Ex Parte Shankar

Board of Patent Appeals and Interferences

Feb 26, 2010

10247298 (B.P.A.I. Feb. 26, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte LAXMAN SHANKAR
____________________

Appeal 2009-005938
Application 10/247,2981
Technology Center 2400
____________________

Decided: February 26, 2010
____________________

Before KENNETH W. HAIRSTON, MARC S. HOFF,
and CARL W. WHITEHEAD, JR., Administrative Patent Judges.

HOFF, Administrative Patent Judge.

DECISION ON APPEAL

1 The real party in interest is Broadcom Corporation.
Appeal 2009-005938
Application 10/247,298
STATEMENT OF THE CASE
Appellant appeals under 35 U.S.C. § 134(a) from a Final Rejection of
claims 1-18. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.
Appellant’s invention concerns a method of controlling data flow in a
network device, wherein an IP multicast group number is determined from a
received incoming data packet. Using the IP multicast group number as an
index, an IP multicast group vector may be queried from an IP multicast
group vector table. Using the IP multicast group vector as an index, a series
of virtual local area network (VLAN) identifiers (IDs) are obtained from a
VLAN ID table corresponding to bit positions defined by the IP multicast
group vector. As a result, the data packet is replicated and forwarded onto
each VLAN ID of the series of VLAN IDs corresponding to each bit in the
IP multicast group vector (Abstract).
Claim 1 is exemplary:
1. A method of controlling data flow in a network device, said method
comprising:
receiving an incoming data packet;
determining an IP multicast group number from said incoming data
packet;
obtaining an IP multicast group vector from an IP multicast group
vector table using said IP multicast group number;
obtaining at least one virtual local area network identifier from a
virtual local area network identifier table, the at least one virtual local area
network identifier corresponding to at least one bit position defined in the IP
multicast group vector; and
replicating and forwarding said data packet onto each virtual local
area network corresponding to each virtual local area network identifier of
said at least one virtual local area network identifier.

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The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Gleeson US 5,595,989 Sep. 28, 1999
Prasad US 6,049,542 Apr. 11, 2000
Claims 1-18 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Prasad in view of Gleeson.
Rather than repeat the arguments of Appellant or the Examiner, we
make reference to the Appeal Brief (filed December 21, 2007), the Reply
Brief (filed April 24, 2008), and the Examiner’s Answer (mailed April 1,
2008) for their respective details.

ISSUE
Appellant contends that Prasad and Gleeson, combined or separately,
fail to teach, disclose, or suggest "at least a virtual local area network
identifier corresponding to at least one bit position defined in an IP multicast
group vector," as recited in claim 1 (App Br.16 ). Appellant contends that
there is no motivation or disclosure for how to combine the VLAN of
Gleeson with Prasad's scalable fabric architecture providing the capability of
being incrementally upgraded to a higher capacity (App. Br. 15). Appellant
further contends that there would be no reasonable expectation of success
when the references are combined according to the Examiner’s findings
(App. Br. 15).
The Examiner concludes that it would have been obvious to one of
ordinary skill in the art at the time of the invention to have the multicast
group of Prasad to include diverse VLAN designations as outlined in
Gleeson to “increase the flexibility of the network” (Ans. 4). Further, the
Examiner concludes that it would have been obvious to one of ordinary skill
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in the art at the time of the invention to obtain at least one VLAN identifier
from a VLAN identifier table corresponding to at least one bit position
defined in the multicast group vector such that the VLAN identifier could be
placed in the packet before forwarding (Ans. 4).
Appellant’s contentions present us with the following issue:
Did Appellant show that the Examiner erred in finding that the
combination of Prasad and Gleeson discloses a method of controlling data
flow in a network device that includes a VLAN identifier table including "at
least a virtual local area network identifier corresponding to at least one bit
position defined in an IP multicast group vector”?

FINDINGS OF FACT
The following Findings of Fact (FF) are shown by a preponderance of
the evidence.
The Invention
1. According to Appellant, the invention concerns a method of
controlling data flow in a network device, wherein an IP multicast group
number is determined from a received incoming data packet. Using the IP
multicast group number as an index, an IP multicast group vector may be
queried from an IP multicast group vector table. Using the IP multicast
group vector as an index, a series of virtual local area network (VLAN)
identifiers (IDs) are obtained from a VLAN ID table corresponding to bit
positions defined by the IP multicast group vector. As a result, the data
packet is replicated and forwarded onto each VLAN ID of the series of
VLAN IDs corresponding to each bit in the IP multicast group vector
(Abstract).
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2. A prior art implementation for replication and distribution of IP
multicast packets over a diverse group of VLAN designations is
accomplished by including the VLAN IDs inserted into the VLAN tag of
tagged Ethernet frames that are sent out over the egress port of the VLANs
represented by each VLAN ID included in a VLAN ID table that is indexed
by the IP multicast group number (Spec. paras [0023] and [0024]).
Prasad
3. Prasad discloses a packet switching architecture implemented
within LANs known as a scalable switch fabric architecture that includes
multicast cells that are forwarded by examining a Multicast Groups Table
maintained in each switching element in each switching stage. The relevant
entry in the Multicast Groups Table is indexed by a multicast group number
carried in the extended header of each cell. The multicast group number is
placed in the header of a cell before the cell arrives at the fabric (Fig. 2, col.
4, ll. 57-63).
4. Prasad discloses that the Multicast Groups Table generates a bit
vector having the same number of bits as there are outputs in the switch
element. For each "1" in the bit vector, a copy of the cell is transmitted from
the corresponding output (col. 5, ll. 61-65).
5. Prasad discloses that the header information of a packet
contains routing tags and/or multi-cast group numbers that are used to
configure switches in the ATM network path to deliver the cells to the final
destination (col. 1, ll. 47-50).
Gleeson
6. Gleeson discloses that in an effort to improve the flexibility of
network 100, it is desirable to support the transmission of message to a
predefined group of entities, including entities of diverse VLAN
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designations, wherein such a message is known as a group multicast
message (col. 3, ll. 44-47).
7. Gleeson discloses that a router 123 creates a subscription list
associating each group multicast address with a list of VLANs on which at
least one subscribing entity resides. Thereafter, entity 17 uses this group
destination address to send multicast messages to the various VLAN
subscribing entities (col. 3, l. 65- col. 4, l. 3).
8. Gleeson discloses in an effort to deliver multicast messages to
subscribers of diverse VLAN designations, router 123 must generate a
separate message for each of the remaining VLAN designations; wherein
four identical copies of the message, each with a different VLAN
designation attached thereto (i.e., blue, green, yellow, and orange) are
generated. Each copy is then sent out on the network 100 by router 123 (col.
5, ll. 6-11).
9. Gleeson discloses that various LANs may be grouped together
to form VLANs (col. 2, ll. 36-37) and that a VLAN arrangement enables any
number of physical ports of a particular switch to be associated with any
number of network groups within the switch, wherein the VLAN
arrangement virtually associates the port with a particular VLAN
designation (col. 1, ll. 56-64).
10. Gleeson discloses a switch or hub for a segmented virtual local
area network with shared media access that associates VLAN designations
with at least one internal port and further associates those VLAN
designations with messages transmitted from any of the ports to which the
VLAN designation has been assigned. The VLAN designation for each
internal port is stored in a memory portion of the switch such that every time
a message is received by the switch on an internal port the VLAN
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designation of that port is associated with the message. Association is
accomplished by a flow processing element which looks up the VLAN
designation in a memory based on the internal port where the message
originated (col. 1, l. 64-col. 2, l. 9).

PRINCIPLES OF LAW
On the issue of obviousness pursuant to 35 U.S.C § 103, the Supreme
Court has stated that “the obviousness analysis cannot be confined by a
formalistic conception of the words teaching, suggestion, and motivation.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 419 (2007). Further, the Court
stated “[t]he combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
Id. at 416. “One of the ways in which a patent’s subject matter can be
proved obvious is by noting that there existed at the time of the invention a
known problem for which there was an obvious solution encompassed by the
patent’s claims.” Id. at 419-420.
The determination of obviousness must consider, inter alia, whether a
person of ordinary skill in the art would have been motivated to combine the
prior art to achieve the claimed invention and whether there would have
been a reasonable expectation of success in doing so. Brown & Williamson
Tobacco Corp. v. Philip Morris Inc., 229 F.3d 1120, 1125 (Fed. Cir. 2000).
Where the teachings of two or more prior art references conflict, the
Examiner must weigh the power of each reference to suggest solutions to
one of ordinary skill in the art, considering the degree to which one
reference might accurately discredit another. In re Young, 927 F.2d 588,
591 (Fed. Cir. 1991). If the proposed modification would render the prior
art invention being modified unsatisfactory for its intended purpose, then
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there is no suggestion or motivation to make the proposed modification. In
re Gordon, 733 F.2d 900, 902 (Fed. Cir. 1984). Further, our reviewing court
has held that “[a] reference may be said to teach away when a person of
ordinary skill, upon reading the reference, would be discouraged from
following the path set out in the reference, or would be led in a direction
divergent from the path that was taken by the applicant.” In re Gurley, 27
F.3d 551, 553 (Fed. Cir. 1994); Para-Ordnance Mfg., Inc. v. SGS Importers
Int’l., Inc., 73 F.3d 1085, 1090 (Fed. Cir. 1995).

ANALYSIS
Claims 1-5
Claim 1 recites “obtaining at least one virtual local area network
identifier from a virtual local area network identifier table, the at least one
virtual local area network identifier corresponding to at least one bit position
defined in the IP multicast group vector.”
Appellant contends that Prasad and Gleeson, combined or separately,
fail to teach, disclose, or suggest "at least a virtual local area network
identifier corresponding to at least one bit position defined in an IP multicast
group vector," as recited in claim 1 (App. Br. 16 ). Appellant contends that
there is no motivation or disclosure for how to combine the VLAN of
Gleeson with Prasad's scalable fabric architecture providing the capability of
being incrementally upgraded to a higher capacity (App. Br. 15). Appellant
contends that simply using VLAN addresses in "the address table of Prasad"
would not correspond to what is claimed (App. Br. 23).
Appellant further contends that there would be no reasonable
expectation of success when the references are combined according to the
Examiner’s findings (App. Br. 15). Specifically, Appellant contends that
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Prasad requires that the bit vector has the same number of bits as the number
of outputs in the switch element. As a result, if Prasad and Gleeson were
combined, fewer bits than the number of outputs would exist, causing
Prasad’s switch to lose its functionality (Reply Br. 5-6).
Appellant contends that the scalable switch fabric architecture of
Prasad is not related to a VLAN and that Prasad does not disclose a VLAN
(App. Br. 13-14). Appellant contends that the disclosure cited by the
Examiner in Prasad is prior art and not its invention (Reply Br. 5).
Appellant contends that both Prasad and Gleeson are silent as to the
advantages shown in the Specification (App. Br. 14). Regarding the
Examiner’s finding that the references are not required to teach advantages
not recited in the claims, Appellant argues that the Examiner’s finding is
non-responsive since "advantages do positively establish non-obviousness
for the presently claimed invention" (App. Br. 17-18).
The Examiner finds that Prasad discloses a multicast group table
indexed by a multicast group number for obtaining a multicast group vector
(Ans. 3, FF 3 and 4). The Examiner finds that Gleeson discloses a VLAN
table mapping the Group Destination Address to the VLAN port number
(Ans. 4, FF 6-7) and that the VLAN designation is included in the packet
when it is forwarded (Ans. 4, FF 8). The Examiner concludes that it would
have been obvious to one of ordinary skill in the art at the time of the
invention to have the multicast group of Prasad to include diverse VLAN
designations as outlined in Gleeson to “increase the flexibility of the
network” (Ans. 4, FF 6).
Further, the Examiner concludes that it would have been obvious to
one of ordinary skill in the art at the time of the invention to obtain “at least
one VLAN identifier from a VLAN identifier table corresponding to at least
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one bit position defined in the multicast group vector” such that the VLAN
identifier could be placed in the packet before forwarding (Ans. 4).
Specifically, the Examiner finds that Prasad must have data structure
mapping between bits in the bit vector and the outputs of the switch such
that each bit of the vector corresponds to a different destination (i.e. for a 4
bit vector, there are destinations: "Destination 1", " Destination 2", "
Destination 3", and" Destination 4") (Ans. 9). The Examiner concludes that
it would be obvious to have the bits of the vector to refer to VLAN
designations rather than output ports (Ans. 9).
We are not persuaded by Appellant’s arguments. We agree with the
Examiner’s finding concerning the motivation to combine, advantages not
recited in the claims, and the reasonable expectation for success when
combining the teachings of the references.
We further agree with the Examiner’s finding that it would have been
obvious to one of ordinary skill in the art at the time of the invention to
modify the multicast group of Prasad to include diverse VLAN designations
as outlined in Gleeson to “increase the flexibility of the network” (Ans. 4,
FF 6). Prasad discloses a packet switching architecture implemented within
LANs known as a scalable switch fabric architecture that includes the use of
a multicast group table indexed by a multicast group number for obtaining a
multicast group vector in an effort to deliver the packet to its final
destination (FF 3-5). Gleeson discloses that various LANs may be grouped
together to form VLANs (FF 9) and that a subscription list (or a VLAN
table) mapping the group multicast address to the VLAN subscribing entities
for the purpose of sending copies of the message to VLAN designations (FF
7 and 8). Gleeson discloses that the VLAN designation is included in the
packet when it is copied and forwarded (FF 8). Appellant discloses in the
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Specification that the prior art implementation for replication and
distribution of IP multicast packets over a diverse group of VLAN
designations is accomplished by including the VLAN IDs inserted into the
VLAN tag of tagged Ethernet frames that are sent out over the egress port of
the VLANs represented by each VLAN ID included in a VLAN ID table that
is indexed by the IP multicast group number (FF 2). Since Prasad includes a
multicast group table that associates a multicast group number with a
multicast group vector and Gleeson discloses a VLAN table associating each
group multicast address with a list of VLAN designations, we agree with the
Examiner’s finding that it would have been obvious to one of ordinary skill
in the art at the time of the invention to obtain “at least one VLAN identifier
from a VLAN identifier table corresponding to at least one bit position
defined in the multicast group vector” such that the VLAN identifier could
be placed in the packet before forwarding (Ans. 4).
We therefore find no error in the Examiner’s rejection of claim 1
under 35 U.S.C. § 103. We, therefore, affirm the Examiner’s rejection of
independent claim 1 and dependent claims 2-5 under 35 U.S.C. § 103.

Claims 6-10
Independent claim 6 recites “obtaining at least one virtual local area
network identifier from a virtual local area network identifier table, the at
least one virtual local area network identifier corresponding to at least one
bit position defined in the IP multicast group vector.”
Appellant contests the rejection of claim 6 using the same arguments
stated for claim 1. As noted supra, however, Appellant has not shown that
the Examiner erred with respect to the rejection of independent claim 1. We,
therefore, affirm the Examiner’s rejection of independent claim 6 and
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dependent claims 7-10 under 35 U.S.C. § 103, for the same reasons
expressed with respect to claim 1, supra.

Claims 11-18
Independent claim 11 recites “a table access device configured to
obtain at least one virtual local area network identifier from a virtual local
area network identifier table, the at least one virtual local area network
identifier corresponding to at least one bit position defined in the IP
multicast group vector.”
Appellant contends that the rejection of claim 11 is erroneous using
the same arguments stated for claim 1. As noted supra, however, Appellant
has not shown that the Examiner erred with respect to the rejection of
independent claim 1. We, therefore, affirm the Examiner’s rejection of
independent claim 11 and dependent claims 12-18 under 35 U.S.C. § 103,
for the same reasons expressed with respect to claim 1, supra.

CONCLUSION OF LAW
Appellant has not shown that the Examiner erred in finding that the
combination of Prasad and Gleeson discloses a method of controlling data
flow in a network device that includes a VLAN identifier table including "at
least a virtual local area network identifier corresponding to at least one bit
position defined in an IP multicast group vector.”

ORDER
The Examiner’s rejection of claims 1-18 is affirmed.
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).
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AFFIRMED

ELD

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