Ex Parte Doshi et al

Board of Patent Appeals and Interferences

Mar 31, 2010

10737995 (B.P.A.I. Mar. 31, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte SACHIN DOSHI, SURYAKANT MAHARANA, and
PRAVEEN K. SUBRAHMANIAN
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Appeal 2009-006971
Application 10/737,995
Technology Center 2400
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Decided: March 31, 2010
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Before ROBERT E. NAPPI, KENNETH W. HAIRSTON, and
MARC S. HOFF, Administrative Patent Judges.

HAIRSTON, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. §§ 6(b) and 134(a) from the final
rejection of claims 1 to 26.
We reverse.

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STATEMENT OF THE CASE
The disclosed invention relates to a method, apparatus, and system for
managing congestion in a data processing and communication using data
packets (Spec. ¶ [0001]). Data packets are sent between switches or nodes
in a network, each switch having multiple ports (Spec. ¶ [0002]). The
switches may be connected together using high-bandwidth ports called
“‘stacked ports’” (Spec. ¶ [0002]). Appellants recognize the existence of
“pause frame” technology to reduce congestion, and that a better traffic flow
management method is needed (Spec. ¶ [0003]). Appellants’ disclosed and
claimed invention includes sending a data packet from a first switch to a
second switch through a stacked port, and using the packet to identify a
congesting port of second switch as a source of the congestion of a port of
the first switch (Abstract; claims 1, 8, 15, 19, and 24).
Claim 1 is representative of the claimed invention, and reads as
follows:
1. A method, comprising:
sending a packet from a first switch to a second switch by way of a
stacked port, the packet identifying a congesting port included in the second
switch as a source of congestion with respect to a congested port included in
the first switch.
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Chin US 6,298,061 B1 Oct. 2, 2001
Hill US 2004/0032827 A1 Feb. 19, 2004
(filed Aug. 15, 2002)
Ahlfors US 7,061,868 B1 Jun. 13, 2006
(filed Oct. 25, 2000)

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(i) The Examiner rejected claims 1 to 3, 5, 6, 8, 9, 11, 13 to 19, 21 to
24, and 26 under 35 U.S.C. § 102(e) based upon the teachings of Ahlfors.
(ii) The Examiner rejected claims 4, 10, and 25 under 35 U.S.C.
§ 103(a) based upon the teachings of Ahlfors and Chin.
(iii) The Examiner rejected claims 7, 12, and 20 under 35 U.S.C.
§ 103(a) based upon the teachings of Ahlfors and Hill.
Appellants argue, inter alia, (Br. 9-12) that the applied reference to
Ahlfors fails to teach or suggest a packet that identifies a congesting port of
the second switch, as set forth in claims 1, 8, 15, 19, and 24. More
specifically, Appellants argue (Br. 10, 11) that instead of identifying a port
in the second switch that is the source of congestion as in the claimed
invention, Ahlfors at best discloses a PAUSE command containing a
destination address of the second switch, and not a port. Appellants contend
(Br. 12) that Ahlfors identifies a port 4 of the first switch 1, and neither
inherently nor explicitly discloses a packet identifying a congesting port of
the second switch as claimed.
With regard to the anticipation rejection of claims 1 to 3, 5, 6, 8, 9, 11,
13 to 19, 21 to 24, and 26, the Examiner relies upon Ahlfors as disclosing
the feature recited in claims 1, 8, 15, 19, and 24 of sending a packet
identifying a congesting port included in the second switch as a source of
congestion with respect to a congested port included in the first switch from
a first switch to a second switch by way of a stacked port (Ans. 4-9).
Specifically, the Examiner cites the Abstract; column 1, lines 45 to 67;
column 2, lines 1 to 6, 35 to 38, and 47 to 63; and Figure 1 of Ahlfors as
disclosing the recited feature of a data packet for identifying a congesting
port in the second switch (Ans. 5). The Examiner contends (Ans. 5) that
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assuming a scenario that sender 2 in Figure 1 of Ahlfors “is a switch with a
single port,” there would only be one source of congestion and that would be
switch 2, making it clear that any destination information in the packet
regarding the second switch must identify the port of that switch. The
Examiner then contends that “switch two must also have a stacked port”
(Ans. 5), and “there is no need to specifically determine the congesting port
of the sender (2)” (Ans. 15). These latter statements contradict the
assumption of the former statement, that the scenario of one port for switch
two is being applied in the rejection.
Ahlfors discloses (Figure 1; Abstract; and column 2, lines 1 to 6 and
25 to 63) a data flow management system and method for transmitting data
packets from a first switch 1 to a second switch 2. Although Ahlfors
discloses transmitting a data packet that identifies a congested port 4 of the
first switch (i.e., the sending switch 1), and teaches the concept of switches
having stacked ports (input ports 4 in Figure 1; column 2, lines 47 to 50),
Ahlfors is silent as to identifying the port of the second switch with the data
packet sent from the first switch to the second switch over a stacked port
arrangement as set forth in the claims on appeal. Ahlfors discloses that
sender 2 may be a switch with stacked (i.e., plural) ports as discussed by
Ahlfors with respect to switch 1 (column 2, line 35), but is silent as to
identifying a particular port in the second switch that causes congestion.
Based on our finding with respect to Ahlfors, we agree with
Appellants (Br. 9-12) that Ahlfors lacks the packet identifying limitation of
the claims, and instead operates to control data flow congestion between
switches by sending pause frames which only identify a congested port of
the sending, or first, switch. This feature is simply missing from Ahlfors,
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and the Examiner has not shown that such a step is inherent in the operation
of Ahlfors.
Thus, with respect to the method, computer-readable medium,
apparatus, and system recited in independent claims 1, 8, 15, 19, and 24,
Ahlfors fails to teach the limitation common to each of these claims of a
packet identifying a congesting port included in the second switch as a
source of congestion with respect to a congested port included in the first
switch. It follows that the Examiner has not established anticipation because
Ahlfors does not disclose each and every limitation of the claimed invention
set forth in independent claims 1, 8, 15, 19, and 24, or the invention set forth
in claims 2, 3, 5, 6, 9, 11, 13, 14, 16 to 18, 21 to 23, and 26, which depend
respectively therefrom. Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342,
1347 (Fed. Cir. 1999); In re Paulsen, 30 F.3d 1475, 1478-79 (Fed. Cir.
1994).
The Examiner has not established a prima facie case of obviousness of
the claimed subject matter set forth in dependent claims 4, 7, 10, 12, 20, and
25 since the teachings of Chin and Hill fail to cure the noted shortcomings of
Ahlfors as set forth above. See In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir.
1992).
The anticipation rejection of claims 1 to 3, 5, 6, 8, 9, 11, 13 to 19, 21
to 24, and 26 is not sustained because Ahlfors does not teach sending a
packet from a first switch to a second switch via a stacked port, where that
packet identifies a congesting port included in the second switch as a source
of congestion with respect to a congested port included in the first switch.
The obviousness rejections of (i) claims 4, 10, and 25 over Ahlfors and
Chin, and (ii) claims 7, 12, and 20 over Ahlfors and Hill are not sustained
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because the Examiner’s articulated reasoning concerning the teachings of
Ahlfors, Chin, and Hill do not support a legal conclusion of obviousness
(KSR Int’l., v. Teleflex, Inc., 550 U.S. 398, 418 (2007)).

CONCLUSIONS
The Examiner erred in rejecting claims 1 to 3, 5, 6, 8, 9, 11, 13 to 19,
21 to 24, and 26 under 35 U.S.C. §102(e).
The Examiner erred in rejecting claims 4, 7, 10, 12, 20, and 25 under
35 U.S.C. §103(a).

ORDER
The Examiner’s decision rejecting claims 1 to 26 is reversed.

REVERSED

KIS

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