alive
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packets; (2) the number of active ports; and (3) detection of “a failure or
non-failure” of the master switch. Id. at 11-12.12

1. The ESRP Keep-Alive Packets

Guess in the following paragraph describes what the Examiner refers
to as “ESRP keep-alive packets”:
[0081] ESRP is configured on a per-VLAN basis on each
switch. This system utilizes ESRP in a two switch
configuration, one master and one standby. The switches
exchange keep-alive packets for each VLAN independently.
Only one switch can actively provide Layer 2 switching for
each VLAN. The switch performing the forwarding for a
particular VLAN is considered the “master” for that VLAN.
The other participating switch for the VLAN is in [“]standby[”]
mode.

(Emphasis added.) We agree with Appellant that the Examiner’s reliance
on these ESRP keep-alive packets is misplaced because they are not
expressly or implicitly described as representing the status of the
transmitting switch. See Br. 8 (“‘Ping keep-alive packets’ and ‘keep-alive
packets’ fail to

12 Although the Examiner (Non-Final Action 9) initially also read the
recited “redundancy control packets” on Guess’s “pings” (presumably the
“ping tracking” described in paragraphs 0090-91), this is no longer the case.
See Advisory Action, mailed November 15, 2012, at 6 (“Ping keep-alive
packets are not relied upon to communicate switch status information
between switches in a virtual switch.”).
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communicate switch status information between switches in a virtual
switch.”) (footnote omitted). See In re Robertson, 169 F.3d 743, 745 (Fed.
Cir. 1999) (“Inherency . . . may not be established by probabilities or
possibilities. The mere fact that a certain thing may result from a given set
of circumstances is not sufficient.”) (citation omitted).

2. The Number of Active Ports
The Examiner relies on Guess’s description of using the number of
active ports in the following paragraph:
[0089] ESRP can be configured to track connectivity to one
or more specified VLANs as criteria for fail-over. The switch
that has the greatest number of active ports for a particular
VLAN takes highest precedence and will become master. If at
any time the number of active ports for a particular VLAN on
the master switch becomes less than the standby switch, the
master switch automatically relinquishes master status and
remains in standby mode.
(Emphasis added.) The Examiner finds that “[t]he ability of a switch to
communicate at least the number of active ports[] reads on the claimed
limitation ‘configured to communicate its status.’”). Answer 12.
Appellant does not deny that the claim term “status” reads on the
number of active ports. Instead, Appellant makes the following two
arguments:
[P]aragraph [0089] of Guess does not state that a master and
back-up switch communicate the number of active ports to each
other (claim 1 requires status to be communicated from one
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switch to another switch in the virtual switch), and paragraph
[0089] makes absolutely no mention of ESRP packets being the
means to communicate the number of active ports (claim 1
requires that a redundancy control packet communicates the
status information).
Reply Br. 5 (emphasis added). Neither of these arguments is persuasive.
We begin with the argument that Guess does not state that a master
and back-up switch communicate the number of active ports “to each other.”
To the extent Appellant is arguing that the claim requires communication of
status information in both directions between Guess’s master and standby
switches, we do not agree. Instead, the claim requires an ability to
communicate in only one direction, i.e., from the recited “a switch” of the
virtual switch to another switch of the virtual switch.
Appellant also contends that “Guess [in paragraph 0089] only
discloses that a master switch automatically relinquishes master status
without ever communicating the number active ports to other switches in a
virtual switch.” Reply Br. 6 (emphasis added). This contention is
unpersuasive because the claim does not expressly or implicitly limit the
recited “a switch” to the master switch in a virtual switch that contains a
master switch and one or more standby switches. Although the ’195 patent
specification describes the hello packets (corresponding to the claimed
“redundancy control packets “) as issued by the master switch, it is improper
to read limitations from examples into the claims. Phillips v. AWH Corp.,
415 F.3d 1303, 1323 (Fed. Cir. 2005) (en banc). Furthermore, assuming for
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the sake of argument the recited “a switch’ cannot be read on an ESRP
standby switch, it reads on Guess’s ESRP master switch because Guess’s
ESRP standby switch cannot determine whether it has the greatest number of
active ports for a particular VLAN and thus should become the master
switch (as stated in the second sentence of paragraph 0089) without being
advised of the number of active ports on the other switch (i.e., the ESRP
master switch) in the virtual switch.
We turn now to Appellant’s above-noted second argument, which is
that paragraph 0089 does not describe ESRP packets as the means to
communicate the number of active ports. As support for this argument,
Appellant (Reply Br. 5) notes (correctly) that “ESRP packets are only
discussed at paragraphs [0085] and [0087],” which read as follows:
[0085] If a switch is master, it actively provides Layer 2
switching between all the ports of that VLAN. Additionally,
the switch exchanges ESRP packets with other switches that are
in standby mode.
[0087] If a switch is in standby mode, it exchanges ESRP
packets with other switches on that same VLAN. When a
switch is in standby, it does not perform Layer 2 switching
services for the VLAN. From a Layer 2 switching perspective,
no forwarding occurs between the member ports of the VLAN.
This prevents loops and maintains redundancy.
(Emphasis added.) Although paragraph 0089’s discussion of the number of
active ports does not mention “ESRP packets,” we find that this paragraph
would have been understood to be describing information communicated
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using ESRP packets. In the first place, it is clear from the mention of
“ESRP” in the first sentence of this paragraph that the “number of active
ports” constitutes ESRP information. Second, ESRP packets are the only
means described by Guess for exchanging ESRP information between the
ESRP master and standby switches. See Guess 0085 (“the [master] switch
exchanges ESRP packets with other switches that are in standby mode”);
and 0087 (“If a switch is in standby mode, it exchanges ESRP packets with
other switches on that same VLAN.”).
For the above reasons, we are not persuaded of error in the
Examiner’s finding that the claimed “redundancy control packets” for
communicating switch status between switches of the virtual switch read on
Guess’s description of communicating the number of active ports between
the two ESRP switches. In the interest of completeness, we also address the
Examiner’s third rationale.

3. Communicating a Failure or Non-Failure of the Sending Switch
The Examiner states the third basis for finding that Guess describes
communicating status information between the ESRP master and standby
switches as follows: “[B]ecause Guess ’501 repeatedly teaches that the
purpose of exchanging ESRP packets is to provide route redundancy in the
event the master switch fails, it is understood that the ESRP packets
communicate a failure or non-failure of the sending switch to the receiving
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switch.” Answer 12.13 We understand this statement to be referring to
communication of a detection of either of the two failure conditions
described in paragraph 0091, which reads in relevant part below:
[0091] . . . Port track is used to detect local failure of a link
directly connected to these switches while ping track is used to
detect core network failures. If a failure is detected anywhere
along the active path 64, ESRP will failover to allow traffic to
flow on the standby path 65. As shown, ESRP port count can
be used to protect dual customer connections to the network.
ESRP ping tracking is used to protect the core VLAN.
(Emphasis added.) “The term ESRP port count” in this paragraph refers to
the above-noted discussion in paragraph 0089 of comparing numbers of
active ports to determine when, for example, the master switch should
relinquish its master status. We agree with the Examiner’s apparent position
that in the event the ESRP master switch determines it must relinquish its
master status, it will necessarily communicate this change in status to the
ESRP standby switch. Furthermore, for the reasons given above, we find
that this change in status will be communicated using ESRP packets.
We reach the same conclusion regarding the use of “ping tracking” to
detect core network failures, as described in paragraph 0091.14 That is, in

13 Appellant has not addressed this position of the Examiner.
14 Ping tracking is described by Guess as follows:
[0090] . . . ESRP can be configured to track connectivity
using a simple ping to any outside responder (ping tracking).
The responder may represent the default route of the switch, or
(Continued on next page.)
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the event the ESRP master switch, based on ping tracking, determines that it
must relinquish its master status, it will necessarily use ESRP packets to
communicate this change in status to the ESRP standby switch.
Thus, we also are not persuaded of error in the Examiner’s finding
that using “redundancy control packets” to communicate switch status
between switches of a virtual switch reads on Guess’s description of
communicating a
a failure or non-failure of the sending switch.

D. Issue 2: Whether Guess’s ESRP Packets That Represent Switch Status
Are Capable of Being Used “For Flooding Throughout the Layer 2
Network”
We begin our analysis of the question of whether Guess’s ESRP
packets representing switch status are capable of being used “for flooding
throughout the Layer 2 network” by noting that Appellant and the Examiner
do not essentially disagree regarding the meaning of the term “flooding.”
Appellant (Reply Br. 8) characterizes the following statement in the ’195
patent as “constitut[ing] at least one definition of the term ‘flooding’”: “As
understood by those skilled in the art, flooding generally occurs when a
packet is forwarded to all devices other than the device from which it was

any device meaningful to network connectivity of the master
ESRP switch. . . . The switch automatically relinquishes
master status and remains in standby mode if a ping keep-alive
(Continued on next page.)
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received, and is generally performed when the packet has no routing
address.” ’195 patent 10:21-24 (emphasis added). The Examiner relies on
the following, similar definition of “flooding”:
If the switch does not know to which port to send a frame
because the destination MAC address is not in the MAC table,
the switch sends the frame to all ports except the port on which
the frame arrived. The process of sending a frame to all
segments is known as flooding. The switch does not forward
the frame to the port on which it arrived because any
destination on that segment will have already received the
frame. Flooding is also used for frames sent to the broadcast
MAC address.
Final Action 9 (emphasis added) (quoting www.highteck.net/EN/Ethernet/
Ethernet.html).
Appellant argues that “[t]he Examiner’s rejection of claim 1 amounts
to mere speculation as to whether a switch of Guess can flood a redundancy
control packet throughout a Layer 2 network, because the ESRP packets of
Guess are never flooded.” Br. 11-12. We do not agree with this
characterization of the rejection. Instead, we understand the rejection to be
based on a finding that Guess’s ESRP packets that represent switch status
inherently are capable of being used “for flooding throughout [a] Layer 2
network.” We find this position to be reasonable on its face, with the result

fails three consecutive times.
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that Appellant has the burden to demonstrate that these ESRP packets in
Guess are incapable of being used for this purpose. See Schreiber, 128 F3d
at 1478 (“The examiner . . . correctly found that Harz established a prima
facie case of anticipation. At that point, the burden shifted to Schreiber to
show that the prior art structure did not inherently possess the functionally
defined limitations of his claimed apparatus.”). Appellant’s arguments,
discussed below, fail to persuade us that such inherency is lacking.
Appellant argues that flooding requires an indirect connection
between the two ESRP switches via a Layer 2 network, whereas Guess
describes only a direct connection between these switches. See Br. 12
(“Guess makes no reference to Layer 2 flooding of ESRP packets and
provides no specific description regarding the method of exchanging ESRP
packets. It is more probable that ESRP packets are exchanged via direct
point-to-point transmission between switches as illustrated in Figure 6 of
Guess . . . .”); id. at 13 (“The direct point-to-point transmission of packets
from a master to one or more standby switches is not flooding under the
definition of the term flooding provided by the Examiner or the definition
provided in the specification of the [’]195 patent.”). We agree that direct
point-to-point transmission of ESRP packets between Guess’s ESRP master
and standby switches does not constitute flooding of these packets
throughout a Layer 2 network. However, it is immaterial to the rejection
how or whether Guess’s ESRP master and standby switches are connected
together. It is only necessary that one of these ESRP switches provide ESRP
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packets representing switch status to one or more switch ports capable of
being coupled indirectly to the other ESRP switch via a Layer 2 network.
Thus, assuming for the sake of argument that Guess provides ESRP packets
on a single port of the ESRP master switch that is directly connected to a
single port of the ESRP standby switch, this direct connection inherently is
capable of being replaced by an indirect connection of these ports via a
Layer 2 network.15
Appellant also argues that the claim language “for flooding
throughout the Layer 2 network” requires that the redundancy control
packets be provided at a plurality of switch ports, which allegedly is not
described by Guess:
The claimed switch can transmit redundancy control packets on
all of its ports connected to the Layer 2 network, and those
packets are propagated throughout the entire Layer 2 network
until they are received at all other switches in the virtual switch.
See e.g., [’]195 patent at col. 10, lines 9-35; col. 12, lines 41-44.

15 Although the claim does not require that Guess describe indirect
communication of ESRP packets between the ERSP master and standby
switches, we note that the Examiner finds that “Guess ’501 exchanges
packets via non-direct connections between switches.” Answer 9. In
support, the Examiner relies on paragraph 0083, which states in relevant
part: “For each VLAN to be made redundant, the switches must have the
ability to exchange packets on the same Layer 2 broadcast domain for that
VLAN. Multiple paths of exchange can be used, and typically exist in most
network system designs that take advantage of ESRP.” (Emphasis added.)
Neither of Appellant’s briefs addresses this finding by the Examiner.
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Guess is completely silent with regard to flooding ESRP
packets and does not disclose forwarding ESRP packets on all
outgoing ports of a switch.
Br. 14 (emphasis added). As support for this argument, Appellant (id. at 13-
14) relies on the ’195 patent’s above-quoted descriptions of Figures 5 and
11, which describe the VSRP master switch (e.g., 504 in Figure 5) as
transmitting hello packets to all three of the VSRP aware switches (508, 510,
and 512). However, it is improper to read this feature from these figures
into the claim. Phillips, 415 F.3d at 1323. The claim does not require
providing the recited redundancy control packets at a plurality of switch
ports in order to permit flooding throughout that Layer 2 network. To the
contrary, the claim expressly permits the redundancy control packets to be
provided at a single port for this purpose by reciting “transmitting, via at
least one of the plurality of ports, redundancy control packets for flooding
throughout the Layer 2 network” (emphasis added).
For the foregoing reasons, we find that Guess’s ESRP packets
representing switch status are inherently capable of being used “for flooding
throughout the Layer 2 network,” as required by the claim.

E. Conclusion
The rejection of claim 1 under 35 U.S.C. § 102(e) for anticipation by
Guess is sustained.

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III. DECISION
The Examiner’s decision that claim 1 is unpatentable under 35 U.S.C.
§ 102(e) for anticipation by Guess is affirmed.
AFFIRMED

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For Appellant/Patent Owner:

2nd Reexam Group - Novak Druce + Quigg LLP
1000 Louisiana Street
Fifty-Third Floor
Houston TX 77002

For Third Party Requester:

Finnegan, Henderson, Farabow, Garrett & Dunner, LLP
901 New York Avenue, N.W.
Washington, D.C. 20001-4413

cu