CN112291147A - Dynamic intelligent SR tunnel application method for 5G service - Google Patents

Abstract

A5G service dynamic intelligent SR tunnel application method, 5G refers to a fifth Generation mobile communication technology (5th Generation mobile networks or 5th Generation wireless systems, 5th-Generation), SR refers to segmented routing (SegmentRouting), MPLS (Multi-Protocol Label Switching) technology is simplified by utilizing SR source routing technology, an existing forwarding mechanism of MPLS is multiplexed to be compatible with an existing MPLS Network, smooth evolution of the existing MPLS Network to an SDN (Software Defined Network) is supported, a new end-to-end flexible service scheduling is formed, an operator is assisted to easily create and manage million-level connections, and the method is an effective solution for ubiquitous connection requirements in the 5G bearing age.

Description

Dynamic intelligent SR tunnel application method for 5G service

Technical Field

The invention relates to a 5G transmission Network technology, in particular to a 5G service dynamic intelligent SR tunnel application method, wherein 5G refers to a fifth Generation mobile communication technology (5th Generation mobile networks or 5th Generation wireless systems, 5th-Generation), SR refers to segmented routing (SegmentRouting), MPLS (Multi-Protocol Label Switching) technology is simplified by utilizing SR source routing technology, an existing forwarding mechanism is multiplexed to be compatible with the current MPLS Network, smooth evolution from the current MPLS Network to an SDN (Software Defined Network) is supported, a new end-to-end flexible service scheduling is formed, MPLS-assisted operators easily create and manage million-level connections, and the method is an effective solution for ubiquitous connection requirements in the 5G bearing age.

Background

At present, the 5G huge data traffic increases the traffic types and the networking architecture changes, and a consensus is formed in the industry that a transmission network needs to be newly built in the 5G era. The maturity of the bearing technology needs standard landing and 5G transmission network standardization, including 5G transmission network architecture, technical scheme, interface, SDN management and control, fragmentation, synchronization and other aspects. While waiting for international standards to be established, industry and particularly operators are actively driving enterprise standards to be established, large connectivity solutions in 5G networks for new transmission technologies.

The 5G mobile backhaul adopts a flat IP architecture, functions of a RAN and a core network are virtualized, service anchor points are deployed in a distributed mode, functions of a L3 (three-layer path) are sunk, and the like, so that service flow direction tends to be complex, the demands of east-west flow are enhanced except for north-south flow (from a base station to the core network), and the number of network connections is improved by more than 10 times compared with that of the 4G era. It is not feasible to create and manage connections by means of conventional approaches, and new end-to-end flexible service scheduling techniques need to be introduced to meet the ubiquitous connectivity needs.

The packet transmission network based on the MPLS technology establishes an end-to-end tunnel through the MPLS label switching technology, and can provide connection-oriented services for services. However, the conventional MPLS tunnel creation technology has the following problems: (1) each label represents 1 connection, the intermediate node needs to maintain the soft state of each connection, and the expandability is poor; (2) the need for a separate signaling protocol to distribute the table is complex; (3) the service deployment needs to issue configuration for all nodes on the end-to-end path, and the efficiency of the service deployment is not high.

The inventor thinks that the label Distribution is realized by depending on signaling protocols such as LDP (Label Distribution protocol), RSVP (resource ReSerVation protocol) and the like, the function is different from that of the MPLS network, the segmented routing SR simplifies the control plane, and the label Distribution is realized by simply expanding the existing IGP (interior Gateway protocol) protocol completely based on the distributed routing protocol. In the forwarding plane, the label represents the information of network topology (node or link), the end-to-end connection is represented by a group of ordered label stacks, the node only needs to maintain the topology information and does not need to maintain the connection state, and the problem of the expandability of the MPLS network is solved. In addition, the end-to-end path establishment can be completed only by operating the head node based on the source routing technology, and the service deployment efficiency is greatly improved. In a word, segment routing (SegmentRouting) as a source routing technology can efficiently simplify the existing MPLS technology, and simultaneously reuse the existing forwarding mechanism of MPLS, so that the existing MPLS network can be well compatible, and the smooth evolution of the existing MPLS network to SDN is supported, so that an operator is assisted to easily create and manage million-level connections, and the SegmentRouting is an effective solution for ubiquitous connection requirements in the 5G bearer era. In view of the above, the present inventors have completed the present invention.

Disclosure of Invention

The invention provides a 5G service dynamic intelligent SR tunnel application method aiming at the defects or shortcomings in the prior art, 5G refers to a fifth Generation mobile communication technology (5th Generation mobile networks or 5th Generation wireless systems, 5th-Generation), SR refers to segmented routing (SegmentRouting), MPLS (Multi-Protocol Label Switching) technology is simplified by utilizing SR source routing technology, meanwhile, the existing forwarding mechanism of MPLS is multiplexed to be compatible with the current MPLS Network, and the smooth evolution of the current MPLS Network to SDN (Software Defined Network) is supported, so that a new end-to-end flexible service scheduling is formed, an operator is helped to easily create and manage million-level connections, and the method is an effective solution aiming at the connection requirements in the 5G bearing period.

The technical solution of the invention is as follows:

A5G service dynamic intelligent SR tunnel application method is characterized by comprising the steps of realizing seamless fusion of a segmented routing SR technology and an SDN framework, realizing end-to-end perception routing computing capacity of a service by using the segmented routing SR technology, realizing dynamic control capacity of a service path by using the segmented routing SR technology, and realizing local protection under any topology by using the segmented routing SR technology.

The seamless fusion of the segment routing SR technology and the SDN framework is based on the flexible programmable characteristic of SR, the characteristic is that the SR identifies connection through a group of ordered label stacks, and the service path can be changed by changing the content of the label stacks.

The transmission network SR architecture formed by seamless fusion adopts a deployment mode of combining an integrated controller and a distributed control surface, the integrated controller calculates an end-to-end SR path and generates complete label stack issuing equipment to complete SR tunnel establishment, and the distributed control surface autonomously completes establishment and modification of a label forwarding table according to network topology change.

The distributed control surface has self-learning, self-adaptation and self-healing capabilities, the centralized controller has the capabilities of overall resource overall planning optimization, centralized scheduling and policy control, and the advantages of SR can be brought into full play by combining the centralized controller and the distributed control surface.

The local protection under any topology realized by utilizing the segmented routing SR technology is based on that a distributed control plane can automatically form a fast reroute FRR according to a network topology, thereby realizing the local protection under any topology.

The method for achieving end-to-end service perception routing computing capacity by utilizing the segment routing SR technology is based on the fact that the SR is a source routing technology, information of an SR tunnel only exists in a head node, other nodes on a path do not perceive services, and bandwidth cannot be reserved for the services in an equipment layer, therefore, traffic engineering TE of the SR tunnel is completed in the centralized controller, the centralized controller maintains global topology and traffic engineering TE information, an end-to-end path is computed according to a service request and a routing strategy, a hop-by-hop strict constraint path is formed, bandwidth reservation is completed in the distributed control plane, and end-to-end routing computing capacity is achieved.

The routing policy associates the following: the minimum hop count, the minimum time delay and the load balance; the service request is associated with the following: node a, node Z, bandwidth.

The routing calculation capability of realizing end-to-end comprises SR tunnel configuration and routing calculation thereof, wherein the SR tunnel configuration comprises 1) starting an interior gateway protocol IGP, a network topology state real-time discovery protocol ISIS, a topology state real-time feedback protocol BGP-LS, a tunnel path real-time issuing update protocol PECP and configuring protocol parameters; 2) allocating an SR node label and a link adjacency label; 3) and creating an SR tunnel, wherein the SR tunnel is an SRTP-BE tunnel and/or an SRTP-TE tunnel.

The SRTP-BE tunnel is an optimal forwarding path calculated to a destination node by equipment without centralized configuration, supports condition setting of source and destination nodes, bandwidth, route calculation strategies and path constraints, and calculates an end-to-end path according to the condition setting.

The SR tunnel is an SRTP-BE tunnel, and the establishment of the SRTP-BE tunnel comprises the following steps: each device in the network is distributed with a node label NodeLabel, the node label is globally unique in an IGP domain, each device in the network needs to start an IGP protocol, the IGP protocol diffuses the node label of the device to other devices in the whole network, when a source node receives a service message destined to other nodes, a layer of node label is added to the service message, an optimal forwarding path to a sink node is calculated, and an optimal next hop-out interface of the sink node label is found so that the service message is transmitted along the optimal forwarding path.

The SR tunnel is an SRTP-TE tunnel, and the establishment of the SRTP-TE tunnel comprises the following steps: distributing local adjacent labels for each link of each equipment, starting a network topology state real-time discovery protocol ISIS, a topology state real-time feedback protocol BGP-LS, an SRTP-TE tunnel forwarding example and a tunnel path real-time issuing updating protocol PCEP according to planning requirements of tunnel forwarding, calculating a tunnel path at an SRTP-TE tunnel source node according to a specified strategy and constraint conditions, acquiring the network topology state in real time, issuing the network topology state to the equipment after path calculation is completed, pressing' an adjacent label stack for marking a forwarding path for a service message, matching an adjacent label table to find a service forwarding interface after the network intermediate node receives the service message, and forwarding the service message after a stack top label is peeled.

The calculation rules of the route calculation include the following: (1) circuit-associated SR tunneling service: associating SR tunnel service data according to a Z-end network element, a Z-end port, a base station Internet protocol version IPV4, a base station Internet protocol version IPV6 and a virtual local area network VLAN of the circuit; (2) the SR tunnel service is associated with the SR tunnel: analyzing the SR tunnel business association SR tunnel according to the data reported by the manufacturer; (3) the SR tunnel inquires the routing of the SR tunnel through a real-time interface: calling a real-time interface according to the ID of the SR tunnel, inquiring the SR tunnel route in real time, and finishing the serial connection of the SR route by combining the topological data; (4) and (3) mounting the routing concatenation under the Mnt term: and the flexible Ethernet cross FlexeCRoss + inter-network element topological serial connection path is automatically acquired through a network slice management function SPN.

The method for realizing the dynamic control capability of the service path by utilizing the segment routing SR technology is a tunnel realization mechanism based on SR source routing, an SR tunnel consists of a series of ordered segment identifiers SID and is used for identifying nodes needing to pass through the SR tunnel or link remote forwarding nodes, a segment identifier list segmentList is packaged into a message header at a source node, equipment can forward the message header according to path information in the message header, in an SR domain, the segment identifiers SID represent an instruction, and the segment identifier list segmentList represents a set of a series of instructions.

The realization of the dynamic control capability of the service path by using the segment routing SR technology is based on a tunnel realization mechanism of SR source routing, and an SR tunnel is only represented by one segment identifier of a destination node or represented by a segment identifier containing all nodes or links along the path.

The SR network topology is represented by node NodeSID and link AdjSID, the NodeSID has global property, i.e. globally visible, globally valid, globally unique, a specific node is uniquely identified and routed through NodeSID, the meaning is 'send message to node N by IGP shortest path', the NodeSID has own block of label space SRGB to prevent collision with MPLS local label exchange with other multi-protocol labels, the Adj SID is local label, is locally valid, is used for representing specific link, has local uniqueness, the meaning of its instruction represents 'send message out from specified link L', and is used for flexibly controlling service path through the combination of NodeSID and AdjSID.

The invention has the following technical effects: the invention discloses a method for applying a 5G service dynamic intelligent SR tunnel, which simplifies a control plane by utilizing SR, is completely based on a distributed routing protocol, and realizes label distribution by simply expanding the existing IGP (interactive Gateway protocols) protocol. In the forwarding plane, the label represents the information of network topology (node or link), the end-to-end connection is represented by a group of ordered label stacks, the node only needs to maintain the topology information and does not need to maintain the connection state, and the problem of the expandability of the MPLS network is solved. In addition, the end-to-end path establishment can be completed only by operating the head node based on the source routing technology, and the service deployment efficiency is greatly improved.

The invention has the following characteristics: 1. seamless fusion with an SDN framework is realized; 2. the perception routing computing capacity of end-to-end service is realized; 3. realizing the dynamic control capability of the service path; 4. and local protection under any topology is realized. The invention combines the precise extraction and deep analysis of the new technical characteristics of 5G transmission (PTN evolution, Packet Transport Network) to provide functional frames and key points of FLexe channel, SR tunnel dynamic adjustment, L3VPN (L3-Virtual Private Network, three-layer Virtual Private Network) configuration and maintenance, and then the system is refined into the technical requirements for guiding the research and development of a network management system and the deployment of a test network, furthermore, by taking the reference of the technology accumulation of end-to-end intelligent distribution of the collected customer service and LTE service, deep combination with SDN, the intelligent path calculation and rerouting functions are introduced, the service configuration process is further perfected and simplified, the fault processing means is enhanced, the intelligent level of network management is improved, the 5G service opening and service recovery efficiency is improved, and the verification and the improvement are carried out in a 5G scale test network, and powerful guarantee is provided for the operation, the maintenance and the optimization of a 5G transmission network.

Drawings

Fig. 1 is a schematic diagram of SRTP-BE tunnel forwarding involved in implementing a dynamic intelligent SR tunnel application method for 5G services according to the present invention. SRTP is Secure Real-time Transport Protocol (Secure Real-time Transport Protocol) and BE is network traffic engineering. The left-hand loop in fig. 1 comprises Node a (Node a, PE) -Node B (Node B, P) -Node C (Node C, P) -Node D (Node D, P) -Node e (Node e) -Node f (Node f) -Node a (Node a, PE), and the right-hand loop comprises Node I (Node I, PE) -Node h (Node h) -Node g (Node g) Node C (Node C, P) -Node D (Node D, P) -Node J (Node J, P) -Node I (Node I, PE). In fig. 1, PE is edge routing equipment, P is routing equipment, and the equipment diffuses a Node I label to Node J/D/C/B/etc. equipment through an IGP protocol (interior Gateway protocol); node a/B/C/D/J nodes respectively run IGP protocols, and use shortest path to calculate the optimal forwarding next hop exit to Node I Node, i.e. send to Node I Node (dotted line arrow line from top left to bottom right in fig. 1) along Node a- > Node B- > Node C- > Node D- > Node J forwarding path, and the middle Node does not add, delete, modify outer label of message.

Fig. 2 is a schematic diagram of SRTP-TE tunnel forwarding involved in implementing a method for applying a dynamic intelligent SR tunnel for 5G services according to the present invention. SRTP-TE is secure real-time Transport Protocol traffic engineering (secure real-time Transport Protocol-traffic engineering). FIG. 2 relates to assigning a local adjacency label to each link of each device; according to the tunnel forwarding planning requirement, a tunnel path (needing to start an ISIS protocol (network topology state real-time discovery), a BGP-LS protocol (topology state real-time feedback) and an SRTP-TE tunnel forwarding example, a PCEP protocol (tunnel path real-time issuing update) is calculated at an SRTP-TE tunnel source node according to a specified strategy and constraint conditions so as to obtain the network topology state in real time and issue the network topology state to equipment after the path calculation is completed, an adjacent label stack (such as AdjA- > AdjB- > AdjE- > AdjF) of a label forwarding path is pressed in for a service message, after the message is received by a network intermediate node, the adjacent label table is matched to find a service forwarding interface, and the service forwarding device is forwarded after a stack top label is peeled.

Fig. 3 is a schematic diagram of an association relationship of an example of a calculation rule of SR tunnel routing. The bottom-up physical link part, the FlexE Group part (FlexEthernet, flexible ethernet technology), and the FlexE Channel part are included in fig. 3. The physical link portion includes device nodes a-B-D-C-a. The Flexe Group part includes four sets of bi-directional connections: flexe group pA-B, Flexe group pB-D, Flexe group pA-C, Flexe group pC-D. The FlexE Channel part comprises four sets of bi-directional connections: flexe channels A-B, Flexe channels B-D, Flexe channels A-C, Flexe channels C-D.

Fig. 4 is a schematic diagram of a single-point and end-to-end correspondence relationship as an example of a calculation rule of SR tunnel routing. In fig. 4, the left single-point object is a physical port, a FlexE Group, and a FlexE Channel/cross from bottom to top. In fig. 4, the right end-to-end object is sequentially optical connection, FlexE GroupFC, and FlexE Channel from bottom to top.

Fig. 5 is a schematic diagram of a 5G service scenario. The 5G service scenario in fig. 5 illustrates that "5G-SPN not only needs to have a basic management and control capability, but also introduces artificial intelligence and big data analysis, more efficiently analyzes massive alarms and performance data, quickly and accurately locates the cause of a fault, predicts and warns energy degradation and flow overrun, achieves the primary targets of centralized management, centralized control and centralized analysis, and finally forms a sleeve-control integrated intelligent and automatic system". The 5G service scene shows that: the transmission integrated network management faces a new SPN network, the function of L3 (three-layer path) is fully sunk to an access layer, the routing is more flexible, the concatenation of the 5G SR tunnel routing faces more complex factors, the concatenation of the 5G SR tunnel routing needs to be realized by combining a full amount of interfaces and real-time interfaces, and the end-to-end path analysis basis of the transmission specialty is provided for services. The invention relies on the configuration analysis data of OMC (Operations & Maintenance Center) northbound interface specification, SPN (Slicing Packet Network, Network slice management function) compares PTN (Packet Transport Network ), has increased new technologies such as slice, Flexe, SR-TP (segmenting routing-Transport Profile, segmentation routing tunnel), and the like, and for the first time of Network access of new technologies, new data model adaptation analysis is added; meanwhile, as the MEC (Multi-access Edge Computing) sinks, the L3 function sinks to the access layer comprehensively, the transmission network enters an end-to-end L3 operation and maintenance stage, and the service association is more complex; according to the OMC interface specification, the SPN object is analyzed to increase SR tunnel service, increase SR tunnel resources, increase SR tunnel routes, increase IGP topology, increase IGP connection, increase network slices, increase MntGroup binding relationship, increase MntChannel, increase Mnt crossing, increase MntChannel protection groups and increase MntChannel protection group-main-standby relationship.

Detailed Description

The invention is described below with reference to the accompanying drawings (fig. 1-5).

Fig. 1 is a schematic diagram of SRTP-BE tunnel forwarding involved in implementing a dynamic intelligent SR tunnel application method for 5G services according to the present invention. Fig. 2 is a schematic diagram of SRTP-TE tunnel forwarding involved in implementing a method for applying a dynamic intelligent SR tunnel for 5G services according to the present invention. Fig. 3 is a schematic diagram of an association relationship of an example of a calculation rule of SR tunnel routing. Fig. 4 is a schematic diagram of a single-point and end-to-end correspondence relationship as an example of a calculation rule of SR tunnel routing. Fig. 5 is a schematic diagram of a 5G service scenario. Referring to fig. 1 to 5, a method for applying a 5G service dynamic intelligent SR tunnel is characterized by implementing seamless fusion of a segment routing SR technology and an SDN framework, implementing end-to-end aware routing computation capability of a service by using the segment routing SR technology, implementing dynamic control capability of a service path by using the segment routing SR technology, and implementing local protection under any topology by using the segment routing SR technology. The seamless fusion of the segment routing SR technology and the SDN framework is based on the flexible programmable characteristic of SR, the characteristic is that the SR identifies connection through a group of ordered label stacks, and the service path can be changed by changing the content of the label stacks. The transmission network SR architecture formed by seamless fusion adopts a deployment mode of combining an integrated controller and a distributed control surface, the integrated controller calculates an end-to-end SR path and generates complete label stack issuing equipment to complete SR tunnel establishment, and the distributed control surface autonomously completes establishment and modification of a label forwarding table according to network topology change. The distributed control surface has self-learning, self-adaptation and self-healing capabilities, the centralized controller has the capabilities of overall resource overall planning optimization, centralized scheduling and policy control, and the advantages of SR can be brought into full play by combining the centralized controller and the distributed control surface. The local protection under any topology realized by utilizing the segmented routing SR technology is based on that a distributed control plane can automatically form a fast reroute FRR according to a network topology, thereby realizing the local protection under any topology. The method for achieving end-to-end service perception routing computing capacity by utilizing the segment routing SR technology is based on the fact that the SR is a source routing technology, information of an SR tunnel only exists in a head node, other nodes on a path do not perceive services, and bandwidth cannot be reserved for the services in an equipment layer, therefore, traffic engineering TE of the SR tunnel is completed in the centralized controller, the centralized controller maintains global topology and traffic engineering TE information, an end-to-end path is computed according to a service request and a routing strategy, a hop-by-hop strict constraint path is formed, bandwidth reservation is completed in the distributed control plane, and end-to-end routing computing capacity is achieved. The routing policy associates the following: the minimum hop count, the minimum time delay and the load balance; the service request is associated with the following: node a, node Z, bandwidth.

The routing calculation capability of realizing end-to-end comprises SR tunnel configuration and routing calculation thereof, wherein the SR tunnel configuration comprises 1) starting an interior gateway protocol IGP, a network topology state real-time discovery protocol ISIS, a topology state real-time feedback protocol BGP-LS, a tunnel path real-time issuing update protocol PECP and configuring protocol parameters; 2) allocating an SR node label and a link adjacency label; 3) and creating an SR tunnel, wherein the SR tunnel is an SRTP-BE tunnel and/or an SRTP-TE tunnel. The SRTP-BE tunnel is an optimal forwarding path calculated to a destination node by equipment without centralized configuration, supports condition setting of source and destination nodes, bandwidth, route calculation strategies and path constraints, and calculates an end-to-end path according to the condition setting. The SR tunnel is an SRTP-BE tunnel, and the establishment of the SRTP-BE tunnel comprises the following steps: each device in the network is distributed with a node label NodeLabel, the node label is globally unique in an IGP domain, each device in the network needs to start an IGP protocol, the IGP protocol diffuses the node label of the device to other devices in the whole network, when a source node receives a service message destined to other nodes, a layer of node label is added to the service message, an optimal forwarding path to a sink node is calculated, and an optimal next hop-out interface of the sink node label is found so that the service message is transmitted along the optimal forwarding path. The SR tunnel is an SRTP-TE tunnel, and the establishment of the SRTP-TE tunnel comprises the following steps: distributing local adjacent labels for each link of each equipment, starting a network topology state real-time discovery protocol ISIS, a topology state real-time feedback protocol BGP-LS, an SRTP-TE tunnel forwarding example and a tunnel path real-time issuing updating protocol PCEP according to planning requirements of tunnel forwarding, calculating a tunnel path at an SRTP-TE tunnel source node according to a specified strategy and constraint conditions, acquiring the network topology state in real time, issuing the network topology state to the equipment after path calculation is completed, pressing' an adjacent label stack for marking a forwarding path for a service message, matching an adjacent label table to find a service forwarding interface after the network intermediate node receives the service message, and forwarding the service message after a stack top label is peeled.

The calculation rules of the route calculation include the following: (1) circuit-associated SR tunneling service: associating SR tunnel service data according to a Z-end network element, a Z-end port, a base station Internet protocol version IPV4, a base station Internet protocol version IPV6 and a virtual local area network VLAN of the circuit; (2) the SR tunnel service is associated with the SR tunnel: analyzing the SR tunnel business association SR tunnel according to the data reported by the manufacturer; (3) the SR tunnel inquires the routing of the SR tunnel through a real-time interface: calling a real-time interface according to the ID of the SR tunnel, inquiring the SR tunnel route in real time, and finishing the serial connection of the SR route by combining the topological data; (4) and (3) mounting the routing concatenation under the Mnt term: and the flexible Ethernet cross FlexeCRoss + inter-network element topological serial connection path is automatically acquired through a network slice management function SPN. The method for realizing the dynamic control capability of the service path by utilizing the segment routing SR technology is a tunnel realization mechanism based on SR source routing, an SR tunnel consists of a series of ordered segment identifiers SID and is used for identifying nodes needing to pass through the SR tunnel or link remote forwarding nodes, a segment identifier list segmentList is packaged into a message header at a source node, equipment can forward the message header according to path information in the message header, in an SR domain, the segment identifiers SID represent an instruction, and the segment identifier list segmentList represents a set of a series of instructions. The realization of the dynamic control capability of the service path by using the segment routing SR technology is based on a tunnel realization mechanism of SR source routing, and an SR tunnel is only represented by one segment identifier of a destination node or represented by a segment identifier containing all nodes or links along the path. The SR network topology is represented by node NodeSID and link AdjSID, the NodeSID has global property, i.e. globally visible, globally valid, globally unique, a specific node is uniquely identified and routed through NodeSID, the meaning is 'send message to node N by IGP shortest path', the NodeSID has own block of label space SRGB to prevent collision with MPLS local label exchange with other multi-protocol labels, the Adj SID is local label, is locally valid, is used for representing specific link, has local uniqueness, the meaning of its instruction represents 'send message out from specified link L', and is used for flexibly controlling service path through the combination of NodeSID and AdjSID.

The invention relates to the change of 5G huge data traffic volume increasing traffic type and networking architecture, and the need of newly building a transmission network in the 5G era has become a consensus in the industry. The maturity of the bearing technology needs standard landing and 5G transmission network standardization, including 5G transmission network architecture, technical scheme, interface, SDN management and control, fragmentation, synchronization and other aspects. While waiting for international standards to be established, industry and particularly operators are actively driving enterprise standards to be established, large connectivity solutions in 5G networks for new transmission technologies. The 5G mobile backhaul adopts a flat IP architecture, functions of a RAN and a core network are virtualized, service anchor points are deployed in a distributed mode, functions of a L3 (three-layer path) are sunk, and the like, so that service flow direction tends to be complex, the demands of east-west flow are enhanced except for north-south flow (from a base station to the core network), and the number of network connections is improved by more than 10 times compared with that of the 4G era. It is not feasible to create and manage connections by means of conventional approaches, and new end-to-end flexible service scheduling techniques need to be introduced to meet the ubiquitous connectivity needs. Segmented routing (SegmentRouting) is used as a source routing technology to efficiently simplify the existing MPLS technology, simultaneously, the existing forwarding mechanism of MPLS is multiplexed, the existing MPLS network can be well compatible, the smooth evolution of the existing MPLS network to the SDN is supported, an operator is helped to easily create and manage million-level connections, and the SegmentRouting is an effective solution for the ubiquitous connection requirement in the 5G bearing era. The SR simplifies the control plane, is completely based on a distributed routing protocol, and realizes label distribution by simply expanding the existing IGP (interactive Gateway protocols) protocol. In the forwarding plane, the label represents the information of network topology (node or link), the end-to-end connection is represented by a group of ordered label stacks, the node only needs to maintain the topology information and does not need to maintain the connection state, and the problem of the expandability of the MPLS network is solved. In addition, the end-to-end path establishment can be completed only by operating the head node based on the source routing technology, and the service deployment efficiency is greatly improved.

The transmission comprehensive network management faces a new SPN network, the L3 function sinks to an access layer comprehensively, the routing is more flexible, the concatenation of the 5G SR tunnel routing faces more complex factors, the concatenation of the 5G SR tunnel routing needs to be realized by combining a full amount of interfaces and real-time interfaces together, and the end-to-end path analysis basis of the transmission specialty is provided for services. The achievement relies on the configuration analysis data of the group OMC northbound interface specification, compared with the PTN, the SPN adds new technologies such as slicing, Flexe, SR-TP and the like, and in the face of the first network access of the new technologies, new data model adaptation analysis is added; meanwhile, as the MEC (Multi-access Edge Computing) sinks, the L3 function sinks to the access layer comprehensively, the transmission network enters an end-to-end L3 operation and maintenance stage, and the service association is more complex; according to the version 201906 of group OMC interface specification, SPN object analysis increases SR tunnel service, increases SR tunnel resources, increases SR tunnel routing, increases IGP topology, increases IGP connection, increases network slices, increases MntGroup binding relationship, increases MntChannel, increases Mnt cross, increases MntChannel protection group, and increases MntChannel protection group-main-standby relationship. As shown in fig. 5G, in a 5G service scenario, based on a general policy of centralized operation, maintenance, management and control integration, an SR tunnel configuration functional framework and a calculation method are described in detail as follows.

SR tunnel configuration and route calculation, the SR tunnel is based on IETFSegmentrouting, the tunnel technology for enhancing the operation and maintenance capability of the transmission field is carried out, and the technical principles of two types of SR tunnels-SRTP-TE (secure real-time Transport Protocol-traffic Engine) and-SRTP-BE (secure real-time Transport Protocol-traffic Engine) are briefly described below, so that the operation points of the interface, configuration and the like of the equipment and the controller are clarified.

SRTP-BE: each device in the network is assigned a node label (nodelael), and each device in the globally unique network of the node label in the IGP domain needs to start an IGP protocol, which spreads the device node labels to other devices throughout the network. When a source node receives a service message with a destination, a layer of node labels are added to the service message, the device calculates the optimal forwarding path to the sink node in a distributed mode, and finds the optimal next hop-out interface of the sink node labels, so that the message is transmitted along the optimal forwarding path. Examples are: the equipment diffuses the Node I label to Node J/D/C/B/other equipment through an IGP protocol; node A/B/C/D/J Node runs IGP protocol respectively, and uses shortest path to calculate the optimal transfer next hop outlet to Node I Node, that is, it is transmitted to Node I Node along Node A- > Node B- > Node C- > Node D- > Node J transfer path, the middle Node does not add, delete, modify the message outer layer label. An example of SRTP-BE tunneling forwarding is shown in fig. 1.

SRTP-TE: firstly, local adjacent labels are distributed to each link of each device, according to the requirement of channel forwarding information planning, a channel path is calculated at an SRTP-TE channel source node according to a specified strategy and constraint conditions (an ISIS protocol (network topology state real-time discovery), a BGP-LS protocol (topology state real-time feedback) and an SRTP-BE channel forwarding example need to BE started, a PCEP protocol (channel path real-time issuing and updating) is carried out to obtain a network topology state in real time and issued to the device after path calculation is finished), an adjacent label stack (such as AdjA- > AdjB- > AdjE- > AdjF) of an identification forwarding path is pressed in for a service message, after the message is received by a network intermediate node, a service forwarding interface is found by matching an adjacent label table, and the service forwarding device is forwarded after a stack top label is stripped. An example of SRTP-TE tunnel forwarding is shown in fig. 2. Analyzing the above, the key point of configuring the SR tunnel should include 1) enabling IGP, ISIS, BGP-LS, PECP protocols and configuring protocol parameters. 2) SR node labels and link adjacency labels are assigned. 3) Creating an SR tunnel: the SRTP-BE tunnel calculates the optimal forwarding path to the destination node by the equipment without centralized configuration; the SRTP-TE tunnel supports the setting of conditions such as source and destination nodes, bandwidth, route calculation strategies, path constraints and the like, and calculates an end-to-end path according to the setting.

The association relationship in the calculation rule of SR tunnel routing is shown in fig. 3. The single-point and end-to-end correspondence in the calculation rule of SR tunnel routing is shown in fig. 4. The bottom-up physical link part, the FlexE Group part (FlexEthernet, flexible ethernet technology), and the FlexE Channel part are included in fig. 3. The physical link portion includes device nodes a-B-D-C-a. The Flexe Group part includes four sets of bi-directional connections: flexe group pA-B, Flexe group pB-D, Flexe group pA-C, Flexe group pC-D. The FlexE Channel part comprises four sets of bi-directional connections: flexe channels A-B, Flexe channels B-D, Flexe channels A-C, Flexe channels C-D. In fig. 4, the left single-point object is a physical port, a FlexE Group, and a FlexE Channel/cross from bottom to top. In fig. 4, the right end-to-end object is sequentially optical connection, FlexE GroupFC, and FlexE Channel from bottom to top.

The calculation rules include the following: (1) circuit-associated SR tunneling service: and associating the SR tunnel service data according to the Z-end network element, the Z-end port, the base station IPV4, the base station IPV6 and the VLAN (virtual Local Area network) of the circuit. (2) The SR tunnel service is associated with the SR tunnel: and analyzing the SR tunnel business association SR tunnel according to the data reported by the manufacturer. (3) The SR tunnel inquires the routing of the SR tunnel through a real-time interface: and calling a real-time interface according to the ID of the SR tunnel, inquiring the SR tunnel route in real time, and finishing the serial connection of the SR route by combining the topological data. (4) And Mnt routing concatenation: and (3) automatically acquiring FlexeCRoss + inter-network element topological serial connection paths through the SPN.

Key points of the invention include the following: seamless fusion with an SDN framework is realized; the perception routing computing capacity of end-to-end service is realized; realizing the dynamic control capability of the service path; and local protection under any topology is realized. Each is described below.

1. Realizing seamless fusion with an SDN framework: the SR identifies the connection through a group of ordered label stacks, the path of the service can be changed by changing the content of the label stacks, and the flexible programmable characteristic can be seamlessly fused with the SDN architecture. Therefore, the SR architecture of the transmission network adopts a deployment mode combining both a centralized controller and a distributed control plane. And the system calculates the end-to-end SR path and generates complete label stack issuing equipment to complete the establishment of the SR tunnel. Distributed routing protocol (IGP + SR) based on SR extensions enables the underlying collection of network topologies. SR label forwarding table formation and FRR (fast reroute) local protection. The distributed control plane has the advantages of self-learning, self-adaption and self-healing capabilities, the establishment and the modification of the label forwarding table can be automatically completed according to the change of the network topology, the integrated controller has the advantages of overall resource overall optimization, centralized scheduling and policy control capabilities, and the SR can be maximally exerted by combining the overall resource overall optimization, the centralized scheduling and the policy control capabilities.

2. The method realizes the service end-to-end perception routing computing capacity: the SR is a source routing technology, information of an SR tunnel only exists in a head node, and other nodes on the path do not sense a service, and thus bandwidth cannot be reserved for the service at the device layer, because flow engineering of the SR needs to be completed at the controller. The controller maintains the global topology and te (trafficengineering) information, and calculates the end-to-end path according to the service request (a node, Z node, bandwidth) and the routing policy (minimum hop count, minimum delay, load balancing, etc.), forms a strict constraint path hop by hop, and completes bandwidth reservation at the control plane, thereby implementing the end-to-end routing calculation capability.

3. The dynamic control capability of the service path is realized: SegmentRouting provides a tunnel implementation mechanism based on source routing, an SR tunnel is composed of a series of ordered Segment identifiers (segmentids), and is used for identifying nodes that need to pass through on the SR tunnel or link-remote forwarding nodes, and only needs to encapsulate a Segment identifier list (SegmentList) into a packet header at a source node, a device can forward according to path information in the packet header, the SR tunnel is very flexible, and can be represented by only one Segment identifier of a destination node or can contain Segment identifiers of all nodes or links along the path, in the SR domain, a Segment Identifier (SID) represents an instruction, a Segment identifier list (SegmentList) represents a set of a series of instructions, and in brief, an SR network topology can be represented by two types of segments, namely, a node SID (nodeid) and a link (AdjSID). (1) NodeSID: and the system has global properties, namely global visibility, global validity and global uniqueness. A node sid can uniquely identify and route a specific node, which means "send the message to node N according to IGP shortest path", because the globally unique attribute of the node sid is not consistent with the locally valid attribute of the MPLS label, a label space srgb (globalblock) needs to be specially allocated to the node sid to prevent collision with other MPLS local labels. (2) Adj SID: the local label is valid locally and used for representing a specific link, only the local uniqueness is required to be ensured, and the meaning of the instruction represents that the message is sent out from the specified link L.

By the combined use of nodeid and AdjSID, the service path can be flexibly controlled, and it is assumed that a packet is to be forwarded from PE (edge routing device) 1 to PE2, after the controller calculates the path, it is PE1- > P2- > P5- > PE2 (combined path), that is, PE1 to P2 can forward according to the shortest path, and P2 to PE2 must pass P5, then the controller uses nodeid labels for PE1 to P2, and P2 to PE2 use AdjSID labels, and converts the path into an SR label stack which is {300, 1003, 800}, and sends the SR label stack to a path head node device PE1, PE1 encapsulates the label stack into the packet head, and a forwarding device P1 'P2' P5 'P6' PE2 on the path forwards according to the label forwarding table.

4. Local protection under any topology is realized: for a long time, the PTN forwarding device lacks a control plane, mainly adopts a service operation and maintenance mode of network management static configuration, and the protection scheme is also the same, and needs to realize the capability of resisting multiple broken fibers by stacking multiple protection mechanisms (such as linear protection stacking and ring network sharing), the deployment is complex and inflexible, after the SR is introduced, the distributed control plane can automatically form FRR according to the network topology, and the local protection under any topology can be realized.

It is pointed out here that the above description is helpful for the person skilled in the art to understand the invention, but does not limit the scope of protection of the invention. Any such equivalents, modifications and/or omissions as may be made without departing from the spirit and scope of the invention may be resorted to.

Claims (15)

1. A5G service dynamic intelligent SR tunnel application method is characterized by comprising the steps of realizing seamless fusion of a segmented routing SR technology and an SDN framework, realizing end-to-end perception routing computing capacity of a service by using the segmented routing SR technology, realizing dynamic control capacity of a service path by using the segmented routing SR technology, and realizing local protection under any topology by using the segmented routing SR technology.

2. The method of claim 1, wherein the implementation of seamless convergence of Segment Routing (SR) technology and SDN architecture is based on SR flexible and programmable property, the property is that SR identifies connections through an ordered set of label stacks, and changing the content of the label stacks can change the path of the service.

3. The method for applying the 5G service dynamic intelligent SR tunnel according to claim 1, wherein a deployment mode combining a centralized controller and a distributed control surface is adopted in the transmission network SR architecture formed by seamless fusion, the centralized controller calculates an end-to-end SR path and generates a complete label stack issuing device to complete SR tunnel establishment, and the distributed control surface autonomously completes establishment and modification of a label forwarding table according to a change of a network topology.

4. The method for 5G service dynamic intelligent SR tunnel application according to claim 3, wherein said distributed control plane has self-learning, self-adapting and self-healing capabilities, said centralized controller has global resource overall optimization, centralized scheduling and policy control capabilities, and both said centralized controller and said distributed control plane combine to maximize SR's advantage.

5. The method for applying the 5G service dynamic intelligent SR tunnel according to claim 3, wherein said utilizing the segmented routing SR technique to achieve local protection under any topology is based on that a distributed control plane can automatically form a fast reroute FRR according to the network topology, thereby achieving local protection under any topology.

6. The method for applying the 5G service dynamic intelligent SR tunnel according to claim 1, wherein the implementation of the service end-to-end aware routing computation capability by using the segment routing SR technique is based on that SR is a source routing technique, information of SR tunnel only exists in a head node, and other nodes on a path do not perceive the service, and thus bandwidth cannot be reserved for the service in a device layer, so that traffic engineering TE of SR is completed in the centralized controller, the centralized controller maintains global topology and traffic engineering TE information, and computes the end-to-end path according to a service request and a routing policy, thereby forming a hop-by-hop strict constraint path, and completing bandwidth reservation in the distributed control plane, thereby implementing the end-to-end routing computation capability.

7. The method for 5G service dynamic intelligent SR tunnel application according to claim 6, wherein said routing policy associates the following: the minimum hop count, the minimum time delay and the load balance; the service request is associated with the following: node a, node Z, bandwidth.

8. The method for applying the 5G service dynamic intelligent SR tunnel according to claim 1, wherein said routing computation capability for implementing end-to-end includes SR tunnel configuration and routing computation thereof, said SR tunnel configuration includes 1) enabling interior gateway protocol IGP, network topology state real-time discovery protocol ISIS, topology state real-time feedback protocol BGP-LS, and tunnel path real-time down-sending update protocol PECP, and configuring protocol parameters; 2) allocating an SR node label and a link adjacency label; 3) and creating an SR tunnel, wherein the SR tunnel is an SRTP-BE tunnel and/or an SRTP-TE tunnel.

9. The method of claim 8, wherein the SRTP-BE tunnel is an optimal forwarding path computed by a device to a sink node without centralized configuration, and supports condition settings of a source sink node, a bandwidth, a routing policy, and a path constraint, and computes an end-to-end path according to the condition settings.

10. The method of claim 1, wherein the SR tunnel is an SRTP-BE tunnel, and the creating of the SRTP-BE tunnel comprises: each device in the network is distributed with a node label NodeLabel, the node label is globally unique in an IGP domain, each device in the network needs to start an IGP protocol, the IGP protocol diffuses the node label of the device to other devices in the whole network, when a source node receives a service message destined to other nodes, a layer of node label is added to the service message, an optimal forwarding path to a sink node is calculated, and an optimal next hop-out interface of the sink node label is found so that the service message is transmitted along the optimal forwarding path.

11. The method for applying the dynamic intelligent SR tunnel for 5G services according to claim 1, wherein said SR tunnel is an SRTP-TE tunnel, and said creating of the SRTP-TE tunnel comprises: distributing local adjacent labels for each link of each equipment, starting a network topology state real-time discovery protocol ISIS, a topology state real-time feedback protocol BGP-LS, an SRTP-TE tunnel forwarding example and a tunnel path real-time issuing updating protocol PCEP according to planning requirements of tunnel forwarding, calculating a tunnel path at an SRTP-TE tunnel source node according to a specified strategy and constraint conditions, acquiring the network topology state in real time, issuing the network topology state to the equipment after path calculation is completed, pressing' an adjacent label stack for marking a forwarding path for a service message, matching an adjacent label table to find a service forwarding interface after the network intermediate node receives the service message, and forwarding the service message after a stack top label is peeled.

12. The method for applying the 5G service dynamic intelligent SR tunnel according to claim 8, wherein said calculation rule of routing calculation includes the following items: (1) circuit-associated SR tunneling service: associating SR tunnel service data according to a Z-end network element, a Z-end port, a base station Internet protocol version IPV4, a base station Internet protocol version IPV6 and a virtual local area network VLAN of the circuit; (2) the SR tunnel service is associated with the SR tunnel: analyzing the SR tunnel business association SR tunnel according to the data reported by the manufacturer; (3) the SR tunnel inquires the routing of the SR tunnel through a real-time interface: calling a real-time interface according to the ID of the SR tunnel, inquiring the SR tunnel route in real time, and finishing the serial connection of the SR route by combining the topological data; (4) and (3) mounting the routing concatenation under the Mnt term: and the flexible Ethernet cross FlexeCRoss + inter-network element topological serial connection path is automatically acquired through a network slice management function SPN.

13. The method of claim 1, wherein the implementation of the dynamic control capability of the service path using the segment routing SR technology is a tunnel implementation mechanism based on SR source routing, the SR tunnel is composed of a series of ordered segment identifiers SID, and is used to identify nodes or link-remote forwarding nodes that need to pass through the SR tunnel, the segment identifier list SegmentList is encapsulated in a packet header at the source node, the device can forward the packet according to the path information in the packet header, in the SR domain, the segment identifier SID represents an instruction, and the segment identifier list SegmentList represents a set of a series of instructions.

14. The method for 5G service dynamic intelligent SR tunnel application according to claim 1, wherein said utilizing segment routing SR technique to implement service path dynamic control capability is based on SR source routing tunnel implementation mechanism, SR tunnel is represented by only one segment identifier of destination node or by segment identifier containing all nodes or links along the way.

15. The method of claim 1, wherein the SR network topology is represented by nodebsid and link AdjSID, the nodebsid has global property, i.e. globally visible, globally valid, globally unique, a specific node is uniquely identified and routed through nodebsd, which means "send packet to node N by IGP shortest path", the nodebsd has its own block of label space SRGB to prevent MPLS local label collision with other multi-protocol label switching, the AdjSID is a local label, locally valid, is used to represent a specific link, has local uniqueness, and its instruction means represents "send packet out from designated link L", and is used to flexibly control the traffic path through the combination of nodebsid and AdjSID.

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