Sathish Kumar. Gnanasekaran et al.

Patent Trials and Appeals Board

Feb 24, 2020

15144541 - (D) (P.T.A.B. Feb. 24, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
15/144,541 05/02/2016 Sathish Kumar Gnanasekaran 12171US02CON 2048
157376 7590 02/24/2020
Xsensus/Broadcom
200 Daingerfield Road, Suite 201
Alexandria, VA 22314
EXAMINER
LINDENBAUM, ALAN LOUIS
ART UNIT PAPER NUMBER
2466
NOTIFICATION DATE DELIVERY MODE
02/24/2020 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
Faith.Baggett@Xsensus.com
Sandy.Miles@Xsensus.com
anaquadocketing@xsensus.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte SATHISH KUMAR GNANASEKARAN, BADRINATH KOLLU,
RICHARD L. HAMMONS, RAMKUMAR VADIVELU,
DAN NORBERT RETTER, JIANQIANG ZHOU,
PONPANDIARAJ RAJARATHINAM, and
DANIEL JI YONG PARK CHUNG
____________

Appeal 2018-003913
Application 15/144,541
Technology Center 2400
____________

Before JASON V. MORGAN, BARBARA A. BENOIT,
and MICHAEL M. BARRY, Administrative Patent Judges.

BARRY, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–12, 14–17, and 19–23, which
constitute all pending claims. Appeal Br. 3.2 We have jurisdiction under
35 U.S.C. § 6(b). We AFFIRM.

1 We use “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42.
Appellant identifies the real party in interest as Brocade Communication
Systems. Appeal Br. 3.
2 We refer to the Specification, filed May 2, 2016 (“Spec.”); Final Office
Action, mailed Mar. 6, 2017 (“Final Act.”); Appeal Brief, filed Sept. 26,
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Introduction
“The present invention relates to the field of network fabric
virtualization and in particular to virtualization of network fabrics through
virtualization of switches.” Spec. ¶ 1. Claim 1 is illustrative:
1. A method of managing a network switch,
comprising:
partitioning a first network switch into a first plurality of
virtual fabrics;
partitioning the first network switch into a first plurality
of logical switches, comprising:
partitioning physical ports of the first network
switch among the first plurality of logical switches, by
assigning each physical port to one logical switch of the
first plurality of logical switches;
mapping each of the physical ports to a logical port
of the one logical switch to which the physical port is
assigned;
assigning each logical switch of the first plurality
of logical switches to a different virtual fabric of the first
plurality of virtual fabrics, wherein each logical switch
can be reassigned to another virtual fabric of the first
plurality of virtual fabrics; and
managing logical ports of each of the first plurality of
logical switches independent of logical ports of each other of
the plurality of the first plurality of logical switches.
Appeal Br. 28 (Claims App’x).

2017 (“Appeal Br.”); Answer, mailed Dec. 29, 2017 (“Ans.”), and the Reply
Brief, filed Feb. 28, 2018 (“Reply Br.”).
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Rejections & References
Claims 1–10, 14–17, and 19–23 stand rejected under 35 U.S.C. § 103
as unpatentable over Dropps (US 2005/0018673 A1; pub. Jan. 27, 2005) and
Jancaitis (US 8,060,630 B1; iss. Nov. 15, 2011). Final Act. 2–25.
Claims 11 and 12 stand rejected under § 103 over Dropps, Jancaitis,
and Riddle (US 2009/0161547 A1; pub. June 25, 2009). Final Act. 25–27.
ANALYSIS
Appellant argues independent claims 1, 7, 15, and 21 together as a
group, designating claim 1 as representative. Appeal Br. 12. Appellant
separately argues independent claim 10 and dependent claims 2, 3, 4 and 6
as a group, and 11 and 12 as a group. Appeal Br. 24–26. Appellant makes
no substantively separate arguments for dependent claims 5, 6, 8, 9, 14, 16,
17, 19, 20, 22, and 23; accordingly, those claims stand or fall with their
respective parent independent claims. 37 C.F.R. § 41.37(c)(1)(iv).
Independent Claim 1
Appellant initially contends the Examiner errs by “interpret[ing] a set
of ports within a switch, which are assigned to a particular virtual fabric, to
be a logical switch” (Final Act. 3), because that interpretation eliminates the
distinction between a virtual fabric and a logical switch. Appeal Br. 12–15.
“On its face, the Examiner’s definition fails, because if the ‘logical switch’
is defined as just ‘a set of ports . . . [which] are assigned to a virtual fabric’,
there is no way to assign the logical switch to a different virtual switch.” Id.
at 13. The Examiner responds by clarifying that
the Examiner interprets that a subset of ports, within a single
physical switch, which are logically grouped together as being
assigned to a same virtual fabric, is a “logical switch.” The
Examiner further interprets that virtual fabric is a set of logical
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switches that are interconnected together. These definitions are
in accordance with Applicant’s Specification. Therefore, in
contrast to Applicant’s assertion, the Examiner’s interpretation
of the claimed terms “logical switch” and “virtual fabric” are
clearly distinguished from each other.
Ans. 30. The Examiner’s interpretations of the terms “logical switch” and
“virtual fabric” are reasonable in light of the Specification and distinguish
the terms. See, e.g., Spec. Fig. 2. Therefore, Appellant’s argument that the
Examiner’s interpretation does not distinguish between a virtual fabric and a
logical switch is unpersuasive.
Appellant’s argument that neither Dropps nor Jancaitis teaches
partitioning a network switch into logical switches is also unpersuasive. See
Appeal Br. 15–17. As the Examiner finds, and we agree, artisans of
ordinary skill would have understood Jancaitis teaches both of the initial two
“partitioning” limitations of claim 1, i.e., “partitioning a first network switch
into a first plurality of virtual fabrics” and “partitioning the first network
switch into a first plurality of logical switches,” as recited. See Ans. 33–34.
Figure 1 of Jancaitis is illustrative and is reproduced below.
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“FIG. 1 illustrates an exemplary [storage area network] including two virtual
fabrics according to one embodiment.” Jancaitis 4:61–62.
As Jancaitis explains, “[i]n one embodiment, creation of a virtual
fabric may be performed by a mechanism that combines virtual switches
connected by an inter-switch link (ISL).” Jancaitis 4:30–32; see also id.
4:33–49. Vis-à-vis the first two partitioning limitations of claim 1, there is
no meaningful difference between the virtual fabrics composed of multiple
virtual switches in Jancaitis and the disclosure of virtual fabrics composed of
multiple logical switches illustrated in Appellant’s Figure 2, which is
reproduced below.
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“Figure 2 is a block diagram illustrating an example of a plurality of logical
switches organized into a plurality of virtual fabrics.” Spec. ¶ 9.
Appellant contends that artisans of ordinary skill would not have
considered the “virtual switches” of Jancaitis to be “logical switches,” as
recited, but instead would have considered a virtual switch in Jancaitis to be
the same thing as a virtual fabric. Appeal Br. 15–17. We disagree. Jancaitis
explains that a virtual switch is a component of a virtual fabric, i.e., not the
same thing as a virtual fabric. See Jancaitis 4:30–49 (explaining that in
addition to virtual switches, a virtual fabric includes various other
components such as “an inter-switch link” and “its own name service,
management service, fabric configuration service, zoning service,” etc.”);
see also id. 2:4–20. Furthermore, Figure 4B of Jancaitis illustrates how
Jancaitis teaches grouping physical switch ports into logical groups (i.e.,
“logical switches”) for assignment into a virtual fabric. Jancaitis Figure 4B
is reproduced below.
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“FIG. 4B illustrates an exemplary display page of the virtual fabric utility for
modifying the membership of a selected existing virtual fabric or a newly
created virtual fabric.” Jancaitis 3:5–8.
The “switch slots” in Jancaitis are switch ports that have been grouped
together to allow them to be treated as a single logical entity and, therefore,
constitute “logical switches,” as recited in claim 1. See Jancaitis 6:12–21,
8:24–10:40. Thus, Jancaitis teaches “partitioning the first network switch
into a first plurality of logical switches,” as recited.
Appellant also contends the Examiner errs because Dropps fails to
teach “assigning each physical port to one logical switch of the first plurality
of logical switches,” as recited. Appeal Br. 17–20. This argument is
unpersuasive because it fails to rebut the rejection’s findings Jancaitis
separately teaches these limitations, which the Examiner reiterates and
supplements in the Answer. See Final Act. 4–5 (citing Jancaitis Fig. 1,
4:30–49, 5:19–24, 9:46–54, 10:29–35, 12:8–43); Ans. 5–7 (concluding that
“[e]ven if, in arguendo, virtual/logical switches were not disclosed in
Dropps, it would have been obvious to a person of ordinary skill in the art, at
the time of the invention, to use virtual/logical switches, as in Jancaitis, in
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the invention of Dropps”). We note Appellant’s Reply Brief includes no
rebuttal of any of the Examiner’s findings with respect to Jancaitis. See
Reply Br. passim.
Appellant further contends the Examiner errs because neither Dropps
nor Jancaitis teaches “mapping each of the physical ports to a logical port of
the one logical switch,” as recited. Appeal Br. 20–21 (arguing “nothing in
Jancaitis recites the use of logical ports and the Examiner does not even
attempt to use Jancaitis for such an argument”). This argument is
inconsistent with the Examiner’s determination that Jancaitis alone teaches
this limitation. See Final Act. 5 (citing Jancaitis 4:30–49, 5:19–24, 12:8–43,
Fig. 1); Ans. 38. Artisans of ordinary skill would have understood that
physical switches have physical ports and logical switches have logical
ports. Because mapping physical ports to a switch slot that is a logical
switch, as taught by Jancaitis, maps those physical ports to the logical ports
of a logical switch, we agree with the Examiner that “mapping each of the
physical ports to a logical port of the one logical switch,” as recited, “reads
on” (Ans. 38) the disclosure of Jancaitis.
Appellant also contends the Examiner errs in relying on Dropps for
teaching “managing logical ports of each of the first plurality of logical
switches independent of logical ports of each other of the plurality of the
first plurality of logical switches,” as recited. Appeal Br. 21–22. The
Examiner responds by finding that, “although not cited as a secondary
reference for this particular limitation in the Examiner’s rejection, Jancaitis
also does not disclose any inter-dependency between the managing of the
ports of separate logical switches.” Ans. 41. We agree with this finding. It
is readily apparent from Jancaitis Figure 4B and related discussion in the
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Specification (see, e.g., Jancaitis 8:24–10:40) that Jancaitis flexibly allows
reassignment of individual logical switches and ports among virtual fabrics,
thereby teaching this disputed limitation.
Accordingly, we sustain the § 103 rejection of claim 1.
Independent Claim 10
In addition to reciting limitations analogous to the steps recited in the
method of claim 1, claim 10 recites limitations for a network switch that
includes “a switch, partitionable into a plurality of logical switches, wherein
each of the plurality of logical switches is a complete and self-contained
network switch.” The Examiner finds Dropps teaches this limitation. Final
Act. 11 (citing Dropps ¶¶ 35, 37, 276). Appellant contends the Examiner
errs because Dropps teaches that “the same lower 16 bits of address are
always assigned ‘for any Virtual Fabric used on a particular port.’” Appeal
Br. 23–24 (citing and quoting Dropps ¶ 218); see also Reply Br. 8. The
Examiner responds, inter alia, by additionally finding Jancaitis also teaches
this disputed limitation. Ans. 42–43 (citing Jancaitis Fig. 1, 4:30–39, 12:8–
43). Appellant does not rebut this finding. See Reply Brief passim.
Appellant otherwise argues error in the rejection of claim 10 for the
same reasons as for claim 1. Appeal Br. 23. Those arguments are
unpersuasive for the reasons discussed above for claim 1. Accordingly, we
sustain the § 103 rejection of claim 10.
Dependent Claim 2
Claim 2 depends from claim 1 and recites “wherein partitioning a first
network switch comprises: dedicating a resource of the first network switch
to a logical switch of the first plurality of logical switches.” The Examiner
finds Dropps teaches the limitations of claim 2 by its disclosure of
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configuring, on a physical switch, an assignment of virtual port
identification numbers to virtual storage area network identification numbers
(VSAN_IDs). Final Act. 6 (citing Dropps ¶ 293). Appellant contends the
Examiner errs “[b]ecause a VSAN_ID is not a logical switch,” and so the
cited disclosure from Dropps “cannot be considered dedicating a resource of
the network switch to a logical switch.” Appeal Br. 24.
The Examiner responds by additionally pointing to, inter alia, Figure
1 of Jancaitis, which, as discussed above for claim 1, shows groups of ports
within a network switch that are partitioned or assigned into subsets of ports
that constitute logical switches. Ans. 43–44. We agree with the Examiner.
An artisan of ordinary skill would have understood that assigning switch
ports to logical switches dedicates resources for those ports to the logical
switches to which they are assigned.
Accordingly, we sustain the § 103 rejection of claim 2.
Claim 3
Claim 3 depends from claim 1 and further requires “isolating data
traffic through a first logical switch of the first plurality of logical switches
from the other logical switches of the first plurality of logical switches.”
The Examiner finds that Dropps teaches this limitation by its disclosure of
routing data frames through a switch. Final Act. 6 (citing Dropps ¶ 46).
Appellant contends this rejection “fails on its face” because “[n]othing in
[Dropps ¶ 46] can remotely be construed as isolating traffic as recited by
claim 3.” Appeal Br. 25.
The Examiner responds that in Dropps, when routing data traffic for a
partitioned subset of ports in a switch (i.e., a logical switch) associated with
a particular virtual storage area network, the traffic routed through those
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ports plainly is isolated from the other ports in the switch. Ans. 44 (citing
Dropps ¶¶ 30, 46). We agree with the Examiner and sustain the § 103
rejection of claim 3.
Dependent Claims 4 and 6
Appellant argues claims 4 and 6 together based on claim 4. Appeal
Br. 25. Claim 4 depends from claim 1 and further requires “defining a link
between a first logical switch of the first plurality of logical switches and a
second switch; and communicating data between the first logical switch and
the second switch.” The Examiner finds that Dropps teaches this limitation
by its disclosure of communication paths and “expansion ports” used to
create an Inter-Switch Link within a virtual fabric. Final Act. 6 (citing
Dropps ¶¶ 29, 73). Appellant contends the Examiner errs, because “[m]erely
pointing to links between physical switches is insufficient to make a prima
facie case that links are defined between a logical switch and a second
switch.” Appeal Br. 25.
The Examiner responds that in Dropps, “switches are linked by ports”
and “data is transported between separate switches through ports that are
linked together.” Ans. 44–45 (additionally citing Dropps ¶¶ 30, 90). In
view of the teaching in Jancaitis that groups of ports within a physical switch
constitute logical switches, as discussed above for claim 1, Appellant does
not persuade us the Examiner errs in finding Dropps teaches the limitations
of claim 4 by its disclosure routing data over inter-switch links.
Accordingly, we sustain the § 103 rejection of claims 4 and 6.
Dependent Claims 11 and 12
Appellant argues claims 11 and 12 together based on claim 11. Claim
11 depends from claim 10 and recites:
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wherein the switch comprises a plurality of network
resources,
wherein each of the plurality of logical switches is
assigned a network resource of the plurality of network
resources,
wherein a first logical switch of the plurality of logical
switches is defined as a default logical switch, and
wherein the default logical switch is assigned any of the
network resources not assigned to any other logical switch.
The Examiner finds Dropps teaches the first two wherein clauses and
Riddle teaches the second two. Final Act. 25–26 (citing Riddle ¶ 115).
Appellant contests only the Examiner’s finding from Riddle. Appeal Br. 26.
In particular, Appellant contends the Examiner errs because Riddle “refers to
partitions, but Riddle uses partitions in a very different way than Dropps and
Jancaitis.” Id. (citing Riddle ¶ 35) (“Such a completely different concept of
‘partition’ has nothing to do with logical switches and would not lend itself
to one of skill in the art when considering how to allocate resources of a
network switch to logical switches.”).
Appellant’s argument is unpersuasive. The Examiner responds with
additional findings and reasoning in the Answer, with which we agree:
Riddle discloses, in paragraph [0115], that packets are assigned
to use a default partition of network resources. A person of
ordinary skill in the art, at the time of the invention, would have
understood that this means that packets are assigned to a default
set of ports and links for routing through a network. Paragraph
[0036] further discusses that partitions are used to divide
network capacity. The Examiner does not look to Riddle to
disclose the claimed “logical switches.” As discussed above,
Dropps and Jancaitis disclose that that a subset of ports, within
a single physical switch, which are logically grouped together
as being assigned to a same virtual fabric, is a logical switch.
Applicant’s claim 1 explicitly recites that the term “partition”
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may be applied to the concept of dividing ports into subsets;
and Applicant’s claim 2 even uses the term “resource of a
network” to refer to a port of a network switch. Accordingly, it
would have been obvious to one of ordinary skill in the art, at
the time of the invention, to use a default policy for resource
[port] assignment to a default partition/subset of ports [logical
switch], in the system of Dropps and Jancaitis. The motivation
would have been to efficiently use . . . all available resources.
Answer 45–46 (brackets in original).
Accordingly, Appellant does not persuade us of error in the rejection
of claims 11 and 12.
CONCLUSION
We affirm the 35 U.S.C. § 103 rejection of claims 1–12, 14–17, and
19–23.
In summary:
Claims
Rejected
35 U.S.C. § References Affirmed Reversed
1–10, 14–17,
19–23
103 Dropps,
Jancaitis
1–10, 14–17,
19–23

11, 12 103 Dropps,
Jancaitis,
Riddle
11, 12
Overall
Outcome
1–12, 14–17,
19–23

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). See 37
C.F.R. § 41.50(f).
AFFIRMED