Ex Parte Block et al

Board of Patent Appeals and Interferences

Jan 22, 2008

09513015 (B.P.A.I. Jan. 22, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________________

Ex parte ROBERT J. BLOCK, JAMES G. HANKO,
and J. KENT PEACOCK
____________________

Appeal 2007-2244
Application 09/513,015
Technology Center 2100
____________________

Decided: January 22, 2008
____________________

Before MAHSHID D. SAADAT, JEAN R. HOMERE,
and SCOTT R. BOALICK, Administrative Patent Judges.

SAADAT, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
Final Rejection of claims 1-5, 7, 8, and 17-28, which constitute all of the
claims pending in this application as claims 6 and 9-16 have been canceled.
We have jurisdiction under 35 U.S.C. § 6(b).
Appellants invented a method and apparatus for making a
computational service available in a multiple server computer environment
by implementing server redundancy and Desktop Unit (DTU) redirection in
a server failure situation (Specification 6). According to Appellants, if a
Appeal 2007-2244
Application 09/513,015

server fails, the failure is detected and the invention switches the DTUs
using that server to another server (Specification 7).
Independent Claim 1 is exemplary and reads as follows:
1. A method of making a computational service available in a
multiple server computing environment comprising:

exchanging information between a plurality of servers;

initiating a connection between a client unit and a first server of
said plurality of servers;

determining a most recently accessed session of a plurality of
sessions on said plurality of servers;

determining at said first server a location of said most recently
accessed session on one of said plurality of servers; and

redirecting said client unit via said first server to a second
server of said plurality of servers having said most recently accessed
session;

wherein each of said plurality of sessions comprises a plurality
of services requested by said client unit;

wherein said first and second servers can each provide said
plurality of services;

wherein said plurality of services comprise state maintenances
for a user of said client unit;

wherein redirecting is executed when said first server fails to
respond to said client unit with a message, the message indicating
availability of said first server, and said redirecting of said client unit
to said second server maintains access to said accessed session while
continuing said plurality of services to said client unit so as to
eliminate a single point failure.
2
Appeal 2007-2244
Application 09/513,015

The Examiner relies on the following prior art in rejecting the claims:
Dean US 6,023,762 Feb. 8, 2000

Narendran US 6,070,191 May 30, 2000

Andresen et al. (Andresen), “SWEB: Toward a Scalable World Wide Web
Server on Multicomputers,” Dept. of Computer Science, Univ. of California,
1996, pp. 1-7.

Lotus IBM (IBM), “High Availability and Scalability with Domino
Clustering and Partitioning on AIX,” 1998.

Claims 1-5, 7, 8, and 17-27 stand rejected as being unpatentable under
35 U.S.C. § 103(a) over Narendran, Andresen, and IBM.
Claim 28 stands rejected as being unpatentable under 35 U.S.C.
§ 103(a) over Narendran, Andresen, IBM, and Dean.
Rather than repeat the arguments here, we make reference to the
Briefs and the Answer for the respective positions of the Appellants and the
Examiner.
We reverse.

ISSUE
To show that the Examiner erred in rejecting the claims under
35 U.S.C. § 103(a), Appellants argue that the claimed “determining a most
recently accessed session of a plurality of sessions on said plurality of
servers” is not taught by Andresen and cannot result from the combination
of the references (Br. 6-8). Therefore, the issue on appeal turns on whether a
preponderance of the evidence before us shows that under 35 U.S.C. § 103,
3
Appeal 2007-2244
Application 09/513,015

the combination of the applied prior art teaches or suggests the claimed
subject matter and specifically a most recently accessed session.

FINDINGS OF FACT
The following findings of fact (FF) are relevant to the issue involved
in the appeal and are believed to be supported by a preponderance of the
evidence.
1. Narendran relates to server systems used for processing client
requests received over communications networks and to server-side
techniques for processing client requests in a server system (col. 1, ll.
6-10). The system includes a set of N document servers and one or more
redirect servers which receive HTTP requests from clients and redirect
requests to the document servers in accordance with pre-computed
redirection probabilities (col. 2, ll. 61-65).
2. As shown in Figure 1, server system 10 includes a round-robin
domain name service (DNS) server 12, a pair of redirection servers 14-1 and
14-2, and a cluster 16 of N document servers S1, S2, . . . SN interconnected as
shown (col. 3, ll. 59-62).
3. Narendran further discloses that, for example, a client may
generate an HTTP request for a particular service hosted by the server
system 10, such as a request for information associated with a particular web
site, and a TCP/IP connection is then established between the client and a
particular one of the document servers 16 (col. 4, ll. 5-10).
4. The round-robin DNS 12 of server system 10 multiplexes client
requests among the redirection servers 14-1, 14-2 such that a single
4
Appeal 2007-2244
Application 09/513,015

redirection server does not become a bottleneck. Other types of DNS
techniques may also be used. The redirection servers 14-1, 14-2 redirect the
incoming client requests to a document server Si that maintains the requested
document (col. 4, ll. 41-47) when a server fails (col. 12, ll. 12-18).
5. Andresen1 similarly relates to directing simultaneous access
requests on a multi-component system (Abstract). Using a DNS caching a
local DNS system caches the name-to-IP address mapping so that the most
recently accessed hosts can quickly be mapped (p. 1, right hand col.).
6. Andresen further discloses that processing HTTP requests, a
client sets up a TCP/IP connection on a server which sends back the result of
the query after which the connection is closed by either the client or the
server (p. 2, left-hand col.).
7. Appellants’ Specification defines “session” as a “representation
of those services which are executing on behalf of a user at any point in
time” (Specification 22:6-8).

PRINCIPLES OF LAW
The examiner bears the burden of establishing a prima facie case of
obviousness. In re Rijckaert, 9 F.3d 1531, 1532 (Fed.Cir. 1993); In re
Oetiker, 977 F.2d 1443, 1445 (Fed.Cir. 1992). Only if this burden is met
does the burden of coming forward with rebuttal argument or evidence shift
to the applicant. Rijckaert, 9 F.3d at 1532. When the references cited by the

1 Narendran cites Andresen (col. 1, l. 45 through col. 2, l. 4) for its
redirection decision based on a dynamic scheduling (col. 1, ll. 57-59), but
finds problem with limited increase in throughput and the need to go over
the network for fetching the document (col. 2, ll. 1-3).
5
Appeal 2007-2244
Application 09/513,015

examiner fail to establish a prima facie case of obviousness, the rejection is
improper and will be overturned. In re Fine, 837 F.2d 1071, 1074 (Fed. Cir.
1988).
The test for obviousness is what the combined teachings of the
references would have suggested to one of ordinary skill in the art. See In re
Kahn, 441 F.3d 977, 987-988 (Fed. Cir. 2006), In re Young, 927 F.2d 588,
591 (Fed. Cir. 1991) and In re Keller, 642 F.2d 413, 425 (CCPA 1981).
Moreover, in evaluating such references it is proper to take into account not
only the specific teachings of the references but also the inferences which
one skilled in the art would reasonably be expected to draw therefrom. In re
Preda, 401 F.2d 825, 826 (CCPA 1968).
Further, a rejection based on section 103 must rest upon a factual
basis rather than conjecture, or speculation. “Where the legal conclusion [of
obviousness] is not supported by the facts it cannot stand.” In re Warner,
379 F.2d 1011, 1017 (CCPA 1967). See also In re Kahn, 441 F.3d at 988.

ANALYSIS
Appellants argue that the Examiner’s characterization of the term “a
most recently accessed session” as Andresen’s “most recently accessed
hosts” is in error since a session is defined in the Specification to comprise
“a plurality of services requested by said client unit” (Br. 7). Appellants
further argue that Andresen’s DNS caching is cited in Narendran, but is
identified as problematic for causing failures (Br. 8).
The Examiner responds that page 22 of Appellants’ Specification
provides the definition of the claimed term “session” as a representation of
6
Appeal 2007-2244
Application 09/513,015

services executed on behalf of the user and characterizes the multi-
workstation HTTP server of Andresen as a service producer associated with
a session (Ans. 10). The Examiner further asserts that the term “most
recently accessed session” has actually been interpreted as the “most
recently accessed host providing a service to the user” (Ans. 11).
Appellants assert that Andresen uses a connection (i.e., session) for
processing an HTTP request to access HTML information, which is
terminated or closed upon completion of the request, leaving no access to the
terminated connection (Rep. Br. 3). Appellants conclude that in Andresen,
the connection established for processing a client’s HTTP requests for
HTML data is terminated and any reference to that connection is lost (Rep.
Br. 4). Additionally, Appellants argue that even if the terminated connection
in Andresen is the de facto most recently accessed session, it would be
impossible to attempt to “determine a location of” or “maintain access to”
the terminated connection (Rep. Br. 4-5).
Upon a review of the teachings in the prior art relied on by the
Examiner, we find that Appellants correctly point out, and the Examiner
acknowledges (Ans. 11), that the most recently accessed host of Andresen is
not the same as the claimed “most recently accessed session.” We also
agree with Appellants that, even if Andresen’s connection through which the
HTTP request is passed may be equated to a “session,” the connection is
terminated upon processing the user’s HTTP request (FF 5-6); making it
impossible to determine a location of or maintain access to such terminated
session. While the last accessed host or the terminated connection in
Andresen may also comprise the last access session (FF 6-7), Appellants
7
Appeal 2007-2244
Application 09/513,015

correctly argue (Rep. Br. 5) that it would be impossible to determine a
location of the session, redirect the client to the server having that session,
and maintain access to the session.
We also disagree with the Examiner that since throughput problems
are not discussed in Narendran (Ans. 12-17), using the redirection schedule
disclosed by Andresen in combination with the data distribution technique of
Narendran is not discouraged. Narendran in fact redirects the requests to a
server with a copy of the document based on the corresponding redirect
probability (FF 1). In that regard, Appellants correctly recognize the
problem with combining the references given the discussed absence of any
correspondence between the terminated connection or session in Andresen
(FF 6) and the redirected request in Narendran (FF 4). Other than
Appellants’ own disclosure and using hindsight reconstruction, we fail to see
how and in what manner the disclosure of Narendran might have been
modified by Andresen to arrive at the claimed subject matter.
We have also reviewed the IBM reference which the Examiner
applied to address the redirecting/scheduling capabilities required by the
claimed invention. We find nothing, however, in the disclosure of IBM
which overcomes the innate deficiencies of Narendran and Andresen
discussed supra.
In view of the discussion made above, since we are of the opinion that
the proposed combination of references set forth by the Examiner does not
support the obviousness rejection, we cannot sustain the 35 U.S.C. § 103
rejection of independent claim 1, nor of claims 2-5, 7, 8, and 17-27
dependent thereon, over Narendran, Andresen, and IBM.
8
Appeal 2007-2244
Application 09/513,015

With respect to the rejection of claim 28, we note that the Examiner
further relies on Dean for teaching the additional feature of initiating
connection between a client and a server by inserting a token into said client
unit. Claim 28, similar to claim 1, requires “determining a most recently
accessed session” and “redirecting of said client unit to said second server”
while access to said accessed session is maintained. However, the Examiner
has not pointed to any additional teachings or convincing rationale in
modifying the combination of Narendran, Andresen, and IBM with the
teachings of Dean that would have overcome the deficiencies of the applied
prior art as discussed above with respect to claim 1. We, therefore, find that
the proposed combination of the applied prior art fails to provide all the
claimed features and cannot support finding claim 28 unpatentable for
obviousness under 35 U.S.C. § 103 over Narendran, Andresen, IBM, and
Dean.
DECISION
The decision of the Examiner rejecting claims 1-5, 7, 8, and 17-28
under 35 U.S.C. § 103 is reversed.

9
Appeal 2007-2244
Application 09/513,015

REVERSED

eld

MARTINE PENILLA & GENCARELLA, LLP
710 LAKEWAY DRIVE
SUITE 200
SUNNYVALE CA 94085
10