DETAILED ACTION
This action is in response to communication filed on 1/20/2026.
Claims 1-20 are pending.
Claims 1, 9, and 17 have been amended.
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 Arguments
Applicant’s arguments, see pages 7-10, filed 1/23/2026, with respect to the rejection(s) of claim(s) 1, 9, and 17 under 35 USC § 102 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Yadav et al. (US 2021/0266251) in view of Saad et al. (US 2023/0224238).
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 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yadav et al. (US 2021/0266251) in view of Saad et al. (US 2023/0224238).
Regarding claim 1, Yadav discloses a non-transitory computer-readable medium storing instructions that, when executed, cause one or more processors to execute steps of:
obtaining a compressed segment list for a calculated path in a Segment Routing network, wherein the Segment Routing network includes a plurality of domains with the calculated path being through at least two domains (see Yadav [0044]; a packet originating at the node 11 and destined for the node 33 includes SIDs 16011, 16014, 40001 where 16011, 16014 are prefix SIDs and 40001 is a binding SID that denotes the node 21 in the domain 7 and the destination of the node 33 in the domain 8. At the node 21, the binding SID 40001 is popped and replaced with SIDs 17021, 17023, 50001 where 17021, 17023 are prefix SIDs, and 50001 is a binding SID that denotes the node 31 in the domain 8 and the destination of the node 33 in the domain 8. At the node 31, the binding SID 50001 is popped and replaced with SIDs 18031, 18033. Thus, the binding SID reduces the SID depth. This discloses obtaining a compressed segment list (initial SID list with binding SIDs replacing multiple prefix/adjacency SIDs to reduce depth) for a calculated path (multi-domain path from node 11 to 33, determined via loose source routing) in a segment routing network (SR with MPLS or IPv6). The mapping discloses the limitation because the source node obtains and encodes a shorter SID list post-path calculation, using binding SIDs to “stitch the path and reduce the SID depth,” ensuring the list fits hardware MSD limits (e.g., 3-4 labels)),
wherein the compressed segment list includes a plurality of Segment Identifiers (SID) each SID identifying a segment (see Yadav [0026; 0030]; in loose source routing, the source node chooses a path and encodes the chosen path in a packet header as an ordered list of segments. This discloses a compressed segment list (ordered list of segments encoded in header, shortened via binding SIDs to address MSD limits) including a plurality of SIDs (segment encoded as list), each identifying a segment. The mapping discloses the limitation because the list is compressed using breach/binding SIDs, where each SID in the list identifies a network segment for routing), and
wherein, when expanded, the compressed segment list matches the calculated path (see Yadav [0051]; In the example of FIG. 7, the node 11 provides a SID list of 16011, 60001, where 60001 is a branch SID with an anycast group, including the nodes 21, 26. This discloses that when expanded (branch SID 60001 bound to policies p2-1/p2-2, allocating binding segments), the compressed list matches the calculated path (policies define domain traversal, ensuring expanded segment follow calculated route). The mapping discloses the limitation because the single branch SID compresses the list, and expansion via policy bindings reproduces the full path);
analyzing the compressed segment list for any domain border routers between two domains of the at least two domains to determine associated anycast SID for the any domain border routers (see Yadav [0006]; a border node in a multi-domain network includes a plurality of ports; and switching circuitry configured to forward packets between the plurality of ports, wherein the border node is configured to receive a packet from a first domain, the packet is destined for a destination node in a same domain as the border node or another domain in the multi-domain network, pop a Segment Identifier (SID) from the packet, wherein the SID represents both an anycast SID and a binding SID, the packet being sent to the border node from the first domain based on the presence of the border node in an anycast group associated with the SID, add one or more SIDs to the packet based on a policy associated with a binding segment for the SID, and forward the packet with the one or more SIDs. This discloses analyzing the compressed segment list (processing the SID stack/list at the border, where the list is compressed via the branch SID replacing multiple SIDs to optimize depth) for domain border routers (dual-homed border nodes between domains, identified via the branch SID in the list). The mapping discloses the limitation because the border node examines (pops and processes) the SID in the list to confirm it is a border router in the anycast group, enabling inter-domain forwarding in multi-domain network); and
utilizing the associated anycast SID in the compressed SID list for resiliency between the two domains (see Yadav; [0006]; pop a Segment Identifier (SID) from the packet, wherein the SID represents both an anycast SID and a binding SID, the packet being sent to the border node from the first domain based on the presence of the border node in an anycast group associated with the SID. This discloses determining an associated anycast SID (popped SID represents anycast, associated with border’s anycast group) for the domain border routers (border node in multi-domain). The mapping discloses the limitation because analysis (popping) determines the SIDs anycast for the border).
However the prior art does not explicitly disclose the following:
analyzing the compressed segment list for any domain border routers between two domains of the at least two domains to determine associated anycast SID for the any domain border routers,
wherein the analyzing includes (i) identifying, from the calculated path, a domain border router between a first domain and a second domain and identifying one or more corresponding domain border routers that participate in both the first domain and the second domain, and (ii) monitoring advertisements in the Segment Routing network to determine an anycast prefix and a corresponding anycast SID that are advertised by exactly the corresponding domain border routers; and
wherein utilizing includes replacing a node SID for the domain border in the compressed segment list with the anycast SID.
Saad in the field of the same endeavor discloses techniques for using domain segment identifiers (domain SIDs), which can be anycast SIDs, advertised by border network devices that straddle multiple domains, so that ingress/egress devices can identify the core domain and the appropriate border devices, then build a compressed inter-domain segment list that leverages those domain SIDs for shortest-path inter-domain routing and automatic resiliency across domain boundaries. In particular, Saad teaches the following:
analyzing the compressed segment list for any domain border routers between two domains of the at least two domains to determine associated anycast SID for the any domain border routers (Saad discloses analyzing paths/list that cross domain boundaries and determining/using domain SIDs (which can be anycast-SIDs) associated with the boarder devices; [0020-0021] “the domain SID may be an anycast-SID, such that each device within the domain will be associated with the domain SID…. leaf domain network 1 and the ingress network device may identify the core domain network (via domain SID 123). Additionally, leaf domain network 1 and the ingress network device may identify that border network device 1 and/or border network device 2 are associated with the core domain network”)
wherein the analyzing includes (i) identifying, from the calculated path, a domain border router between a first domain and a second domain and identifying one or more corresponding domain border routers that participate in both the first domain and the second domain (Saad discloses identifies border network devices from the inter-domain path and notes that the same boarder devices participate in both the leaf domain and the core domain; [0021-0023] “border network device 1 and/or border network device 2 may advertise the core domain SID 123 to leaf domain network 1… may advertise leaf domain network 1 domain SID 100 to the core domain network” and [0048] “border network device 1 may be associated with the core domain network and leaf domain network 1. Border network device 2 may be associated with the core domain network, leaf domain network 1, and leaf domain network 2. Border network device 3 may be associated with the core domain network and leaf domain network 2”), and
(ii) monitoring advertisements in the Segment Routing network to determine an anycast prefix and a corresponding anycast SID that are advertised by exactly the corresponding domain border routers (Saad discloses monitoring the advertisements from precisely the border devices that straddle the two domains. Those devices advertise the domain SID, which is an anycast SID since the border devices that belong to both domains advertise both domain SIDs; [0020] “The domain SID may be an anycast-SID, such that each device within the domain will be associated with the domain SID… each border network device may advertise (e.g., broadcast, transmit, and/or the like) each domain network that the border network device is associated with”); and
wherein utilizing includes replacing a node SID for the domain border in the compressed segment list with the anycast SID (Saad discloses using the anycast domain SID (instead of individual node SIDs) in the inter-domain segment list/BGP-SR-TE list, which inherently provides resiliency (traffic can reach any border device in the anycast group). The “replacing” step is performed by performed by the ingress device when it builds the compressed list; [0020] “The domain SID may be an anycast-SID, such that each device within the domain will be associated with the domain SID” and [0032] “The border network device 3 and/or the border network device 4 may advertise the BGP-SR-TE segment list to the border network device 1 and/or the border network device 2. The border network device 1 and/or the border network device 2 may add to the egress network device location segment by adding the domain SID identifying the core domain network (e.g., 123). The border network device 1 and/or the border network device 2 may advertise the BGP-SR-TE segment list (including the egress network device location segment identifying the core domain SID, the originating leaf domain SID, and the egress network device SID) to the ingress network device”. Note the ingress device substitutes the anycast domain SID for the individual border node SIDs when compressing the list, enabling automatic failover to any border device in the group).
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 Saad to enable identification of inter-domain border routers and allow the ingress device to build compressed segment lists that achieve automatic resiliency and shortest-path routing across domains, thereby conserving computing and network resource that would otherwise be consumed by propagating full forwarding state information.
Regarding claim 2, Yadav-Saad discloses the non-transitory computer-readable medium of claim 1, wherein the analyzing further includes steps of identifying a domain border router between the two domains (see Yadav [0058]; for a packet destined for a destination node in another domain in a multi-domain network, adding a list of Segment Identifiers (SIDs) to the packet for loose source-based routing from a source node, through a first domain, and to the another domain (step 81); and forwarding the packet via a port with the list of SIDs (step 82), wherein the list of SIDs includes at least one SID representing both an anycast SID and a binding SID); and
for the identified domain border router, identifying corresponding one or more domain border routers and determining the associated anycast SID based thereon (see Yadav [0059]; the at least one SID can be associated with an anycast group that includes a plurality of nodes in a second domain, connected to the first domain. The first domain can be configured to send the packet with the at least one SID to a closest node of the plurality of nodes. The at least one SID can be associated with a binding segment in the second domain, and the binding segment includes a different SID list for each node of the plurality of nodes).
Regarding claim 3, Yadav-Saad discloses the non-transitory computer-readable medium of claim 1, wherein the plurality of Segment Identifiers (SID) include node SIDs (see Yadav [0030]; a SID can be one of the following types an adjacency SID, a prefix SID, a node SID, a binding SID, and an anycast SID. Each SID represents an associated segment, e.g., an adjacency segment, a prefix segment, a node segment, a binding segment, and an anycast segment).
Regarding claim 4, Yadav-Saad discloses the non-transitory computer-readable medium of claim 1, wherein the plurality of Segment Identifiers (SID) include node SIDs and adjacency SIDs (see Yadav [0030]; a SID can be one of the following types an adjacency SID, a prefix SID, a node SID, a binding SID, and an anycast SID. Each SID represents an associated segment, e.g., an adjacency segment, a prefix segment, a node segment, a binding segment, and an anycast segment).
Regarding claim 5, Yadav-Saad discloses the non-transitory computer-readable medium of claim 1, wherein the steps further include prior to the obtaining, performing a path calculation for the calculated path without considering the any domain border routers (see Yadav [0069]; a source node in a first domain in a multi-domain network includes a plurality of ports; and switching circuitry configured to forward packets between the plurality of ports, wherein the source node is configured to, for a packet destined for a destination node in another domain in the multi-domain network, add a list of Segment Identifiers (SIDs) to the packet for loose source-based routing from the source node, through the first domain, and to the another domain).
Regarding claim 6, Yadav-Saad discloses the non-transitory computer-readable medium of claim 5, wherein the steps further include prior to the obtaining and subsequent to the performing, determining the compressed segment list with node SIDs and with zero or more adjacency SIDs (see Yadav [0044]; a packet originating at the node 11 and destined for the node 33 includes SIDs 16011, 16014, 40001 where 16011, 16014 are prefix SIDs and 40001 is a binding SID that denotes the node 21 in the domain 7 and the destination of the node 33 in the domain 8).
Regarding claim 7, Yadav-Saad discloses the non-transitory computer-readable medium of claim 2, wherein the analyzing the compressed segment list includes identifying the domain border router based on a corresponding node SID in the plurality of SIDs (see Yadav [0044]; a packet originating at the node 11 and destined for the node 33 includes SIDs 16011, 16014, 40001 where 16011, 16014 are prefix SIDs and 40001 is a binding SID that denotes the node 21 in the domain 7 and the destination of the node 33 in the domain 8).
Regarding claim 8, Yadav-Saad discloses the non-transitory computer-readable medium of claim 1, wherein the steps further include monitoring advertisements from the Segment Routing network to determine the domain border routers and the associated anycast SIDs (see Yadav [0033]; An anycast segment is a type of prefix segment that represents an anycast group and is advertised with its P-Flag (no PHP) bit set for ISIS, NP-Flag for OSPFv2, and for OSPFv3 set prefix SID sub-Type-Length-Value (TLV) bit to 1 and E-Flag to 0).
Regarding claim(s) 9-16 and 17-20, do(es) not teach or further define over the limitation in claim(s) 1-8 and 1-3, 8 respectively. Therefore claim(s) 9-16 and 17-20 is/are rejected for the same rationale of rejection as set forth in claim(s) 1-8 and 1-3, 8 respectively.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
For the reason above, claims 1-20 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