Prosecution Insights
Last updated: April 19, 2026
Application No. 18/440,791

PROVIDING DUAL-HOMED, ACTIVE-ACTIVE DEVICES ON NETWORK FABRICS

Non-Final OA §103
Filed
Feb 13, 2024
Examiner
ROBINSON, CHRISTOPHER B
Art Unit
2443
Tech Center
2400 — Computer Networks
Assignee
Cisco Technology Inc.
OA Round
1 (Non-Final)
89%
Grant Probability
Favorable
1-2
OA Rounds
2y 2m
To Grant
96%
With Interview

Examiner Intelligence

Grants 89% — above average
89%
Career Allow Rate
422 granted / 472 resolved
+31.4% vs TC avg
Moderate +6% lift
Without
With
+6.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 2m
Avg Prosecution
27 currently pending
Career history
499
Total Applications
across all art units

Statute-Specific Performance

§101
9.4%
-30.6% vs TC avg
§103
60.0%
+20.0% vs TC avg
§102
18.6%
-21.4% vs TC avg
§112
5.1%
-34.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 472 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Information Disclosure Statement The information disclosure statement (IDS) submitted on 02/13/2024 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Allowable Subject Matter Claim(s) 2-3, 6-7, 11-12, 15-16, 19-20 is/are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1, 4-5, 10, 13-14, 17-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Xiong et al. (US 2012/0014386 A1) and further in view of Li et al. (US 2013/0294451 A1). Re Claim 1, 10 & 17, Xiong teaches a first edge node of a network fabric, the first edge node comprising: one or more processors; and (Xiong; FIG. 1-39; ¶ [0053], [0249]; Processors.) one or more non-transitory computer-readable media storing computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising: (Xiong; FIG. 1-39; ¶ [0249]-[0253]; A processor, executing the instructions, stored in computer-readable media.) receiving a first Layer-2 (L2) broadcast message from a second edge node and over the network fabric, the first L2 broadcast message originating at an endpoint that is connected to the second edge node; (Xiong; FIG. 1-15; ¶ [0051]-[0088]; Receiving at a Layer-2, a broadcast message, the broadcast message being transmitted over a network between edge nodes. The message originates from endpoint devices interconnected to the edge nodes.) identifying, from the first L2 broadcast message, a first source media access control (MAC) address of the endpoint; (Xiong; FIG. 1-15; Background, ¶ [0060]-[0080], [0084]-[0115]; Identifying, from L2 related broadcasts, MAC address of endpoint devices.) storing the first source MAC address of the first L2 broadcast message in a local cache of the first edge node; (Xiong; FIG. 1-15; Background, Summary, ¶ [0060]-[0080], [0084]-[0115], [0156]-[0163]; Storing the MAC address of the L2 broadcast in an edge switch (node) local cache.) forwarding the first L2 broadcast message to an L2 device connected to the first edge node, wherein the L2 device is configured to access the network fabric via the first edge node and a third edge node; (Xiong; FIG. 1-35, 38; Background, Summary, ¶ [0069]-[0088], [0140], [0182]-[0195], [0248]-[0250]; Forwarding L2 related messages to L2 related component devices connected to an edge node, the device is capable of accessing the network via the edge node(s). receiving a second L2 broadcast message from the L2 device; (Xiong; FIG. 1-15, 38; ¶ [0051]-[0088], [0248]-[0250]; Transmitting a plurality of L2 related broadcast messages to L2 related devices.) identifying, from the second L2 broadcast message, a second source MAC address and a destination MAC address that is a broadcast address; (Xiong; FIG. 1-35; Summary, ¶ [0060]-[0072], [0075]-[0100], [0144]-[0150], [0154]-[0177]; Identifying, transmitting MAC addresses in a broadcast message.) Xiong does not explicitly suggest determining whether the second source MAC address corresponds to the first source MAC address stored in the local cache; in response to determining that the second source MAC address corresponds to the first source MAC address, dropping the second L2 broadcast message; or in response to determining that the second source MAC address does not correspond the first source MAC address, adding the second source MAC address to a source MAC address table corresponding to the L2 device. However, in analogous art, Li teaches determining whether the second source MAC address corresponds to the first source MAC address stored in the local cache; (Li; FIG. 1-5; Background, Summary, ¶ [0056]-[0104], [0116]-[0142]; The embodiment(s) detail comparable methodology that includes various MAC addresses, a source related MAC address and storing address in device cache.) in response to determining that the second source MAC address corresponds to the first source MAC address, dropping the second L2 broadcast message; or in response to determining that the second source MAC address does not correspond the first source MAC address, adding the second source MAC address to a source MAC address table corresponding to the L2 device. (Li; FIG. 1-5; Background, Summary, ¶ [0056]-[0104], [0116]-[0142]; Adding the MAC address to a table when the MAC address does not correspond to a MAC address.) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention (AIA ) to modify Xiong in view of Li to determine the status of MAC addresses for the reasons of updating a MAC table in a data link layer protocol. (Li Abstract) Re Claim 4 & 13, Xiong-Li discloses the first edge node of claim 1, the operations further comprising, in response to determining that the second source MAC address corresponds to the first source MAC address: querying a control-plane of the network fabric to determine whether the endpoint is registered to another edge node of the network fabric; and (Xiong; Table 3-9; FIG. 20-25; ¶ [0119], [0164]-[0177]; Control plane related endpoint registration of edge nodes/switches in a network.) receiving, from the control-plane, an indication that the endpoint is registered to the second edge node of the network fabric. (Xiong; Table 3-9; FIG. 20-25; ¶ [0119], [0164]-[0177]; Control plane related endpoint device registration.) Re Claim 5 & 14, Xiong-Li discloses the first edge node of claim 1, the operations further comprising, in response to determining that the second source MAC address corresponds to the first source MAC address: adding the second source MAC address to a flood map-cache table stored in the first edge node, wherein the flood map-cache table stores source MAC addresses received in L2 broadcast messages that belong to endpoints which are registered to other edge nodes of the network fabric. (Xiong; FIG. 1-25; ¶ [0156]-[0177]; The storing of MAC addresses in APR cache tables (flood map-cache table).) Re Claim 18, Xiong-Li discloses the computer-implemented method of claim 17, further comprising refraining from adding the source MAC address to a source MAC address table corresponding to the L2 device. (Li; FIG. 1; ¶ [0072]-[0078]; A MAC address table is not updated.) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention (AIA ) to modify Xiong in view of Li to determine the status of MAC addresses for the reasons of updating a MAC table in a data link layer protocol. (Li Abstract) Claim(s) 8-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Xiong et al. (US 2012/0014386 A1), in view of Li et al. (US 2013/0294451 A1) and further in view of Jain et al. (US 2023/0199465 A1). Re Claim 8, Xiong-Li discloses the first edge node of claim 1, yet does not explicitly suggest wherein: the network fabric is a software-defined access (SDA) fabric; and the SDA fabric is associated with a Locator/Identifier Separation Protocol (LISP) control plane. However, in analogous art, Jain teaches wherein: the network fabric is a software-defined access (SDA) fabric; and (Jain; FIG. 1; Background, Summary; SDA network fabric.) the SDA fabric is associated with a Locator/Identifier Separation Protocol (LISP) control plane. (Jain; FIG. 1; Background, Summary, ¶ []; SDA fabric, LISP, control plane.) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention (AIA ) to modify Xiong-Li in view of Jain to include a SDA fabric for the reasons of extend network access to various enterprise fabrics of external network. (Jain Background/Summary) Re Claim 9 , Xiong-Li discloses the first edge node of claim 1, yet does not explicitly suggest wherein: the network fabric includes an Ethernet Virtual Private Network (EVPN) fabric; and the EVPN fabric is associated with a Border Gateway Protocol (BGP) control plane that includes a route reflector. However, in analogous art, Jain teaches wherein: the network fabric includes an Ethernet Virtual Private Network (EVPN) fabric; and (Jain; FIG. 1; Background, Summary; EVPN fabric.) the EVPN fabric is associated with a Border Gateway Protocol (BGP) control plane that includes a route reflector. (Jain; FIG. 1; Background, Summary; EVPN fabric, BGP control plane includes a route reflector.) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention (AIA ) to modify Xiong-Li in view of Jain to include a SDA fabric for the reasons of extend network access to various enterprise fabrics of external network. (Jain Background/Summary) Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER B ROBINSON whose telephone number is (571)270-0702. The examiner can normally be reached M-F 7:00-3:00 EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nicholas R Taylor can be reached at 571-272-3889. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CHRISTOPHER B ROBINSON/Primary Examiner, Art Unit 2443
Read full office action

Prosecution Timeline

Feb 13, 2024
Application Filed
Jan 14, 2026
Non-Final Rejection — §103
Apr 07, 2026
Interview Requested

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
89%
Grant Probability
96%
With Interview (+6.4%)
2y 2m
Median Time to Grant
Low
PTA Risk
Based on 472 resolved cases by this examiner. Grant probability derived from career allow rate.

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