DETAILED ACTION
This action is in response to communication filed on 5/20/2026.
Claims 1-13 are pending.
Claims 14-20 are withdrawn.
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 10/31/2024 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
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 of this title, 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.
Claims 1-2, 4-5, 8, 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Singh (US 2017/0099180) in view of Kalburgi (US 2019/0207803).
Regarding claim 1, Singh discloses a network device, comprising: a network-side interface; a host-side interface; a processor; and a memory communicatively coupled to the processor, wherein the memory comprises a tracking logic that is configured to:
transmit, to a host device via the host-side interface, a first tracking request including a first data sequence (Singh discloses transmitting ESI Ping request packets (first tracking request) that includes ESI and BFD discriminator (first data sequence/identifying information) toward the multi-homed side. The ESI and BFD discriminator functions as the data sequence/identifying tuple used to initiate and correlate the tracking session with the multi-home entity. Transmission occurs via the interface facing the multi-homed segment (host-side); [0043-0046] “PE router 10C may send ESI Ping request packets to exercise all paths of an ESI … an ESI Ping request packet may be a Label-Switch Path Ping (“LSP Ping”) exploration message that further includes a label stack for routing the packet within an EVPN … The ESI Ping request packet may include, but is not limited to: a local discriminator (or “My Discriminator”) generated by PE router 10C based on the LSP-Ping protocol that uses the BFD protocol… The local discriminator may correspond to or identify a participant in a particular BFD session”);
receive, at the network-side interface, a tracking response for the transmitted first tracking request (Singh discloses receiving the ESI Ping reply (tracking response) at the remote PE; [0047] “PE router 10B may receive the ESI Ping request packet that is sent by PE router 10C … PE router 10B may send the ESI Ping reply back to PE router 10C”).
Singh teaches that upon receiving the reply, the remote PE executes/continues the per ESI BFD session, which inherently involves ongoing BFD control packets (additional tracking requests) after the initial ESI Ping exchange. However, Singh does not explicitly disclose:
generate one or more second tracking requests based on receiving the tracking response at the network-side interface, wherein each of the one or more second tracking requests includes a second data sequence that is different from the first data sequence; and
transmit the generated one or more second tracking requests to the host device via the host-side interface.
Kalburgi in the field of the same endeavor discloses techniques for detecting link faults in network paths containing Link Aggregation Groups (LAGs) by establishing BFD sessions that use a dynamically assigned UDP source port identifier in packet headers to influence the hashing algorithm and force selection/testing of different member links within the LAG. In particular, Kalburgi teaches the following:
generate one or more second tracking requests based on receiving the tracking response at the network-side interface, wherein each of the one or more second tracking requests includes a second data sequence that is different from the first data sequence (Kalburgi discloses generating subsequent packets with a different data parameter/sequence (new dynamically assigned UDP source port identifier) precisely so the hash algorithm selects a different link/path; [0028] “As shown by reference number 155, LSR A may execute the hash algorithm using the new dynamically assigned UDP source port identifier. In this case, the hash algorithm may be used to select a link in the LAG. The selected link may be different than the link selected in association with the previous encapsulated packet as a result of using the hash algorithm with the new dynamically assigned UDP source port identifier”); and
transmit the generated one or more second tracking requests to the host device via the host-side interface (Kalburgi discloses after generating a BFD packet, the network device transmits/provides that packet via the outgoing interface to the next device (LAG device) for forwarding over the selected link/path; [0032] “LER A may dynamically update the UDP source port identifier each time LER A transmits a packet to LSR A. In this case, LSR A may use a hash algorithm to select a different link in the LAG during each packet transmission (e.g., as a result of LER A dynamically updating the UDP source port identifier). In this way, all of the links in the LAG can be tested using BFD”).
Therefore, it would have been obvious to a person of ordinary skill in the art at the time the invention was effectively filed to combine the prior art with the teaching of Kalburgi. One would have been motivated because both address reliable fault detection in redundant multi-path environments, and applying the known method of varying a hash affecting field (UDP source port) in BFD packets would predictably enable better control over which links/paths are exercised and tested in Singh’s multi-homed setup.
Regarding claim 2, Singh-Kalburgi discloses the network device of claim 1, wherein the tracking logic is further configured to:
track, based on the first tracking request and the one or more second tracking requests, a virtual network function associated with the host device (Singh discloses establishing and maintaining per ESI BFD sessions (tracking requests/responses) to monitor the multi-homed customer edge router/host. The tracking is performed based on the exchange of BFD packets and the system determines operational state from the continued receipt (or loss) of replies; [0050] “PE router 10C and PE router 10B may exchange BFD packets, which include the local and remote discriminators, in the BFD session according to a mode specified in RFC 5880, such as Asynchronous or Demand mode, or using an adjunct Echo function … if either communication link 16E fails or a network device or a link on a path between route reflector 18 and PE router 10B fails, PE router 10C may no longer receive BFD reply messages that correspond to a BFD session for ESI 200 from PE router 10B”); and
determine a status of the virtual network function as one of an active state or an inactive state based on the tracking (Singh [0050] “As such, PE router 10C may determine that a BFD session has terminated or has been interrupted if either communication link 16E fails or network device or link on a path between route reflector 18 and PE router 10B fails. That is, if either communication link 16E fails or a network device or a link on a path between route reflector 18 and PE router 10B fails, PE router 10C may no longer receive BFD reply messages that correspond to a BFD session for ESI 200 from PE router 10B”).
Regarding claim 4, Singh-Kalburgi discloses the network device of claim 1, wherein the tracking logic is further configured to:
receive, at the host-side interface, a new tracking response for a second tracking request of the one or more second tracking requests (Kalburgi teaches dynamically changing a parameter in BFD packets (UDP source port identifier, which forms part of the host input/data sequence) so that subsequent packets in the session hash to different links/paths in a LAG; [0027] “LER A may generate and encapsulate a second packet, in the same manner described above. In this case, the second packet may be encapsulated with a UDP header that includes a new dynamically assigned UDP source port identifier”); and
designate the second data sequence of the second tracking request as an active data sequence for one or more subsequent tracking requests (Singh discloses BFD (ESI Ping/per ESI BFD sessions) in active-active multi-homing EVPN topologies, where responses are used to determine reachability and trigger actions (e.g., redirect); [0042] “PE router 10C may run BFD sessions on a per-ESI basis with each PE router operating in active-active mode in the same Ethernet Segment (e.g., having the same ESI). In this way, if PE router 10C determines for example, via a per-ESI BFD session with PE router 10B, that network traffic cannot reach CE router 8B from via PE router 10B, then PE router 10C may immediately re-direct network traffic for the Ethernet Segment away from PE router 10B and to other PE routers that are coupled to PE router 10C in active-active mode in the same Ethernet Segment, such as PE router 10A”).
Regarding claim 5, Singh-Kalburgi discloses the network device of claim 4, wherein the first tracking request and the one or more second tracking requests are associated with a response timeout parameter (Kalburgi [0019] “A BFD session may involve periodically sending encapsulated packets over the LSP to determine whether one or more links in the LSP are faulty. The BFD session values may include one or more sender discriminator values and one or more receiver discriminator values, a BFD session identifier, a transmission interval value, a minimum receiver-side speed value (e.g., a limit on a speed at which a receiving device can process packets), a transmission multiplier value (e.g., used in determining a time until packet timeout occurs, as described further herein), or the like”).
Regarding claim 8, Singh-Kalburgi discloses the network device of claim 1, wherein the first tracking request and the one or more second tracking requests correspond to bidirectional forwarding detection (BFD) requests (Singh [0042] “PE router 10C may run BFD sessions on a per-ESI basis with each PE router operating in active-active mode in the same Ethernet Segment (e.g., having the same ESI). In this way, if PE router 10C determines for example, via a per-ESI BFD session with PE router 10B, that network traffic cannot reach CE router 8B from via PE router 10B, then PE router 10C may immediately re-direct network traffic for the Ethernet Segment away from PE router 10B and to other PE routers that are coupled to PE router 10C in active-active mode in the same Ethernet Segment, such as PE router 10A”).
Regarding claim 11, Singh-Kalburgi discloses the network device of claim 1, wherein the host-side interface is communicatively coupled to the host device via a single-hop connection (Singh [0034] “CE router 8B is coupled to PE routers 10A and 10B via links 16D and 16E, respectively, where PE routers 10A and 10B are capable of providing access to EVPN for L2 customer network 6B via CE router 8B”).
Regarding claim 12, Singh-Kalburgi discloses the network device of claim 1, wherein the network-side interface is communicatively coupled to the host device via a multi-hop connection (Singh; [0034] “In EVPN, a CE router may be said to be multi-homed when it is coupled to two physically different PE routers on the same EVI when the PE routers are resident on the same physical Ethernet Segment. As one example, CE router 8B is coupled to PE routers 10A and 10B via links 16D and 16E, respectively, where PE routers 10A and 10B are capable of providing access to EVPN for L2 customer network 6B via CE router 8B”).
Regarding claim 13, Singh-Kalburgi discloses the network device of claim 1, wherein the network device is a member of a multi-homing set coupled to the host device (Singh [0034] “In instances where a given customer network (such as customer network 6B) may couple to service provider network 12 via two different and, to a certain extent, redundant links, the customer network may be referred to as being “multi-homed””).
Claims 3 are rejected under 35 U.S.C. 103 as being unpatentable over Singh (US 2017/0099180) in view of Kalburgi (US 2019/0207803).
Regarding claim 3, Singh-Kalburgi discloses the invention substantially, however the prior art does not explicitly disclose the network device of claim 2, wherein the virtual network function corresponds to a virtual network forwarder (VNF).
Lee in the field of the same endeavor discloses techniques for a Global Resource Orchestrator (GRO) that collects VNF resource container (RC) tables and connectivity matrix updates from multiple VNF forwarders, builds a unified node-VNF RC connectivity matrix, and uses it to dynamically select VNF instances (VNFIs), compute optimal VNF service chain sequences/paths, and re-steer traffic on failures in NFV/SDN networks. In particular, Lee teaches the following:
wherein the virtual network function corresponds to a virtual network forwarder (VNF) (Lee [0039] “The data-forwarding network elements that are attached to the VNF resource containers are referred to as VNF forwarders. Switches or routers are an example of VNF forwarders”).
Therefore, it would have been obvious to a person of ordinary skill in the art at the time the invention was effectively filed to combine the prior with the teaching of Lee. One would have been motivated because Lee teaches that virtual network forwarders are known network elements that forward traffic to VNF instances in NFV/SDN environments and manage connectivity for VNF chaining, making it obvious to apply the multi-home EVPN tracking and dynamic LAG fault-detection techniques of Singh and Kalburgi to virtual network forwarders as a specific, common type of VNF to improve reliability and failure detection in virtualized multi-homed networks.
Allowable Subject Matter
Claims 6-7 and 9-10 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.
Conclusion
For the reason above, claims 1-13 have been rejected and remain pending.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JIMMY H TRAN whose telephone number is (571)270-5638. The examiner can normally be reached Monday-Friday 9am-5pm PST.
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JIMMY H TRAN
Primary Examiner
Art Unit 2451
/JIMMY H TRAN/Primary Examiner, Art Unit 2451
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