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 .
Response to Amendment
Claims 1-20 are pending in the application. Claims 1, 11, and 19-20 are currently amended. No claims have been canceled. No claims are currently added.
Response to Arguments
With regard to Applicant’s remarks dated July 8, 2026:
Regarding the rejection of claims 1-20 under 35 U.S.C. 103, Applicant’s amendment and arguments have been fully considered and are persuasive. Applicants argue that the instant application distinguishes congestion ACKs used for throttling from redirect ACKs used for rerouting. In particular, Applicants argue at pages 11-12 of the Remarks, as filed, that “for congestion at a remote egress port or a local egress LAG port, the system can throttle the flow based on a congestion ACK. In contrast, when a flow experiences "mid-fabric congestion," including congestion "at the egress LAG port in the first network fabric in a flow which extends across two network fabrics," the system "can reroute the flow based on a redirect ACK sent from the egress LAG port in the first network fabric to an ingress port of the first network fabric." More specifically, the network device associated with LAG port 273 "can determine mid-point or mid-fabric congestion at LAG port 273 and can send upstream a redirect ACK (286) indicating that the flow is to be considered as a candidate flow to be rerouted.” The ingress-side network device then selects the flow from the candidate flows and forwards the selected flow on a second path over a second LAG port. The application also describes FIG. 2D as including "redirect ACKs from LAG ports in a first network fabric which prompt an ingress port in the first network fabric to reroute a flow." Furthermore, the system "may determine a certain level of congestion associated with [selected] LAG port 273" and "[b]ecause the flow extends across two network fabrics," the detected congestion "may be referred to as 'mid-fabric' congestion ". Examiner agrees.
Regarding teachings of Liu, Applicants argue that “a query packet which is a controller- directed report of port load information for adjusting traffic distribution among physical ports (as in Liu) is not the same as a redirect ACK generated by a first LAG port after determining mid-fabric congestion, does not identify an already-forwarded flow as a rerouting candidate, and does not cause an ingress-side device to reroute that flow over another LAG port (as in the instant claims).” Examiner agrees. Therefore, the rejection has been withdrawn. Upon further search and consideration, new grounds of rejection have been made in view of the newly discovered references, presented below.
As to any arguments not specifically addressed, they are the same as those discussed above.
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Venkatesh et al. (US 2014/0198656 A1) in view of Liu et al. (US 2021/0352018 A1) and in further view of Kopser et al. (US 2022/0191127 A1).
As to claim 1, Venkatesh teaches a computer-implemented method, comprising:
receiving, by a network device in a first network fabric, a to be forwarded flow over a link aggregation group (LAG) comprising a plurality of physical ports aggregated as a single logical port [identifying traffic flow through the switch] (par. [0010], [0038]-[0039]);
determining loads associated with the LAG ports [compare link utilization with load threshold] (par. [0042], [0078]);
selecting a first LAG port for the flow based on a first load associated with the first LAG port [distribute packets of different flows across the links of link aggregation based on a distribution policy for link aggregation] (par. [0059]);
forwarding the flow on a first path over the selected first LAG port (par. [0059]);
storing a state of the flow, wherein the flow is forwarded in a second network fabric [storing state of the flow in the hash distribution table] (par. [0069], [0073]);
selecting the flow from a plurality of candidate flows to be rerouted [changing traffic distribution across links based on the corrective action] (par. [0065], [0079]); and
forwarding the selected flow on a second path over a second LAG port (par. [0076]).
While Venkatesh teaches comparing respective utilizations of links in link aggregation to detect high link utilization (par. [0078]), Venkatesh fails to expressly teach receiving, from the first LAG port, a redirect acknowledgment (ACK) indicating that the flow is to be considered as a candidate flow to be rerouted; and determining, based on the redirect ACK, that the first LAG port has detected mid-fabric congestion.
Liu is directed to traffic balancing (abstract). In particular, Liu teaches receiving, from the first LAG port, a redirect acknowledgment (ACK) [query packet that carries load information of each physical port in a plurality of physical ports of a logical port, based on which the amount of traffic carried on each port is adjusted] (par. [0044], [0077]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method and system of Venkatesh by receiving, from the first LAG port, a redirect acknowledgment (ACK) in order to provide an alternative way to adjusting a hash factor used in hash calculation in the system of Venkatesh (par. [0052] in Liu).
Kopser is directed to facilitating a fair allocation of bandwidth at the ingress port (abstract). In particular, Kopser teaches receiving, from an ingress edge port, a redirect acknowledgment (ACK) indicating that the flow is to be considered as a candidate flow to be rerouted; and determining, based on the redirect ACK, that the first LAG port has detected mid-fabric congestion [the ACK type field can be used to indicate various types and severity of congestion, such as a new congestion on a flow, persistent congestion on a flow, severe congestion at the egress edge port, or mid-fabric localized congestion that calls for rerouting of the flow to rebalance the load across the entire fabric] (par. [0065], [0170], Fig. 3B).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method and system of Venkatesh in view of Liu by receiving, from the first LAG port, a redirect acknowledgment (ACK) indicating that the flow is to be considered as a candidate flow to be rerouted; and determining, based on the redirect ACK, that the first LAG port has detected mid-fabric congestion, in order to notify the network device operating in the first network fabric of different types of network condition and facilitate flow rerouting (par. [0065], [0097], [0170] in Kopser).
As to claim 2, Venkatesh in view of Liu teaches that determining the loads associated with the LAG ports comprises: receiving, from one or more other network devices in the first network fabric, information associated with usage of: the LAG ports; and paths in the first network fabric from the network device to the LAG ports [load information of each physical port] (par. [0042], [0090] in Venkatesh; par. [0052], [0059] in Liu).
As to claim 3, Venkatesh in view of Liu teaches that a respective load associated with a respective LAG port comprises a value in a plurality of ranges of values, and wherein a respective range indicates a level of usage of the respective LAG port (par. [0059]-[0060] in Liu).
As to claim 4, Venkatesh in view of Liu teaches selecting the first LAG port in response to the flow comprising at least one of: unordered packets; or a new flow (par. [0051] in Liu).
As to claim 5, Venkatesh teaches that selecting the first LAG port comprises: identifying a set of LAG ports associated with loads less than a first predetermined threshold (par. [0079]); and selecting the first LAG port from the identified set of LAG ports based on at least one of: performing a hash on one or more fields of a header of a packet in the flow; or selecting the first LAG port from the identified set of LAG ports based on a random number generator (par. [0077], [0098]).
As to claim 6, Venkatesh in view of Liu teaches waiting a predetermined amount of time prior to forwarding the flow over the selected first LAG port or the second LAG port; wherein the predetermined amount of time is based on at least one of: a default amount of time; a round trip time associated with sending a packet of the flow to a destination of the flow; or whether a notification to pause the flow is received by the network device in the first network fabric [port load information is collected and send to the controller device periodically, so forwarding the flow of the second LAG port would only happen periodically upon receiving and analyzing the query packet] (par. [0086]-[0087] in Liu).
As to claim 7, Venkatesh in view of Liu teaches determining the second path over the second LAG port over which to forward the selected flow based on at least one of: a second load associated with the second LAG port being less than a second predetermined threshold, wherein the redirect ACK is received based on the first load associated with the first LAG port exceeding the second predetermined threshold [changing traffic distribution across links based on the corrective action] (par. [0065], [0079] in Venkatesh; par. [0058]-[0059] in Liu); a cost of reaching a respective LAG port of the LAG ports; a group associated with the respective LAG port; a type of the selected flow; a Quality of Service associated with the selected flow; or the state of the selected flow.
As to claim 8, Venkatesh in view of Liu teaches receiving at least one of: from a respective LAG port, a first congestion ACK indicating a first value of congestion for the flow at the respective LAG port [load information of one or more physical ports] (par. [0061] in Liu); or from the second network fabric, a second congestion ACK indicating a second value of congestion for the flow at an egress of the second network fabric, wherein storing the state comprises storing the first value and the second value (par. [0089] in Liu).
As to claim 9, Venkatesh in view of Liu teaches throttling the flow based on at least one of: the received first congestion ACK indicating the first value; the received second congestion ACK indicating the second value; or the respective congestion ACK indicating a greater of the first value and the second value (par. [0065]-[0066] in Venkatesh; par. [0058]-[0059] in Liu).
As to claim 10, Venkatesh in view of Liu teaches receiving the redirect ACK from the first LAG port in response to at least one of: a respective load associated with the first LAG port exceeding a third predetermined threshold; a total load associated with the LAG ports exceeding a fourth predetermined threshold; or a change in the loads associated with the LAG ports exceeding a fifth predetermined threshold [query packet is sent to the controller when it is determined that the traffic of the at least one physical port exceeds the present threshold] (par. [0092] in Liu).
As to claim 11, Venkatesh in view of Liu and Kopser teaches a network device operating in a first network fabric [switch 500 in Venkatesh], the network device comprising: one or more processing resources (par. [0110] in Venkatesh); and a storage device storing instructions (par. [0115] in Venkatesh) which when executed by the one or more processing resources comprise instructions to perform the method steps, as discussed per claim 1 above.
As to claims 12-17, Venkatesh in view of Liu teaches all the elements, as discussed per corresponding method claims 2-10 above.
As to claim 18, Venkatesh teaches that the first network fabric and the second network fabric comprise at least one of: an Ethernet network; a network comprising entities which communicate using an Ethernet-based protocol; or a network based on Ultra Ethernet Consortium (UEC) (par. [0021], [0044] in Venkatesh).
As to claims 19-20, Venkatesh in view of Liu and Kopser teaches a non-transitory computer-readable medium storing instructions (par. [0115] in Venkatesh) to perform the method steps, as discussed per claim 1 above.
Pertinent Prior Art
Dhamal Gopalarathnam (US 2024/0073124 A1) is directed to quality-based load balancing for multipath routing in networks (abstract). In particular, Dhamal Gopalarathnam teaches determining link quality values associated with links based on link quality factors and selecting links using link quality (par. [0073], Fig. 4).
Ye et al. (US 2026/0025426 A1) is directed to cluster load balancing method and apparatus (abstract). In particular, Ye teaches congestion along the path and switching the connection to less congested path (Fig. 6, par. [0073]-[0095]).
Ma et al. (US Patent 10,205,629 B2) is directed to triggering protection switching by signal degrade of a link aggregation port (abstract). In particular, Ma teaches receiving a port status and performing switching in response to the signal degrade status (col. 6 lines 25-49).
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.
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/OLEG SURVILLO/Primary Examiner, Art Unit 2457
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