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 .
Applicant amended claims 10, 12, and 21 and canceled claims 11 and 13 in the amendment filed on 03/10/2026.
The claims 1-10, 12, and 14-19, and 21 are pending.
Response to Arguments
Applicant's arguments filed 03/10/2026 have been fully considered but they are not persuasive.
A. Applicant argues that Singh does not disclose
A.1: “wherein the second edge device is attached to the second network segment of the virtual network and allowed to forward traffic to/from the second network segment of the virtual network”;
A.2: “the first edge device detecting that the second edge device is unreachable”;
A.3: “wherein the third edge device is attached to the second network segment of the virtual network and is not allowed to forward traffic to/from the second network segment of the virtual network”.
In reply, the examiner respectfully disagrees.
A.1: Singh discloses PEs 6, 12 may receive customer traffic from local VXLANs 14 and forward the traffic through WAN 3 via the EVPN 23; PEs 6 may be perform the techniques of this disclosure with respect to multiple Ethernet segments on multiple different VXLANs). One of the multiple PE devices in each of the Ethernet segments is elected to operate as an active designated forwarder (DF) to forward inbound Ethernet frames from EVPN 23 to the customer network device 8A via the Ethernet segment, thereby avoiding traffic loops within VXLANs 14 (col. 5, lines 20-29). Accordingly, the active designated forwarder (DF) is to forward the inbound Ethernet frames from EVPN 23 to the customer network device 8A via the Ethernet segment.
A.2: Singh discloses in response to detecting a failure of the active DF, the PEs elect for the Ethernet segment a new DF (col. 2, lines 23-38); PE 6A may experience a failure condition that prevents PE 6A from satisfying the requirements of an active DF for a multi-homed active-standby EVPN configuration (col. 6, lines 39-52). Claim 9 also disclose a first PE triggering, in response to determining a failure condition for a second PE of the plurality of Pes. Accordingly, the first PE detects a failure condition for a second PE of the plurality of PEs.
A.3: Singh discloses in response to being elected the new active DF, previous standby non-DF PE 6B (third PE) unblocks core-to-VXLAN traffic forwarding for the Ethernet segment implemented at least in part by VXLAN 14A (col. 5, line 8 – col. 7, line 25). Claim 9 further discloses in response to the first PE detecting the failure condition of the active DF PE (second PE), the first PE triggering an election of one of the plurality of PEs (third PE) as a designated Forwarder to forward the traffic.
Accordingly, Singh teaches in response to the first PE (first edge device) detecting the failure condition of the active DF PE (second edge device), triggering an election of one of the plurality of PEs (third PE) as a Designated Forwarder to forward the traffic.
B. Applicant argues that Singh does not disclose creating the session with the second edge device to detect reachability of the second edge device after the third edge device receives Ethernet Segment (ES) route for the second network segment of the virtual network from the second edge device.
In reply, the examiner respectfully disagrees.
Singh teaches PEs 6 may elect PE 6B as the new DF based on the PEs 6, 12 exchange EVPN routes and based on route type 1 (i.e., Ethernet Auto-Discovery (A-D), which may be per Ethernet Segment Identifier) routes, and route type 4 (Ethernet segment) routes and a Bidirectional Forwarding Detection (BFD) session for detecting PE 6 failure (col. 6, lines 48-59). Accordingly, Singh discloses the argued claim limitations.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-8, 10, 12, 14-17, 19, and 21 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Singh et al (US Patent No. 10,666,500 B2).
With respect to claim 1, Singh teaches a method performed by a first edge device (PE 6, 12; network device 30 representing any of the PEs 6, configured to perform the techniques) in a network, comprising: receiving traffic of a first network segment of a virtual network, wherein the traffic is to be forwarded to a second network segment of the virtual network via a second edge device in the network (col. 4, lines 45-50; col. 7, lines 53-58; Figs. 1-2; disclose PEs 6, 12 may receive customer traffic from local VXLANs 14 and forward the traffic through WAN 3 via the EVPN 23; PEs 6 may be perform the techniques of this disclosure with respect to multiple Ethernet segments on multiple different VXLANs), wherein the second edge device is attached to the second network segment of the virtual network and allowed to forward traffic to/from the second network segment of the virtual network (col. 5, lines 20-29 disclose one of the multiple PE devices in each of the Ethernet segments is elected to operate as a designated forwarder (DF) to forward inbound Ethernet frames from EVPN 23 to the customer network device 8A via the Ethernet segment, thereby avoiding traffic loops within VXLANs 14. For example, PE 6A may be elected the designated forwarder for Ethernet segment 13A with respect to unicast traffic as well as broadcast, unidentified unicast and multicast (BUM) traffic received from EVPN 23. As designated forwarder, PE 6A forwards the traffic into Ethernet segment 13A); detecting that the second edge device is unreachable (col. 6, lines 39-52 disclose PE 6A may experience a failure condition that prevents PE 6A from satisfying the requirements of an active DF for a multi-homed active-standby EVPN configuration, e.g., for DCI. Example failure conditions may include isolation from WAN 3 such that PE 6A is unable to send or receive network packets on WAN 3, failure of the data center-facing interface or IGP link or other Ethernet segment 13A failure with respect to PE 6A such that PE 6A is unable to send or receive packets on VXLAN 14A, and failure of the PE 6A itself); and switching the traffic to a third edge device (standby non-DF PE 6B) in the network based on the detection of the second edge device being unreachable, wherein the third edge device is attached to the second network segment of the virtual network and is not allowed to forward traffic to/from the second network segment of the virtual network (col. 5, line 8 – col. 7, line 25 disclose in response to being elected the new active DF, previous standby non-DF PE 6B unblocks core-to-VXLAN traffic forwarding for the Ethernet segment implemented at least in part by VXLAN 14A).
With respect to claim 2, Singh teaches creating a session with the second edge device to detect reachability of the second edge device (col. 6, lines 48-52 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure).
With respect to claim 3, Singh teaches wherein the session comprises a bidirectional forwarding detection (BFD) session (col. 6, lines 48-52 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure).
With respect to claim 4, Singh teaches wherein creating the session with the second edge device to detect reachability of the second edge device comprises: creating the session with the second edge device to detect reachability of the second edge device after the first edge device receives Ethernet Auto-Discovery (A-D) route for the second network segment of the virtual network from the second edge device (col. 6, lines 48-59 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure; based on service configuration for PEs 6, the PEs 6, 12 exchange EVPN routes and based on route type 1 (i.e., Ethernet Auto-Discovery (A-D), which may be per Ethernet Segment Identifier) routes, and route type 4 (Ethernet segment) routes, PEs 6 may elect PE 6B as the new DF).
With respect to claim 5, Singh teaches wherein switching the traffic to the third edge device in the network based on the detection of the second edge device being unreachable comprises: updating a forwarding entry to switch the traffic to the third edge device in the network based on the detection of the second edge device being unreachable (col. 11, line 64-col. 12, line 8 disclose PE 6A may determine that one of PEs 6 is in a failure condition (106). PE 6A and PE 6B perform designated forwarder election to determine a new designated forwarder for the Ethernet segment (108). If PE 6A was previously the designated forwarder and another PE (e.g., PE 6B) is elected the new designated forwarder (YES branch of 110), PE 6A may modify its routing information to increase a routing cost from CE device 8A to PE 6A on network 15A).
With respect to claim 6, Singh teaches wherein the first edge device is a designated forwarder (DF) provider edge (PE) device (remote PE 12) for the first network segment of the virtual network, the second edge device is a DF PE device (DP PE 6A) for the second network segment of the virtual network, and the third edge device is a non-DF PE device (non-DP PE 6B) for the second network segment of the virtual network (Figs. 1-2 disclose one of the multiple PE devices in each of the Ethernet segments is elected to operate as a designated forwarder (DF) to forward inbound Ethernet frames from EVPN 23 to the customer network device 8A via the Ethernet segment).
With respect to claim 7, Singh teaches wherein the virtual network is a Border Gateway Protocol (BGP) Multiprotocol Label Switching (MPLS) based Ethernet Virtual Private Network (EVPN) (Figs. 1-2; col. 3, line 46-col. 2, line 9 disclose BGP MPLS-Based Ethernet VPN).
With respect to claim 8, Singh teaches wherein the network is a network running BGP and MPLS protocol (Figs. 1-2; col. 3, line 46-col. 2, line 9 disclose BGP MPLS-Based Ethernet VPN).
With respect to claim 10, Singh teaches a method performed by a third edge device (standby non-DF PE 6B) in a network, comprising: creating a session with the second edge device to detect reachability of the second edge device (col. 6, lines 48-52 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure), wherein creating the session with the second edge device to detect reachability of the second edge device comprises: creating the session with the second edge device to detect reachability of the second edge device after the third edge device receives Ethernet Segment (ES) route for the second network segment of the virtual network from the second edge device (col. 6, lines 48-59 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure; based on service configuration for PEs 6, the PEs 6, 12 exchange EVPN routes and based on route type 1 (i.e., Ethernet Auto-Discovery (A-D), which may be per Ethernet Segment Identifier) routes, and route type 4 (Ethernet segment) routes, PEs 6 may elect PE 6B as the new DF); blocking traffic to/from a second network segment of a virtual network, wherein the third edge device is attached to the second network segment of the virtual network and is not allowed to forward traffic to/from the second network segment of the virtual network (Fig.1; col. 5, line 8 – col. 7, line 25 disclose standby non-DF PE 6B for Ethernet segment 13A elected as the new active DF 6B unblocking core-to-VXLAN traffic forwarding for the Ethernet segment implemented at least in part by VXLAN 14A; that is the standby non-DF PE 6B was not allowed to forward the traffic prior to being elected the new active DF; only one PE 6 is active at any time); detecting that a second edge device (active DF PE 6A) of the network is unreachable (col. 6, lines 39-52 disclose PE 6A may experience a failure condition that prevents PE 6A from satisfying the requirements of an active DF for a multi-homed active-standby EVPN configuration, e.g., for DCI. Example failure conditions may include isolation from WAN 3 such that PE 6A is unable to send or receive network packets on WAN 3, failure of the data center-facing interface or IGP link or other Ethernet segment 13A failure with respect to PE 6A such that PE 6A is unable to send or receive packets on VXLAN 14A, and failure of the PE 6A itself), wherein the second edge device is attached to the second network segment of the virtual network and allowed to forward traffic to/from the second network segment of the virtual network (col. 5, lines 20-29 disclose one of the multiple PE devices in each of the Ethernet segments is elected to operate as a designated forwarder (DF) to forward inbound Ethernet frames from EVPN 23 to the customer network device 8A via the Ethernet segment, thereby avoiding traffic loops within VXLANs 14. For example, PE 6A may be elected the designated forwarder for Ethernet segment 13A with respect to unicast traffic as well as broadcast, unidentified unicast and multicast (BUM) traffic received from EVPN 23. As designated forwarder, PE 6A forwards the traffic into Ethernet segment 13A); receiving traffic of a first network segment of the virtual network from a first edge device in the network, wherein the traffic is to be forwarded to the second network segment of the virtual network (col. 4, line 45-58 disclose PEs 6, 12 may receive customer traffic from local VXLANs 14 and forward the traffic through WAN 3 via the EVPN 23. Similarly, PEs 6 may receive tunneled L2 communications from EVPN 23 and forward the L2 communications via VXLANs 14 for transport through the local data centers 5 via the respective underlay networks 15); and unblocking traffic to/from the second network segment of the virtual network based on the detection of the second edge device being unreachable (col. 5, line 8 – col. 7, line 25 disclose in response to being elected the new active DF, PE 6B unblocks core-to-VXLAN traffic forwarding for the Ethernet segment implemented at least in part by VXLAN 14A).
With respect to claim 12, Singh teaches wherein the session comprises a bidirectional forwarding detection (BFD) session (col. 6, lines 48-52 disclose non-DF PE 6B monitors a health of DF PE 6A via network 15A using a Bidirectional Forwarding Detection (BFD) or other Operation, Administration, and Maintenance (OAM) technique for detecting PE 6 failure).
With respect to claim 14, Singh teaches wherein unblocking traffic to/from the second network segment of the virtual network based on the detection of the second edge device being unreachable comprises: updating a forwarding entry to unblock traffic to/from the second network segment of the virtual network based on the detection of the second edge device being unreachable (col. 11, line 64-col. 12, line 8 disclose PE 6A may determine that one of PEs 6 is in a failure condition (106). PE 6A and PE 6B perform designated forwarder election to determine a new designated forwarder for the Ethernet segment (108). If PE 6A was previously the designated forwarder and another PE (e.g., PE 6B) is elected the new designated forwarder (YES branch of 110), PE 6A may modify its routing information to increase a routing cost from CE device 8A to PE 6A on network 15A).
With respect to claim 15, Singh teaches wherein the first edge device is a designated forwarder (DF) provider edge (PE) device (remote PE 12) for the first network segment of the virtual network, the second edge device is a DF PE device (DP PE 6A) for the second network segment of the virtual network, and the third edge device is a non-DF PE device (non-DP PE 6B) for the second network segment of the virtual network (Figs. 1-2).
With respect to claim 16, Singh teaches wherein the virtual network is a Border Gateway Protocol (BGP) Multiprotocol Label Switching (MPLS) based Ethernet Virtual Private Network (EVPN) (Figs. 1-2; col. 3, line 46-col. 2, line 9 disclose BGP MPLS-Based Ethernet VPN).
With respect to claim 17, Singh teaches wherein the network is a network running BGP and MPLS protocol (Figs. 1-2; col. 3, line 46-col. 2, line 9 disclose BGP MPLS-Based Ethernet VPN).
The limitations of claim 19 are rejected in the analysis of claim 1 above, and the claim is rejected on that basis.
The limitations of claim 21 are rejected in the analysis of claim 10 above, and the claim
is rejected on that basis.
Claim Rejections - 35 USC § 103
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.
Claims 9 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Singh et al (US Patent No. 10,666,500 B2) in view of Singh et al (US Publication No. 2017/0099180 A1) (hereinafter Singh_2).
With respect to claim 9, Singh discloses the claimed subject matter as discussed above except wherein there is a route reflector in the network and there is a BGP session between an edge device in the network and the route reflector.
However, Singh_2 teaches wherein there is a route reflector in the network (route reflector 18 as per Fig. 1) and there is a BGP session between an edge device in the network and the route reflector (paragraph 0022; 0054 disclose route reflector 18 processing the BGP control plane message from PE router 10B and forwarding it to PE router 10C) in order to provide a simplified network configuration solution. Therefore, based on Singh in view of Singh_2, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to utilize the teaching of Singh_2 to the system of Singh in order to provide a simplified network configuration solution.
The limitations of claim 18 are rejected in the analysis of claim 9 above, and the claim
is rejected on that basis.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHEIKH T NDIAYE whose telephone number is (571)270-3914. The examiner can normally be reached Monday-Friday 8:00am-5:30pm.
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/CHEIKH T NDIAYE/Primary Examiner, Art Unit 2447
4/2/2026