Prosecution Insights
Last updated: April 19, 2026
Application No. 18/318,619

METHOD AND SYSTEM FOR SUPPORTING EXPEDITED ROAMING IN AN EVPN ENVIRONMENT

Non-Final OA §103
Filed
May 16, 2023
Examiner
PHUNG, LUAT
Art Unit
2468
Tech Center
2400 — Computer Networks
Assignee
Arista Networks, Inc.
OA Round
3 (Non-Final)
76%
Grant Probability
Favorable
3-4
OA Rounds
3y 7m
To Grant
88%
With Interview

Examiner Intelligence

Grants 76% — above average
76%
Career Allow Rate
455 granted / 599 resolved
+18.0% vs TC avg
Moderate +12% lift
Without
With
+11.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
38 currently pending
Career history
637
Total Applications
across all art units

Statute-Specific Performance

§101
4.8%
-35.2% vs TC avg
§103
55.8%
+15.8% vs TC avg
§102
23.8%
-16.2% vs TC avg
§112
7.6%
-32.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 599 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status 99The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Amendment Applicants’ arguments filed on 2 March 2025 have been fully considered but they are moot in view of the new ground of rejection. Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2 March 2026 has been entered. 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 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. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim 1-3, 13, 14, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Samar (US 2009/0116445 A1) in view Lin et al. (US Pub. 2016/0165506). Regarding claim 1, Samar discloses “a method of operating a wireless access point, comprising:” (Samar ¶0025–¶0033, describing operation of a radio node providing wireless connectivity to an access terminal). Samar discloses “wirelessly transmitting signals to an end-host;” (Samar ¶0025, ¶0029, describing a radio node including carrier control elements (CCEs) that provide wireless communication with an access terminal). Samar discloses “determining whether the end-host has roamed from the wireless access point to an additional wireless access point;” (Samar ¶0047–¶0048, describing detecting that an access terminal has moved from an old radio node to a new radio node during handoff and initiating mobility procedures in response). Samar discloses “subsequent to determining that the end-host has roamed from the wireless access point to the additional wireless access point,” (Samar ¶0048, describing that once the handoff to the new radio node is identified, mobility management procedures are performed). Samar discloses forwarding packets via a tunnel during handoff (¶0048). Samar does not disclose forwarding packets via a tunnel having a first end connected to the wireless access point and a second end connected to the additional wireless access point. However, Lin discloses that, after roaming, a foreign access point (FAP) encapsulates packets and sends the encapsulated packets to a home access point (HAP) using a roaming tunnel having endpoints at the respective access points (Lin ¶0071–¶0072). Lin further discloses that traffic is transferred between the HAP and the FAP using the roaming tunnel (Lin ¶0068), thereby teaching forwarding of packets between wireless access points via a tunnel having endpoints at the respective access points. It would have been obvious to one of ordinary skill in the art at the time of the invention to modify Samar to forward packets via a tunnel established between wireless access points as taught by Lin et al., because Samar teaches tunneling during handoff to maintain connectivity, and Lin et al. teaches direct access point-to-access point tunneling for forwarding roaming traffic, thereby representing a predictable application of known tunneling techniques to improve handoff performance. Regarding claim 2, Samar discloses receiving a data packet from an access layer switch connected to the wireless access point(¶[0025], Fig. 1: radio network routers (RNRs) coupled between RNEs and PDSNs; the RNRs route packets between the RNEs and the core, functioning as access layer switches) and conveying the data packet received from the access layer switch to the end-host (¶[0039]–[0040]: RNE conveys packets received from the RNR/core to the AT). Regarding claim 3, Samar discloses conveying host information associated with the end-host to the additional wireless access point prior to determining that the end-host has roamed (¶[0047]–[0048]: before the handoff, the oRNE transfers session/context information of the AT to the nRNE). Claim 13 recites a method of operating a network device, complimentary to the method of claim 1, and is thus similarly rejected. Regarding claim 14, Samar further discloses creating a tunnel between the network device and the additional network device, wherein the additional data is forwarded through the tunnel (¶[0048]: “the oRNE sets up an IP tunnel between the oRNE and the nRNE”). Regarding claim 18, Samar discloses an access point (Fig. 1, 3; ¶[0029], CDMA carrier element (CCE), radio network element (RNE), access point) comprising: wireless circuitry configured to communicate with an end-host and a neighboring access point (Fig. 1, 3; ¶[0029]); memory circuitry configured to store a host association table listing a media access control (MAC) address of the end-host (Fig. 1, 3; ¶[0019], ¶[0037], routing of packets having the destination address of the access terminal); and processing circuitry configured to substantially perform the method of claim 1, and is thus similarly rejected. Claims 4–6, 10, and 12 are rejected under 35 U.S.C. §103 as being unpatentable over Samar et al. (US 2009/0116445) in view of Lin et al, and further in view of RFC 8365 (A Network Virtualization Overlay Solution Using EVPN, March 2018). Regarding claim 4, Samar discloses conveying host information prior to handoff (¶[0047]–[0048]) but does not disclose that the host information comprises a name of the access layer switch. RFC 8365 discloses conveying a name of the access layer switch (Section 5.1.2). It would have been obvious to include switch identifiers in host context because EVPN uses them to uniquely identify nodes, predictably improving Samar’s handoff mapping. Regarding claim 5, Samar discloses context transfer (¶[0047]–[0048]) but does not disclose conveying an IP address of the access layer switch. RFC 8365 discloses conveying an IP address of the access layer switch (Section 5.1.1). It would have been obvious to include IP addresses in host context because EVPN uses them for tunnel setup, predictably improving Samar’s routing continuity. Regarding claim 6, Samar discloses conveying host context (¶[0047]–[0048]) but does not disclose conveying a MAC address of the end-host. RFC 8365 discloses conveying a MAC address of the end-host (Section 5.1.1). It would have been obvious to include MACs because MAC/IP advertisement is fundamental in EVPN, predictably enhancing Samar’s forwarding consistency. Regarding claim 10, Samar discloses tunneling (¶[0048]–[0049]) but does not disclose tying tunnel timers to EVPN updates. RFC 8365 discloses the configurable timer expiring after an EVPN update (Section 5.1.1, 8.1.2). It would have been obvious to link timers to EVPN updates because this synchronizes host state, predictably improving Samar’s tunnel stability. Regarding claim 12, Samar discloses tunneling (¶[0048]) but does not disclose specific tunnel types. RFC 8365 discloses VXLAN, NVGRE, GRE, MPLS, etc. (Section 5.1.3). It would have been obvious to apply known encapsulations because they were widely used and interchangeable, predictably enhancing Samar’s mobility tunnels. Claims 7–9, 11, 15–17, 19, and 20 are rejected under 35 U.S.C. §103 as being unpatentable over Samar et al. (US 2009/0116445) in view of Lin et al, and further in view of RFC 7432 (BGP MPLS-Based Ethernet VPN, February 2015). Regarding claim 7, Samar discloses acknowledgments during handoff (¶[0047]–[0049]) but does not disclose starting a configurable timer upon MAC detection. RFC 7432 discloses starting a configurable timer upon MAC detection (Section 15). It would have been obvious to add timers because EVPN uses them to manage MAC moves, predictably improving Samar’s handoff control. Regarding claim 8, Samar discloses tunneling (¶[0048]) but does not disclose specific timer durations. RFC 7432 discloses timer ranges between 100–4000 ms (Section 15.1). It would have been obvious to configure timers in this range because it was conventional in EVPN, predictably balancing responsiveness and stability in Samar’s system. Regarding claim 9, Samar discloses tunnel release after handoff (¶[0049]) but does not disclose timer-driven tunnel deactivation. RFC 7432 discloses deactivation in response to timer expiry (Section 15.1). It would have been obvious to tie tunnel shutdown to timer expiry because this ensures predictable cleanup of stale resources in Samar’s mobility tunnels. Regarding claim 11, Samar discloses mobility (¶[0047]–[0049]) but does not disclose removing a MAC from a host association table. RFC 7432 discloses removing stale MAC addresses after mobility (Section 15.2). It would have been obvious to remove stale MACs because this prevents conflicts, predictably improving Samar’s forwarding. Regarding claim 15, Samar discloses tunneling (¶[0048]) but does not disclose starting a configurable timer. RFC 7432 discloses starting a configurable timer after detecting mobility (Section 15). It would have been obvious to include such a timer because EVPN timers coordinate handoff state, predictably improving Samar’s reliability. Regarding claim 16, Samar discloses tunneling (¶[0048]) but does not disclose specific timer ranges. RFC 7432 discloses mobility timer durations configurable between 100–4000 ms (Section 15.1). It would have been obvious to adopt this range because it was well-known and predictable, enhancing Samar’s timer control. Regarding claim 17, Samar discloses tunnel teardown (¶[0049]) but does not disclose teardown in response to timer expiry or EVPN updates. RFC 7432 discloses closing tunnels in response to timer expiry or EVPN updates (Section 4, 11.2, 15.2). It would have been obvious to adopt these triggers because EVPN uses them for synchronization, predictably ensuring reliable tunnel closure in Samar’s handoff. Regarding claim 19, Samar discloses tunneling (¶[0048]) but does not disclose deactivation of the tunnel when a configurable timer expires. RFC 7432 discloses deactivating tunnels when timers expire (Section 4, 11.2, 15.2). It would have been obvious to implement this because timer-based cleanup is predictable, preventing stale state in Samar’s system. Regarding claim 20, Samar discloses tunneling (¶[0048]) but does not disclose deactivation of the tunnel in response to a BGP update. RFC 7432 discloses deactivating tunnels in response to BGP EVPN updates of host mobility (Section 4, 11.2, 15.1). It would have been obvious to apply BGP-triggered tunnel closure because EVPN relies on BGP for MAC mobility updates, predictably synchronizing Samar’s tunnels with network-wide state. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure (see form 892). Any inquiry concerning this communication or earlier communications from the examiner should be directed to LUAT T PHUNG whose telephone number is (571)270-3126. The examiner can normally be reached on M-F 9 AM - 6 PM. 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, Marcus Smith can be reached on (571) 272-3988. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Luat Phung/ Primary Examiner, Art Unit 2468
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Prosecution Timeline

May 16, 2023
Application Filed
Aug 23, 2025
Non-Final Rejection — §103
Oct 23, 2025
Applicant Interview (Telephonic)
Oct 25, 2025
Examiner Interview Summary
Oct 27, 2025
Response Filed
Feb 07, 2026
Final Rejection — §103
Feb 27, 2026
Applicant Interview (Telephonic)
Mar 02, 2026
Request for Continued Examination
Mar 07, 2026
Examiner Interview Summary
Mar 10, 2026
Response after Non-Final Action
Apr 04, 2026
Non-Final Rejection — §103 (current)

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

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Prosecution Projections

3-4
Expected OA Rounds
76%
Grant Probability
88%
With Interview (+11.9%)
3y 7m
Median Time to Grant
High
PTA Risk
Based on 599 resolved cases by this examiner. Grant probability derived from career allow rate.

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