SFC path change scheme based on SRV6

Abstract

The invention relates to the technical field of communication, in particular to an SFC path change scheme based on SRV6, which comprises the following steps: S1, a service function node (SF) processes a data packet and returns the data packet to a service function transponder (SFF); s2, the SFF judges whether a service function chain SFC path needs to be adjusted according to a processing result of the SF; s3, if the path needs to be adjusted, the SFF executes a path adjustment operation, including adding or deleting a service function node; s4, the SFF updates the information in a Segment Routing Header (SRH), wherein the information comprises a Segment List (SID list) and a Segment Left (SL) value, and the SFF updates the information in the Segment Routing Header (SRH), wherein the Segment List (SID list) and the Segment Left (SL) value are included; and S5, the SFF forwards the data packet to the next node in the new path according to the updated SRH information. According to the invention, the service function chain can dynamically adjust the path and the node according to the processing result of the service function node on the datagram, thereby better coping with changing service requirements, and remarkably improving the flexibility and adaptability of the network; through intelligent path selection and node management, resource utilization is optimized, and resource waste is avoided.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an SFC path changing solution based on SRV6. Background Art

[0002] In the process of network data message transmission, in order to meet the security and stability requirements of the business, it is usually necessary to pass through multiple service nodes in sequence according to the predetermined business logic, such as firewalls, intrusion prevention systems, application accelerators, and network address translation. SRv6 SFC (Service Function Chaining) technology embeds SRv6 path information in the original message to ensure that the message passes through these service nodes in sequence according to the predetermined path, thereby effectively realizing the above business requirements.

[0003] The combination of SRv6 and SFC provides a flexible and efficient way to implement network service function chains. By mapping service function nodes to SRv6 Segment Identifiers (SIDs), network operators can flexibly define and dynamically adjust service paths. This approach not only simplifies the complexity of network management, but also significantly reduces the protocol overhead in traditional service chain deployment methods.

[0004] Currently, the combination of SRv6 and SFC usually adopts static service chain configuration, that is, when a data packet enters the network, the service function node path it passes through has been pre-defined. Figure 1 Figure 1 shows an SRv6 SFC instance of a service chain static proxy. After receiving the original IPv4 message from the user network, the source node SC introduces the traffic into the SRv6 TE policy. SC encapsulates the message according to the SRv6 TE policy. At this time, the destination address of the IPv6 message is the End.ASSID of the SFF node, and the SRH (Segment Routing Header) header contains the path information of the SRv6 TE policy and the End.DT4 SID of the tail node. When the SFF node receives the message, it finds that the destination address is the local End.ASSID by searching the local SID table and records the current SL (Segment Left) value. The SFF node then performs the operation corresponding to the End.ASSID, decapsulates the message, removes the IPv6 message header, and sends the original message to the service function (SF) node through the configured outbound interface for processing. After the SF node processes the message, it returns it to the SFF node.

[0005] The SFF node searches for configuration based on the inbound interface and VLAN information of the message, and re-encapsulates the SRv6 message according to the SID list. In the encapsulated message, the SID list in the SRH is consistent with the SRv6 TE policy path on the source node SC, and the SL value is reduced by 1. At this time, the destination address of the SRv6 message is updated to the next SID of the local End.ASSID, that is, the EndSID of Device C. The SFF node then searches the IPv6 routing table and forwards the message according to the destination IPv6 address of the message. After receiving the message, the Device C node searches the local SID table and finds that the destination address is the local End SID, and processes the message according to the SRv6 forwarding process. After processing, the destination address is replaced with D1 (that is, the End SID of the tail node), and the SL value is reduced by 1. Device C continues to forward the message by searching the IPv6 routing table. After receiving the message, the egress node searches the local SID table and finds that the destination address D1 is the local SID, and replaces it with D2 (that is, the End.DT4 SID of the egress node), and sets the SL value to 0. The egress node performs the operation corresponding to the End.DT4 SID, decapsulates the SRv6 message, and forwards the original message to the corresponding VPN or public network.

[0006] There are two proxy modes for SFC based on SRv6, service chain static proxy and service chain pseudo proxy; but no matter which mode is used, it is based on a series of SID paths determined by the SC head node. This method lacks flexibility and cannot dynamically adjust the service path according to the real-time network status, traffic load or specific business needs. This static nature limits the network's ability to cope with complex and changing traffic, which may lead to uneven resource utilization or reduced service quality.

[0007] In the existing service function chain, the SC service classification node selects the path based on predefined rules and lacks the ability to dynamically respond to real-time conditions or processing results. This limitation may lead to unnecessary path delays or resource waste when facing different business scenarios or processing requirements. For example, when a service function node fails to process or requires additional processing, the path of the data packet cannot be dynamically adjusted, resulting in a decrease in the overall efficiency of the service chain.

[0008] like Figure 2 As shown in the figure, if a new service node (marked as "new SF" in the figure) needs to be added to the service function chain, the existing path configuration needs to be manually modified or the entire service function chain needs to be reconfigured. This not only increases the complexity of the configuration, but may also lead to misconfiguration or service interruption. In addition, data packets can only pass through the specified service function node along a fixed path. This fixed path selection cannot be dynamically adjusted according to the real-time network status (such as traffic, delay), which may cause some paths to be overloaded and other paths to be idle. Summary of the invention

[0009] The purpose of the present invention is to overcome the above problems or at least partially solve the above problems, and to propose an SFC path change solution based on SRV6.

[0010] To achieve the above object, the present invention provides the following technical solution: a SFC path change solution based on SRV6, characterized in that it includes the following steps:

[0011] S1, the service function node SF processes the data packet and returns it to the service function forwarder SFF;

[0012] S2, SFF determines whether the service function chain SFC path needs to be adjusted based on the processing result of SF;

[0013] S3. If the path needs to be adjusted, the SFF performs the path adjustment operation, including adding or deleting a service function node;

[0014] S4 and SFF update the information in the Segment Routing Header (SRH), including the Segment List (SID list) and Segments Left (SL) values;

[0015] S5 and SFF forward the data packet to the next node in the new path according to the updated SRH information.

[0016] In a preferred embodiment, the path adjustment operation includes at least one of the following:

[0017] Adding a service function node: SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information;

[0018] Delete service function node: SFF deletes the SID corresponding to the specified service function node from the Segment List and updates the SRH information.

[0019] In a preferred embodiment, the path adjustment operation is triggered by one or a combination of the following two new SID actions:

[0020] END-SL SID: used to select whether to add a new service function node in the existing path according to the processing result of the service function node SF.

[0021] END-CD SID: It is used to dynamically select the next SFC path and modify the SRH according to the processing result of the service function node SF.

[0022] In a preferred embodiment, the actions of the END-SL SID include:

[0023] Check conditions: SFF checks the processing results of the SF node and decides whether to add a new service function node based on the matching conditions;

[0024] Path adjustment: If the conditions for adding a new service function node are met, SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information. If the conditions for not adding a new service function node are met, SFF does not make any path adjustment and the data packet continues to be forwarded according to the original Segment List.

[0025] Forwarding operation: Based on the updated Segment List, SFF selects the appropriate outbound interface and sends the data packet to the new service forwarding node.

[0026] In a preferred embodiment, the actions of the END-CD SID include:

[0027] Check conditions: SFF checks the processing results of the SF node and decides whether to adjust the path based on the matching conditions, which include:

[0028] Condition 1: The processing result of SF meets the predefined conditions for continuing the original path;

[0029] Condition 2: The processing result of SF meets the predefined conditions for adding a new service function node;

[0030] Condition 3: The processing result of SF meets the predefined condition of deleting the next service function node in the current path;

[0031] Path Adjustment:

[0032] If condition 1 is met, continue with the original path without modifying the SRH;

[0033] If condition 2 is met, SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information;

[0034] If condition three is met, the SFF deletes the SID corresponding to the specified service function node from the Segment List and updates the SRH information;

[0035] Forwarding operation: Based on the updated Segment List and SRH information, the SFF searches the local SID table, selects the appropriate outbound interface, and sends the data packet to the next node in the updated path.

[0036] In a preferred embodiment, the path adjustment operation further includes dynamically obtaining path instructions: the SFF obtains new path instructions through a network controller or local calculation, and adjusts the Segment List according to the instructions.

[0037] Compared with the prior art, the present invention has the following beneficial effects: the service function chain can dynamically adjust the path and nodes according to the processing results of the service function node on the datagram, so as to better cope with the changing business needs and significantly improve the flexibility and adaptability of the network; through intelligent path selection and node management, resource utilization can be optimized to avoid resource waste; dynamic adjustment of the path and service function nodes ensures that the network can always maintain the best performance in different scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is an instance of the SRv6 SFC service chain static proxy mode;

[0039] Figure 2 Add new service node instances to the SRv6 SFC service chain;

[0040] Figure 3 It is a schematic diagram of the application of END-SL SID and END-CD SID in the service chain static proxy mode of the present invention;

[0041] Figure 4 It is a schematic diagram of the combination of END-SL SID and END-CD SID of the present invention;

[0042] Figure 5 This is the END-SL SID flow chart of the present invention;

[0043] Figure 6 END-CD SID flow chart of the present invention;

[0044] Figure 7 This is a specific example of the combined use of END-SL SID and END-CD SID of the present invention;

[0045] Figure 8 for Figure 7 An example continuation diagram of . DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] See also Figure 3-Figure 8 ,The present invention provides two new designs and actions of SID, enriching the processing methods of SFC in different scenarios to improve the scalability and flexibility of SFC.

[0048] 1. END-SL SID

[0049] definition:

[0050] SID name: END-SELECT SID;

[0051] Function: According to the processing result of the service function node SF, choose whether to add a new SF as a normal or conditional node.

[0052] action:

[0053] Check conditions: After the message is sent from the application service function node SF to the forwarding node SFF, SFF checks the processing result of the SF node and follows the original path or adds a node according to the matching conditions 1 / 2.

[0054] Path Adjustment:

[0055] Condition 1 is met: the original path is continued, the SRH is not modified, the original SRH header is added, SL-1 is added, and the packet is forwarded according to the outbound interface associated with the END.SL SID;

[0056] Condition 2 is met: SFF adds the SID of the SFF corresponding to the new SF node to the Segment List, adds the modified SRH, the SL value remains unchanged, and searches the local SID table for the new node SID outbound interface for forwarding.

[0057] The following steps are involved:

[0058] Step S1: When the service function node SF processes the data packet and returns it to the application forwarding node SFF, the SFF starts to process the returned message;

[0059] Step S2: SFF first analyzes the message returned from SF, and determines whether it is necessary to add a new service function node to the existing service function chain according to the processing result of SF;

[0060] Step S3: If a new node needs to be added: the process continues and goes to the next step; if a new node does not need to be added: directly send the data packet to the predetermined next node according to the forwarding operation of the local SID table and the END-SL SID binding interface;

[0061] Step S4: SFF checks whether a new path instruction has been obtained from the network controller or through local calculation;

[0062] Step S5: Obtain a new service function node SID through the network controller or local calculation, add the newly calculated service function node SID to the Segment List, and change the SRH information, such as Segments Left (SL). Note: Here, the END-SL SID node performs a function similar to that of the SC, i.e., adding a new SRH.

[0063] Step S6: According to the updated Segment List, the SFF selects a suitable outbound interface and sends the data packet to the new service forwarding node.

[0064] 2. END-CD SID

[0065] definition:

[0066] SID name: END.CONDITION SID;

[0067] Function: Dynamically select the next SFC path according to the processing result of the service function node SF and modify the SRH.

[0068] action:

[0069] Check conditions: After the message goes from the application service function node SF to the forwarding node SFF, SFF checks the processing result of the SF node and takes subsequent actions based on the matching conditions 1 / 2 / 3 (which can be placed in the Option TLV).

[0070] Path Adjustment:

[0071] If condition 1 is met: continue the original path, do not modify the SRH, add the original SRH header, SL-1, and forward according to the outbound interface associated with END.CDSID;

[0072] If condition 2 is met: SFF adds the SIDs of the SFFs corresponding to some new SF nodes to the Segment List, adds the modified SRH, the SL value changes according to the number of added nodes, and searches the local SID table for the new SID outbound interface for forwarding;

[0073] If condition 3 is met: SFF deletes the SID corresponding to the SL=[x-1] node (ie, deletes the original next SFF), adds the modified SRH, SL-1, and searches for the outbound interface forwarding according to the local SID table.

[0074] The following steps are involved:

[0075] Step S1: When the service function node SF processes the data packet and returns it to the service function forwarder SFF, SFF takes different actions according to the processing result of SF;

[0076] Step S21: If the SF processing result meets condition 1, the SFF does not need to modify the current path, so the data packet will continue to be forwarded according to the original Segment List;

[0077] Step S22: The SFF sends the data packet to the next service function node through the outbound interface associated with the END-CD SID;

[0078] Step S31: If the SF processing result meets condition 2, the SFF will add a new service function node SF;

[0079] Step S32: SFF adds the SID of the new SF node to the existing SegmentList according to pre-configuration or active calculation. Note: END-CD SID may add more than one service function node SF, which is different from END-SL SID;

[0080] Step S33: After adding the new SF node, the SFF updates the basic information in the SRH to ensure that the data packet can be correctly forwarded according to the new Segment List;

[0081] Step S34: According to the updated Segment List and SRH information, the SFF searches the local SID table, selects a suitable outbound interface, and sends the data packet to the newly added service function node;

[0082] Step S41: If the SF processing result satisfies condition 3, the SFF deletes the next service function node in the current path, and the SFF deletes the corresponding SID (SL = [x-1] node) in the Segment List to simplify the path;

[0083] Step S42: After deleting the SID, the SFF updates the SL and other information in the SRH to ensure that the data packet continues to be transmitted according to the modified Segment List;

[0084] Step S5: The SFF searches the local SID table according to the new Segment List and SRH, selects a suitable outbound interface, and sends the data packet to the next node in the updated path.

[0085] The following are the operation processes and action explanations of END-SL SID and END-CD SID respectively: In order to highlight the role of the two new SIDs, the listed examples are all performed in the service chain static proxy mode, that is, SF cannot identify SRv6 messages; without loss of generality, it is set that both END-SL SID and END-CD SID can realize the function of END.ASSID, that is, 1. Before the message is sent from the forwarding node SFF to the application service function node SF, SFF first decapsulates the message, and then forwards the message according to the outbound interface associated with End.ASSID; 2. After the message is from the application service function node SF to the forwarding node SFF, SFF re-encapsulates the message according to the inbound interface of the message or the End.ASSID associated with the inbound interface and VLAN and its configuration.

[0086] To more clearly distinguish the difference between the two in the service function node result processing impact path, such as Figure 3 and Figure 4 As shown in the figure, the application scenarios and functional differences of the two are respectively demonstrated. The combination of the two can be applied to more complex scenarios. END-SLSID highlights the selection function and emphasizes adding an SF node to process the business flow, which is suitable for simple scenarios. END-CD SID highlights the conditional function and emphasizes different processing according to different conditions. It can realize the functions of adding multiple SF nodes and deleting path nodes, which is suitable for complex scenarios. Figure 4 It shows how the two can be used in combination for more complex scenarios. By adding a conditional point CD.SID through SL.SID, it is equivalent to implementing the process of going to the new node for result processing to determine the subsequent path. By using the two in combination, the business processing logic in most complex scenarios can be solved, effectively improving the flexibility of SFC.

[0087] END-SL SID is mainly used to decide whether to add a new service function node to the existing service chain based on the processing results of the service function node SF. For example, if the processing result of a SF node indicates that further security inspection or traffic analysis is required, the corresponding new node can be added through END-SL SID. It highlights a selection function, emphasizing the addition of new nodes without changing the existing path to meet specific business needs. END-CD SID is used for more complex conditional judgment and path adjustment. It dynamically determines the next path of SFC according to different conditions (such as business traffic characteristics, security policies, etc.), and can perform operations such as adding and deleting service function nodes. For example, if a SF node fails to process or needs to reselect the path based on the real-time network status, END-CD SID can flexibly adjust the Segment List, delete useless nodes or add new nodes. This method can realize multi-conditional path adjustment in complex scenarios, which is a more conditional and flexible operation.

[0088] The difference between the two SIDs lies in the different triggering conditions and methods for handling path adjustment: END-SL SID focuses more on selection operations, while END-CD SID emphasizes flexible processing of conditional judgments. By combining the two, the selection function can be used in simple scenarios, and conditional judgment can be used in complex scenarios, to achieve more flexible and diversified path adjustment strategies, thereby improving the service quality and resource utilization efficiency of the network.

[0089] Example 1: Combination of END-SL SID and END-CD SID

[0090] The original initial path of the SFC in this embodiment is as follows: Figure 7 As shown in (D2, D1, C, B, A), the SFC constructed by the source node SC is taken as an example to illustrate the solution of the present invention.

[0091] like Figure 7 As shown, after the source node SC constructs the initial path, the source node A performs the following operations:

[0092] 1) Source node A encapsulates the SRv6 path information in SRH, specifies the SID of the BC, C-D1 link, and also encapsulates SID D2 published by point D (this SID corresponds to an IPv4VPN of node E). There are a total of 4 SIDs, which are pressed into the SID sequence in reverse order. At this time, SL (Segment Left) = 3, and the Segment list value is copied to the destination address DA field. The IPv6 routing table is searched according to the longest match principle and forwarded to node B.

[0093] After receiving the SRv6 message from node A, node B performs the following operations:

[0094] 1) After receiving the message, SFF1 searches the Local SID table and finds that the destination address is the local End.SL SID. It decapsulates the message, removes the IPv6 message header, and sends the original message to SF1 through the configured outbound interface for processing.

[0095] 2) After SF1 processes the message, it sends the message back to SFF1.

[0096] 3) SFF1 first determines whether to add a node based on the processing result of SF1. If it is determined that no modification is needed, SFF1 keeps the current Segment List unchanged, that is, (D2, D1, C, B), and forwards the data packet directly to the next designated node C according to the outbound interface bound to the End.SL SID.

[0097] 4) If the processing result requires adding a new service function node (for example, additional traffic analysis or security checks are required under certain conditions), SFF1 will insert the service forwarding node E into the Segment List. The new Segment List will become (D2, D1, C, E, B), and the Segments Left field will be updated to 3 accordingly. SFF1 then determines the next hop to which the data packet should be forwarded by searching the local SID table, and selects the appropriate outbound interface for forwarding based on the updated Segment List.

[0098] After receiving the SRv6 message from node B, node E performs the following operations:

[0099] 1) After receiving the message, SFF3 searches the Local SID table and finds that the destination address is the local End.SL SID. It decapsulates the message, removes the IPv6 message header, and sends the original message to SF3 through the configured outbound interface for processing.

[0100] 2) After SF3 processes the message, it sends the message back to SFF3.

[0101] 3) Based on the processing result of SF3, if condition 1 is met, SFF3 determines that the current path does not need to be modified (such as all business functions can be completed), then the Segment List (D2, D1, C, E, B) remains unchanged and the data packet continues to be forwarded.

[0102] 4) If condition 2 is met, a new service function node (such as F, G, H) needs to be added, and SFF3 will update SegmentList to add the new node. The updated Segment List may become (D2, D1, C, H, G, F, E, B), and the Segments Left field will be adjusted accordingly.

[0103] 5) If condition 3 is met, the next node in the original path, i.e. DA = SL[x-1] (e.g. C), needs to be deleted. SFF3 will remove these nodes from the Segment List and update the Segment List to (D2, D1, E, B) and Segments Left = 1 to ensure that the data packet can be transmitted along the modified path.

[0104] After receiving the SRv6 message from node E, node C performs the following operations:

[0105] 1) After receiving the message, SFF2 searches the Local SID table and finds that the destination address is the local End.AS SID. It decapsulates the message, removes the IPv6 message header, and sends the original message to SF2 through the configured outbound interface for processing.

[0106] 2) After SF2 processes the message, it sends the message back to SFF2.

[0107] 3) After the message is sent from the application service node SF2 to the forwarding node SFF2, SFF2 re-encapsulates the message according to the associated End.ASSID and its configuration, and searches the IPv6 routing table to forward the message according to the destination IPv6 address of the message.

[0108] After receiving the SRv6 message from node C, node D performs the following operations:

[0109] 1) After receiving the message, the egress node searches the Local SID table and finds that the destination address D1 is the local SID. It replaces the destination address with D2 (i.e., the End.DT4 SID of the egress node), and SL-1 becomes 0. The egress node executes the instruction corresponding to the End.DT4 SID, that is, decapsulates the SRv6 message, and forwards the original message to the corresponding VPN or public network.

[0110] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A SFC path change solution based on SRV6, It is characterized in that The following steps are involved: S1, the service function node SF processes the data packet and returns it to the service function forwarder SFF; S2, SFF determines whether the service function chain SFC path needs to be adjusted based on the processing result of SF; S3. If the path needs to be adjusted, the SFF performs the path adjustment operation, including adding or deleting a service function node; S4 and SFF update the information in the Segment Routing Header (SRH), including the Segment List (SID list) and Segments Left (SL) values; S5 and SFF forward the data packet to the next node in the new path according to the updated SRH information.

2. According to the SRV6-based SFC path change solution of claim 1, Features: The path adjustment operation includes at least one of the following: Adding a service function node: SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information; Delete service function node: SFF deletes the SID corresponding to the specified service function node from the Segment List and updates the SRH information.

3. According to the SRV6-based SFC path change solution of claim 1, Features: The path adjustment operation is triggered by one or a combination of the following two new SID actions: END-SL SID: used to select whether to add a new service function node in the existing path according to the processing result of the service function node SF. END-CD SID: It is used to dynamically select the next SFC path and modify the SRH according to the processing result of the service function node SF.

4. A SFC path change solution based on SRV6 according to claim 3, Features: The actions of the END-SLSID include: Check conditions: SFF checks the processing results of the SF node and decides whether to add a new service function node based on the matching conditions; Path adjustment: If the conditions for adding a new service function node are met, SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information. If the conditions for not adding a new service function node are met, SFF does not make any path adjustment and the data packet continues to be forwarded according to the original Segment List. Forwarding operation: Based on the updated Segment List, SFF selects the appropriate outbound interface and sends the data packet to the new service forwarding node.

5. A SFC path change solution based on SRV6 according to claim 3, Features: The actions of the END-CDSID include: Check conditions: SFF checks the processing results of the SF node and decides whether to adjust the path based on the matching conditions, which include: Condition 1: The processing result of SF meets the predefined conditions for continuing the original path; Condition 2: The processing result of SF meets the predefined conditions for adding a new service function node; Condition 3: The processing result of SF meets the predefined condition of deleting the next service function node in the current path; Path Adjustment: If condition 1 is met, continue with the original path without modifying the SRH; If condition 2 is met, SFF adds the SID corresponding to the new service function node to the Segment List and updates the SRH information; If condition three is met, the SFF deletes the SID corresponding to the specified service function node from the Segment List and updates the SRH information; Forwarding operation: Based on the updated Segment List and SRH information, the SFF searches the local SID table, selects the appropriate outbound interface, and sends the data packet to the next node in the updated path.

6. The SFC path change solution based on SRV6 according to claim 1, Features: The path adjustment operation also includes dynamically obtaining path instructions: the SFF obtains new path instructions through a network controller or local calculation, and adjusts the Segment List according to the instructions.

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