Nicira, Inc.

Patent Trials and Appeals Board

Sep 3, 2021

2020000818 (P.T.A.B. Sep. 3, 2021)

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.
15/012,718 02/01/2016 Igor Ganichev N040.C1 (NCRA.P0129C) 5454
109858 7590 09/03/2021
ADELI LLP
P.O. Box 516
Pacific Palisades, CA 90272
EXAMINER
SEFCHECK, GREGORY B
ART UNIT PAPER NUMBER
2477
NOTIFICATION DATE DELIVERY MODE
09/03/2021 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):
ipadmin@vmware.com
mail@adelillp.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte IGOR GANICHEV, PANKAJ THAKKAR, PAUL FAZZONE,
TEEMU KOPONEN, and DANIEL J. WENDLANDT
Appeal 2020-000818
Application 15/012,718
Technology Center 2400
Before JUSTIN BUSCH, JOYCE CRAIG, and STEVEN M. AMUNDSON,
Administrative Patent Judges.
BUSCH, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 30–32, 34–36, and 38–51. We have
jurisdiction under 35 U.S.C. § 6(b).
We reverse.

1 We use the term Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42(a) (2018). Appellant identifies the real party in interest as Nicira, Inc.
Appeal Br. 2.
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Application 15/012,718
2
CLAIMED SUBJECT MATTER
Appellant’s invention generally relates to a method for tracing the
physical path a packet flow takes in a virtual network that uses tunnels to
send packets from a logical source to a logical destination. Spec. ¶¶ 2–8. To
accomplish the trace, a network controller generates a packet with the
corresponding source and destination addresses, inserts the packet into the
managed forwarding element (MFE) through which the source address
connects to the logical network, and receives observations from the MFEs
that receive the trace packet. Spec. ¶ 3. Notwithstanding the virtual
network’s use of tunnels, the systems and methods may determine the path
taken through the physical network used by the virtual network because each
managed forwarding element through which the trace packet passes sends a
message to the network controller indicating the operations performed on the
packet—i.e., forwarding the packet through a tunnel or delivering the packet
to the logical port associated with the destination address. Spec. ¶¶ 3–6, 33.
Claim 30 is exemplary and reads as follows:
30. For a network controller that manages a plurality of managed
forwarding elements (MFEs) operating at a plurality of hosts, a method
comprising:
at the network controller, receiving a request to trace a specified
packet having a particular source on a logical forwarding element
implemented by the MFEs;
at the network controller, defining data for a packet according to
the packet specification, the data defined for the packet comprising an
indicator that the packet is for a trace operation;
inserting the defined packet data into a MFE associated with the
particular source in order for the MFE to process the packet data as
though receiving a packet from the particular source; and
receiving a plurality of messages at the network controller, sent
to the network controller from a set of at least two of the MFEs that
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Application 15/012,718
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process the packet data, regarding operations performed on the packet
data by the MFEs.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Breslau US 7,180,856 B1 Feb. 20, 2007
Nakil US 8,750,288 B2 June 10, 2014
REJECTION
Claims 30–32, 34–36, and 38–51 stand rejected under 35 U.S.C. § 103
as obvious over Nakil and Breslau. Non-Final Act. 2–5.
ANALYSIS
The Examiner finds the combination of Nakil and Breslau teaches or
suggests every limitation recited in independent claim 30. Non-Final
Act. 2–4. Generally, the Examiner finds Nakil teaches every limitation
recited in independent claim 30, except Nakil’s VNC receives a message
from only a single MFE and “does not expressly show a plurality of
messages from a set of destination MFEs.” Non-Final Act. 3; see also
Ans. 7 (finding that Nakil is “directed to the same type of ‘trace’ operation
through multiple forwarding elements and reporting of this trace to a
network controller”).
More specifically, the Examiner finds Nakil’s virtual network
controller (VNC) 22 teaches the claimed network controller and Nakil’s
server 12A is equivalent to one of the recited MFEs. Non-Final Act. 2–3
(citing Nakil 2:40–82, 5:46–64, 7:1–5, 8:23–34, 8:55–57, 12:38–55, 17:37–
18:7, 18:13–28, Figs. 1, 2, 4–6). The Examiner further finds that Nakil’s
switches 16A–16N and 18A–18M teach the recited MFEs and that these
switches send ICMP Time Exceeded messages to server 12A. Non-Final
Act. 2–3.
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The Examiner finds server 12A then sends a single message (response
29B) to VNC 22 that includes a list identifying the physical route taken by
the packet flow. Non-Final Act. 3; see also Ans. 7 (reiterating that “Nakil
only provides a single message to the network controller”), 9 (finding
Nakil’s “single message sent to the network controller includes collected,
aggregated responses from multiple servers and switches (equated to the
MFEs, as claimed) along the traced route” and, therefore, Nakil suggests
multiple messages but not that the multiple messages are sent from at least
two MFEs)). The Examiner finds Breslau, however, teaches “receiving a
plurality of messages from a set of destination MFEs.” Non-Final Act. 3
(citing Breslau 8:38–9:21, Fig. 2); see also Ans. 7–10 (finding Breslau cures
this deficiency by teaching “that each of multiple routers may individually
respond to a monitor query,” and explaining that Breslau’s particular
teachings regarding packet counts are not relied on in the rejection).
The Examiner determines it would have been obvious to modify Nakil
with Breslau’s teaching to receive a plurality of messages from a set of
destinations in order to “display[] the status for each identified router and
indicating an alarm per router, where appropriate, based on predetermined
threshold values for each router.” Non-Final Act. 3–4; see Ans. 10
(reiterating the alleged motivation).
Appellant argues Nakil’s single message that server 12A sends to
VNC 22, which the Examiner cites as teaching a network controller
receiving a message from an MFE, is merely a list of physical addresses that
server 12A generates using Internet Control Message Protocol (ICMP) time
exceeded messages responsive to trace packets that server 12A generates
and transmits. Appeal Br. 7–8; Reply Br. 3. Appellant argues that, each
switch either processes (i.e., forwards) the trace packet received from the
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Application 15/012,718
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server or discards the packet and sends a Time Exceeded message to the
server (not the network controller), but the switches do not both process a
packet and send a message. Reply Br. 4.
Appellant argues Breslau’s cited disclosures do not teaching receiving
a plurality of messages from a set of destination MFEs because Breslau’s
messages merely provide packet counts sent in response to a packet count
query multicast message sent to a set of identified routers. Appeal Br. 9
(citing Breslau 8:10–21, 8:38–55); Reply Br. 3. Appellant argues that,
absent Breslau’s teaching of sending packet counts in response to packet
count queries from the monitor, which the Examiner finds is not relevant to
the rejection, Breslau does not teach any reason for the routers to send a
message to the monitor. Reply Br. 5. Appellant further asserts that, without
Breslau’s teaching of packet counts, Breslau merely teaches “generally
receiving data from switches,” rather than what is claimed. Reply Br. 5.
Finally, Appellant argues the Examiner’s rationale is insufficient
because the rationale merely identifies an aspect of Breslau’s invention that
is unrelated to Nakil and that there is no logical way or reason to combine
Breslau’s cited teachings with Nakil’s cited teachings. Appeal Br. 11–12.
Thus, Appellant contends the proposed combination is merely the result of
piecemeal analysis reliant only upon impermissible hindsight to arrive at the
claimed features. Appeal Br. 12.
Nakil discloses systems and methods for determining a physical
network path in a virtualized network taken by packets in a network packet
flow. Nakil, Abstract. To do this, Nakil discloses that VNC 22 generates
and sends request 29A to server 12A’s VN agent 35A to determine a
physical network path traversed by packets of a particular packet flow that
server 12A has allocated. Nakil 6:23–26. Server 12A’s VN agent 35A
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Application 15/012,718
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sends the request to server 12A’s flow trace module (FTM) 48 in virtual
switch 30A, which builds flow trace packet 45A with a time-to-live (TTL)
set to 1 and a field of the packet header set to indicate that the packet is a
flow trace packet. Nakil 6:26–39, 9:39–41, 9:44–54.
The first element in the physical network path (TOR switch 16A)
receives packet 45A, decrements the TTL from 1 to 0 and, because the TTL
is now 0, returns ICMP (Internet Control Message Protocol) Time Exceeded
message 47A to FTM 48. Nakil 6:35–48, 9:54–61. ICMP time Exceeded
message 47A “has a source IP address of TOR switch 16A and a destination
IP address that is the source IP address of flow trace packet 45A (e.g., the IP
address of virtual machine 36 VM1).” Nakil 9:62–10:3. Nakil creates and
sends second packet 45B with a TTL value of 2 to TOR switch 16A, which
decrements the TTL value to 1 and forwards the packet to the second
element in the physical network path (e.g., chassis switch 18M), which
decrements the TTL value to 0 and, accordingly, returns ICMP Time
Exceeded message 47B to server 12A. Nakil 10:6–16.
Nakil’s server 12A continues generating new trace flow packets until
it receives a confirmation message (e.g., an ICMP Echo Reply message)
indicating that the trace flow packet reached its ultimate destination. Nakil
10:20–25. As a result, server 12A receives an ICMP Time Exceeded
message from each physical network element in the packet flow’s physical
network path. Nakil 10:25–28. When server 12A’s FTM 48 receives a
confirmation message, it builds a list of the physical network elements the
packet flow traversed by aggregating the source network addresses in the
ICMP Time Exceeded messages and sends the list to VCN 22 in reply 29B.
Nakil 10:28–32.
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Application 15/012,718
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Breslau generally relates to systems and methods for monitoring
traffic in a multicast network. Breslau, Abstract. Breslau’s disclosures cited
by the Examiner teach a monitor querying identified routers “to determine
packet counts for each specified multicast session.” Breslau 8:10–12. By
determining whether a particular router’s packet count in a response is
significantly greater than the packet count in the router’s most recent prior
response, the monitor may determine whether there is a problem with that
particular router—i.e., whether that “router is no longer receiving data
packets.” Breslau 8:10–56.
As the Examiner acknowledges, see Final Act. 3; Ans. 7, other than
server 12A, Nakil’s switches 16, 18 do not send messages to VNC 22, and
Nakil’s server 12A sends only one message (i.e., response 29B) to VNC 22.
The Examiner does not find either that Nakil’s server 12A teaches the
recited network controller2 or that Nakil’s MFEs send the recited messages
to VNC 22. The Examiner’s finding that the single message, which Nakil’s
server 12a sends to VNC 22, includes aggregated responses from multiple
switches and, therefore, suggests multiple messages, Ans. 7, 9, does not
demonstrate a teaching of the specific claim language requiring the network
controller to receive a plurality of messages from multiple MFEs that

2 It appears that Nakil’s server 12A performs at least some of the functions
that claim 30’s recited network controller performs. For example, Nakil’s
server 12A receives message 29A, which is a request to determine a physical
network path traversed by packets in a particular packet flow, defines and
generates a trace packet including a trace packet indicator, sends the packet
via a virtual network agent, and receives a plurality of messages from
switches 16, 18, including ICMP Time Exceeded messages and one ICMP
Echo Reply message. Nakil 6:23–65, 7:52–65, 9:39–10:38, Figs. 1, 6, 7.
However, no rejection based on a finding that Nakil’s server 12A teaches or
suggests the recited network controller is before us.
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Application 15/012,718
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process the packet data. The Examiner agrees but finds Breslau cures these
deficiencies. See Final Act. 3; Ans. 7, 10 (“Thus, Breslau is introduced to
illustrate that each of multiple routers may individually respond to a monitor
query.”)
However, we disagree with the Examiner that Breslau remedies this
acknowledged deficiency in Nakil. As Appellant argues, Appeal Br. 9;
Reply Br. 3, Breslau relates to a monitor that sends requests to identified
routers and receives responses. It is true that Breslau teaches routers
responding to a monitor query. See Breslau 8:10–55. Yet it is unclear how
and why a person of ordinary skill in the art would have incorporated the
teaching of routers responding to queries from a monitor into Nakil’s packet
trace systems and methods to arrive at the recited feature that a network
controller receives messages from multiple MFEs that process the packet
data of a trace packet.
As already discussed, Breslau teaches routers sending messages to a
monitor only directly in response to the monitor sending a request to the
routers. Even accepting that Breslau’s monitor and routers are similar to
Nakil’s VNC 22 and switches 16, 18, respectively, it is unclear how
combining these teachings with Nakil’s packet trace systems and methods
would result in sending a message to the network controller from multiple
MFEs that processed the trace packet. At most, the proposed combination
would suggest that each of Nakil’s switches 16, 18 could respond to a query
from VNC 22, but Nakil does not send requests from VNC 22 to switches
16, 18. To the extent the Examiner’s proposed combination results in server
12A sending a query to each of switches 16, 18 and each of switches 16, 18
responding to server 12A, that does not remedy Nakil’s admitted deficiency
that VNC 22 receives only a single message from server 12A. Accordingly,
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constrained by the record before us, we cannot sustain the Examiner’s
rejection of independent claim 30, independent claim 41, which recites
limitations having commensurate scope, and dependent claims 31, 32, 34–
36, 38–40, and 42–51, which ultimately depend from and incorporate the
limitations of one of independent claims 30 and 41.
Because this deficiency is dispositive with respect to every pending
claim, we do not address other issues raised by Appellant related to these
claims. See Beloit Corp. v. Valmet Oy, 742 F.2d 1421, 1423 (Fed. Cir.
1984) (finding an administrative agency is at liberty to reach a decision
based on “a single dispositive issue”).
We reverse the rejection of claims 30–32, 34–36, and 38–51 under
35 U.S.C. § 103.
DECISION SUMMARY
Claims Rejected 35 U.S.C. § References Affirmed Reversed
30–32, 34–36,
38–51
103 Nakil, Breslau 30–32, 34–36,
38–51

REVERSED