CN114827022A

CN114827022A - Routing message processing method, routing message issuing device and communication system

Info

Publication number: CN114827022A
Application number: CN202110064662.5A
Authority: CN
Inventors: 吴燕飞; 张耀坤
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-01-18
Filing date: 2021-01-18
Publication date: 2022-07-29
Also published as: WO2022152224A1

Abstract

The application discloses a routing message processing method, a routing message publishing device and a communication system, and belongs to the technical field of networks. The network device generates a routing message comprising a prefix SID of the destination network device, the routing message further comprising an indication indicating whether to create an SR-BE tunnel to the destination network device. The network device issues a routing message. The network device receiving the routing message determines whether to create an SR-BE tunnel to the destination network device according to the indication. The method and the device improve the tunnel creation flexibility among the network devices by adding the indication for indicating whether to create the SR-BE tunnel to the network devices in the routing messages issued by the network devices.

Description

Routing message processing method, routing message issuing device and communication system

Technical Field

The present application relates to the field of network technologies, and in particular, to a routing message processing method, a routing message issuing device, and a communication system.

Background

Segment Routing (SR) is a protocol designed based on the concept of source routing to forward packets in a network. The SR divides a network path into segments, and assigns Segment Identifiers (SIDs) to the segments and nodes in the network, and a forwarding path can be obtained by arranging the segments and network nodes in order. Wherein a node in the network is a network device. The implementation modes of the SR include, but are not limited to, a segment routing traffic engineering (SR-TE) mode and a segment routing best effort (SR-BE) mode. The SR-BE mode is implemented based on an Interior Gateway Protocol (IGP) and is used to implement shortest path (i.e., minimum cost path) forwarding.

Under the SR-BE mode, messages are transmitted among nodes in the network through SR-BE tunnels. A node in the network may publish its own prefix SID in an IGP domain where the node is located, and after receiving the prefix SID, other nodes in the IGP domain calculate a tag value according to their SR global block (SRGB), and generate a tag forwarding entry, thereby creating an SR-BE tunnel to the node.

After any node in the IGP domain issues the prefix SID of the node, all other nodes in the IGP domain can receive the prefix SID, and therefore all other nodes can create SR-BE tunnels to the node. At present, each time a node in a network receives a prefix SID issued by other nodes, an SR-BE tunnel to the other node is created, and some tunnels are not needed, so that the tunnel creation flexibility is low.

Disclosure of Invention

The application provides a routing message processing method, a routing message issuing device and a communication system, which can solve the problem of low flexibility of the existing SR-BE tunnel creation.

In a first aspect, a method for processing a routing message is provided. The method comprises the following steps: the first network equipment receives a routing message issued by the second network equipment, wherein the routing message comprises a prefix SID of the second network equipment, and the routing message also comprises a first indication which is used for indicating whether to create an SR-BE tunnel to the second network equipment. The first network device determines whether to create an SR-BE tunnel from the first network device to the second network device according to the first indication.

In the method and the device, the indication for indicating whether to create the SR-BE tunnel to the network equipment is added in the routing message issued by the network equipment, so that after one network equipment in the same IGP domain receives the routing message issued by the other network equipment, whether to create the SR-BE tunnel to the other side is determined according to the indication in the routing message, the tunnel creation flexibility among the network equipment is improved, and unnecessary SR-BE tunnels are prevented from being created.

In a possible implementation manner, the first indication is used to indicate that no SR-BE tunnel to the second network device is created, and the determining, by the first network device, whether to create the SR-BE tunnel from the first network device to the second network device according to the first indication includes: and the first network equipment determines not to create the SR-BE tunnel from the first network equipment to the second network equipment according to the first indication.

In the application, the network equipment can determine whether to establish the SR-BE tunnel to the other side according to the indication in the received routing message, so that the SR-BE tunnel can BE established between the network equipment as required. By default, an indication in a routing message issued by a network device is used to indicate that no SR-BE tunnel to the network device is created. When the indication in the routing message issued by the network device is used to indicate that the SR-BE tunnel to the network device is not created, other network devices may acquire the prefix SID of the network device, that is, may acquire the route of the network device, but do not create the SR-BE tunnel to the network device.

In a possible implementation manner, after the first network device determines not to create the SR-BE tunnel from the first network device to the second network device according to the first indication, the method further includes: and in response to the existence of the message to BE transmitted to the second network equipment in the first network equipment, the first network equipment creates an SR-BE tunnel from the first network equipment to the second network equipment. And the first network equipment transmits the message through the SR-BE tunnel.

In the application, when a message to BE transmitted to another network device exists in one network device, the network device may create an SR-BE tunnel to the other network device according to the prefix SID of the other network device, thereby implementing a function of creating the SR-BE tunnel as needed and triggered by traffic between network devices.

Or after the first network device determines not to create the SR-BE tunnel from the first network device to the second network device according to the first indication, the method further includes: the first network device receives a tunnel creation indication message sent by a third network device, wherein the tunnel creation indication message includes an identifier of the second network device, and the tunnel creation indication message is used for indicating the first network device to create an SR-BE tunnel to the second network device, and the third network device is a convergence layer device. And the first network equipment creates an SR-BE tunnel from the first network equipment to the second network equipment based on the tunnel creation indication message. And the first network equipment transmits the message to BE transmitted to the second network equipment through the SR-BE tunnel.

In this application, when a convergence layer device senses that there is a service transmission requirement from one access layer device to another access layer device, the convergence layer device may send a tunnel creation indication message for indicating creation of an SR-BE tunnel to the another access layer device to the access layer device, so that the access layer device can create the SR-BE tunnel to the another access layer device, and a function of creating the SR-BE tunnel as needed and triggered by traffic between the access layer devices is realized.

In a possible implementation, the tunnel creation indication message further includes a prefix SID of the second network device.

In one possible implementation, the first network device is located in the same access ring as the second network device.

In one possible implementation, the routing message is a link state message or a link state advertisement.

In one possible implementation, the routing message includes a prefix SID subtype length value (TLV) field, and the first indication is in a flag bit field of the prefix SID sub-TLV field.

In one possible implementation, the first network device is an access stratum device.

In the application, the access layer device determines whether to create the SR-BE tunnel to the other side according to the indication in the routing message, and after receiving the routing message issued by the other network device, the convergence layer device can ignore the indication in the routing message for indicating whether to create the SR-BE tunnel to the network device, and always create the SR-BE tunnel to the network device, that is, no matter whether the indication carried in the routing message received by the convergence layer device is used for indicating to create the SR-BE tunnel or indicating not to create the SR-BE tunnel, the convergence layer device always creates the SR-BE tunnel to the other side, so as to ensure effective communication between the convergence layer device and the other network device, and further ensure the communication performance of the communication system.

In a second aspect, a method for issuing a routing message is provided. The method comprises the following steps: the first network device generates a routing message comprising a prefix segment identification, SID, of the destination network device, the routing message further comprising a first indication for indicating whether to create a segment routing best effort, SR-BE, tunnel to the destination network device. The first network device issues a routing message.

In the application, the routing message including the indication for indicating whether to create the SR-BE tunnel to the destination network equipment is issued, so that the network equipment receiving the routing message determines whether to create the SR-BE tunnel to the destination network equipment according to the indication in the routing message, and the tunnel creation flexibility among the network equipment is improved.

In a possible implementation manner, the destination network device is a first network device, and an implementation process of the first network device for issuing the routing message includes: the first network equipment issues a routing message in an IGP domain where the first network equipment is located.

In this implementation, the first network device is an access stratum device, and the first indication is used to indicate that no SR-BE tunnel to the destination network device is created. Or, the first network device is a convergence layer device, and the first indication is used for indicating the creation of an SR-BE tunnel to the destination network device.

For access layer equipment in a communication system, because SR-BE tunnels between most access layer equipment in the same IGP domain are useless, a routing message issued by the access layer equipment can carry an indication for indicating that the SR-BE tunnel of the access layer equipment is not created, so that other access layer equipment cannot create the SR-BE tunnel of the access layer equipment after receiving the routing message, a large number of useless SR-BE tunnels are prevented from being created between the access layer equipment, and the maintenance difficulty of the access layer equipment is reduced. For a convergence layer device in a communication system, because the convergence layer device needs to communicate with each network device in an access ring in which the convergence layer device is located, a routing message issued by the convergence layer device may carry an indication for indicating the creation of an SR-BE tunnel to the convergence layer device, so that the access layer device or other convergence layer devices respectively create SR-BE tunnels to the convergence layer device after receiving the routing message.

In another possible implementation manner, the destination network device is different from the first network device, and the implementation process of the first network device to issue the routing message includes: the first network device sends a routing message to the second network device, the first indication indicating the creation of the SR-BE tunnel to the destination network device, the routing message further including an identification of the destination network device. The first network device is a convergence layer device, and the second network device is an access layer device.

In the application, the convergence layer device can issue a tunnel creation indication message indicating that an SR-BE tunnel is created between two access layer devices, so that the tunnel creation flexibility is improved.

In a possible implementation manner, an implementation process of sending, by a first network device, a routing message to a second network device includes: and responding to the message which is received by the first network equipment and sent by the second network equipment and takes the destination address as the destination network equipment, and sending the routing message to the second network equipment by the first network equipment.

In the application, when the convergence layer device senses that service transmission is required from one access layer device to another access layer device, the convergence layer device may send a tunnel creation indication message for indicating creation of an SR-BE tunnel to the another access layer device to the access layer device, so that the access layer device can create the SR-BE tunnel to the another access layer device, thereby implementing creation of SR-BE tunnels as required, reducing the number of useless SR-BE tunnels between network devices, and effectively creating SR-BE tunnels between network devices with requirements, thereby improving tunnel creation flexibility.

In a possible implementation manner, an implementation process of generating a routing message by a first network device includes: and the first network equipment modifies a second indication in the original message issued by the destination network equipment into the first indication to obtain a routing message, wherein the second indication is used for indicating that an SR-BE tunnel to the destination network equipment is not created.

In a possible implementation manner, in response to that the first network device receives a packet whose destination address sent by the second network device is the destination network device, the first network device may further send a route retransmission indication message to the destination network device, where the route retransmission indication message is used to indicate the destination network device to issue a new route message, and the new route message carries a prefix SID of the destination network device and an indication indicating that an SR-BE tunnel to the destination network device is created. And after receiving the routing retransmission indication message, the destination network equipment issues a new routing message in the IGP domain, wherein the new routing message comprises the prefix SID of the destination network equipment and an indication indicating the creation of the SR-BE tunnel to the destination network equipment.

In one possible implementation, the routing message includes a prefix SID sub-TLV field, the first indication being in a flag bit field of the prefix SID sub-TLV field.

In a third aspect, a routing message processing apparatus is provided. The apparatus comprises a plurality of functional modules that interact to implement the method of the first aspect and its embodiments described above. The functional modules can be implemented based on software, hardware or a combination of software and hardware, and the functional modules can be combined or divided arbitrarily based on specific implementation.

In a fourth aspect, a routing message publishing device is provided. The apparatus comprises a plurality of functional modules that interact to implement the method of the first aspect and its embodiments described above. The functional modules can be implemented based on software, hardware or a combination of software and hardware, and the functional modules can be combined or divided arbitrarily based on specific implementation.

In a fifth aspect, a network device is provided, which includes: a memory and a processor;

the memory is used for storing a computer program;

the processor is configured to execute the computer program stored in the memory to cause the network device to perform the method of the first aspect and its embodiments and/or the method of the second aspect and its embodiments.

A sixth aspect provides a computer readable storage medium having stored therein instructions which, when executed by a processor, implement the method of the first aspect and its embodiments above and/or the method of the second aspect and its embodiments above.

In a seventh aspect, a communication system is provided, including: a first network device comprising the apparatus according to the third aspect or being the network device according to the fifth aspect, and a second network device comprising the apparatus according to the fourth aspect or being the network device according to the fifth aspect.

In an eighth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method as in the first aspect and its embodiments described above and/or the method as in the second aspect and its embodiments described above.

In a ninth aspect, a chip is provided, which comprises programmable logic circuits and/or program instructions, and which, when run, implements the method of the first aspect and its embodiments and/or the method of the second aspect and its embodiments.

The beneficial effect that technical scheme that this application provided brought includes at least:

according to the method and the device, the network device which receives the routing message determines whether to create the SR-BE tunnel to the other side according to the indication in the routing message by issuing the indication which is used for indicating whether to create the SR-BE tunnel to the destination network device, so that the tunnel creation flexibility between the network devices is improved, and unnecessary SR-BE tunnels are avoided being created. For access layer equipment in a communication system, because SR-BE tunnels between most access layer equipment in the same IGP domain are useless, a routing message issued by the access layer equipment can carry an indication for indicating that the SR-BE tunnel of the access layer equipment is not created, so that other access layer equipment cannot create the SR-BE tunnel of the access layer equipment after receiving the routing message, a large number of useless SR-BE tunnels are prevented from being created between the access layer equipment, and the maintenance difficulty of the access layer equipment is reduced. For a convergence layer device in a communication system, because the convergence layer device needs to communicate with each network device in an access ring in which the convergence layer device is located, a routing message issued by the convergence layer device may carry an indication for indicating the creation of an SR-BE tunnel to the convergence layer device, so that the access layer device or other convergence layer devices respectively create SR-BE tunnels to the convergence layer device after receiving the routing message. In addition, after receiving the routing message issued by other network devices, the convergence layer device may ignore the indication used for indicating whether to create the SR-BE tunnel to the network device in the routing message, and always create the SR-BE tunnel to the network device, that is, regardless of whether the indication carried in the routing message received by the convergence layer device is used for indicating to create the SR-BE tunnel or indicating not to create the SR-BE tunnel, the convergence layer device always creates the SR-BE tunnel to the other side, so as to ensure effective communication between the convergence layer device and other network devices, thereby ensuring communication performance of the communication system.

In addition, when the convergence layer device senses that there is a service transmission requirement from one access layer device to another access layer device, the convergence layer device may send a tunnel creation indication message for indicating creation of an SR-BE tunnel to the another access layer device to the access layer device, so that the access layer device can create the SR-BE tunnel to the another access layer device; or, when there is a message to BE transmitted to another access layer device in the access layer device, the access layer device may create an SR-BE tunnel to the another access layer device according to the stored prefix SID of the another access layer device, thereby implementing a function of creating an SR-BE tunnel between the access layer devices as needed. The number of useless SR-BE tunnels among the network devices is reduced, the SR-BE tunnels can BE effectively established among the network devices with requirements, and the tunnel creation flexibility is further improved.

Drawings

Fig. 1 is a schematic configuration diagram of a communication system in the related art;

fig. 2 is a schematic configuration diagram of another communication system in the related art;

fig. 3 is a schematic structural diagram of a communication system according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a prefix SID sub-TLV field in a routing message according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a prefix SID sub-TLV field in another routing message provided in the embodiment of the present application;

fig. 6 is a flowchart illustrating a method for issuing a routing message according to an embodiment of the present application;

fig. 7 is a flowchart illustrating a method for processing a routing message according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a routing message processing apparatus according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of another routing message processing apparatus according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a routing message issuing apparatus according to an embodiment of the present application;

fig. 11 is a block diagram of a network device according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application provides a communication system, and the communication system supports an SR forwarding technology. For example, the communication system may support an SR forwarding technology (abbreviated as SRv6) based on internet protocol version 6 (IPv 6). Alternatively, the communication system may support a multi-protocol label switching (MPLS) SR forwarding technique (SR-MPLS). The communication system includes a plurality of network devices. The communication system can implement an SR-BE mode, that is, messages can BE transmitted among a plurality of network devices in the communication system through SR-BE tunnels.

Alternatively, the communication system may be a Data Center Network (DCN), a metropolitan area network, a wide area network, a campus area network, or the like. The communication system may adopt a three-layer network architecture, that is, the communication system may be a three-layer network, including: core layer, convergence layer and access layer. The core layer is a high-speed switching backbone of the network, and is connected to a backbone network (which may also be referred to as a core network), for example, to a controller in the backbone network. The convergence layer is used to provide a convergence connection (connecting the access layer and the core layer). The access stratum is used to access the workstation to the network. The station may be a base station or an Access Point (AP), etc. In the embodiment of the present application, a network device located in an access layer is referred to as an access layer device, a network device located in an aggregation layer is referred to as an aggregation layer device, and a network device located in a core layer is referred to as a core layer device.

Optionally, a Virtual Private Network (VPN) function is deployed in the communication system, and the communication system may adopt a hierarchical VPN (VPN of VPN) structure. The HoVPN is a hierarchical VPN, and multiple Provider Edge (PE) devices play different roles, form a hierarchical structure, and together complete the function of one PE device, so as to reduce the performance requirement on the PE device. In a three-layer network using the hopvpn structure, an access layer device is a user provider end edge (UPE) device, and may be a base station side gateway (CSG), for example. The convergence layer device is an SPE (service provider end) device, and may be an Access Service Gateway (ASG), for example. The core layer device is a Network Provider Edge (NPE) device, and may be a radio network controller site (RSG), for example. In order to reduce the pressure of the UPE device to store the route information and at the same time, to implement the nearby forwarding to save the bandwidth, the SPE device only issues a default route (also called a default private network route) to the UPE device and detailed routes of other UPE devices in the same access ring with the UPE device.

Optionally, an access ring may be formed between the access layer device and the convergence layer device; a convergence ring is formed between the convergence layer device and the core layer device. The access ring is connected with the base station and used for receiving a network signal of the base station and transmitting the network signal to the convergence ring, wherein the network signal can bear interconnection services among the base stations and/or multi-homing services of the base stations and the like; the convergence ring is used for processing the network signal and realizing the separation and transmission of interconnection service among base stations and/or multi-homing service of the base stations.

At present, in SR-BE mode, a network device may issue a routing message including its prefix SID in an IGP domain where the network device is located, and after receiving the routing message issued by the network device, other network devices in the IGP domain calculate a tag value according to the prefix SID in the routing message and their SRGB, respectively, and generate a tag forwarding table entry, thereby creating an SR-BE tunnel to the network device. However, SR-BE tunnels between partial network devices in the same IGP domain are useless, for example, one or more access rings connected to the same aggregation ring are generally planned as an IGP domain, and there is no traffic flow between most access layer devices located in the same access ring, so SR-BE tunnels between most access layer devices located in the same access ring are useless, and communication between access layer devices located in different access rings is necessarily required to pass through the aggregation layer device, so SR-BE tunnels between access layer devices located in different access rings are also useless. At present, each time the network device receives routing messages issued by other network devices, an SR-BE tunnel to the other side is created, which causes the network device to create and maintain a large number of useless SR-BE tunnels, and the creation of useless SR-BE tunnels causes the waste of processing resources of the network device and increases the burden of the network device for maintaining label forwarding entries.

For example, fig. 1 is a schematic structural diagram of a communication system in the related art. As shown in fig. 1, the communication system 10 includes CSGs 101A-101F (collectively CSG 101), ASGs 102A-102B (collectively ASGs 102), and RSGs 103A-103B (collectively RSGs 103). The CSG101A, CSG 101B, CSG 101C, ASG 102A and ASG 102B form an access ring 1, the CSG 101D, CSG 101E, CSG 101F, ASG 102A and ASG 102B form an access ring 2, and the CSG101A and CSG 101D are respectively connected to one base station. The ASG 102A, ASG 102B, RSG 103A and RSG 103B form a convergence ring 1 therebetween, and the RSG 103A and RSG 103B are respectively connected to the backbone network. Both access ring 1 and access ring 2 are connected to a convergence ring 1. The IGP employed by the communication system may be an intermediate system to intermediate system (IS-IS) routing protocol.

Optionally, the communication system further includes a provider (P) device, which is located in the convergence layer and serves as an intermediate node for accessing to a provider network (e.g., a 4G network or a 5G network). For example, referring to fig. 1, the communication system 10 also includes P devices 102C-102F. Among them, P device 102C and P device 102D serve as intermediate nodes for accessing the 4G network, and P device 102E and P device 102D serve as intermediate nodes for accessing the 5G network.

In the communication system shown in fig. 1, in order to control the amount of private network routes, the ASG 102 issues a default private network route downstream, so that the CSG101 only needs to maintain one default route, and the equipment pressure is low. In the communication system shown in fig. 1, IGP IS deployed in an IS-IS routing protocol partition (level) manner, where an access ring IS level-1 and a convergence ring IS level 2. level-1 configures BGP peer (BGP peer) and SR-BE tunnel on protocol surface, and configures BGP L3VPN on forwarding surface; the level-2 is configured with BGP peer and SR-BE tunnel on the protocol surface, BGP L3VPN on the forwarding surface, and the level-2 can also BE configured with segment routing-traffic engineering (SR-TE) tunnel on the protocol surface. Because the access ring 1 and the access ring 2 are both connected to the convergence ring 1, in this scenario, the public networks of the access ring 1 and the access ring 2 are opened, that is, the access ring 1 and the access ring 2 are located in the same IGP domain, and the devices in the same access ring and the devices in different access rings can learn the route of the other party to each other, so as to create a corresponding SR-BE tunnel, that is, in this scenario, the devices in the access ring 1 and the access ring 2 can mutually establish the SR-BE tunnel of the other party to each other.

However, in the communication system shown in fig. 1, it is not necessary that all devices establish an SR-BE tunnel with each other, for example, an SR-BE tunnel between CSG101A and CSG 101D is not necessary, and an SR-BE tunnel between CSG101A and CSG 101B, CSG 101C is also not necessary. Since the traffic between the CSG101 is forwarded to the ASG 102 according to the default private network route, and then forwarded to the destination by the ASG 102 according to the detailed route, only the SR-BE tunnel between the CSG101 and the ASG 102 is needed in this scenario.

For another example, fig. 2 is a schematic configuration diagram of another communication system in the related art. As shown in fig. 2, the communication system 20 includes CSGs 201A-201L (collectively CSG 201), ASGs 202A-202D (collectively ASGs 202), and RSGs 203A-203B (collectively RSGs 203). The CSG 201A, CSG 201B, CSG 201C, CSG 201D, ASG 202A and ASG 202B form an access ring 1, the CSG 201E, CSG 201F, CSG 201G, CSG 201H, ASG 202A and ASG 202B form an access ring 2, the CSG 201I, CSG 201J, CSG 201K, CSG 201L, ASG 202C and ASG 202D form an access ring 3, and the access ring 1, the access ring 2 and the access ring 3 are respectively connected to the base station. The RSG 203 is deployed in a backbone network, and is connected to an Evolved Packet Core (EPC) controller. A convergence ring 1 is formed between the ASG 202A, ASG 202B, RSG 203A and the RSG 203B, a convergence ring 2 is formed between the ASG 202C, ASG 202D, RSG 203A and the RSG 203B, and the RSG 103A and the RSG 103B are respectively connected to the backbone network. Both access ring 1 and access ring 2 are connected to a convergence ring 1. The IGP used by the communication system may be an Open Shortest Path First (OSPF) protocol.

Optionally, the communication system further comprises a P device located at the access stratum and serving as an intermediate node for accessing the operator network. For example, referring to fig. 2, the communication system 20 also includes P devices 201M-202R.

In the communication system shown in fig. 2, in order to control the amount of private network routing, the ASG202 issues a default private network routing downstream. In the communication system shown in fig. 2, the IGP is deployed in an OSPF routing protocol zoning (area) manner, where an access ring is OSPF 10area 1-N and an aggregation ring is OSPF 1area 0. The ASG202 is an Area Border Router (ABR). OSPF 10area 1-N configures BGP peer and SR-BE tunnel on protocol plane, and configures BGP L3VPN on forwarding plane; OSPF 1area 0 has BGP peer, SR-BE tunnel and Label Distribution Protocol (LDP) configured on the protocol plane, and BGP L3VPN configured on the forwarding plane. In this scenario, the public networks of the access ring 1, the access ring 2, and the access ring 3 are opened, wherein the access ring 1 and the access ring 3 are opened through the RSG 203, that is, the access ring 1, the access ring 2, and the access ring 3 are located in the same IGP domain, and two devices in the same access ring and two devices in different access rings can learn the routes of each other to create corresponding SR-BE tunnels, that is, in this scenario, two devices in the access ring 1, the access ring 2, and the access ring 3 can establish SR-BE tunnels of each other.

However, in the communication system shown in fig. 2, it is not necessary that all devices establish an SR-BE tunnel with each other, for example, an SR-BE tunnel between CSG 201A and CSG 201E is not required, and an SR-BE tunnel between CSG 201A and CSG 201B, CSG 201C, CSG 201D is also not required. Since the traffic between the CSG 201 is forwarded to the ASG202 according to the default private network route, and then forwarded to the destination by the ASG202 according to the detailed route, in this scenario, only the SR-BE tunnel between the CSG 201 and the ASG202 is required.

The communication system provided by the embodiment of the present application is obtained based on abstract generalization of the communication system in the related art, and is used as an exemplary illustration only and not as a limitation on a communication scenario. For example, fig. 3 is a schematic structural diagram of a communication system according to an embodiment of the present application. As shown in fig. 3, the communication system includes access layer devices 301A-301D (collectively referred to as access layer devices 301), convergence layer devices 302A-302B (collectively referred to as convergence layer devices 302), and core layer devices 303A-303B (collectively referred to as core layer devices 303). The number and connection manner of the access layer device 301, the convergence layer device 302, and the core layer device 303 in the communication system shown in fig. 3 are only used as an exemplary illustration, and are not used as a limitation to the communication system provided in the embodiment of the present application. In the embodiment of the present application, a communication system including one access ring is taken as an example for explanation, and in an actual application scenario, the communication system may include a plurality of access rings, and the working principle of each access ring is similar, which is not described in detail in the embodiment of the present application.

According to the method and the device, the indication for indicating whether the SR-BE tunnel to the network device is created is added in the routing message issued by the network device, so that after one network device in the same IGP domain receives the routing message issued by the other network device, whether the SR-BE tunnel to the other side is created is determined according to the indication in the routing message, the tunnel creation flexibility among the network devices is improved, and unnecessary SR-BE tunnels are prevented from being created. For access layer equipment in a communication system, because SR-BE tunnels between most access layer equipment in the same IGP domain are useless, a routing message issued by the access layer equipment can carry an indication for indicating that the SR-BE tunnel of the access layer equipment is not created, so that other access layer equipment cannot create the SR-BE tunnel of the access layer equipment after receiving the routing message, a large number of useless SR-BE tunnels are prevented from being created between the access layer equipment, and the maintenance difficulty of the access layer equipment is reduced. For a convergence layer device in a communication system, because the convergence layer device needs to communicate with each network device in an access ring in which the convergence layer device is located, a routing message issued by the convergence layer device may carry an indication for indicating the creation of an SR-BE tunnel to the convergence layer device, so that the access layer device or other convergence layer devices respectively create SR-BE tunnels to the convergence layer device after receiving the routing message. In addition, after receiving a routing message issued by another network device (access layer device or another convergence layer device), the convergence layer device may ignore an indication used for indicating whether to create an SR-BE tunnel to the network device in the routing message, and always create the SR-BE tunnel to the network device, that is, regardless of whether the indication carried in the routing message received by the convergence layer device is used for indicating to create the SR-BE tunnel or indicating not to create the SR-BE tunnel, the convergence layer device always creates an SR-BE tunnel to the other side, so as to ensure effective communication between the convergence layer device and the other network device, thereby ensuring communication performance of the communication system.

For example, in the communication system shown in fig. 1, the CSG101A may carry an indication indicating that no SR-BE tunnel to the CSG101A is created in a published routing message, and then the CSGs 101B to 101F do not create an SR-BE tunnel to the CSG101A based on the indication in the routing message after receiving the routing message from the CSG101A, and the

ASGs

102A and 102B ignore the indication in the routing message and create SR-BE tunnels to the CSG101A respectively after receiving the routing message from the CSG 101A. The device can create useful SR-BE tunnels and avoid creating unnecessary SR-BE tunnels.

For another example, in the communication system shown in fig. 2, CSG 201A may carry an indication indicating that no SR-BE tunnel to CSG 201A is created in a published routing message, CSG 201B-201L may not create an SR-BE tunnel to CSG 201A based on the indication in the routing message after receiving the routing message from CSG 201A, and ASGs 202A-202F may ignore the indication in the routing message and create SR-BE tunnels to CSG 201A respectively after receiving the routing message from CSG 201A. The device can create useful SR-BE tunnels and avoid creating unnecessary SR-BE tunnels.

For another example, in the communication system shown in fig. 3, the access stratum device 301A may carry, in a published routing message, an indication indicating that an SR-BE tunnel to the access stratum device 301A is not created, and then the access stratum device 301B, the access stratum device 301C, and the access stratum device 301D do not create an SR-BE tunnel to the access stratum device 301A based on the indication in the routing message after receiving the routing message from the access stratum device 301A, and after receiving the routing message from the access stratum device 301A, the convergence layer device 302A and the convergence layer device 302B ignore the indication in the routing message and respectively create SR-BE tunnels to the access stratum device 301A. The convergence layer device 302A may carry, in the issued routing message, an indication for indicating that the SR-BE tunnel of the convergence layer device 302A is created, and then the access layer device 301A, the access layer device 301B, the access layer device 301C, the access layer device 301D, and the convergence layer device 302B respectively create the SR-BE tunnels of the convergence layer device 302A after receiving the routing message from the convergence layer device 302A.

Optionally, the IGP used in the communication system provided in the embodiment of the present application may be an OSPF protocol or an IS-IS routing protocol. In the OSPF scenario, the routing message issued by the network device may be a Link State Advertisement (LSA). In an IS-IS scenario, a routing message issued by a network device may be a Link State Packet (LSP).

Optionally, the routing message includes a prefix SID sub-TLV field, and the indication in the routing information issued by the network device to indicate whether to create the SR-BE tunnel to the network device is in a flag bit field of the prefix SID sub-TLV field.

For example, in the OSPF scenario, the routing message is OSPFv2 opaque LSA (OSPFv2 routing information opaque LSA), and OSPFv2 opaque LSA contains fields and definitions of the fields may refer to a request for comments (RFC) document numbered 7770. The OSPFv2 opaque LSA routing information may be configured with an OSPFv2 extended prefix TLV (OSPFv2 extended prefix TLV) field, and the fields contained in the OSPFv2 extended prefix TLV field and the definition of each field may refer to the RFC document with the number 7684. The OSPFv2 extended prefix TLV field may include a prefix SID sub-TLV field, and fig. 4 is a schematic structural diagram of the prefix SID sub-TLV field in the routing message provided in the embodiment of the present application. As shown in fig. 4, the prefix SID sub-TLV field includes a type (type) field, a length (length) field, a flag bit (flags) field, a reserved (reserved) field, a multi-topology identifier (MT-ID) field, an algorithm (algorithm) field, and a SID/index (index)/tag (able) field. Wherein, the SID/index/label field is variable length (variable), and the prefix SID in the routing message issued by the network device is in the SID/index/label field. The indication of whether to create the SR-BE tunnel to the network equipment in the routing information issued by the network equipment is in a flag bit field. The definition of each of the prefix SID sub-TLV fields can refer to the RFC document numbered 8665. The length of the flag bit field specified in RFC 8665 is 8 bits, where the 6 th bit and the 7 th bit of the flag bit field are not yet defined, and therefore, as a possible implementation manner for carrying an indication to indicate whether to create an SR-BE tunnel according to the embodiment of the present application, the 6 th bit or the 7 th bit of the flag bit field may BE defined as an indication to indicate whether to create an SR-BE tunnel, and specific definitions of the 0 th bit to the 5 th bit of the flag bit field may BE referred to RFC 8665. For example, the 6 th bit of the flag bit field is defined as an indication for indicating whether to create an SR-BE tunnel, and when the 6 th bit of the flag bit field takes a value of 0, the indication is used for indicating not to create the SR-BE tunnel, and when the 6 th bit of the flag bit field takes a value of 1, the indication is used for indicating to create the SR-BE tunnel.

For another example, in an IS-IS scenario, the routing message IS an LSP, the LSP may carry TLV-135 (extended IP reachability TLV) in variable length fields (variable length fields), and the definition of the fields and each field included in TLV-135 may refer to the RFC document numbered 5305. The TLV-135 may include a prefix SID sub-TLV field, and fig. 5 is a schematic structural diagram of the prefix SID sub-TLV field in another routing message provided in this embodiment of the present application. As shown in fig. 5, the prefix SID sub-TLV field includes a type (type) field, a length (length) field, a flag bit (flags) field, an algorithm (algorithmm) field, and a SID/index (index)/tag (able) field. Wherein, the SID/index/label field is variable length (variable), and the prefix SID in the routing message issued by the network device is in the SID/index/label field. The indication of whether to create the SR-BE tunnel to the network equipment in the routing information issued by the network equipment is in a flag bit field. The definition of each of the prefix SID sub-TLV fields can refer to the RFC document numbered 8667. The length of the flag bit field specified in RFC 8667 is 8 bits, where the 6 th bit and the 7 th bit of the flag bit field are not yet defined, and therefore, as a possible implementation manner for carrying an indication to indicate whether to create an SR-BE tunnel according to the embodiment of the present application, the 6 th bit or the 7 th bit of the flag bit field may BE defined as an indication to indicate whether to create an SR-BE tunnel, and specific definitions of the 0 th bit to the 5 th bit of the flag bit field may BE referred to RFC 8667. For example, the 6 th bit of the flag bit field is defined as an indication for indicating whether to create an SR-BE tunnel, and when the 6 th bit of the flag bit field takes a value of 0, the indication is used for indicating not to create the SR-BE tunnel, and when the 6 th bit of the flag bit field takes a value of 1, the indication is used for indicating to create the SR-BE tunnel.

The embodiment of the application provides a routing message issuing method and a routing message processing method respectively. The method for publishing the routing message is used for describing a process of publishing the routing message by using the network equipment as a publishing end of the routing message. The routing message processing method is used for describing the routing message processing process of the network equipment as the receiving end of the routing message.

Fig. 6 is a flowchart illustrating a method for issuing a routing message according to an embodiment of the present application. The method may be applied to a network device in a communication system as shown in any of fig. 1 to 3. As shown in fig. 6, the method includes:

step 601, the network device 1 generates a routing message, where the routing message includes a prefix SID of the destination network device, and the routing message further includes an indication 1, where the indication 1 is used to indicate whether to create an SR-BE tunnel to the destination network device.

The prefix SID of the destination network device is a label allocated to the address prefix of the destination network device, and the label is globally unique in the SR domain and is a value between SRGB. SRGB is a set of local labels reserved for segment routing.

In an alternative embodiment of the present application, the destination network device is network device 1. In this case, if the network device 1 is an access stratum device, for example, the network device 1 is the CSG101 in the communication system shown in fig. 1, or the network device 1 is the CSG 201 in the communication system shown in fig. 2, or the network device 1 is the access stratum device 301 in the communication system shown in fig. 3, and the indication 1 is used to indicate that the SR-BE tunnel to the destination network device is not created, that is, the indication 1 in the routing message generated by the network device 1 is used to indicate that the SR-BE tunnel to the network device 1 is not created. If the network device 1 is a convergence layer device, the indication 1 is used to indicate that an SR-BE tunnel to the destination network device is created, that is, the indication 1 in the routing message generated by the network device 1 is used to indicate that an SR-BE tunnel to the network device 1 is created.

In the embodiment of the application, because the SR-BE tunnels between most access stratum devices in the same IGP domain are useless, by carrying an indication for indicating that an SR-BE tunnel to the access stratum device is not created in a routing message generated by the access stratum device, other access stratum devices cannot create the SR-BE tunnel to the access stratum device after receiving the routing message, thereby avoiding creating a large number of useless SR-BE tunnels between the access stratum devices and reducing the maintenance difficulty of the access stratum devices. Since the convergence layer device needs to communicate with each network device in the access ring where the convergence layer device is located, the routing message generated by the convergence layer device carries an indication for indicating the creation of the SR-BE tunnel to the convergence layer device, so that the access layer device or other convergence layer devices can respectively create the SR-BE tunnels to the convergence layer device after receiving the routing message, thereby ensuring effective communication from other network devices to the convergence layer device, and further ensuring the communication performance of the communication system.

In another alternative embodiment of the present application, the destination network device is not the network device 1, i.e. the destination network device is different from the network device 1. In this case, the network device 1 may be an convergence layer device, for example, the network device 1 may be an ASG 102 in the communication system shown in fig. 1, or the network device 1 may be an ASG202 in the communication system shown in fig. 2, or the network device 1 may be a convergence layer device 302 in the communication system shown in fig. 3, and the destination network device may be an access layer device. In the routing message generated by the network device 1, the indication 1 is used to indicate that an SR-BE tunnel is created to a destination network device, and the routing message further includes an identifier of the destination network device, that is, the routing message generated by the network device 1 is used to indicate that other network devices create an SR-BE tunnel to the destination network device.

Optionally, the implementation process of the network device 1 generating the tunnel creation indication message includes: the network device 1 modifies the indication 2 in the original message issued by the destination network device into the indication 1 to obtain a tunnel creation indication message, where the indication 2 is used to indicate that the SR-BE tunnel to the destination network device is not created, that is, the network device 1 modifies the indication in the original message issued by the destination network device, which is used to indicate that the SR-BE tunnel to the destination network device is not created, into the indication used to indicate that the SR-BE tunnel to the destination network device is created, to obtain the tunnel creation indication message. In conjunction with the example related to fig. 2 or fig. 3, the network device 1 may modify and set the bit 6 of the flag bit field in the prefix SID sub-TLV field in the original message issued by the destination network device to 1 from 0, as the generated tunnel creation indication message. The original message issued by the destination network device is a routing message issued by the destination network device and containing the prefix SID of the destination network device.

Alternatively, the network device 1 may also directly generate a tunnel creation indication message, where the tunnel creation indication message includes the prefix SID of the destination network device and/or the identifier of the destination network device, and the tunnel creation indication message is used to indicate the network device that receives the tunnel creation indication message to create the SR-BE tunnel to the destination network device. The identification of the destination network device may be an IP address of the destination network device, etc. For example, the format of the tunnel creation indication message generated by the network device 1 may refer to OSPFv2 opaque LSA routing information, where OSPFv2 suspended under OSPFv2 opaque LSA extends an address prefix (address prefix) field in a prefix TLV field to BE an IP address of the destination network device, a flag bit field in a prefix SID sub-TLV field has a 6 th position of 1 (for indicating the SR-BE tunnel created to the destination network device), and a SID/index/tag field in the prefix SID sub-TLV field is a prefix SID of the destination network device. For another example, the tunnel creation indication message generated by network device 1 may refer to an LSP, where an IP prefix (IPv4 prefix) field in TLV-135 suspended from the LSP is set to the IP address of the destination network device, a 6 th position of a flag bit field in a prefix SID sub-TLV field is 1 (for indicating creation of an SR-BE tunnel to the destination network device), and a SID/index/tag field in the prefix SID sub-TLV field is set to the prefix SID of the destination network device. The tunnel creation instruction message may also be a message in other formats or a custom message, which is not limited in this embodiment of the present application.

In the embodiment of the application, the convergence layer device can issue a tunnel creation indication message indicating that an SR-BE tunnel is created between two access layer devices, so that the tunnel creation flexibility is improved.

Step 602, the network device 1 issues a routing message.

In an optional embodiment of the present application, the destination network device is network device 1, and the implementation process of step 602 includes: the network device 1 issues routing messages within the IGP domain in which the network device 1 is located. The network device 1 may advertise and distribute the routing messages using a link state protocol so that all network devices located within the same IGP domain as the network device 1 can receive the routing messages issued by the network device 1.

In another alternative embodiment of the present application, the destination network device is not network device 1, and the implementation procedure of step 602 includes: the network device 1 sends a routing message to the network device 2, the indication 1 being used to indicate the creation of an SR-BE tunnel to the destination network device, the routing message further comprising an identification of the destination network device. That is, the network device 1 transmits a tunnel creation instruction message for instructing the network device 2 to create an SR-BE tunnel to the destination network device to the network device 2. The network device 1 is a convergence layer device, and the network device 2 is an access layer device. For example, the network device 1 is an ASG 102 in the communication system shown in fig. 1, and the network device 2 is a CSG101 in the communication system shown in fig. 1; or, the network device 1 is an ASG202 in the communication system shown in fig. 2, and the network device 2 is a CSG 201 in the communication system shown in fig. 2; still alternatively, the network device 1 is a convergence layer device 302 in the communication system shown in fig. 3, and the network device 2 is an access layer device 301 in the communication system shown in fig. 3.

Optionally, network device 1 is located in the same access ring as network device 2.

Optionally, in response to the network device 1 receiving the message sent by the network device 2 and addressed to the destination network device, that is, when the network device 2 has traffic to be transmitted to the destination network device, the network device 1 sends the routing message (tunnel creation indication message) to the network device 2.

In the embodiment of the application, because the routing message issued by the access stratum equipment contains the indication for indicating that the SR-BE tunnel to the access stratum equipment is not created, the SR-BE tunnel to the opposite party is not created after the routing message issued by the opposite party is received between the access stratum equipment. When there is a service flow to be transmitted to another access layer device (destination network device) in one access layer device, the access layer device will send a packet to the convergence layer device first, and then the convergence layer device forwards the packet to the destination network device. At this time, the convergence layer device senses that the access layer device has a service transmission requirement to the destination network device, and the convergence layer device can send a tunnel creation indication message for indicating the creation of the SR-BE tunnel to the destination network device to the access layer device, so that the access layer device can create the SR-BE tunnel to the destination network device, thereby realizing the creation of the SR-BE tunnel as required, reducing the number of useless SR-BE tunnels between network devices, effectively establishing the SR-BE tunnel between network devices with requirements, and improving the flexibility of tunnel creation.

Optionally, in response to that the network device 1 receives a packet whose destination address is sent by the network device 2 as a destination network device, that is, when service traffic to BE transmitted to the destination network device is to BE received in the network device 2, the network device 1 may further send a route retransmission indication message to the destination network device, where the route retransmission indication message is used to indicate the destination network device to issue a new route message, and the new route message carries a prefix SID of the destination network device and an indication indicating that an SR-BE tunnel is created to the destination network device. After receiving the route retransmission indication message, the destination network device issues a new route message in the IGP domain, where the new route message includes a prefix SID of the destination network device and an indication indicating that an SR-BE tunnel to the destination network device is created, and after receiving the new route message, other access layer devices (including the network device 2) create an SR-BE tunnel to the destination network device, and further transmit a packet to BE transmitted to the destination network device through the SR-BE tunnel. For example, when the network device 1 senses that there is a service transmission requirement from a plurality of access stratum devices to the destination network device, the network device 1 may send a route retransmission indication message to the destination network device, so that after the destination network device issues a new route message, the plurality of access stratum devices may respectively create SR-BE tunnels to the destination network device.

Fig. 7 is a flowchart illustrating a method for processing a routing message according to an embodiment of the present application. The method may be applied to a network device in a communication system as shown in any of fig. 1 to 3. As shown in fig. 7, the method includes:

in step 701, the network device 3 receives a routing message issued by the network device 4, where the routing message includes a prefix SID of the network device 4, and the routing message further includes an indication 3, where the indication 3 is used to indicate whether to create an SR-BE tunnel to the network device 4.

Optionally, network device 3 is located in the same access ring as network device 4. When the network device 3 is a convergence layer device, for example, the network device 3 is an ASG 102 in the communication system shown in fig. 1, or the network device 3 is an ASG202 in the communication system shown in fig. 2, or the network device 3 is a convergence layer device 302 in the communication system shown in fig. 3, after the network device 3 receives a routing message issued by the network device 4, the network device 3 always creates an SR-BE tunnel from the network device 3 to the network device 4, regardless of whether an indication 3 in the routing message is used to indicate that an SR-BE tunnel to the network device 4 is created or indicate that an SR-BE tunnel to the network device 4 is not created. When the network device 3 is an access stratum device, for example, the network device 3 is the CSG101 in the communication system shown in fig. 1, or the network device 3 is the CSG 201 in the communication system shown in fig. 2, or the network device 3 is the access stratum device 301 in the communication system shown in fig. 3, the following step 702 is executed.

Optionally, the process of one network device creating an SR-BE tunnel to another network device includes: the network equipment calculates a label value according to the prefix SID of the other network equipment and the SRGB of the network equipment, and generates a label forwarding table entry according to the label value.

Step 702, the network device 3 determines whether to create the SR-BE tunnel from the network device 3 to the network device 4 according to the indication 3.

In an optional embodiment of the present application, the indication 3 is used to indicate that no SR-BE tunnel to the network device 4 is created, and the network device 3 determines, according to the indication 3, that no SR-BE tunnel from the network device 3 to the network device 4 is created. The network device 4 may be an access stratum device, for example, the network device 4 is a CSG101 in the communication system shown in fig. 1, or the network device 4 is a CSG 201 in the communication system shown in fig. 2, or the network device 4 is an access stratum device 301 in the communication system shown in fig. 3.

Optionally, the network device 3 may store the prefix SID of the network device 4 after determining that the SR-BE tunnel from the network device 3 to the network device 4 is not created.

In this embodiment, one network device may determine not to create an SR-BE tunnel to another network device based on an indication in a routing message issued by the other network device, and store a prefix SID in the routing message issued by the other network device. Because the network device only needs to store the prefix SID of another network device, compared with the SR-BE tunnel established to the other network device, the network device does not need to calculate the label value and generate the label forwarding table entry, thereby reducing the consumed calculation resource and storage resource and also reducing the device maintenance difficulty.

In a possible case, after determining that the SR-BE tunnel from the network device 3 to the network device 4 is not created, in response to the presence of a packet to BE transmitted to the network device 4 in the network device 3, the network device 3 creates the SR-BE tunnel from the network device 3 to the network device 4 according to the prefix SID of the network device 4. Then the network device 3 transmits the message through the SR-BE tunnel.

In the embodiment of the application, when a message to BE transmitted to another access layer device exists in the access layer device, the access layer device may create an SR-BE tunnel to the another access layer device according to the stored prefix SID of the another access layer device, thereby implementing functions of flow-triggered and SR-BE tunnel creation on demand between the access layer devices.

In another possible case, after determining not to create the SR-BE tunnel from the network device 3 to the network device 4, the network device 3 receives a tunnel creation indication message sent by the network device 5, where the tunnel creation indication message includes an identifier of the network device 4, and the tunnel creation indication message is used to instruct the network device 3 to create the SR-BE tunnel to the network device 4. The network device 3 creates an SR-BE tunnel from the network device 3 to the network device 4 based on the tunnel creation indication message. Then, the network device 3 transmits the message to BE transmitted to the network device 4 through the SR-BE tunnel. Wherein, the network device 5 is a convergence layer device.

Optionally, the tunnel creation indication message further includes the prefix SID of the network device 4.

In the embodiment of the application, when the convergence layer device senses that service transmission is required from one access layer device to another access layer device, the convergence layer device may send a tunnel creation indication message for indicating creation of an SR-BE tunnel to the another access layer device to the access layer device, so that the access layer device can create the SR-BE tunnel to the another access layer device, and a function of creating the SR-BE tunnel as needed and triggered by traffic between the access layer devices is realized.

Optionally, the network device may set an aging duration for the SR-BE tunnel triggered by the traffic and created as needed, and if the network device does not transmit a packet through the SR-BE tunnel within the aging duration, the network device may remove the SR-BE tunnel, that is, delete the corresponding tag forwarding entry, thereby reducing the maintenance difficulty of the network device. If the network device transmits the message through the SR-BE tunnel within the aging duration, the network device can reset the aging duration of the SR-BE tunnel once every time the network device transmits the message through the SR-BE tunnel, that is, the network device can take the last time of transmitting the message through the SR-BE tunnel as the initial timing time of the aging duration of the SR-BE tunnel.

In another optional embodiment of the application, the indication 3 is used to indicate that an SR-BE tunnel to the network device 4 is created, and the network device 3 determines to create the SR-BE tunnel of the network device 3 to the network device 4 according to the indication 3.

In the routing message publishing method and the routing message processing method, numbering the network devices and numbering the indications in the routing message is only for convenience of description, and the publishing end of the routing message and the receiving end of the routing message may refer to the same network device, for example, the network device 1 and the network device 3 may refer to the same device, or the publishing end of the routing message and the receiving end of the routing message may also refer to different network devices, which is not limited in this embodiment of the present application.

Referring to the communication system shown in fig. 3, an example of the implementation process of the method provided by the embodiment of the present application is as follows:

access stratum device 301A issues a routing message within the IGP domain that includes a prefix SID of access stratum device 301A and an indication a indicating that no SR-BE tunnel to access stratum device 301A is created. After receiving the routing message, the access layer devices 301B-301D determine not to create an SR-BE tunnel to the access layer device A according to the indication A; after the convergence layer devices 302A-302B receive the routing message, ignore the indication a to respectively create SR-BE tunnels to the access layer device a. When there is a packet to BE transmitted to the access layer device 301A in the access layer device 301C, the access layer device 301C creates an SR-BE tunnel to the access layer device 301A according to the prefix SID of the access layer device 301A; or, the access layer device 301C sends the message to the convergence layer device 302B, and then the convergence layer device 302B forwards the message to the access layer device 301A, at this time, the convergence layer device 302B senses that there is a service transmission requirement from the access layer device 301C to the access layer device 301A, and the convergence layer device 302 sends a tunnel creation instruction message to the access layer device 301C, where the tunnel creation instruction message is used to instruct the access layer device 301C to create an SR-BE tunnel to the access layer device 301A. After receiving the tunnel creation instruction message, the access layer device 301C creates an SR-BE tunnel that the access layer device 301C creates to the access layer device 301A, and transmits a packet whose destination address is to BE transmitted by the access layer device 301A through the SR-BE tunnel.

The order of steps of the routing message issuing method and the routing message processing method provided by the embodiment of the application can be properly adjusted, and the steps can be correspondingly increased or decreased according to the situation. Any method that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application is covered by the protection scope of the present application, and thus the detailed description thereof is omitted.

In summary, in the embodiment of the present application, by issuing the indication including the SR-BE tunnel used for indicating whether to create the SR-BE tunnel to the destination network device, the network device that receives the routing message determines whether to create the SR-BE tunnel to the other side according to the indication in the routing message, so that the tunnel creation flexibility between the network devices is improved, and unnecessary SR-BE tunnels are avoided from being created. For access layer equipment in a communication system, because SR-BE tunnels between most access layer equipment in the same IGP domain are useless, a routing message issued by the access layer equipment can carry an indication for indicating that the SR-BE tunnel of the access layer equipment is not created, so that other access layer equipment cannot create the SR-BE tunnel of the access layer equipment after receiving the routing message, a large number of useless SR-BE tunnels are prevented from being created between the access layer equipment, and the maintenance difficulty of the access layer equipment is reduced. For a convergence layer device in a communication system, because the convergence layer device needs to communicate with each network device in an access ring in which the convergence layer device is located, a routing message issued by the convergence layer device may carry an indication for indicating the creation of an SR-BE tunnel to the convergence layer device, so that the access layer device or other convergence layer devices respectively create SR-BE tunnels to the convergence layer device after receiving the routing message. In addition, after receiving the routing message issued by other network devices, the convergence layer device may ignore the indication used for indicating whether to create the SR-BE tunnel to the network device in the routing message, and always create the SR-BE tunnel to the network device, that is, regardless of whether the indication carried in the routing message received by the convergence layer device is used for indicating to create the SR-BE tunnel or indicating not to create the SR-BE tunnel, the convergence layer device always creates the SR-BE tunnel to the other side, so as to ensure effective communication between the convergence layer device and other network devices, thereby ensuring communication performance of the communication system.

Fig. 8 is a schematic structural diagram of a routing message processing apparatus according to an embodiment of the present application, which is applied to a first network device. As shown in fig. 8, the apparatus 80 includes:

a receiving module 801, configured to receive a routing message issued by a second network device, where the routing message includes a prefix SID of the second network device, and the routing message further includes a first indication, where the first indication is used to indicate whether to create an SR-BE tunnel to the second network device. For a specific implementation process, please refer to the detailed description of step 701 in the embodiment shown in fig. 7, which is not described herein again.

A determining module 802, configured to determine whether to create an SR-BE tunnel from the first network device to the second network device according to the first indication. For a specific implementation process, reference is made to the detailed description of step 702 in the embodiment shown in fig. 7, which is not described herein again.

Optionally, the first indication is used to indicate that no SR-BE tunnel to the second network device is created, and the determining module 802 is configured to: according to the first indication, it is determined not to create an SR-BE tunnel from the first network device to the second network device.

Optionally, as shown in fig. 9, the apparatus 80 further comprises: a creation module 803 and a transmission module 804.

In an implementation manner, the creating module 803 is configured to, after the first network device determines not to create the SR-BE tunnel from the first network device to the second network device according to the first indication, create the SR-BE tunnel from the first network device to the second network device in response to a message to BE transmitted to the second network device existing in the first network device. A transmission module 804, configured to transmit the message through the SR-BE tunnel. For a specific implementation process, please refer to the detailed description of step 702 in the embodiment shown in fig. 7, which is not described herein again.

In another implementation, the receiving module 801 is further configured to receive a tunnel creation indication message sent by a third network device after the first network device determines, according to the first indication, that the SR-BE tunnel from the first network device to the second network device is not created, where the tunnel creation indication message includes an identifier of the second network device, and the tunnel creation indication message is used to indicate the first network device to create the SR-BE tunnel to the second network device, where the third network device is a convergence layer device. A creating module 803, configured to create an SR-BE tunnel from the first network device to the second network device based on the tunnel creation indication message. A transmission module 804, configured to transmit, through the SR-BE tunnel, a packet to BE transmitted to the second network device. For a specific implementation process, please refer to the detailed description of step 702 in the embodiment shown in fig. 7, which is not described herein again.

Optionally, the tunnel creation indication message further includes a prefix SID of the second network device.

Optionally, the first network device is located in the same access ring as the second network device.

Optionally, the routing message is a link state message or a link state advertisement.

Optionally, the routing message includes a prefix SID sub-TLV field, the first indication being in a flag bit field of the prefix SID sub-TLV field.

Optionally, the first network device is an access stratum device.

Fig. 10 is a schematic structural diagram of a routing message issuing device according to an embodiment of the present application. Applied to a first network device. As shown in fig. 10, the apparatus 100 includes:

a generating module 1001 configured to generate a routing message, where the routing message includes a prefix segment identity SID of a destination network device, and the routing message further includes a first indication, where the first indication is used to indicate whether to create a segment routing best effort SR-BE tunnel to the destination network device. For a specific implementation process, please refer to the detailed description of step 601 in the embodiment shown in fig. 6, which is not described herein again.

A message publishing module 1002, configured to publish the routing message. For a specific implementation process, please refer to the detailed description of step 602 in the embodiment shown in fig. 6, which is not described herein again.

Optionally, the destination network device is a first network device, and the message publishing module 1002 is configured to: and issuing the routing message in an Interior Gateway Protocol (IGP) domain in which the first network equipment is positioned.

Optionally, the first network device is an access stratum device, and the first indication is used to indicate that no SR-BE tunnel to the destination network device is created; or, the first network device is a convergence layer device, and the first indication is used for indicating the creation of an SR-BE tunnel to the destination network device.

Optionally, the destination network device is different from the first network device, and the message publishing module 1002 is configured to: and sending a routing message to the second network equipment, wherein the first indication is used for indicating the creation of the SR-BE tunnel to the destination network equipment, and the routing message also comprises the identification of the destination network equipment. The first network device is a convergence layer device, and the second network device is an access layer device.

Optionally, the message publishing module 1002 is configured to: and sending a routing message to the second network equipment in response to the first network equipment receiving a message which is sent by the second network equipment and has a destination address as the destination network equipment.

Optionally, the generating module 1001 is configured to: and modifying a second indication in the original message issued by the destination network equipment into the first indication to obtain a routing message, wherein the second indication is used for indicating that an SR-BE tunnel to the destination network equipment is not created.

With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

It should be understood that the network device provided in the embodiments of the present application may also be implemented by an application-specific integrated circuit (ASIC), or a Programmable Logic Device (PLD), which may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof. The routing message publishing method and/or the routing message processing method provided by the foregoing method embodiments may also be implemented by software, and when the routing message publishing method and/or the routing message processing method provided by the foregoing method embodiments are implemented by software, each module in the network device may also be a software module.

An embodiment of the present application further provides a network device, including: a memory and a processor;

the memory is used for storing a computer program;

the processor is configured to execute the computer program stored in the memory to cause the network device to perform the actions performed by the network device according to the above-described method embodiments.

Illustratively, fig. 11 is a block diagram of a network device provided in an embodiment of the present application. The network device may be a CSG or an ASG in the communication system shown in fig. 1 or fig. 2, or the network device may be an access stratum device or an aggregation stratum device in the communication system shown in fig. 3. As shown in fig. 11, the network device 110 includes: a processor 1101 and a memory 1102.

A memory 1102 for storing a computer program comprising program instructions;

a processor 1101, configured to invoke the computer program, to implement the actions performed by the network device in the method embodiment shown in fig. 6 or the actions performed by the network device in the method embodiment shown in fig. 7.

Specifically, when the network device 110 is the network device 1 in the method embodiment shown in fig. 6, the processor 1101 is configured to generate a routing message, the routing message includes a prefix SID of the destination network device, and the routing message further includes an indication that indicates whether to create an SR-BE tunnel to the destination network device. The processor 1101 is also used to control the transceiver to issue routing messages. For a specific implementation process, please refer to the detailed description of step 601 to step 602 in the embodiment shown in fig. 6, which is not repeated herein.

Furthermore, in the case where the modules (including the generation module 1001 and the message publishing module 1002) in fig. 10are implemented in software, the program modules may be stored in the memory 1102, and the processor 1101 executes the software modules in the memory 1102 to perform the processing steps and functions of the network device according to the method embodiment.

Specifically, when the network device 110 is the network device 3 in the method embodiment shown in fig. 7, the processor 1101 is configured to receive a routing message issued by the network device 4, where the routing message includes a prefix SID of the network device 4, and the routing message further includes an indication that indicates whether to create an SR-BE tunnel to the network device 4. The processor 1101 is further configured to determine whether to create an SR-BE tunnel from the network device 3 to the network device 4 according to the indication. For a specific implementation process, please refer to the detailed description of step 701 to step 702 in the embodiment shown in fig. 7, which is not repeated herein.

Furthermore, in the case where the modules in fig. 8 (including the receiving module 801 and the determining module 802) or the modules in fig. 9 (including the receiving module 801, the determining module 802, the creating module 803, and the transmitting module 804) are implemented in software, the program modules may be stored in the memory 1102, and the processor 1101 executes the software modules in the memory 1102 to perform the processing steps and functions of the network device according to the above-described method embodiment.

Optionally, referring to fig. 11, the network device 110 further includes a communication bus 1103 and a communication interface 1104.

The processor 1101 includes one or more processing cores, and the processor 1101 executes various functional applications and data processing by running a computer program.

The memory 1102 may be used to store computer programs. The memory 1102 may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and direct bus RAM (DR RAM).

The communication interface 1104 may be plural, and the communication interface 1104 is used for communication with other devices. For example, in an embodiment of the subject application, communication interface 1104 may be used to issue routing messages.

The memory 1102 and the communication interface 1104 are connected to the processor 1101 by a communication bus 1103, respectively.

The embodiment of the present application further provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed by a processor, the instructions implement the actions performed by the network device in the foregoing method embodiments.

An embodiment of the present application further provides a communication system, including: a first network device including the apparatus shown in fig. 8 or 9 or the network device shown in fig. 11, and a second network device including the apparatus shown in fig. 10 or the network device shown in fig. 11.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

In the embodiments of the present application, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" in this application means two or more, e.g., a plurality of network devices means two or more network devices. The terms "system" and "network" are often used interchangeably herein.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The above description is intended only to illustrate the alternative embodiments of the present application, and not to limit the present application, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for processing routing messages, the method comprising:

the method comprises the steps that a first network device receives a routing message issued by a second network device, wherein the routing message comprises a prefix Segment Identification (SID) of the second network device, and the routing message also comprises a first indication which is used for indicating whether a segment routing best effort forwarding (SR-BE) tunnel to the second network device is created or not;

the first network device determines whether to create an SR-BE tunnel from the first network device to the second network device according to the first indication.

2. The method of claim 1, wherein the first indication indicates that no SR-BE tunnel to the second network device is created, and wherein the first network device determines whether to create the SR-BE tunnel from the first network device to the second network device according to the first indication, comprising:

the first network device determines not to create an SR-BE tunnel from the first network device to the second network device according to the first indication.

3. The method of claim 2, wherein after the first network device determines not to create the SR-BE tunnel from the first network device to the second network device according to the first indication, the method further comprises:

responding to the first network equipment to have a message to BE transmitted to the second network equipment, and creating an SR-BE tunnel from the first network equipment to the second network equipment by the first network equipment;

and the first network equipment transmits the message through the SR-BE tunnel.

4. The method of claim 2, wherein after the first network device determines not to create the SR-BE tunnel from the first network device to the second network device according to the first indication, the method further comprises:

the first network device receives a tunnel creation indication message sent by a third network device, wherein the tunnel creation indication message comprises an identifier of the second network device, and the tunnel creation indication message is used for indicating the first network device to create an SR-BE tunnel to the second network device, and the third network device is a convergence layer device;

the first network equipment creates an SR-BE tunnel from the first network equipment to the second network equipment based on the tunnel creation indication message;

and the first network equipment transmits a message to BE transmitted to the second network equipment through the SR-BE tunnel.

5. The method of claim 4, wherein the tunnel creation indication message further comprises a prefix SID of the second network device.

6. The method according to any of claims 1 to 5, wherein the first network device and the second network device are located in the same access ring.

7. The method according to any of claims 1 to 6, wherein the routing message is a link state packet or a link state advertisement.

8. The method of claim 7, wherein the routing message comprises a prefix SID subtype-length-value (TLV) field, and wherein the first indication is in a flag bit field of a prefix SID sub-TLV field.

9. The method of any of claims 1 to 8, wherein the first network device is an access stratum device.

10. A method for issuing routing messages, the method comprising:

the method comprises the steps that a first network device generates a routing message, the routing message comprises a prefix Segment Identification (SID) of a destination network device, and the routing message further comprises a first indication which is used for indicating whether a segment routing best effort (SR-BE) tunnel to the destination network device is created or not;

and the first network equipment issues the routing message.

11. The method of claim 10, wherein the destination network device is the first network device, and wherein the first network device issues the routing message, comprising:

the first network device issues the routing message within an Interior Gateway Protocol (IGP) domain in which the first network device is located.

12. The method of claim 11, wherein the first network device is an access stratum device, and wherein the first indication indicates that no SR-BE tunnel to the destination network device is created; or the like, or, alternatively,

the first network device is a convergence layer device, and the first indication is used for indicating the creation of an SR-BE tunnel to the destination network device.

13. The method of claim 10, wherein the destination network device is different from the first network device, and wherein the first network device issues the routing message, comprising:

the first network device sending the routing message to a second network device, the first indication indicating that an SR-BE tunnel to the destination network device is created, the routing message further including an identification of the destination network device;

the first network device is a convergence layer device, and the second network device is an access layer device.

14. The method of claim 13, wherein sending the routing message from the first network device to a second network device comprises:

and in response to the first network device receiving the message sent by the second network device and having the destination address of the destination network device, the first network device sends the routing message to the second network device.

15. The method of claim 13 or 14, wherein the first network device generates a routing message comprising:

and the first network equipment modifies a second indication in the original message issued by the destination network equipment into the first indication to obtain the routing message, wherein the second indication is used for indicating that an SR-BE tunnel to the destination network equipment is not created.

16. A routing message processing apparatus, applied to a first network device, the apparatus comprising:

a receiving module, configured to receive a routing message issued by a second network device, where the routing message includes a prefix segment identity SID of the second network device, and the routing message further includes a first indication, where the first indication is used to indicate whether to create a segment routing best effort SR-BE tunnel to the second network device;

a determining module, configured to determine whether to create an SR-BE tunnel from the first network device to the second network device according to the first indication.

17. The apparatus of claim 16, wherein the first indication indicates that no SR-BE tunnel is created to the second network device, and wherein the means for determining is configured to:

determining not to create an SR-BE tunnel from the first network device to the second network device according to the first indication.

18. The apparatus of claim 17, further comprising:

a creating module, configured to, after the first network device determines, according to the first indication, that an SR-BE tunnel from the first network device to the second network device is not created, in response to a presence of a packet to BE transmitted to the second network device in the first network device, create an SR-BE tunnel from the first network device to the second network device;

and the transmission module is used for transmitting the message through the SR-BE tunnel.

19. The apparatus of claim 17, further comprising:

the receiving module is further configured to receive a tunnel creation indication message sent by a third network device after the first network device determines, according to the first indication, that an SR-BE tunnel from the first network device to the second network device is not created, where the tunnel creation indication message includes an identifier of the second network device, and the tunnel creation indication message is used to indicate the first network device to create an SR-BE tunnel to the second network device, where the third network device is a convergence layer device;

a creating module, configured to create an SR-BE tunnel from the first network device to the second network device based on the tunnel creation indication message;

and the transmission module is used for transmitting the message to BE transmitted to the second network equipment through the SR-BE tunnel.

20. A routing message distribution apparatus applied to a first network device, the apparatus comprising:

a generating module, configured to generate a routing message, where the routing message includes a prefix segment identity, SID, of a destination network device, and the routing message further includes a first indication, where the first indication is used to indicate whether to create a segment routing best effort, SR-BE, tunnel to the destination network device;

and the message publishing module is used for publishing the routing message.

21. The apparatus of claim 20, wherein the destination network device is the first network device, and wherein the message publishing module is configured to:

and issuing the routing message in an Interior Gateway Protocol (IGP) domain in which the first network equipment is positioned.

22. The apparatus of claim 21, wherein the first network device is an access stratum device, wherein the first indication indicates that no SR-BE tunnel to the destination network device is created; or the like, or, alternatively,

23. The apparatus of claim 20, wherein the destination network device is different from the first network device, and wherein the message publishing module is configured to:

sending the routing message to a second network device, wherein the first indication is used for indicating the creation of an SR-BE tunnel to the destination network device, and the routing message further comprises the identification of the destination network device;

24. The apparatus of claim 23, wherein the message publishing module is configured to:

and sending the routing message to the second network equipment in response to the first network equipment receiving the message which is sent by the second network equipment and has the destination address as the destination network equipment.

25. The apparatus of claim 23 or 24, wherein the generating means is configured to:

and modifying a second indication in the original message issued by the destination network equipment into the first indication to obtain the routing message, wherein the second indication is used for indicating that an SR-BE tunnel to the destination network equipment is not created.

26. A computer-readable storage medium having stored thereon instructions which, when executed by a processor, implement the method of any one of claims 1 to 15.

27. A communication system, comprising: a first network device comprising the apparatus of any of claims 16 to 19 and a second network device comprising the apparatus of any of claims 20 to 25.