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
This office action is in response to amendment/reconsideration filed on 2/5/2026, the amendment/reconsideration has been considered. Claims 1-20 are pending for examination as cited below.
Response to Arguments
Applicant's arguments filed 2/5/2026 have been fully considered but they are not persuasive. In remarks applicant argues:
I. Applicant’s arguments regarding “determining that the first gateway is closer…”
Applicant argues that Boutros does not disclose or suggest determining that a first gateway is closer to an access node than a second gateway based on receiving two TLVs from two gateways.
Applicant further argues that Boutros merely describes anycast forwarding behavior and does not teach the claimed determination. These arguments are not persuasive.
(a) Boutros explicitly teaches determining the nearest gateway
Boutros discloses that packets addressed to an anycast address are forwarded to the nearest node according to an IGP:
“A packet send to an anycast address is forwarded to a nearest node (also referred to as a closest node or along a shortest path) according to an internal gateway protocol (IGP) (e.g., OSPF, RIP, IS-IS.” (Boutros, [0019]).
This is an explicit disclosure of determining which gateway is closer based on routing information.
Applicant asserts that Boutros does not disclose the determination being made “subsequent to receiving two TLVs.” However, the claim does not require the TLVs themselves to contain distance information – only that the determination occurs in response to receiving them.
Boutros teaches:
ESGs advertise reachability information (e.g., anycast VTEP IP) to forward elements. (Boutros [0034]-[0035]).
Forwarding element use IGP metrics to determine the nearest ESG (Boutros, [0039]).
Thus, Boutros teaches receiving gateway-oriented information (analogous to TLVs) and determining which gateway is closer. The claim does not require the TLVs to contain distance metrics; it only requires the determination to occur after receiving them. Hence, Boutros satisfies this.
II. Applicant’s argument regarding “in response to determining that the L2 I-SID exists in LSDB…”
Applicant argues that Farkas does not disclose determining that the L2 I-SID exists in the LSDB of the access node, nor does it disclose the claimed “in response” relationship.
(a) Farkas explicitly teaches storing services instance identifies (SIDs) in a control plane database
Farkas discloses:
Extracting the SID from received MMRPDUs (Farkas, [0006], [0007])
Saving the SID and associated MAC addresses into a control plane database (Farkas, [0007], fig.7, step-704).
Maintain this information for forwarding decision.
This is equivalent to storing the SID in a link0state database (LSDB) of the node. The LSDB is simply a control-plane database containing link-state or service-state information. The claim does not require a specific LSDB format.
Thus, Farkas teaches determining the SID exists in the node’s database.
(b) The “in response to” relationship is obvious
Applicant argues that the office action did not show that the determination of gateway closeness in made “in response to” determining that the SID exists in the LSDB.
However, the combination of Boutros and Farkas renders this relationship obvious:
Farkas teaches the node extracts and stores the SID in its control-plane database ([0007], fig.7).
Boutros teaches that the node determines the nearest gateway using routing information ([0009], [0039]).
It would have been obvious for the node to perform the gateway-selection logic after confirming that the service instance (SID) is active, because:
Farkas teaches that forwarding behavior is conditioned on the SID being present ([0006], [0007]).
Boutros teaches that gateway selection is performed when forwarding traffic for service instance ([0036]-[0039]).
Thus, the “in response to” relationship is a logical and necessary sequencing of two known operations.
The law does not require explicit disclosure of exact sequence when the ordering is inherent or obvious from the combined teaches. See MPEP 2143, KSR v. Teleflex.
III. Applicant’s argument that the reference do not teach the claimed TLV-based determination
Applicant asserts that neither reference teaches receiving two TLVs from two gateways and determining which gateway is closer. This is not persuasive.
(a) Boutros teaches receiving gateway-originated advertisement
Boutros discloses:
ESGs advertise the anycast VTEP IP address to forwarding element ([0034]).
Forwarding elements receive these advertisements and use them to determine reachability ([0034]-[0035]).
These advertisements are type-length-value (TLV)-like structures, as they contain structured routing information. The claim does not require specific TLV format.
(b) Farkas teaches receiving structured control messages (MMRPDUs)
Farkas discloses:
Receiving MMRPDUs containing structured lists of interested nodes ([0006], fig.3, step-302).
Extracting SIDs and MAC lists from the se structured messages ([0006]-[0007]). MMRPDUs are also TLV-like structures.
(c ) Combining the two reference is obvious
It would have been obvious to:
Use the SID-based service-instance information from Farkas, and
Use the gateway-reachability information from Boutros,
To determine which gateway is closer after confirming the service instance is active.
Accordingly, the rejection of claims 1, 8 and 15 and their dependents, under 35 U.S.C. 103 is maintained. 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.
Claim(s) 1-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Boutros et al. (Pub. No.: US 2018/0097734 A1), hereinafter “Bou” in view of “Farkas et al. (Pub. No.: US 2015/0222492 A1), hereinafter “Far”.
As to claim 1. Bou discloses, a method for using gateways in a Shortest Path Bridging (SPB) network (Bou, [0003], OSPF), the method comprising:
receiving, by an access node, a first Type-Length-Value (TLV) from a first gateway, wherein the first TLV comprises a Client Media Access Control (CMAC) address for the first gateway, an Internet Protocol (IP) address of the first gateway, and a layer 2 (L2) Instance Service Identifiers (I-SID) associated with the first gateway (Bou, [0025], advertising, by edge service gateways (ESGs), availability of an anycast inner IP address and an anycast virtual extensible local area network tunnel endpoint ( VTEP) IP address at a hypervisor VTEP IP address to peers on an ESG uplink (see paragraph), and a packet sent to an anycast address is forwarded to a nearest node (a closest node or a shortest path) according to an internal gateway protocol (IGP) (e.g., open shortest path first (OSPF) or intermediate system to intermediate system (IS-IS)) (see paragraph [0019]);
receiving, by the access node, a second TLV from a second gateway, wherein the second TLV comprises the CMAC address, the IP address, and the L2 I-SID (Bou, [0002], wherein multiple edge service gateways (ESGs) may use a same anycast inner IP address and a same anycast inner media access control (MAC) address (see paragraph);
in response to determining that the L2 I-SID exists in Link State Databases (LSDB) of the access node, determining that the first gateway is closer to the access node than the second gateway (Bou, [0019], and a packet sent to an anycast address is forwarded to a nearest node (a closest node or a shortest path) according to an internal gateway protocol (IGP) (e.g., open shortest path first (OSPF) or intermediate system to intermediate system (IS-IS));
storing the CMAC address in a database to point to the first gateway based on the determination (Bou, storing the anycast VTEP IP address as available via physical forwarding elements that have advertised availability of the anycast VTEP IP address in a forwarding table (see paragraph [0048]), wherein a physical forwarding element will continue to advertise the availability of the anycast VTEP IP address as long as one ESG is executing on a host connected to the physical forwarding element (see paragraph [0035]).
Bou however is silent to disclose explicitly, "receiving, by an access node, a first Type-Length- Value (TLV) from a first gateway, wherein the first TLV comprises a Client Media Access Control (CMAC) address for the first gateway, an Internet Protocol (IP) address of the first gateway, and a layer 2 (L2) Instance Service Identifiers (I-SID) associated with the first gateway", and "determining that the L2 I-SID exists in Link State Databases (LSDB) of the access node".
For, however teaches a similar concept in the same field of endeavor e.g., the different features would be easily derived from the disclosure of D2 (see paragraphs [0054], [0057): a node, within a network complying with an implementation of multiple mac registration protocol (MMRP) and using a shortest path bridging (SPB) protocol, sends a set of MMRPDUs to links associated with a service instance, the set of MMRPDUs containing a set of MAC addresses are encapsulated in a set of Ethernet frames containing references to the service instance, and the set of MAC addresses are stored in the encapsulating frames in a type length value (TLV) field when other protocols are used; and see paragraph [0067): if an extracted service instance is associated with a backbone virtual LAN identifier (B-VID) that a designated forwarder (DF) within an internetworking routing module (620) is proxy for, the internetworking routing module extracts the service instance identifier (e.g., an I-SID) and MAC addresses interested in the service instance identifier and stored in an internetworking database (622), the internetworking database may be a frame forwarding database on a control plane, and it may be used for frame forwarding using an implementation of intermediate system-intermediate system (IS-IS) protocol).
Therefore, before the effective filing date of the instant application it would have been obvious to one of the ordinary skilled in the art to incorporate the teachings of “Far” into those of “Bou” to provide a method involves sending a set of multiple media access control (MAC) registration protocol data units (MMRPDUs) to a set of links associated with a service instance, where the MMRPDUs contain a set of MAC addresses interested in the instance including MAC addresses not received from the links. A filtering unit is installed at a node (1000) such that an Ethernet frame is forwarded to destination if the Ethernet frame is destined to interested nodes identified by another set of MAC addresses. Logical loop free topologies are created by implementing a protocol.
As to claims 8 and 15 are rejected for same rationale as applied to claim 1 above. It is further noted that the amended portion of claim 15 is well known in the art as evident by (Kuwata et al. Pub. No.: 20170244572 A1, [0057]).
As to claims 2, 9 and 16. The combined system of Bou and Far discloses the invention as in parent claim above including, wherein the first gateway has a first priority for forwarding the packet and the second gateway has a second priority for forwarding a packet (Bou, [0019]: such a nearest node along a route is calculated based on administrative distance values, used to determine a priority, with larger values indicating lower priority types of route).
As to claims 3, 10 and 17. The combined system of Bou and Far discloses the invention as in parent claim above including, determining that the first gateway is unavailable; and updating the database such that the CMAC address points to the second gateway as the first priority for forwarding the packet (Bou, [0048]; claim 4; and figure 8: an edge gateway in the plurality of edge gateways advertises the availability of the anycast VTEP IP address to a forwarding element connecting the edge gateway to an underlay network, and an physical forwarding element 845 runs an IGP (interior gateway protocol) that recognizes physical forwarding elements 840A and 840B as being a next hop for the VTEP IP address (e.g., through a forwarding table that stores the anycast VTEP IP address as available via the physical forwarding elements that have advertised the availability of the any cast VTEP IP address)).
As to claim 4. The combined system of Bou and Far discloses the invention as in parent claim above including, receiving a third TLV from a third gateway, wherein the third TLV comprises the CMAC address, the IP address, and the L2 I-SID (Bou, [0019]: anycast addressing allows a same address to be used for multiple destinations (redundant destinations), a packet sent to the anycast address is forwarded to a nearest node (also referred to as a closest node or along a shortest path) according to an internal gateway protocol (IGP) (e.g., open shortest path first (OSPF), routing information protocol (RIP), intermediate system to intermediate system (IS-IS), etc.), and such a nearest node along a route is calculated based on administrative distance values, used to determine a priority, with larger values indicating lower priority types of route);
determining that the third gateway is closer to the access node than the first and second gateways; and updating the database such that the CMAC address points to the third gateway as the first priority for forwarding the packet (Far, [0037], [0073]: a internetworking node 802 may create SPBM (shortest path bridging-MAC mode) service identifier and unicast sub address TLVs in order to leak the extracted MMRP information into a control plane database for frame forwarding using ISIS, and the I-SID (identifying a service instance) and associated MAC addresses are saved in the control plane database for frame forwarding).
As to claims 5, 12 and 19. The combined system of Bou and Far discloses the invention as in parent claim above including, determining a first cost metric associated with the first gateway; determining a second cost metric associated with the second gateway; and in response to the second cost metric being greater than the first cost metric, determining that the first gateway is closer to the access node than the second gateway (Bou, [0049]: the load balancing protocol gives more weight to a particular physical forwarding element based on the total capacity of the edge service gateways (ESGs) connected to the physical forwarding element as opposed to the number of ESGs (e.g., one ESG that is provisioned to handle twice as much traffic as another ESG being assigned a weight that is twice (or some other multiple) as great as the other ESG)).
As to claims 6, 13 and 20. The combined system of Bou and Far discloses the invention as in parent claim above including, wherein: the first TLV further comprises a first cost value, the second TLV further comprises a second cost value, determining the first cost metric comprises determining a first combination of the first cost value and a cost value of a first link between the access node and the first gateway, and determining the second cost metric comprises determining a second combination of the second cost value and a cost value of a second link between the access node and the second gateway (Bou, [0019]; a nearest node along a route is calculated based on administrative distance values, used to determine a priority, with larger values indicating lower priority types of route), and D2 (see paragraph [0072]: a SPB (shortest path bridging) network forwards Ethernet frames along shortest path trees, each node within the SPB network may contain a filtering database (FDB) to guide Ethernet frame forwarding, in other word, each node within the SPB network contains a local view of the link state of the network).
As to claims 7 and 14. The combined system of Bou and Far discloses the invention as in parent claim above including, wherein the first gateway and the access node are located in a first network area in a multi-area network and the second gateway is located in a second network area of the multi-area network, and wherein the second network area is different from the first network area (Bou, [0024]; and figure 1: edge service gateways (ESGs) 115A-X are connected to an external network 150 and provide virtual machines or other data compute nodes connected to a data center fabric 130 access to the external network 150 by performing routing services), and D2 (see paragraph [0065]; and figure 6: an internetworking node 602 interconnects an MMRP network 610 and a non-MMRP network 612).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Please see the attached PTO-892.
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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/Tauqir Hussain/Primary Examiner, Art Unit 2446