CN105450437B - A method of allocating SID and SR node - Google Patents

Abstract

The invention discloses a method for distributing SID and SR node, comprising SR management node obtaining address information of SR node in network and distributing SID information to SR node; the SR management node sends the distributed SID information to each SR node in the network through the multicast mode of IGP message or the expansion of configuration management message. By the method, IP configuration, SID configuration and the like are not needed to be carried out on nodes or ports on the network, and automatic distribution and learning of SID information of SR nodes without numbered interfaces are realized. In addition, the method establishes the service channel between the SR management node and each SR node in the network, thereby realizing the automatic establishment of the service channel between the SR control node and each SR node and greatly simplifying the complexity of the establishment and the configuration of the service channel.

Description

A method of allocating SID and SR node

technical field

The present invention relates to IP-based transport network (IP RAN) technology, and more particularly, to a method for allocating SIDs and an SR node.

Background technique

At present, on the IP-based transport network (IP RAN), also known as the unnumbered interface network, there is already a data communication network (DCN, Data Communication Network) management channel automatic establishment and configuration method, mainly through the automatic setting of DCN on each node. Port, the default route ID (Router ID) is generated by the extension of the Open Shortest Path First (OSPF, OpenShortest Path First) protocol, Address Resolution Protocol (ARP, Address Resolution Protocol), Link Layer Discovery Protocol (LLDP) and other protocols. Realize the management IP address, DCN port, and MAC address learning between each node, so as to realize the automatic establishment and configuration of DCN channel.

However, for the establishment of service channels between SR nodes, such as between access nodes and aggregation nodes, a large amount of manual configuration is required, such as the configuration of the IP address of each port, the configuration of the interior gateway protocol (IGP, Interior Gateway Protocol). configuration, configuration of LDP protocol, configuration of pseudowire information, etc. With the increase of the number of access nodes, the complexity of configuration will be greatly increased, and the risk of corresponding configuration errors will also be greatly increased.

In the existing segment routing (SR, Segment Routing) technology, that is, in the implementation of the SR extension function based on the IGP protocol, the SR extension on the IGP protocol carries the SR ID (SR ID, Segment Routing ID, also abbreviated as SID). ), and calculates the shortest path to each SID through the IGP algorithm; and the SID stack information in the packet header encapsulation can guide the packet to be forwarded according to the encapsulation stack path. In this way, the configuration of the corresponding LDP protocol and pseudowire information can be greatly reduced. However, the prior art solution does not provide a specific implementation solution of how to use the SR extension on the IGP protocol to realize the allocation of the SID, and the automatic establishment of the service channel cannot be achieved.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a method for allocating SIDs and an SR node, which can realize automatic allocation of SIDs.

In order to achieve the purpose of the present invention, the present invention provides a method for allocating segment routing identifier SID, comprising: the segment routing SR management node obtains the address information of the SR node in the network and assigns the SID information to the SR node;

The SR management node sends the allocated SID information to each SR node in the network by extending the interior gateway protocol IGP message or the configuration management message.

The sending includes:

The SR management node, by extending the IGP message, carries the SID information corresponding to one or more SR node address information by multicast and sends it to the SR nodes.

The extended information is carried by the SID Allocation TLV of ISIS or OSPF.

The sending also includes:

The SR management node sends the SID information corresponding to the address information of one or more SR nodes to each SR node respectively by extending the configuration management message and through the configuration management channel.

The method also includes:

After each SR node receives the SID information, all SR nodes in the network flood the network with their own SID information by flooding the multicast message.

Before sending the allocated SID information to each SR node in the network, the method further includes: the SR management node sends a notification that it has the SID allocation capability to each SR node in the network;

The announcing that the node has the SID allocation capability specifically includes:

The SR management node notifies each SR node in the network through an OSPF or ISIS message or a configuration management message provided with an allocation capability identification field.

The SR management node includes two or more, and the method further includes:

The SR node that receives the notification selects an SR management node that sends the notification as the final SR management node according to a preset policy.

After the SR node in the network obtains the allocation capability possessed by the SR management node, the method further includes: calculating a default SR service channel from the SR node to the SR management node.

The SID information includes the address information of the node and the SID label information Label; wherein, the SID Label includes the label range, and the index or global Label.

When the newly added SR node is accessed in the network, the method further includes:

The SR management node is expanded through the multicast or unicast mode, and assigns a SID to the address information of the newly added SR node, and the expansion also carries the original assigned address in the network to which the newly added SR node joins. SID information of other nodes;

After receiving the extension mode announcement message, each SR node in the network updates the mapping relationship between the SID allocation information and the address information according to the information from the SR management node.

When there is an SR node failure in the network, the method further includes:

After sensing the failed SR node, the SR management node revokes the SID information allocated to the address information of the failed SR node, and floods it to other SR nodes in the network;

After each SR node in the network receives the revocation information, it recalculates through the SPF algorithm, and deletes the SR forwarding entry to the failed SR node.

The present invention also provides an SR node, which at least includes a configuration management module, an allocation processing module, and an establishment module, wherein,

The configuration management module is used to automatically establish a configuration management channel;

The allocation processing module is used to receive the allocated SID information through the extended IGP message or the configuration management message; flood the SID information of the node to the network.

It also includes a establishing module for calculating a default SR service channel to the SR management node.

When the SR node is determined to be the SR management node, it also includes an allocation module and a processing module, wherein,

The allocation module is used to allocate the SID information to the SR node address information; send the allocated SID information to each SR node in the network by extending the IGP message or the configuration management message;

The processing module is used to acquire the topology relationship of the entire network through learning, and output the SID information and the topology relationship of the entire network to the establishment module.

The distribution module is specifically used for: by extending the IGP message, sending the allocated SID information to each SR node in the network in a multicast mode; or, by extending the configuration management message, in a unicast mode. The allocated SID information is sent to each SR node in the network.

The SR node further includes a notification module, configured to send a notification that it has the SID allocation capability to each SR node in the network.

The allocating module is also used for: allocating a SID information for accessing the newly added SR node;

The establishing module is further configured to update the mapping relationship between the SID information and the address information according to the information from the SR management node after receiving the extension mode announcement message.

The allocating module is also used for: sensing the failed SR node, revoke the SID information allocated to the failed SR node, and flood to other SR nodes in the network;

The establishment module is further configured to delete the SR forwarding entry to the failed SR node through recalculation by the SPF algorithm after receiving the revocation information.

Compared with the prior art, the technical solution of the present application includes that the SR management node obtains the address information of the SR node in the network and allocates SID information to the SR node; the SR management node uses the multicast mode of the IGP message or the extension of the configuration management message, Send the allocated SID information to each SR node in the network. With the method of the invention, it is not necessary to configure the IP and SID of the nodes or ports on the network, thereby realizing the automatic allocation and learning of the SID information of the SR nodes with no numbered interface.

In addition, the method of the present invention establishes a service channel between the SR management node and each SR node in the network, thereby realizing the automatic establishment of the service channel between the SR control node and each SR node, and greatly simplifies the complexity of the establishment and configuration of the service channel. sex.

Furthermore, the method of the present invention, through the establishment of the backup SR service channel, timely switches the service path when the original SR service channel fails, thereby realizing the rapid protection of the SR service channel.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the description, claims and drawings.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 is the flow chart of the method for allocating SID of the present invention;

Fig. 2 is the schematic diagram of SID distribution unicast message data frame encapsulation format of the present invention;

Fig. 3 is the schematic diagram of flooding multicast message format of the present invention;

4 is a schematic diagram of the composition structure of an SR node of the present invention;

5 is a schematic diagram of a network architecture according to the first embodiment of the present invention;

6 is a schematic diagram of a network architecture according to a second embodiment of the present invention;

FIG. 7 is a schematic diagram of IP RAN network forwarding according to the present invention;

8 is a schematic diagram of adding and forwarding according to an embodiment of adding an SR node according to the present invention;

FIG. 9 is a schematic diagram of deletion and forwarding of an embodiment of deleting an SR node according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, the embodiments in the present application and the features in the embodiments may be arbitrarily combined with each other if there is no conflict.

The SR management node described in the present invention is an SR node with a convergence management function elected in the network, and the SR node is other SR nodes in the network except the SR management node. Among them, how to select is a well-known technology of those skilled in the art, and its specific implementation is not used to limit the protection scope of the present invention, and will not be repeated here.

Fig. 1 is the flow chart of the method for allocating SID of the present invention, as shown in Fig. 1, including:

Step 100: The SR management node acquires the address information of the SR node in the network and allocates SID information to the SR node.

In this step, by establishing the DCN management channel, the SR management node can learn the router IDs and management loopback IP addresses and other related information of all SR nodes in the network. The process of establishing the DCN management channel belongs to the well-known technology of those skilled in the art, and the specific implementation is not used to limit the protection scope of the present invention, and will not be repeated here.

The SID information allocated by the SR management node in this step includes:

The SR management node is based on pre-planned (generated by default rules of the network, such as setting the SID value within the range of the SID area divided from low to high according to the size of the Router ID) or configured (for example, the administrator has pre-configured the SID value) SID information, SID information is allocated to each SR node in the network and to the SR management node itself. Wherein, those skilled in the art know that the SID information includes IPv6 Router ID or SID label information (Label), wherein the SID Label includes a label range, and an index (index) or a global Label.

Step 102: The SR management node sends the allocated SID information to each SR node in the network by extending the IGP message or the configuration management message. specifically,

In this step, the SR management node sends the allocated SID information to each SR node in the network in a multicast manner by extending the IGP message. Specifically include:

The SR management node extends the message from the intermediate system to the intermediate system (ISIS) or OSPF, and carries the SID information corresponding to one or more SR node address information by multicast and sends it to each SR node in the network. The extended information can be It is carried by the SID Allocation TLV field of ISIS or OSPF. The value in the extension field, that is, the SID allocation information, includes but is not limited to the Router ID or loopback IP address carrying the SR node, and the SID label information (SID Lable) of the allocated SID; wherein, the SID Lable includes the label range, index (index ) or global label.

Specifically, for example, OSPF or ISIS is extended in advance to carry the SID Allocation TLV field of the SRSID allocation information for the corresponding prefix to the node. That is to say, similar to the Prefix SID sub-tlv format carried in the OSPF extension prefix TLV, or the ISIS SID Sub-TLV format, the extension adds a SID Allocation TLV field to carry SID information;

The SR management node sends the IGP protocol message with the newly added SID Allocation TLV field to each SR node in the network by multicast (eg 224.0.0.5). Here, the SID information of each SR node in the network is encapsulated into the newly added SID Allocation TLV field of the OSPF prefix TLV format or the newly added SID Allocation TLV field of the ISIS SID Sub-TLV format by means of TLV. Added Value in the SID Allocation TLV field to carry the Router ID or loopback IP address of the SR node, and the SID Lable of the allocated SID (label range + index or global label).

After receiving the IGP protocol message, each SR node in the network obtains the SID Label information allocated by the router ID corresponding to the node according to the Router ID carried in the SID AllocationTLV field of the IGP protocol message.

In this step, the SR management node sends the allocated SID information to each SR node in the network through the expansion of the configuration management message and through the configuration management channel. The SID information allocated by each SR node, carrying the SID information corresponding to one or more SR node address information, is sent to each SR node in a unicast manner.

Specifically, for example, through the configuration management channel such as the DCN management channel, the SR management node will distribute the SID and other information allocated to each SR node in the network in a unicast mode, and distribute the unicast message through the SID and expand the configuration management message. sent to each SR node separately. Among them, the DCN management channel learns the topology connection between each other through the default OSPF process, the management node will obtain all the node address information in the network, and directly communicate with the network nodes through the node address information. For example, when the corresponding configuration is delivered to the SR node through a protocol such as NETCONF or SNMP, the application module generates UDP or TCP format packet encapsulation according to the configuration on the B device, and sends these configuration management packets through the DCN management channel to the corresponding Node to configure. After receiving the message, the node to be configured parses the information carried in the configuration management message, and sends it to the configuration management module for analysis. The configuration management module parses the configuration information into a corresponding configuration protocol and sends it to a related protocol process for processing. For example, the data frame encapsulation format of SID allocation unicast message is shown in Figure 2, which includes: IP message field, in which a new SID unicast message extension is defined, which is used to carry a specific port number to indicate that the message is a SID single broadcast message, and then carry specific SID specific allocation information, including specific SID mapping such as Router ID mapping.

After each SR node in the network obtains the SID information of its own node, all SR nodes in the network flood the network with the SID information of its own node through a flooding multicast message in a multicast manner. The format of the flooding multicast packet is shown in Figure 3, which includes: OSPF IP packet field, which is extended in the prefix TLV, which is used to carry the SID Allocation TLV format.

In this step, the SR management node sends the SID information to the SR nodes in the network through multicast or unicast, and after each SR node receives the SID information, it further includes: all SR nodes in the network flood the Multicast packets flood the network with their own SID information.

After step 100 and before step 102, the method of the present invention further includes:

Step 101: The SR management node sends a notification that it has the SID allocation capability to each SR node in the network. It should be noted that step 101 can be omitted, that is, when the SR node is elected as the SR management node by default, the SR node defaults that the current SR management node has the SR ID allocation capability.

The specific implementation of this step includes: the SR management node notifies all SR nodes in the network that the node has the SID allocation capability by extending the IGP protocol. In this way, after the SR node receives the notification information message, the SR node will confirm the allocation of the SID information by the SR management node through the DCN channel or the IGP manner. specifically,

When the SR management node allocates SID information through multicast, the SR management node in this step announces to all SR nodes in the network that this node has the SID allocation capability by extending the IGP protocol, which specifically includes:

The SR management node sets an allocation capability identification field in the OSPF or ISIS message, or expands a TLV or sub-TLV to add an allocation capability identification field to identify the node with the ability to perform node SID allocation;

The SR management node advertises each SR node in the network through OSPF or ISIS multicast with the allocation capability identification field set. In this way, each SR node in the network can confirm the message carrying the SID Allocation TLV from the SR management node according to the allocation capability identification field.

When the SR management node allocates SID information through unicast, the SR management node in this step announces to all SR nodes in the network that this node has the SID allocation capability by extending the IGP protocol, which specifically includes:

The SR management node sends a notification supporting the SRSID allocation capability to each SR node in the network through the DCN channel, so as to form the establishment of an automatic service channel. For details, please refer to the method of setting an allocation capability identification field in an OSPF or ISIS packet, or extending a TLV or sub-TLV to add an allocation capability identification field, which is not limited here. In this way, after each SR node receives the SR SID allocation capability announcement message from the SR management node, if it needs to establish an SR service channel, it can actively send an SR SID allocation request message to the SR management node, and then the SR manages it. The node allocates SID information to the SR node in a unicast manner.

It should be noted that, when there are two or more SR nodes that send the announcement that they have the SID allocation capability to each SR node in the network, the SR node that receives the announcement selects one to send the announcement according to the preset policy. The SR node is an SR management node, and the preset policy may be to select the largest or smallest Router ID according to the size of the Router ID.

Further, the inventive method also includes:

Step 103: Establish a service channel between the SR management node and each SR node in the network. Specifically include:

After the SR node and SR management node in the network learn the SID information of themselves and other nodes, they use the SR IGP process to extend the local Router ID and SID through OSPF to extend the prefix SID sub-tlv format carried in the prefix TLV or similar to the ISIS SID. The newly added SID Allocation TLV field in the Sub-TLV format is used for multicast advertisement, so that the service topology between SR nodes can obtain the topology information of all SR nodes in the network through multicast packets; here, how to learn is the prior art, It is not intended to limit the protection scope of the present invention, and will not be repeated here;

Next, each SR node calculates an optimal path that can reach the SR management node through the SPF algorithm. By default, the shortest path from each SR node to the SR management node is calculated using the SID of the SR management node as the destination address, and an SR service channel is automatically created.

Further, in the case of failure of the original SR service channel, in order to switch the service path in time to realize the rapid protection of the SR service channel, the method of the present invention further includes:

The SR management node delivers the backup path policy to the SR node that created the SR service channel, so that the SR node pre-configures or calculates a backup SR service channel that satisfies the backup path policy;

Alternatively, the SR management node calculates an SR backup path, and notifies the relevant SR nodes on the SR backup path of relevant forwarding table information to construct a backup SR service channel.

Here, the specific implementation of the fast protection of the SR service channel belongs to the well-known technology of those skilled in the art, and is not used to limit the protection scope of the present invention, and will not be repeated here.

When the newly added SR node is accessed in the network, the method further includes:

The SR management node allocates a SID to the Router ID of the newly added SR node through the SID Allocation TLV field, and the SID Allocation TLV field also carries the original SID information in the network to which the newly added SR node joins;

After receiving the extended mode announcement message, each SR node in the network updates the mapping relationship between the SID information and the Router ID according to the information from the SR management node.

When there is an SR node failure in the network, the method further includes:

After sensing the failed SR node, the SR management node revokes the SID information allocated to the failed SR node, and floods it to other SR nodes in the network;

After each SR node in the network receives the revocation information, it recalculates through the SPF algorithm and deletes the SR forwarding entry to the failed SR node.

Through the method of the present invention, it is not necessary to perform IP configuration and SID configuration on the nodes or ports on the network, and the automatic allocation and learning of the SID information of the SR nodes with no numbered interface is realized, thereby realizing the connection between the SR control node and each SR node. The automatic establishment of service channels greatly simplifies the complexity of establishment and configuration of service channels.

FIG. 4 is a schematic diagram of the composition structure of an SR node according to the present invention. As shown in FIG. 4, it at least includes a configuration management module and an allocation processing module, wherein,

The configuration management module is used to automatically establish a configuration management channel;

The allocation processing module is used to receive the allocated SID information through the extended IGP message or the configuration management message; obtain the topology relationship of the whole network through learning; and flood the SID information of the node into the network.

It also includes: establishing a module for calculating a default SR service channel that can reach the SR management node through the SPF algorithm according to the SID information and the topology relationship of the entire network.

Further, the establishment module is further configured to receive the backup path policy, so as to preconfigure or calculate a backup SR service channel that satisfies the backup path policy.

When the SR node is elected as the SR management node, it also includes an allocation module and a processing module, wherein,

The allocation module is used to obtain the address information of the SR node accessing the network and allocate the SID information by using the DCN management channel establishment process; by extending the IGP message or the configuration management message, the allocated SID information is sent to each network in the network. SR node; specifically, through the expansion of the IGP message, the allocated SID information is sent to each SR node in the network by multicast; The SID information is sent to each SR node in the network.

The processing module is used to acquire the topology relationship of the entire network through learning, and output the SID information and the topology relationship of the entire network to the establishment module.

It also includes a notification module, configured to send a notification that it has the SID allocation capability to each SR node in the network after the configuration management channel is established.

Further, the allocation module is further configured to issue a backup path policy.

Further, the allocation module is further configured to calculate an SR backup path, and notify relevant SR nodes on the SR backup path of relevant forwarding table information to construct a backup SR service channel.

further,

The allocation module is also used for: allocating a SID information for accessing the newly added SR node; correspondingly,

The establishing module is further configured to: update the mapping relationship between the SID information and the address information according to the information from the SR management node after receiving the extension mode announcement message.

further,

The allocation module is also used for: sensing the failed SR node, revoke the SID information allocated to the failed SR node, and flood to other SR nodes in the network; accordingly,

The establishment module is further used for: after receiving the revocation information, through recalculation by the SPF algorithm, delete the SR forwarding entry to the realization SR node.

The method of the present invention will be described in detail below with reference to specific embodiments.

FIG. 5 is a schematic diagram of a network architecture according to the first embodiment of the present invention. As shown in FIG. 5 , the network includes an SR management node, namely Node B, and three SR nodes, namely Node A1, Node A2 and Node A3. Assume that when node A1, node A2, and node A3 in the network access the network, the DCN management channel is automatically established after the default configuration is loaded and started, and the SR IGP process on each access node is started by loading the default configuration.

The first implementation uses multicast to send SID information, and the specific implementation of establishing a service channel includes:

First, through the automatic establishment of the DCN management channel, Node B learns the Router IDs and management loopback IP addresses of all SR nodes, namely Node A1, Node A2, and Node A3; and according to the pre-planned or configured SR ID information, Node B gives each Each SR node, namely node A1, node A2, node A3 and node B itself allocates SIDs;

Next, Node B identifies that this node has the ability to perform node SID allocation by setting an allocation capability identification field in the OSPF or ISIS message, or extending a TLV or sub-TLV to add a new allocation capability identification field; The OSPF or ISIS multicast mode of the capability identification field advertises other SR nodes, namely node A1, node A2 and node A3;

After that, Node B encapsulates the SID information of each SR node, namely Node A1, Node A2, and Node A3, into the SID Allocation TLV field newly added by the OSPF prefix TLV or the SIDAllocation TLV field newly added by the ISIS protocol by means of TLV. Send to each SR node, namely node A1, node A2 and node A3 through specific multicast (such as 224.0.0.5);

When each SR node, namely node A1, node A2 and node A3, receives the extended OSPF or ISIS message that carries the SID Allocation TLV sent by node B, it determines which node is the router based on the Router ID and SID Label carried in it. The allocated SID information corresponding to the ID, and save the SID information of node B and the SID information of other SR nodes, for example: node A1 saves its own SID information, but also saves the SID information of node A2, node A3 and node B;

After each SR node, namely node A1, node A2 and node A3 learns the SR ID information of itself and other nodes, it uses the SR IGP process to extend the prefix SIDsub-tlv format carried in the prefix TLV to the local Router ID and SID through OSPF Or the newly added SID Allocation TLV field in the ISIS SID Sub-TLV format carries out multicast announcement, thus, the business topology obtains the topology information of the network node via the multicast address;

After that, each SR node, namely node A1, node A2 and node A3, respectively calculates an optimal path that can reach node B according to the SPF algorithm, and automatically establishes the SR service working channel; by default, each SR node is node A1, node A2 And the shortest path calculation from node A3 to node B is calculated with the SID of node B as the destination address.

In this way, when there is a packet P that needs to be forwarded to the outside through node B, the SID packet header of the shortest path to node B is added to the packet P by default. The SID indicates that the packet must be forwarded through Node B. Specifically, in the message forwarding process, the forwarding entry of each SR node can be obtained by mapping the shortest path interface of the SID.

FIG. 6 is a schematic diagram of a network architecture according to a second embodiment of the present invention. As shown in FIG. 6 , the network includes an SR management node, namely Node B, and three SR nodes, namely Node A1, Node A2 and Node A3. Assume that when node A1, node A2, and node A3 in the network access the network, the DCN management channel is automatically established after the default configuration is loaded and started, and the SR IGP process on each access node is started by loading the default configuration.

The second implementation uses unicast to send SID information, and the specific implementation of establishing a service channel includes:

First, through the automatic establishment of the DCN management channel, Node B learns the Router IDs and management loopback IP addresses of all SR nodes, namely Node A1, Node A2, and Node A3; and according to the pre-planned or configured SR ID information, Node B gives each Each SR node, namely node A1, node A2, node A3 and node B itself allocates SIDs;

Next, Node B sends a notification that supports SR SID allocation capability to each SR node in the network through the DCN channel;

Afterwards, Node B allocates the unicast packet data frame encapsulation format according to the SID shown in Figure 2 through the DCN management channel, and sends the SID and other information allocated to each SR node in the network to each SR node in a unicast manner. The SR nodes are node A1, node A2 and node A3;

When the SR nodes, namely node A1, node A2 and node A3, receive the SID allocation notification message sent by node B, save the SID information allocated by this node;

After the SR nodes, namely node A1, node A2 and node A3, receive the SID of the local node, use the SR IGP process to extend the local Router ID and SID through OSPF to the prefix SID sub-tlv format carried in the prefix TLV or ISISSID Sub-TLV The newly added SID Allocation TLV field in the format performs multicast announcement, whereby the service topology obtains the topology information of the network node via the multicast address;

After that, each SR node, namely node A1, node A2 and node A3, respectively calculates an optimal path that can reach node B according to the SPF algorithm, and automatically establishes the SR service working channel; by default, each SR node is node A1, node A2 And the shortest path calculation from node A3 to node B is calculated with the SID of node B as the destination address.

In this way, when there is a packet P that needs to be forwarded to the outside through node B, the SID packet header of the shortest path to node B is added to the packet P by default. The SID indicates that the packet must be forwarded through Node B. Specifically, in the message forwarding process, the forwarding entry of each SR node can be obtained by mapping the shortest path interface of the SID.

Fig. 7 is a schematic diagram of IP RAN network forwarding according to the present invention. When a node is added in the IP RAN network, the plug-and-play function of IP RAN network nodes can be automatically realized without any configuration by using the SID allocation method of the present invention. A schematic diagram of adding and forwarding according to the embodiment of adding an SR node according to the present invention is shown in FIG. 8 . Assume that node A7 is a newly added SR node in the network as shown in FIG. 7 , and the automatic establishment of the channel after the access of node A7 includes:

When the device of node A7 is powered on and started, the configuration required for establishing the DCN automatic management channel and the default SRIGP process are loaded by default, and the Router ID of node A7 will be generated based on the establishment of the DCN management channel.

After the Node B, which is the SR management node, perceives the existence of the node A7 according to the Router ID advertised by the DCN, it allocates a SID to the Router ID of the node A7 through the SID Allocation TLV field in step 102 shown in FIG. 1 of the present invention. In addition, the SID Allocation TLV field also carries the original SID information in the network shown in FIG. 7 (ie, the SID information of the node A1 to the node A7 and the node B). The SID Allocation TLV field is carried in the type 10 LSA packet through the OSP IP packet field as shown in Figure 3, or is advertised to each The SR nodes are node A1-node A7.

After each SR node, that is, node A1-node A7, receives the extension mode announcement message, it updates the mapping relationship between the SID information and the Router ID according to the information from node B, that is, the SR forwarding table is updated. The SR forwarding of the node A7 is the forwarding entry of A3\A1 shown in bold italics in FIG. 8 , and all the SR forwarding entries are stored on the node A7. The SR forwarding table is formed as each SR node publishes its own local SID information through the SRIGP protocol after receiving the mapping relationship between Router ID and SID information, and each SR node forms an SR forwarding table according to the received SR IGP topology information.

In this way, when a message is sent to node B, the shortest path needs to be forwarded by node A7, node A7 searches for the next hop of the SID from the local to node B, and searches the SR forwarding table in node A7 as shown in Figure 8. , which maps out the int2 interface.

When a node is deleted in the IP RAN network, as shown in Figure 9, it is assumed that the node A3 in the IPRAN network of the plan shown in Figure 7 fails and needs to be deleted, including:

After sensing the failure of node A3, management node B revokes the SID information allocated to node A3, and floods it to other SR nodes, namely node A1, node A2, and node A4 to node A6;

After each SR node, that is, node A1, node A2, and node A4 to node A6, after receiving the revocation information, after recalculation by the SPF algorithm, the SR forwarding entry to node A3 is deleted, such as the entry deleted by the bold black slash in Figure 9. ; and recalculate the shortest path from itself to node B, such as node A1, recalculate the shortest path to node B to be reachable through A4\A5\A6.

The above descriptions are only preferred examples of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (19)

1. A method for assigning a segment routing identity, SID, comprising: the method comprises the steps that a SR management node in a segmented route acquires address information of an SR node in a network and distributes SID information to the SR node;

the SR management node sends the distributed SID information to each SR node in the network through the extension of the IGP message or the configuration management message.

2. The method of claim 1, wherein the sending comprises:

and the SR management node carries SID information corresponding to one or more SR node address information to multicast and send the SID information to each SR node through the extension of the IGP message.

3. The method of claim 2, wherein the extended information is carried by a SID Allocation TLV of ISIS or OSPF.

4. The method of claim 1, wherein the sending further comprises:

and the SR management node carries SID information corresponding to one or more SR node address information through the expansion of the configuration management message and the configuration management channel and respectively sends the SID information to each SR node.

5. The method of claim 1, 2 or 4, further comprising:

after each SR node receives the SID information, all SR nodes in the network flood their own SID information to the network through flooding multicast messages.

6. The method of claim 1, wherein before sending the assigned SID information to each SR node in the network, the method further comprises: and the SR management node sends an announcement with SID distribution capability to each SR node in the network.

7. The method of claim 6, wherein said notifying that the local node has SID assignment capability specifically comprises:

the SR management node informs each SR node in the network through an OSPF or ISIS message or a configuration management message provided with a distribution capability identification field.

8. The method of claim 6, wherein the SR management node comprises two or more, the method further comprising:

and the SR node receiving the notice selects one SR management node sending the notice as a final SR management node according to a preset strategy.

9. The method according to claim 6, wherein after the SR node in the network acquires the allocation capability of the SR management node, the method further comprises: and calculating a default SR service channel from the SR node to the SR management node.

10. The method of claim 1 or 6, wherein the SID information includes address information of the node and SID tag information Label; wherein, the SID Label includes a Label range and an index or a global Label.

11. The method according to claim 1 or 6, wherein when a new SR node is accessed in the network, the method further comprises:

the SR management node is expanded in a multicast or unicast mode, a SID is allocated to the address information of the newly added SR node, and the expansion also carries the SID information which is originally allocated to other nodes in the network where the newly added SR node is added;

and after each SR node in the network receives the expansion mode notification message, updating the mapping relation between SID distribution information and address information according to the information from the SR management node.

12. The method according to claim 1 or 6, characterized in that when there is a SR node failure in the network, the method further comprises:

after sensing the failed SR node, the SR management node cancels SID information distributed to the address information of the failed SR node and floods other SR nodes in the network;

after receiving the revocation information, each SR node in the network recalculates through an SPF algorithm and deletes the SR forwarding entry of the failed SR node.

13. A Segment Routing (SR) node, comprising at least a configuration management module, an allocation processing module, and an establishment module, wherein,

the configuration management module is used for automatically establishing a configuration management channel;

the distribution processing module is used for receiving distributed SID information through the extended IGP message or the configuration management message; and flooding SID information of the node to the network.

14. The SR node of claim 13 further comprising an establishment module configured to compute a default SR service path to the SR management node.

15. The SR node of claim 13, further comprising an assignment module, and a processing module, when said SR node is determined to be a SR management node, wherein,

the distribution module is used for distributing the address information of the SR node and the SID information; the distributed SID information is sent to each SR node in the network through the extension of IGP message or configuration management message;

and the processing module is used for acquiring the whole network topological relation through learning and outputting the SID information and the whole network topological relation to the establishing module.

16. The SR node of claim 15, wherein the allocation module is specifically configured to: through the extension of IGP message, the distributed SID information is sent to each SR node in the network in a multicast mode; or, the allocated SID information is sent to each SR node in the network in a unicast manner through the extension of the configuration management packet.

17. The SR node of claim 15, further comprising an advertisement module configured to send an advertisement with SID assignment capability to each SR node in the network.

18. The SR node of claim 15 wherein the assignment module is further configured to: distributing SID information for accessing the newly added SR node;

the establishing module is further configured to: and after receiving the extended mode notification message, updating the mapping relation between the SID information and the address information according to the information from the SR management node.

19. The SR node of claim 15 wherein the assignment module is further configured to: sensing a failure SR node, revoking SID information distributed to the failure SR node, and flooding the SID information to other SR nodes in the network;

the establishing module is further configured to: after receiving the revocation information, the SR forwarding entry to the failed SR node is deleted through recalculation of an SPF algorithm.

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