Search

EP-4120742-B1 - PATH ESTABLISHMENT METHOD, DATA TRANSMISSION METHOD AND APPARATUS, NETWORK NODE, AND STORAGE MEDIUM

EP4120742B1EP 4120742 B1EP4120742 B1EP 4120742B1EP-4120742-B1

Inventors

  • DU, Zongpeng
  • GENG, Liang

Dates

Publication Date
20260506
Application Date
20210309

Claims (11)

  1. A path establishment method performed by a first network node, the path establishment method comprising: generating (601) a first message for establishing a first path; and transmitting (602) the first message to a next-hop network node, wherein the first message comprises a first Segment Routing IPv6, SRv6, Segment Identifier, SID, of each network node of the first path, the first SRv6 SID is used to establish a connection-oriented path, and the first network node is an initial network node of the first path, wherein the first path is a connection-oriented path, the path establishment method being characterized by further comprising: receiving a feedback message from the next-hop network node for the first message; assigning a second SRv6 SID corresponding to the first path in accordance with the feedback message, the second SRv6 SID being used to forward a message for a connection-oriented path; and generating a local mapping relation table between the second SRv6 SID of the first path.
  2. The path establishment method according to claim 1, wherein the establishing the connection-oriented path comprises establishing a mapping relation between second SRv6 SIDs of the first path, and the second SRv6 SID is used to forward a message for the connection-oriented path.
  3. The path establishment method according to claim 1, wherein the first SRv6 SID of each network node of the first path is carried in a payload of the first message; or wherein the first SRv6 SID of each network node of the first path is carried in a specific Type Length Value, TLV, of a payload of the first message, wherein the first message is a ping message, and the specific TLV is a newly-defined TLV.
  4. The path establishment method according to any one of claims 1 to 3, wherein the mapping relation table comprises a message incoming second SRv6 SID, a message outgoing second SRv6 SID, and an outgoing interface.
  5. A path establishment method performed by a second network node, the path establishment method comprising: receiving (1101) a first message for establishing a first path from a previous hop network node; and performing (1102) a corresponding path establishment operation in accordance with the received first message, wherein the first message comprises a first SRv6 SID of each network node of the first path, the first SRv6 SID is used to establish a connection-oriented path, and the second network node is a network node in the first path other than an initial network node and a last network node, wherein the first path is a connection-oriented path, the path establishment method being characterized in that wherein the performing the corresponding path establishment operation comprises: in the first path, determining that resources are capable of being assigned for the first path, and forwarding the first message to a next-hop network node in the first path; and in a backward path of the first path, performing the following operations: upon the receipt of a feedback message from the next-hop network node corresponding to the first message, assigning a second SRv6 SID corresponding to the first path in accordance with the received feedback message, taking first Argument, ARG, information about a SID corresponding to a destination address in the received feedback message as ARG information about a forwarding SID of the next-hop network node in the first path; generating second ARG information, modifying the SID corresponding to the destination address in the received feedback message in accordance with the second ARG information, and transmitting the modified feedback message to the previous hop network node; and generating a local mapping relation table between the second SRv6 SID of the first path.
  6. The path establishment method according to claim 5, wherein the first SRv6 SID of each network node of the first path is carried in a payload of the first message.
  7. The path establishment method according to claim 5, wherein subsequent to the generating the local mapping relation table between second SRv6 SID of the first path, a data transmission method performed by the second network node is executed, the data transmission method comprising: receiving (1401) a data packet from the previous-hop network node; obtaining (1402) a second SRv6 SID whose destination address is the second network node from the received data packet; looking up (1402) a second SRv6 SID of the next-hop network node corresponding to the second SRv6 SID of the second network node and an outgoing interface in the local mapping relation table between the second SRv6 SIDs; and forwarding (1403) the received data packet in accordance with the second SRv6 SID of the next-hop network node and the outgoing interface, wherein the second SRv6 SID is used to represent that the first path has been established for a first service, the first path comprises M network nodes, the received data packet comprises N SIDs, N is smaller than M, M and N are each an integer greater than 1, and the second network node is a network node in the first path other than an initial network node and a last network node.
  8. A path establishment device arranged at a first network node, comprising: a first generation unit (201) configured to generate a first message for establishing a first path; and a first transmission unit (202) configured to transmit the first message to a next-hop network node, wherein the first message comprises a first SRv6 SID of each network node of the first path, the first SRv6 SID is used to establish a connection-oriented path, and the first network node is an initial network node of the first path, wherein the first path is a connection-oriented path, the path establishment device being characterized by configured further to: receive a feedback message for the first message from the next-hop network node; assign a second SRv6 SID corresponding to the first path in accordance with the feedback message, the second SRv6 SID being used to forward a message for a connection-oriented path; and generate a local mapping relation table between the second SRv6 SID of the first path.
  9. A path establishment device arranged at a second network node, comprising: a first reception unit (211) configured to receive a first message for establishing a first path from a previous hop network node; and a first establishment unit (212) configured to perform a corresponding path establishment operation in accordance with the received first message, wherein the first message comprises a first SRv6 SID of each network node of the first path, the first SRv6 SID is used to establish a connection-oriented path, and the second network node is a network node in the first path other than an initial network node and a last network node, wherein the first path is a connection-oriented path, the path establishment device (212) being characterized in that wherein the first establishment unit is further configured to: in the first path, determine that resources are capable of being assigned for the first path, and forward the first message to a next-hop network node in the first path; and in a backward path of the first path, perform the following operations: upon the receipt of a feedback message corresponding to the first message from the next-hop network node, assign a second SRv6 SID corresponding to the first path in accordance with the received feedback message; take first Argument, ARG, information about a SID corresponding to a destination address in the received feedback message as ARG information about a forwarding SID of the next-hop network node in the first path; generate second ARG information, modify the SID corresponding to the destination address in the received feedback message in accordance with the second ARG information, and transmit the modified feedback message to the previous hop network node; and generate a local mapping relation table between the second SRv6 SID of the first path.
  10. The data transmission device according to claim 9, further comprising: a third reception unit (241) configured to receive a data packet from the previous-hop network node; an obtaining unit (242) configured to obtain a second SRv6 SID whose destination address is the second network node from the received data packet; and a lookup unit (243) configured to look up a second SRv6 SID of the next-hop network node corresponding to the second SRv6 SID of the second network node and an outgoing interface in the local mapping relation table between the second SRv6 SIDs; and a forwarding unit (244) configured to forward the received data packet in accordance with the second SRv6 SID of the next-hop network node and the outgoing interface, wherein the second SRv6 SID is used to represent that the first path has been established for a first service, the first path comprises M network nodes, the received data packet comprises N SIDs, N is smaller than M, M and N are each an integer greater than 1.
  11. A storage medium storing therein a computer program, wherein the computer program is executed by a processor so as to implement the steps of the path establishment method according to any one of claims 1 to 4, the steps of the path establishment method according to any one of claims 5 to 7.

Description

CROSS-REFERENCE TO RELATED APPLICATION TECHNICAL FIELD The present disclosure relates to the field of Internet Protocol (IP) network, in particular to a path establishment method, a path establishment device, a data transmission method, a data transmission device, a network node, and a storage medium. BACKGROUND A future network is intended for a 5th-Gengeration (5G) mobile communication technology. For the 5G, a bearer network needs to be adjusted accordingly, so as to be simplified, provide low delay, and achieve Software Defined Network (SDN)/Network Function Virtualization. For the development of a 5G network, a user hopes to achieve a Virtual Private Network (VPN) by means of an Internet Protocol Version 6 (IPv6) address in a simpler manner. For a Segment Routing IPv6 (SRv6) technology, using an existing IPv6 forwarding technology, a processing similar to label forwarding is implemented through extending a header field of an IPv6 message, i.e., a Segment Routing Header (SRH). When a strict explicit path is achieved through SRv6, in the case of a large quantity of hops in the network, a Segment Identifier (SID) of each network node needs to be included in the SRH, so a packet header is relatively large. At this time, it is impossible to support a forwarding mode with a small packet header, i.e., it is impossible to establish a connection-oriented path. The document WO2019201299 discloses a method where a sink node determines the transmission path of a data packet according to a path identifier in the data packet, such that a source node transmits the data packet to a next node in the transmission path. The document WO2020010999 discloses a method for obtaining information of a forwarding path of a data packet in segment routing. The document US20200044936 discloses a method for path creation element driven dynamic setup of forwarding adjacencies and explicit path. The document XP015138308, named "Connection-oriented Path in SRv6 Network; draft-du-spring-connection-oriented-srv6-00.txt" proposes a method to support connection-oriented path in the SRv6 network. SUMMARY An object of the present disclosure is to provide a path establishment methods and path establishment devices and a storage medium, so as to solve the above-mentioned problems. The present invention is defined by the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing architecture of Segment Routing (SR) in the related art;FIG. 2 is a schematic view showing an SRv6 packet header in the related art;FIG. 3A is a schematic view showing a forwarding procedure using a prefix SID in the related art;FIG. 3B is a schematic view showing a forwarding procedure using an adjacency SID in the related art;FIG. 4 is a schematic view showing an SID list for an explicit path in an SRv6 network in the related art;FIG. 5 is a schematic view showing purposes of an SRv6 technology in the related art;FIG. 6 is a flow chart of a path establishment method for a first network node according to one embodiment of the present disclosure;FIG. 7 is a schematic view showing an End-type SID format;FIGS. 8A and 8B are schematic views showing two End.X-type SID formats;FIG. 9 is a schematic view showing a ping6 request message format according to one embodiment of the present disclosure;FIG. 10 is a schematic view showing a ping6 reply message format according to one embodiment of the present disclosure;FIG. 11 is a flow chart of a path establishment method for a second network node according to one embodiment of the present disclosure;FIG. 12 is a flow chart of a path establishment method for a third network node according to one embodiment of the present disclosure;FIG. 13 is a flow chart of a data transmission method for the first network node according to one embodiment of the present disclosure;FIG. 14 is a flow chart of a data transmission method for the second network node according to one embodiment of the present disclosure;FIG. 15 is a schematic view showing an SRv6 network according to one embodiment of the present disclosure;FIG. 16 is a schematic view showing contents of a data section in a ping message according to one embodiment of the present disclosure;FIG. 17 is a schematic view showing the change in a destination address in the ping message during the path establishment according to one embodiment of the present disclosure;FIG. 18 is a schematic view showing the change in a destination address in a feedback message of the ping message during the path establishment according to one embodiment of the present disclosure;FIG. 19 is a schematic view showing the change in a source address and a designation address of a packet in a message forwarding procedure according to one embodiment of the present disclosure;FIG. 20 is a schematic view showing a path establishment device according to one embodiment of the present disclosure;FIG. 21 is ano