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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2/25/2026 has been entered.
Response to Arguments
Applicant’s arguments regarding the 103 rejection have been considered and they are not persuasive. The combination of Voyer. Topolcic and Xu teaches each and every limitation in the amended claims. Detailed response can be found in the new ground of rejection in claim 11.
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, 4-11, 14, 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Voyer (Segment Routing Point-to-Multipoint Policy; draft-voyer-pim-sr-p2mp-policy-02. txt", 2020-07-10, cited via IDS) in view of Xu (CN 105337785, cited in IDS) further in view of Topolcic (Experimental Internet Stream Protocol, Version 2 (ST-II), RFC 1190, October 1990).
Regarding claim 11 (similarly to 1, 19, 20), Voyer discloses a first node in a point-to-multipoint (P2MP) tree in a segment routing (SR) domain (Section 2, P2MP tree, a P2MP tree in a SR domain connects a Root to a set of Leaf nodes via a set of intermediate Replication nodes), the first node comprising:
a processor; and a memory coupled to the processor and storing program instructions for execution by the processor, the program instructions instructing the processor to:
determine a first next-hop node of the first node based on replication branch information (section 4.2, computes the tree of Active candidate path. The PCE MAY compute P2MP trees for all Candidate paths. If tree computation is successful, PCE instantiates the P2MP tree(s) using Replication segments on Root, Replication, and Leaf nodes. Here, selecting the candidate path where the node next to the first node or root is the determined first next-hop node of the first node or root; Sections A.1 and A,2, the PCE instantiates the P2MP tree by stitching Replication Segments at R1, R2, (R6 and R7), R2 is the first next-hop node); wherein the first node is a root node of the P2MP tree, and the first next-hop node of the first node is an intermediate replication node of the P2MP tree (Fig. 1, R1 is the root, R2 is the next-hop node).
send a first request message to the first next-hop node (Section A.1, since R1 is directly connected to R2, R1 performs PUSH operation with just <T-SID1> label for the replicated copy and sends it to R2 on interface L12).
Voyer does not explicitly disclose
a processor; and a memory coupled to the processor and storing program instructions for execution by the processor.
wherein the first request message comprises a segment identifier (SID) of the first next-hop node, and a first identifier indicating that the first request message is for connectivity detection.
Xu discloses a processor; and a memory coupled to the processor and storing program instructions for execution by the processor (Xu, fig. 13, [0165]);
send a first request message to the first next-hop node , wherein the first request message comprises a segment identifier (SID) of the first next-hop node, and a first identifier indicating that the first request message is for connectivity detection (Xu, [0003], [0006] and [0102]-[0118], a path connectivity detection method in an SR-SFC network. The method comprises: a transmitting node constructs an Echo Request message, the Echo Request message comprising an identifier of an SF, a message header of the Echo Request message comprising information of a path to the SF, the path information comprising an SID of the SF and explicit path information, wherein the explicit path information comprises the SID of each SN to a destination SN and the SID of the SF; the transmitting node sends the Echo Request message according to the path information. The path information can be considered as identifier for connection detection).
It would have been obvious to a person of ordinary skill in the art before the time of effective filing to combine the teachings of establishing a tree in SR networks as given by Voyer with the teachings of using SID to identify the components in the path given by Xu. The motivation for doing so would have been to provide a path connectivity detection method and device, which can detect path connectivity in an SR network, and are beneficial to realizing OAM functions in an SR-SFC network (Xu, [0006]).
Voyer and Xu do not explicitly disclose for each leaf node on a path passing through the first next-hop node:
in response to the first node receiving a second response message sent by the leaf node on the path passing through the first next-hop node, determine that a path from the first node to the leaf node is connected, wherein the second response message is a response message for the first request message; and the leaf node verifies validity of the first request message based on a second identifier for identifying the P2MP tree prior to sending the second response message;
in response to the first node not receiving a response message sent by the leaf node on the path passing through the first next-hop node and responsive to the first request message, determine that the path from the first node to the leaf node is disconnected.
Topolcic discloses for each leaf node on a path passing through the first next-hop node:
in response to the first node receiving a second response message sent by the leaf node on the path passing through the first next-hop node, determine that a path from the first node to the leaf node is connected, wherein the second response message is a response message for the first request message (Topolcic, section 3.1, page 23, an ST agent that is the target of a CONNECT, whether from an intermediate ST agent, or directly from the origin host ST agent, must respond first; the responses to the CONNECT message are sent to the previous hop from which the CONNECT was received. Section 3.1.8, page 26, the origin will eventually receive an ACCEPT message from each of the targets. When ACCEPTs from all targets have been
received at the origin, the application is notified that stream setup is complete, and that data may be sent, that is the path is connected. Here, the CONNECT is the first request message, the ACCEPT is the second response message, target agent can be considered as leaf, a stream can be considered as a path from the root to the leaf) and the leaf node verifies validity of the first request message based on a second identifier for identifying the P2MP tree prior to sending the second response message (Topolcic, P 107, the processing of a received CONNECT message requires care (or validation) to avoid routing loops that could result from delays in propagating routing information among ST agents. If a received CONNECT contains a new Name, a new stream should be created (unless the Virtual Link Identifier matches a known link in which case an ERROR-IN-REQUEST should be sent, that is, the CONNECT message is invalid based on the virtual link identifier). Furthermore, it is a common practice to validate the received message before sending a response).
in response to the first node not receiving a response message sent by the leaf node on the path passing through the first next-hop node and responsive to the first request message, determine that the path from the first node to the leaf node is disconnected (Topolcic, section 3.1, page 23, page 26, Topolcic discloses only when all the response are received from all nodes in a path, the path is considered, which implicitly discloses if one of the response is not received, the path is not connected, the path will not be setup. Section 3.5, if a message is not acknowledged after a few retransmissions a fault or disconnection is reported, a DISCONNECT is sent to the next-hop (in case the response to the CONNECT is the message that was lost or not received; page 49, the ST agent may discover that the communication with neighboring ST agent has ceased or disconnected because it has not received any traffic, page 50, 4th para. Furthermore, there are many well-known connection detection methods, such as ping program in the internet, if no reply was received from the next hop node after sending out the request message, it is assumed that the first node and the next-hop node is not connected).
It would have been obvious to a person of ordinary skill in the art before the time of effective filing to combine the teachings of establishing a tree in SR networks as given by Voyer and Xu with the teachings of detecting the connectivity of the path given by Topolcic. The motivation for doing so would have been to provide a path connectivity detection method and device, which can detect path connectivity in an SR network.
Regarding claim 14, Voyer, Xu and Topolcic disclose the first node according to claim 11, the programming instructions further instruct the processor to:
receive the second response message sent by the leaf node on the path passing through the first next-hop node (Voyer, fig. 1; Xu, [0114], receives an Echo Reply message of a receiving node responding to the Echo Request message; [0116][0130], determines, according to the Echo Reply message, whether the path to the SF is connected, return code of 0 indicating the path from the first node to a leaf node is connected. Here, the procedure of replication is repeated; Topolcic, section 3.1, page 23, page 26). The motivation of the combination is same as in claim 11.
Regarding claim 16 (similarly to 7), Voyer and Xu disclose the first node according to claim 11, wherein the programming instructions further instruct the processor to:
determine a second next-hop node of the first node based on the replication branch information (Voyer, section A.1, node R2 performs role of a transit node replicating to R6 and R7. Replication to R6, using N-SID6, steers packet via IGP shortest path to that node. Replication to R7, using N-SID7. Here, the first node can be R2); and
send a second request message to the second next-hop node, wherein the second request message comprises a SID of the second next-hop node and the first identifier (Xu, [0003], [0006] and [0102]-[0118], a path connectivity detection method in an SR-SFC network. The method comprises: a transmitting node constructs an Echo Request message, the Echo Request message comprising an identifier of an SF, a message header of the Echo Request message comprising information of a path to the SF, the path information comprising an SID of the SF and explicit path information, wherein the explicit path information comprises the SID of each SN to a destination SN and the SID of the SF; the transmitting node sends the Echo Request message according to the path information. The path information can be considered as identifier for connection detection. Here, the each request taught by Xu can be sent from R2 to R6 or R7 taught by Voyer). The motivation of the combination is same as in claim 11.
Regarding claim 17 (similarly to 8), Voyer and Xu disclose the first node according to claim 11, wherein the first request message comprises the second identifier for identifying the P2MP tree (Voyer, section 3, A SR P2MP Policy is identified by the tuple <Root, Tree-ID>. Xu, the Echo Request message comprising an identifier of an SF, a message header of the Echo Request message comprising information of a path to the SF, the path information comprising an SID of the SF and explicit path information, SF ID can be considered as a tree-ID). The motivation of the combination is same as in claim 11.
Regarding claim 18 (similarly to 9), Voyer and Xu disclose the first node according to claim 17, wherein the second identifier is one or more of address of the root node of the P2MP tree, a replication identifier of a replication segment, or a tree identifier of the P2MP tree (Voyer, section 3, A SR P2MP Policy is identified by the tuple <Root, Tree-ID>. Xu, the Echo Request message comprising an identifier of an SF, a message header of the Echo Request message comprising information of a path to the SF, the path information comprising an SID of the SF and explicit path information, SF ID can be considered as a tree-ID). It is noted that the applicant uses selective language in this claim and the examiner is only showing one of the claimed options. The motivation of the combination is same as in claim 11.
Regarding claim 4, Voyer and Xu disclose the method according to claim 1, wherein the replication branch information comprises a path from the first node to a downstream node, and the first next-hop node is a node on the path from the first node to the downstream node (Voyer, fig. 1, section A.1, assume PCE computes a P2MP tree with Root node R1, Intermediate and Leaf node R2, and Leaf nodes R6 and R7. The PCE instantiates the P2MP tree by stitching Replication Segments at R1, R2, R6 and R7. Replication Segment at R1 replicates to R2. Replication Segment at R2 replicates to R6 and R7. Xu, [0027], the path information includes the ID of all the nodes in the path); and determining the first next-hop node of the first node comprises: determining, by the first node, the first next-hop node based on an identifier of the path (Xu, [0027], the path information includes the ID of all the nodes in the path, therefore, the first next-hop node is determined based on the path info). The motivation of the combination is same as in claim 11.
Regarding claim 5, Voyer and Xu disclose the method according to claim 1, wherein the replication branch information comprises a SID of a downstream node of the first node, and the SID of the downstream node comprises the SID of the first next-hop node (Voyer, sections 2 and 3, and A.1, a packet steered into a P2MP tree is replicated by the Replication segment at Root node to each downstream node in the Replication segment, with the Replication SID of the Replication Segment at the downstream node. A downstream node could be a Leaf node or an intermediate Replication node. Xu, [0109], the path information comprising an SID of the SF and explicit path information, wherein the explicit path information comprises the SID of each SN to a destination SN and the SID of the SF. Here, the downstream node can be the first next-hop node); and
determining the first next-hop node of the first node comprises: determining, by the first node, the SID of the first next-hop node based on the SID of the downstream node (Voyer, sections 2 and 3, and A.1, a packet steered into a P2MP tree is replicated by the Replication segment at Root node to each downstream node in the Replication segment, with the Replication SID of the Replication Segment at the downstream node. A downstream node could be a Leaf node or an intermediate Replication node. Xu, [0109], the explicit path information comprises the SID of each SN to a destination SN. Here, the downstream node can be the first next-hop node). The motivation of the combination is same as in claim 11.
Regarding claim 6, Voyer and Xu disclose the method according to claim 5, wherein when a SID in the SID of the downstream node is a segment routing over internet protocol version 6 IPv6 segment identifier (SRv6 SID), the SID of the first next-hop node comprises an IPv6 address of the first next-hop node (Voyer, section 3. Xu, [0003][0134], here the segment identifier (Segment Identifier, SID) is an identifier assigned by the SR network to the SN or service function SF for guiding forwarding, when SID is represented by an IPv6 address, the SID of SN is an IPv6 global address). The motivation of the combination is same as in claim 11.
Regarding claim 10, Voyer and Xu disclose the method according to claim 1, wherein the first request message comprises time to live (TTL) or a hop limit (HL), and values of the TTL and the HL are natural numbers (Voyer, section 3, packets are transmitted over IPv4 or IPv6, Xu, each request is coded into an IPv4 or IPv6 packet, and it is well known that an IPv6 packet has a field of TTL or HL). The motivation of the combination is same as in claim 11.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZHENSHENG ZHANG whose telephone number is (571)270-1985. The examiner can normally be reached Monday-Thursday 8:00am-6:00pm.
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/ZHENSHENG ZHANG/Primary Examiner, Art Unit 2474
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