Ex Parte McDysan

Patent Trial and Appeal Board

Feb 15, 2013

10023043 (P.T.A.B. Feb. 15, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte DAVID E. MCDYSAN
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Appeal 2012-002620
Application 10/023,043
Technology Center 2400
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Before ROBERT E. NAPPI, DEBRA K. STEPHENS, and MICHAEL J.
STRAUSS, Administrative Patent Judges.

NAPPI, Administrative Patent Judge

DECISION ON APPEAL
Appeal 2012-002620
Application 10/023,043

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This is a decision on appeal under 35 U.S.C. § 134(a) of the rejection
of claims 1 through 4, 6, 7, 9 through 12, 14, 16 through 28.

We affirm.
INVENTION
The invention is directed to a communications system using a Virtual
Private Network (VPN), in which traffic outside the VPN is prevented from
degrading the quality of service provided to the VPN. See paragraphs 0012-
0013 of Appellant’s Specification. Claim 1 is representative of the invention
and reproduced below:
1. A network system providing a virtual private network (VPN),
said network system comprising:

one or more egress routers having connections to an access
network including an access link, wherein said one or more egress
routers transmit intra-VPN traffic to a destination host belonging to
the VPN from sources within the VPN within a first access network
logical connection for intra-VPN traffic and all extra-VPN traffic to
the destination host from sources outside the VPN within a second
access network logical connection for extra- VPN traffic, separate
from the first access network logical connection, wherein intra-VPN
traffic is given precedence over extra-VPN traffic by assigning a
higher priority to the first access network logical connection; and

a plurality of ingress routers coupled to the one or more egress
routers for communication utilizing a network-based VPN protocol
that logically partitions intra-VPN and extra-VPN traffic, such that the
intra-VPN traffic and the extra-VPN traffic are logically separated
into different paths, whereby denial of service attacks on said access
link originating from sources outside the VPN are prevented.

Appeal 2012-002620
Application 10/023,043

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REJECTIONS AT ISSUE
The Examiner has rejected claims 1, 3, 4, 6, 7, 9, 11, 12, 14, 16, 18
through 23, and 25 through 28 under 35 U.S.C. § 103(a) as unpatentable
over Seid (U.S.5,768,271, Jun. 16, 1998) and Larson (U.S. 7,188,180 B2,
Mar. 6, 2007 (filed Nov. 7, 2003)). Answer 4-141.
The Examiner has rejected claims 1 through 4, 6, 7, 9 through 12, 14,
16 through 28 under 35 U.S.C. § 103(a) as unpatentable over Appellant’s
Admitted Prior art, Seid and Larson. Answer 14-19.

ISSUE
Rejection based upon Seid and Larson
Appellant argues on pages 8 through 15 of the Appeal Brief and
pages 2 through 8 of the Reply Brief that the Examiner’s rejection under 35
U.S.C. § 103(a) based upon Seid and Larson is in error.2 These arguments
present us with the issues:
a) Did the Examiner err in finding the combination of Seid and
Larson teaches assigning a higher priority to a first access network
logic network logical connection on which intra-VPN traffic is
transmitted as recited in representative claim 1?
b) Did the Examiner err in finding the skilled artisan would combine
the teachings of Seid and Larson?

1 Throughout this opinion we refer to the Examiner’s Answer mailed on
August 04, 2011.
2 Throughout this opinion we refer to Appellant’s Appeal Brief May 17,
2011 and Reply Brief dated September 30, 2011.
Appeal 2012-002620
Application 10/023,043

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Rejection based upon Appellant’s admitted prior art Seid and Larson
Appellant asserts that this rejection is in error for the same reasons
discussed above, and provided additional arguments with respect to claims
26, 27 and 28. Appeal Brief 15-18. These arguments present us with the
following issues:
a) With respect to claim 26, did the Examiner error in finding the
combination of the references teach a WAN physical port contains
a scheduler?
b) With respect to claim 27, did the Examiner error in finding that the
combination of the references teaches a classifier which uses a
table to determine how the packets will be handled by a router?
c) With respect to claim 28, did the Examiner error in finding that the
combination of the references teaches using one of the tunnel
protocols listed in claim 28?
ANALYSIS
Rejection based upon Seid and Larson
We have reviewed Appellant’s arguments in the Briefs, the
Examiner’s rejection and the Examiner’s response to the Appellant’s
arguments. We disagree with Appellant’s conclusion that the Examiner
erred in finding the combination of Seid and Larson teaches assigning a
higher priority to a first access network logic connection on which intra-
VPN traffic is transmitted and that the skilled artisan would combine the
teachings of these two references.
First issue:
Appellant argues that Larson teaches non-VPN packets are sent along
the same path or connection as valid VPN packets, but at a lower priority.
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Brief 10. As such, Appellant concludes that Larson does not teach assigning
a higher priority to a first access network logical connection (with VPN
traffic) than the second access network connection (with non-VPN traffic) as
Larson does not teach the traffic is segregated into two different paths. Brief
11.
The Examiner responds to Appellant’s arguments on pages 19 through
23 of the Answer. In this response the Examiner considers the claimed
logical paths, when interpreted in light of the specification, to include logical
paths on the same physical link. Answer 23 (citing Specification figure 4,
and pages 11-12). We concur, with the Examiner’s finding and note that
Appellant’s figures 5, 6A and the description on pages 12 through 16 of the
Specification, also support this claim interpretation.
Based upon this interpretation, the Examiner considers Larson’s
single link to correspond to the physical link and not the claimed logical
link. Answer 22-23. The Examiner finds that it is well known to partition
traffic over a physical link to a plurality of logical connections. Answer 21,
22, and 24. We concur with this finding by the Examiner, as it is supported
by the disclosure of Seid.3
Seid discusses that VPN traffic travels over virtual paths (VP) and that
multiple VPs can be multiplexed onto a physical path. See figure 7, col. 5,
ll. 43-46, col. 6, ll. 5-8. Seid, also teaches that non-VPN traffic, Frame

3 We note that Appellant, in the Reply Brief, has objected to the Examiner’s
citations to references which are not identified in the statement of the
rejection (e.g. Erwin and DOD Standard Transmission Protocol references
which the Examiner alleges to have cited earlier in prosecution). Reply
Brief 3, 5. We did not review or consider these documents in deciding this
appeal.
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Relay (FR) traffic, also travels over the same physical link in separate
pseudo -VPs. Seid, col.12, l. 66- Col. 13, l. 5. Further, as depicted in figure
7 and discussed in columns 8 and 9, the VPN communication VPs are
assigned to different ports on the same physical link as the non-VPN traffic
(e.g. link line 25-39).
Thus, we concur with the Examiner’s finding that the skilled artisan
would understand that Larson’s teaching of priority, which is discussed with
respect to a physical link, would apply to a physical link that is partitioned
into different logical paths (note Seid does not place VPN and non-VPN on
the same VP, thus assigning a priority to a VPN connection is applying a
priority to the VP and port that carries the VPN traffic). As such, we do not
find that the Examiner erred in finding that the combination of Seid and
Larson teaches assigning a higher priority to a first access network logic
connection on which intra-VPN traffic is transmitted.

Second issue:
Appellant argues there is no indication that Larson teaches VPN
traffic and non-VPN traffic are logically separated into different paths. Brief
13. Further, Appellant argues that the ability to separate these paths does not
necessarily suggest why a person skilled in the art would separate the paths.
Brief, 14. Accordingly, Appellant asserts that the suggestion to use
priorities over different paths exists only in Appellant’s disclosure and the
Examiner’s finding that the skilled artisan would combine the references is
hindsight. Brief, 14.
The Examiner, in response, finds that the skilled artisan would be lead
to the combination by Larson’s teaching that the use of prioritization helps
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prevent a denial of service attacks. Answer 25.4 We concur, with this
conclusion by the Examiner as it is supported by evidence of record which
shows that the combination of Seid and Larson is nothing more than using
known methods to perform their known function. Accordingly, we are not
persuaded the Examiner erred in combining the teachings of Seid and
Larson.
As Appellant’s arguments directed to the first two issues are the only
arguments presented with respect to both rejections of claims1, 3, 4, 6, 7, 9,
11, 12, 14, 16, 18 through 23, and 25 under 35 U.S.C. § 103(a), we sustain
the Examiner’s rejections of these claims.

Rejection of claim 26
Appellant argues on pages 15 and 16 of the Appeal Brief, that none of
AAPA, Seid, and Larson discloses a scheduler that multiplexes packets as
claimed. The Examiner finds that Seid teaches that the routers handling
virtual paths are required to multiplex packers from VPN and non-VPN onto
one physical connection. Answer 26. We concur, as discussed above we
find that Seid teaches both VPN and non-VPN traffic travels over the same
physical connection. Further, column 6 and the discussion of figure 7 in
column 8 and 9 provide support for the Examiner’s finding that Seid
multiplexes the traffic as claimed. Accordingly, we sustain the Examiner’s
rejection of claim 26.

4 The Examiner also finds that Seid, by not discarding VPN traffic as readily
as non-VPN traffic, shows that Seid implies a prioritization. We disagree
with this alternative rationale as we do not find that Seid discriminates based
upon whether the traffic is VPN or not when discarding traffic.
Footnote continued on next page.
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Rejection of claim 27
Appellant argues on page 16 of the Appeal Brief that none of AAPA,
Seid, and Larson teaches a classifier which uses a table to determine how the
packets will be handled by a router. The Examiner cites to a table in column
8, and a discussion in column 9, to show that Seid teaches this limitation.
Answer 27. We concur with the Examiner as we find that the cited passages
Seid provide ample evidence to show that Seid teaches this limitation.
Accordingly, we sustain the Examiner’s rejection of claim 27.

Rejection of claim 28
Appellant argues on pages 16 and 17 of the Appeal Brief that none of
AAPA, Seid, and Larson teaches using one of the tunnel protocols listed in
claim 28. The Examiner responds on pages 28 and 29 of the Answer by
finding that claim 28 merely cites well known pre-existing technologies.
The Examiner cites to Erwin and Larson to support this limitation. We
concur with the Examiner that Larson teaches use of one of the protocols
recited in claim 28 (IPSEC, discussed in column 43, l. 21).5 Accordingly,
we sustain the Examiner’s rejection of claim 28.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

5 We note, Appellant, in the Reply Brief, objected to the use of the Erwin
reference. Reply Brief 10. As discussed supra, we did not review or
consider these documents in deciding this appeal.

Appeal 2012-002620
Application 10/023,043

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ORDER
The decision of the Examiner to reject claims 1 through 4, 6, 7, 9
through 12, 14, and 16 through 28 is affirmed.

AFFIRMED

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