CN112491587B

CN112491587B - Method and system for realizing S-SCN of SPTN (shortest Path bridging) network

Info

Publication number: CN112491587B
Application number: CN202011224740.5A
Authority: CN
Inventors: 施先清
Original assignee: Fiberhome Telecommunication Technologies Co Ltd
Current assignee: Fiberhome Telecommunication Technologies Co Ltd
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2022-09-09
Anticipated expiration: 2040-11-05
Also published as: CN112491587A

Abstract

The invention discloses a method and a system for realizing S-SCN of an SPTN network, relating to the field of software defined networks, wherein the method comprises the following steps: after the equipment is electrified and the initialization of the exchange chip is completed, the establishment and configuration management of the management VLAN are completed; configuring a forwarding mode of a management VLAN into a non-relay forwarding mode; the DHCP client module selects one port from the ports which receive the DHCP message as an uplink port of the equipment, and uses the uplink port to perform subsequent DHCP interaction, Netconf and OpenFlow protocol communication; and after the OpenFlow connection is established, changing the forwarding mode of the management VLAN from a non-relay forwarding mode to a relay forwarding mode. According to the method and the system for realizing the S-SCN of the SPTN network, the input/output port filtering technology is combined with the non-mobility control function of the static MAC address, so that the forwarding tree is prevented from forwarding a loop, and a broadcast storm is thoroughly avoided.

Description

Method and system for realizing S-SCN of SPTN (shortest Path bridging) network

Technical Field

The invention relates to the field of Software Defined networks, in particular to a method and a system for realizing an SPTN (Software Defined Packet transport network) network S-SCN (SPTN Signal control network).

Background

With the advent of SDN (Software defined networking) technology, transport networks opened a new era of gradual evolution from PTN (Packet transport network) to SPTN. The SPTN control network (S-SCN) is the basis of the SPTN system, and the S-SCN establishes a control channel connected with a DC (Domain Controller) on the SPTN equipment so as to construct a control network which can be communicated and communicated with each SPTN equipment by the DC, so that a standard southbound interface protocol message communicated between the DC and the SPTN equipment is borne, the Controller manages and controls the SPTN equipment, and the SPTN equipment has no communication requirement. The Chinese communication standards Association CCSA has specified S-SCN in SPTN related standards documents, some of which require the following: the S-SCN Network is a Network based on two-layer bridging forwarding of MAC addresses, the forwarding behavior is in accordance with 802.1Q specification, and the relay forwarding of southbound interface protocol messages is realized by a management VLAN (Virtual Local Area Network) module on SPTN equipment; the S-SCN should avoid broadcast storm caused by Ethernet loop; the SPTN equipment should support to establish communication with the domain controller through an in-band S-SCN channel, and the in-band S-SCN channel adopts a fixed VLAN value 4094; the SPTN device should support a mode of acquiring a management IP address through a DHCP (Dynamic Host Configuration Protocol) server and communicate with the domain controller, and in this mode, the domain controller should integrate a DHCP server plug-in and allocate the management IP address to the SPTN device.

It is well known that loops are catastrophic to the ethernet layer two switching network, and looping can cause broadcast storms resulting in network failure. In engineering application, the networking topology of SPTN equipment is complex and various, an Ethernet loop formed by actual physical links is visible everywhere, and an in-band S-SCN network constructed based on the physical network is also a two-layer switching network, so that how to avoid broadcast storms is of great importance. The mainstream idea in the industry at present is to construct an in-band S-SCN tree topology network without a loop on a physical network with a loop, and generally adopt a scheme that a DC and a device simultaneously and jointly control a management VLAN of the device and realize real-time dynamic change of a member port of the management VLAN, that is: the device DHCP Client module is responsible for selecting the only uplink port of the device to the DC control channel and informing the management VLAN to add the port into the member port; the DHCP Server module, the OpenFlow module and the netconf module of the DC cooperate together to complete addition and deletion management of a member port corresponding to a downstream port of a control channel in a relay device management VLAN, so as to allow or prohibit relay forwarding of a control packet of a downstream device by the relay device.

The prior implementation scheme has the following defects:

a. in order to construct an in-band S-SCN tree topology network, an additional topology management module is required on a DC and is specially responsible for the topology management of the S-SCN network; in addition, VLAN member port information needs to be interactively managed between the DC and the equipment in real time through a Netconf protocol interface.

b. DHCP messages require special handling. The device at the beginning of power-on actively applies for device management IP to the DC in a DHCP mode, at this time, a control channel between the device and the DC is not established yet, for example, an uplink port of the device and a downlink port of an upstream relay device are not added with a management VLAN, so that DHCP protocol messages can not be forwarded by the management VLAN and need to be processed in a special way: the non-management VLAN member port of the device also needs to receive and send the DHCP message, the upstream relay device supports the forwarding processing of the DHCP session message of the downstream device and the DC in the relay device by adopting a packet-in/out mode of an OpenFlow protocol, and meanwhile, an OpenFlow protocol instance corresponding to the relay device on the DC supports the forwarding processing of the DHCP session message of the downstream device and the DC in the DC by adopting a peer-to-peer packet-out/in mode.

c. The special processing mode of the DHCP messages puts forward additional requirements on a core switching chip of the equipment, the chip needs to support a deep matching and extracting mechanism of the DHCP messages, the DHCP messages sent to the equipment by a DC need to be matched and extracted to a DHCP module for processing, and the DHCP messages sent to the DC by a downstream equipment need to be matched and extracted to an OpenFlow module for packet-in processing. Ordinary low-end chips cannot meet the requirement, and high-end chips cause equipment cost to rise, which is unacceptable for cost-first miniaturized SPTN equipment.

d. In the aspect of software design, in order to support S-SCN, communication needs to be carried out between a DC and an originally unrelated protocol module in equipment, and the increase of the coupling degree between the modules inevitably leads to the complexity of a software architecture and the reduction of the stability. Communication interfaces and corresponding processing are required to be added between DHCP and Netconf and between DHCP and OpenFlow inside the DC; inside the device, communication interfaces and corresponding processing need to be added between DHCP and Netconf, between management VLAN and Netconf, and between the control message transceiver module and OpenFlow.

e. The method for managing the VLANs through the DC and the equipment double-end management and control needs the mutual cooperation and real-time communication coordination of the two, the confusion of the management VLANs and even the ring formation of S-SCN networks can be caused by improper cooperation, the fault tolerance capability is reduced, and the disaster risk is increased.

f. The S-SCN network structure has uncertainty, and the change of the physical network state (such as the link connection state and the equipment running state) can cause the S-SCN network structure to change at any time.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method and a system for realizing the S-SCN of the SPTN network, wherein the input/output port filtering technology is adopted to combine with the non-mobility control function of a static MAC address, so that the forwarding tree is realized to avoid a forwarding loop, and the broadcast storm is thoroughly avoided.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

an SPTN network S-SCN implementation method includes:

after equipment is powered on and the initialization of a switching chip is completed, a management VLAN is established and an input port filtering rule is configured; configuring a static table entry for the equipment management MAC address in an MAC address table of a management VLAN, and discarding a message when the message with a source MAC address equal to the static MAC address is received from an unexpected port; and after the OpenFlow connection is established, changing an input port filtering rule of the management VLAN.

On the basis of the above technical solution, the step of configuring the input port filter rule includes: configuring an input port filtering table entry for the output direction of each member port of the VLAN domain; configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a port after forwarding and searching, if an input port of the message is enabled in an input port filtering table item of the port, the message is transmitted; if not, the message is discarded.

On the basis of the technical scheme, the forwarding mode of the management VLAN comprises a relay forwarding mode and a non-relay forwarding mode, and after the equipment is started, the forwarding mode of the management VLAN is configured to be the non-relay forwarding mode; and after the OpenFlow connection is established, changing the forwarding mode of the management VLAN from a non-relay forwarding mode to a relay forwarding mode.

On the basis of the above technical solution, the step of configuring the forwarding mode of the management VLAN to be the non-relay forwarding mode after the device is turned on includes:

configuring an input port filter table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; and configuring an input port filter table entry of a member port corresponding to the external physical port, wherein the CPU port is enabled, and all other ports are disabled.

On the basis of the above technical solution, after configuring the management VLAN to be in the non-relay forwarding mode, the method further includes: the DHCP client module selects one port from the ports which receive the DHCP message as an uplink port of the equipment; after an upper connection port of the equipment is appointed, a DHCP client module is used for acquiring an MAC address corresponding to a domain controller in a DHCP session process; configuring a static table entry for an MAC address corresponding to a domain controller in an MAC address table of a management VLAN; a DHCP client applies for an equipment management IP address; the DHCP client configures the device management IP address to a TCP/IP protocol stack and Netconf and OpenFlow protocol modules.

On the basis of the above technical solution, the step of changing the forwarding mode of the management VLAN from the non-relay forwarding mode to the relay forwarding mode includes:

modifying an input port filter table item of a CPU port, setting an upper connection port as enabled, and setting all other ports as disabled; modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled; and modifying the input port filter table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.

On the basis of the above technical solution, the step of creating a management VLAN and configuring an input port filtering rule further includes:

creating a new VLAN field, configuring the VLAN value of the VLAN field to be 4094, and naming the VLAN field as a management VLAN; adding all physical ports of a device network side and a client side into a management VLAN; adding a CPU port of a switching chip into a management VLAN; when each physical port with the receiving direction is configured to receive the tag message with the VLAN4094, the tag message enters a corresponding member port of a management VLAN in a classified mode, and then is forwarded through the management VLAN; all messages sent out by each member port of the management VLAN with the configured sending direction carry the label of the VLAN 4094.

The invention also provides an SPTN network S-SCN implementation system, including:

the domain controller comprises a DHCP service module, an OpenFlow module and a netconf module; the device comprises at least two SPTN devices connected through a link, wherein each SPTN device comprises at least two ports, a DHCP client module and a management VLAN module, the management VLAN module is used for configuring a forwarding mode of a management VLAN to be a non-relay forwarding mode after the device is powered on to complete initialization of a switching chip, and after OpenFlow connection is established, the forwarding mode of the management VLAN is changed from the non-relay forwarding mode to a relay forwarding mode; configuring a static table entry for the equipment management MAC address in an MAC address table of the management VLAN, and discarding a message when the message with a source MAC address equal to the static MAC address is received from an unexpected port; and the DHCP client module is used for selecting one port from the ports receiving the DHCP message as an uplink port of the equipment, and using the uplink port to perform subsequent DHCP interaction, Netconf and OpenFlow protocol communication.

On the basis of the above technical solution, the VLAN management module is further configured to: configuring an input port filtering table entry for the output direction of each member port of the VLAN domain; and configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a port after forwarding and searching, if an input port of the message is enabled in an input port filtering table item of the port, the message is transmitted; if not, the message is discarded.

On the basis of the above technical solution, the VLAN management module is further configured to:

after the SPTN equipment is started, configuring an input port filter table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; configuring an input port filter table entry of a member port corresponding to an external physical port, wherein a CPU port is enabled, and all other ports are disabled; after the OpenFlow connection is established, modifying an input port filtering table item of a CPU port, setting an upper connection port as enabled, and setting all other ports as not enabled; modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled; and modifying the input port filter table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.

Compared with the prior art, the invention has the advantages that:

(1) the SPTN network S-SCN implementation method of the invention allows topology ring formation on the premise of fixing the topology structure of the S-SCN network, achieves the purpose of avoiding broadcast storm by controlling the forwarding behavior of the equipment management VLAN, and is completely different from the existing S-SCN scheme. Due to the fact that the technical threshold is low, the chip does not need to support complex functions such as a DHCP message deep matching extraction mechanism, the requirement on the classification matching of the interactive chip is not high, the equipment is allowed to adopt a low-end chip, and the method is particularly suitable for being used by the miniaturized SPTN equipment with cost as a first element.

(2) The method for realizing the SPTN network S-SCN does not need to perform related operations among DC or DHCP, Netconf and OpenFlow in the equipment on the premise of avoiding broadcast storm, avoids communication interfaces which do not conform to the specification among different protocol modules, reduces the module coupling degree, has clear software architecture and improves the stability.

(3) The method for realizing the S-SCN of the SPTN network adopts a static topological structure, does not implement dynamic adjustment of the S-SCN network topology due to the change of the states (such as links and node states) of the SPTN physical network, thoroughly eliminates the situation that a domain controller and equipment multi-head control equipment manage the VLAN, also avoids the trouble that the two need to implement dynamic interactive management of VLAN member information for coordination and coordination, and ensures that the whole S-SCN network is more robust.

(4) The SPTN network S-SCN implementation method achieves the aim of avoiding broadcast storm by controlling the forwarding behavior of the equipment management VLAN on the premise of fixing the topological structure of the S-SCN network. The method limits the forwarding behavior of a southbound interface protocol message on equipment into a Tree forwarding model by adopting an input/output port filtering technology in a management VLAN of the equipment and combining with a non-mobility control function of a static MAC address, the whole S-SCN network constructed based on the management VLAN controlled by the forwarding behavior is actually a huge forwarding Tree, the function of the management control message is equivalent to an Ethernet Tree (E-Tree) service, DC is a Tree root, and a CPU of each equipment is a leaf. Although the whole S-SCN network may have loops on the topology, such a forwarding tree avoids forwarding loops for the management control packet forwarding behavior, thus completely avoiding broadcast storms.

Drawings

Fig. 1 is a schematic diagram of an architecture for implementing VLAN management in an SPTN network according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an SPTN network S-SCN implementation system in an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating S-SCN configuration and online flow in an SPTN network S-SCN implementation method according to an embodiment of the present invention;

FIG. 4 is a diagram of a physical loop application case architecture in a non-all-online scenario for a device in an embodiment of the invention;

fig. 5 is a diagram of a physical loop application case architecture in an all-online scenario of a device in an embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The embodiment of the invention provides an SPTN network S-SCN implementation method, which comprises the following steps: after the equipment is electrified and the initialization of the exchange chip is completed, the establishment and configuration management of the management VLAN are completed; configuring a forwarding mode of a management VLAN into a non-relay forwarding mode; the DHCP client module selects one port from the ports which receive the DHCP message as an uplink port of the equipment, and uses the uplink port to perform subsequent DHCP interaction, Netconf and OpenFlow protocol communication; and after the OpenFlow connection is established, changing the forwarding mode of the management VLAN from a non-relay forwarding mode to a relay forwarding mode.

Specifically, the step of completing the creation and configuration management of the management VLAN further includes:

creating a new VLAN field, configuring the VLAN value of the VLAN field to be 4094, and naming the VLAN field as a management VLAN; adding all physical ports of a device network side and a client side into a management VLAN; adding a CPU port of a switching chip into a management VLAN; all member ports of the management VLAN are set to be in a tagged mode, and the VID value is configured to be 4094, namely: when each physical port with the receiving direction is configured to receive the tag message with the VLAN4094, the tag message enters a corresponding member port of a management VLAN in a classified mode, and then is forwarded through the management VLAN; all messages sent out by each member port of the management VLAN with the configured sending direction carry the labels of the VLAN 4094.

In a preferred embodiment, the step of completing the creation and configuration management of the management VLAN in the above process may include: configuring an input port filtering table entry for the output direction of each member port of the VLAN domain; configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a certain port after forwarding and searching, if the input port of the message is enabled in the input port filtering table entry of the port, the message is transmitted; if not, the message is discarded.

Specifically, after the device is turned on, the step of configuring the forwarding mode of the management VLAN to be the non-trunking forwarding mode includes:

configuring an input port filtering table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; and configuring an input port filter table entry of a member port corresponding to the external physical port, wherein the CPU port is enabled, and all other ports are disabled.

And after configuring the management VLAN into a non-relay forwarding mode, configuring the management MAC address of the equipment into an MAC table of the management VLAN in a static mode.

On the basis of the scheme, after the upper connection port of the equipment is specified, the method also comprises the following steps: in the DHCP conversation process, a DHCP client module is used for obtaining an MAC address corresponding to a domain controller; configuring a static table entry for an MAC address corresponding to a domain controller in an MAC address table of a management VLAN; a DHCP client applies for an equipment management IP address; the DHCP client configures the device management IP address to a TCP/IP protocol stack and Netconf and OpenFlow protocol modules.

In order to ensure that the forwarding mode of the management VLAN is changed from a non-relay forwarding mode to a relay forwarding mode and avoid broadcast storm, the method can be set according to the following steps:

modifying an input port filter table item of a CPU port, setting an upper connection port as enabled, and setting all other ports as not enabled; modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled; and modifying the input port filter table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.

The invention also provides an SPTN network S-SCN implementation system, which includes:

the domain controller comprises a DHCP service module, an OpenFlow module and a netconf module; the system comprises at least two SPTN devices connected through a link, wherein each SPTN device comprises at least two ports, a DHCP client module and a management VLAN module. The device comprises a management VLAN module, a switching chip, a management VLAN module and an OpenFlow connection module, wherein the management VLAN module is used for configuring a forwarding mode of a management VLAN into a non-relay forwarding mode after the device is powered on and the initialization of the switching chip is completed, and changing the forwarding mode of the management VLAN from the non-relay forwarding mode into a relay forwarding mode after the OpenFlow connection is established; and the DHCP client module is used for selecting one port from the ports which receive the DHCP message as an uplink port of the equipment, and using the uplink port to perform subsequent DHCP interaction, Netconf and OpenFlow protocol communication.

In a preferred embodiment, the management VLAN module is further configured to:

configuring an input port filtering table entry for the output direction of each member port of the VLAN domain; and configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a certain port after being forwarded and searched, if the input port of the message is enabled in the input port filtering table item of the port, the message is transmitted; if not, the message is discarded. After the SPTN equipment is started, configuring an input port filter table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; and configuring an input port filter table entry of a member port corresponding to the external physical port, wherein the CPU port is enabled, and all other ports are disabled.

In order to ensure smooth switching of forwarding settings of the management VLAN module and prevent formation of broadcast storms during switching, the management VLAN module may be further configured to:

after the OpenFlow connection is established, modifying an input port filtering table item of a CPU port, setting an uplink port as enabled, and setting all other ports as not enabled; modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled; and modifying the input port filtering table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.

The following description is given with respect to a specific embodiment:

s1, creating and configuring management VLAN. The management VLAN of the equipment is a VLAN field with a VLAN value of 4094, and after the equipment is electrified and the initialization of the exchange chip is completed, the creation and the configuration management of the management VLAN are completed through the steps of establishing the VLAN field of 4094, adding member ports, configuring member attributes and the like. In this embodiment, the specific process of the above steps is as follows:

s101, creating a new VLAN field, configuring the VLAN value of the new VLAN field to be 4094, and naming the new VLAN field as a management VLAN;

s102, adding external physical ports, and adding all the physical ports of a device network side and a client side into a management VLAN;

s103, adding an internal CPU port, and adding the CPU port of the exchange chip into a management VLAN;

s104, setting member port attributes, setting all member ports of the management VLAN as tag (tag) attributes, and configuring the VID value to be 4094; the receiving direction is as follows: the label messages with VLAN4094 received by each physical port can enter corresponding member ports of the management VLAN in a classified mode and then are forwarded through the management VLAN; the sending direction is as follows: all messages sent out by each member port of the management VLAN are provided with labels of the VLAN 4094.

And S2, subsequently, starting the port configuration of the initial stage equipment, and setting the initially started SPTN equipment to be in a non-relay forwarding mode.

In this patent document, the VLAN management module has two forwarding modes: relay forwarding and non-relay forwarding. In the non-relay forwarding mode, the CPU port is a root port, and all other external physical ports are leaf ports, at this time, the management VLAN only receives and transmits control messages for communication between the device and the DC, and for control messages for communication between other devices and the DC, the management VLAN is discarded and not relayed (the control messages are sent to the CPU of the device and then discarded by a corresponding protocol software module), so that the management VLAN in the non-relay forwarding mode only supports communication between the device and the DC and does not support communication between downstream devices and the DC, for example, in fig. 2, the device SE3 is in the non-relay forwarding mode, the CPU port of the device is the root port, and all external ports such as P3 and P4 are leaf ports; in the relay forwarding mode, the uplink port is a root port, and other member ports are leaf ports, so that the management VLAN can not only receive and send control messages of the device communicating with the DC, but also can perform relay forwarding on the control messages of other devices communicating with the DC without discarding, and the management VLAN in the relay forwarding mode supports communication between the device and the DC, and supports communication between downstream devices and the DC; in fig. 2, the device SE2 is in the relay forwarding mode, its P1 port is a root port, all other external ports such as P2 port and CPU ports are leaf ports, and the device SE2 can communicate with DC and also supports SE3 to communicate with DC.

Because the uplink port of the initial stage equipment is unknown, in order to avoid broadcast storm caused by a forwarding loop formed by improper relay forwarding of the equipment, the management VLAN is forbidden to forward the message between external ports; and because the upstream port is unknown at this time, in order to support the device attempting to establish a control channel with the DC via any one of the external physical ports, the management VLAN should be allowed to forward messages between the CPU port and any external port. Therefore, the initial forwarding mode of the management VLAN should be configured as a non-trunking forwarding mode, which can be implemented by appropriately configuring the input port filtering table entry of each member port, and if the input port of the packet is enabled in the input port filtering table entry, the packet is sent out, and if the input port of the packet is not enabled, the packet is discarded. By using the input/output port filtering function, the forwarding behavior of the VLAN domain can be easily controlled.

In the present embodiment, the following configuration is adopted: 1. configuring an input port filter table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; 2. and configuring an input port filter table entry of a member port corresponding to the external physical port, wherein the CPU port is enabled, and all other ports are disabled. After the configuration, the CPU port becomes a root port, all other ports become leaf ports, the management VLAN enters a non-relay forwarding mode, the CPU port can forward messages with any external port, and the messages can not be forwarded between the external ports.

After the above steps are completed, the member ports of the VLAN field are actually divided into root ports (root) and leaf ports (leaf) from the forwarding perspective, i.e. the forwarding attribute of the member port is either root or leaf; the messages are not allowed to be forwarded between the leaf ports, and the messages can be forwarded between the root ports and the leaf ports; for the management VLAN of the device, only one member port may be selected from the member list as a root port, and the other ports are all leaf ports, so that a tree forwarding model may be constructed. The managed VLAN tree forwarding model can be implemented with appropriate configuration using input-output port filtering functions: configuring an input port filter table entry of a root port to enable all other ports except the port; the input port of the leaf port is configured with a filter table entry, so that the root port is enabled, and all other ports are disabled.

And S3, configuring the equipment management MAC address. The management MAC address of the equipment is configured into the MAC table of the management VLAN in a static mode, and the matched received message is properly controlled in the MAC learning and searching stage by utilizing the special attribute field of the static table entry of the MAC table, so that the non-mobility management function of the static MAC address can be realized.

By configuring a static address table entry for the management VLAN in the MAC table, when a packet having a source MAC address equal to the static MAC address is received from an unexpected port, it is possible to prevent the source MAC address from being learned erroneously and to discard the packet from an improper entry. The address table entry of the MAC table that manages VLANs contains the following relevant attribute fields: VLAN domain, MAC address, member port, static flag, mobility flag. Here, the VLAN field and the MAC address constitute a key for HASH lookup in the MAC table; the member port represents an expected receiving port of the message of which the source MAC is matched with the table item or a forwarding-out port of the message of which the target MAC is matched with the table item; when the static flag is TRUE, the table entry is statically configured and aging is not allowed, and when the static flag is FALSE, the table entry is a dynamic table entry which is dynamically learned and aging is allowed to expire; the mobility flag indicates whether to allow the MAC address to be learned, update the member port attribute field of the entry, and allow the message whose receiving port has moved to be forwarded: when the source MAC of the received message is equal to the table entry MAC and the input port is not equal to the table entry member port, it indicates that the receiving port of the source MAC address of the message is moved, if the mobility flag is FALSE, it indicates that the message is not allowed, it indicates that the message is received from the wrong entry, and the message is an illegal message, and the MAC table entry should be discarded and not updated, if the message is TRUE, the situation is opposite, that is, the message is allowed to be forwarded and the member port information of the MAC table entry is updated.

The configuration of the relevant attribute field of the entry in this embodiment is as follows: the VLAN field is 4094, the MAC address is the device's management MAC address, the member port is the CPU port, the static flag is TRUE, and the mobility flag is flag. When each protocol software module of the equipment sends messages to the DC, the messages can be sent into a management VLAN through a CPU port and then forwarded to an external port, and the communication between the equipment and the DC is supported; when the device receives a source MAC (media access control) message from an external port, the source MAC message is judged as an illegal message by the management VLAN and is discarded, and the MAC table entry cannot be updated mistakenly, so that the communication disorder between the device and the DC caused by the fact that other devices accidentally misuse the management MAC of the device can be avoided.

Through the non-mobility function of the static MAC address, the system can selectively control the legality of a message input port, only messages received from an expected port can be forwarded and processed, and messages received from other ports are all regarded as illegal messages and discarded.

S4, DHCP session is attempted. Starting the DHCP client module of the equipment, and starting to apply for the management IP address of the equipment to the DC DHCP server module. The client module broadcasts discover messages to all external ports through the management VLAN, and attempts to perform DHCP session interaction with the DC. When the management VLANs of all upstream SPTN devices (which are relay devices relative to the device) on a certain path from the device to the DC are in the relay forwarding mode state, a control channel for communication between the device and the DC is opened on the path, and the device can start DHCP interaction with the DC through the control channel.

And S5, selecting the upper connection port. In the process of a DHCP session, if an SPTN device client module can receive DHCP messages replied by a server module from a plurality of ports, the client module selects a unique port from the ports as an uplink port of the device, and the device always uses the uplink port to communicate with a DC, and maintains subsequent DHCP interaction through the port, and performs protocol communication such as Netconf and OpenFlow.

And S6, configuring the MAC address corresponding to the DC. During the DHCP session, the client module of the device may obtain the MAC address corresponding to the DC. Configuring a static table entry for the MAC address corresponding to the DC in a MAC address table for managing the VLAN, wherein the relevant attribute field of the table entry is configured as follows: the VLAN field is 4094, the MAC address is DC-corresponding, the member port is uplink, the static flag is TRUE, and the mobility flag is flag. After the static table entry is configured, under the effect of the non-mobility function of the static MAC address, the MAC corresponding to the DC is locked on the uplink port, and for the packet sent by the DC and reaching the device, the packet is forwarded by the management VLAN only when received from the uplink port, and is discarded as an illegal packet when received from other ports.

And S7, applying and configuring the device management IP. According to the DHCP specification flow, the device continues a DHCP session with the DC. The DHCP client side module firstly tries to apply for the equipment management IP, starts the configuration of the equipment management IP address when successfully applying for the equipment management IP address, and then performs lease maintenance management of the IP address. In the process of configuring the IP, the device management IP address is configured to a TCP/IP protocol stack and related protocol modules such as Netconf and OpenFlow, and preparation is made for Netconf connection and OpenFlow connection in a network layer and a transport layer.

And S8, preparing and establishing the Netconf connection. And starting the NetconfServer on the equipment, and waiting for the Netconfclient of the DC to initiate connection. Shortly after the DC allocates the management IP to the device, the DC initiates a netcoonf connection request to the device in the role of a client (client), and the device NetcoonfServer responds to the DC according to a standard procedure until a Netconf connection is established.

And S9, configuring and establishing OpenFlow connection. Firstly, the DC issues information such as its IP address to the device through the Netconf channel, and waits for OpenFlow connection of the device. After the device knows the IP of the DC, the OpenFlow module initiates connection to the DC by the Client identity, and tries to establish OpenFlow connection with the DC by adopting a standard flow until the connection is successful. After the OpenFlow connection is established, the device enters a state completely controlled and managed by the DC, and can accept DC delivery service configuration at any time.

And S10, setting a relay forwarding mode after the OpenFlow connection is established. After the OpenFlow connection is established, the device can change the forwarding mode of the management VLAN, the non-relay forwarding mode is changed into the relay forwarding mode, and a tree forwarding model with the upper connection port as the root is formed without a forwarding loop. Mode transitions may be implemented by appropriately configuring the input port filter entries for each member port. In this embodiment, the related configuration method adopts the following steps: 1. changing an input port filter table item of a CPU port, wherein an uplink port is enabled, and all other ports including the CPU port are disabled; 2. changing an input port filter table item of an uplink port, wherein the uplink port is not enabled, and all other ports including a CPU port are enabled; 3. and changing the input port filtering table items of other external ports, wherein the uplink port is enabled, and all other ports including the CPU port are disabled. After the configuration, the uplink port becomes a root port, other external ports except the uplink port become leaf ports, and the CPU port also becomes a leaf port; the management VLAN module enters a relay forwarding mode, the uplink port can forward messages with the CPU port, can forward messages with any other external port except the uplink port, and cannot forward messages between any other external port except the uplink port.

In the tree forwarding model with the uplink port as the root, in the uplink direction, traffic from the downstream device received by other ports can be converged to the uplink port and sent out towards the DC direction, and in the downlink direction, in contrast, for the traffic from the DC received by the uplink port, the traffic can be forwarded to the corresponding port and sent out to the downstream device, or forwarded to the CPU port and sent to the device for receiving processing. In the trunk forwarding mode, the management VLAN supports both the various protocol communications of the present device with the DC and the various protocol communications of the downstream devices with the DC, and a forwarding loop formation broadcast storm does not occur. The device management VLAN thereafter maintains this normal relay forwarding mode as long as the control channel between the device uplink to the DC is open. After the management VLAN is changed into a relay forwarding mode, the equipment enters a normal working state, and the equipment finishes an on-line process.

In the embodiment of the invention, the S-SCN network is a centralized control network taking DC as the center, only the communication between the DC and each SPTN device exists in the network, and the communication of a control management layer is not needed among the devices. The control message flows sent by the devices to the DC constitute uplink flows, the flow directions of which are uplink directions, and the control message flows sent by the DC to the devices constitute downlink flows, the flow directions of which are downlink directions. The uplink and downlink traffic is further subdivided into unicast traffic and broadcast traffic: the source MAC address of the uplink message is a management MAC address of the sending equipment, wherein the target MAC of the uplink unicast message is the MAC corresponding to the DC, and the target MAC address of the uplink broadcast message is a broadcast address; the source MAC address of the downlink message is the MAC corresponding to the DC, wherein the destination MAC address of the downlink unicast message is the management MAC of the receiving equipment, and the destination MAC address of the downlink broadcast message is the broadcast address.

In the embodiment of the invention, the device in the online state supports the communication between the device and the DC, and supports the communication between the downstream device and the DC through the relay forwarding function.

In the uplink direction: (1) control messages (namely messages sent by a CPU) sent by the equipment are only sent towards the DC direction, namely sent out from a management VLAN root port and sent to the DC through an upstream equipment relay, and are not sent out from a leaf port, namely only sent to a root-leaf link and not sent to a leaf-leaf link (an uplink message of the head-end equipment is directly sent to the DC from the root port); (2) for the control message directly sent by the downstream equipment or the control message sent by other downstream equipment forwarded by the relay, the control message only enters from the class A leaf port at the upstream equipment and is sent out from the root port through the relay forwarding; (3) for all upstream traffic (including unicast and broadcast), either at the source device or at the upstream device of the pathway, it will only enter from the class a leaf port, not enter from the root port or the class B leaf port, and will only exit from the root port, not exit from the leaf port. (A leaf port connecting leaf-leaf links is called a class B leaf port, a leaf port connecting root-leaf links is called a class A leaf port, and a CPU port of an online device is also a class A leaf port)

In the downstream direction: (1) for the head-end equipment, downlink message flow enters from a root port; for the downlink unicast message, the message with the destination of the device is sent to a CPU for processing and ending, and other destination messages are sent out from a certain class A leaf port after being forwarded by the two layers of the management VLAN; for the broadcast message, a plurality of copies of the broadcast message are sent out from all leaf ports including a CPU port; (2) the secondary end equipment comprises: for the downlink unicast message, as the condition of the head-end equipment, the message only arrives from the root port, then the port is determined through two-layer forwarding processing, the message destined to the equipment is sent to the CPU for processing and ending, and other destination messages are sent out from a certain class A leaf port; for downlink broadcast messages, if there are N leaf-leaf links between the device and other devices, besides receiving one message from the root port, N shares of other messages can be received from N class B leaf ports, and the reception process of the N +1 shares of broadcast messages is different: only the downlink broadcast message received by the root port is received and is subjected to conventional two-layer forwarding processing, and the downlink broadcast message received from the class B leaf port is discarded (due to the non-mobility management function of the static MAC address); (3) in a word, the downlink unicast traffic only arrives from the root port, does not arrive from the leaf ports, only sends out from the class a leaf ports (including the CPU ports), and does not send out from the root port or the class B leaf ports; the downlink broadcast traffic arrives from the root port and possibly from the class B leaf port, (but the downlink broadcast traffic received by the class B leaf port is discarded and only the downlink broadcast traffic received by the root port is forwarded), does not arrive from the class a leaf port, is copied to all leaf ports and is sent out from the root port.

Finally, the operation process of a specific embodiment is used to explain the principle of implementing broadcast storm prevention in the SPTN network S-SCN implementation system embodiment of the present invention:

when a device on the loop is in an initialization state, the CPU port of the device is a root port, the two ports on the loop are leaf ports, and the two loop ports cannot mutually forward messages, so that the loop is naturally broken at the device from the message forwarding perspective, and the broadcast message is transmitted to the device and then only transmitted to the CPU for processing, and cannot be transmitted to an external port to continue to be transmitted to an adjacent device. For example, in fig. 4, 4 SPTN devices (SE2, SE3, SE4, SE5) and 4 links (L23, L34, L45, L25) form a physical loop, SE4 is in an initialization state, ports P3 and P4 of SE4 are leaf ports, when a broadcast message is received by a port P3, the broadcast message is not sent out to port P4, and when a broadcast message is received by a port P4, the broadcast message is not sent out to port P3, so the broadcast message is sent to a CPU at the SE4 device and terminated, thereby avoiding a broadcast storm.

When all devices on the loop are on-line. If the N devices are all on-line, each device has only one root port and N total root ports, then at least one root port of one device is not on the loop (otherwise, all devices on the loop cannot communicate with the DC because the devices must communicate with the DC via the root ports), that is, at most (N-1) root ports are on the N physical links of the loop, then at least one link has no root port, and the link is a leaf-leaf link, and its two ends are class B leaf ports. As described above, uplink traffic and downlink unicast traffic do not appear on the link, only downlink broadcast traffic may appear on the link, and since the downlink broadcast traffic received by the class B leaf port is discarded by the device, all traffic including the broadcast traffic is terminated by the leaf-leaf link and is not forwarded to the next link. Therefore, from the message forwarding perspective, the broadcast storm on the physical loop in this scenario is also eliminated. For example, in fig. 5, 4 SPTN devices (SE2, SE3, SE4, SE5) and 4 links (L23, L34, L45, L25) form a physical loop, 4 devices are all brought online, where two ports (P1 port and P2 port) of the device SE2 on the loop are leaf ports, a root port (P0 port) of the device SE2 is not on the loop, ports at two ends of the link L45 are respectively a P4 port of the device SE4 and a P6 port of the device SE5, and both ports are leaf ports, so that the link L45 is a leaf-leaf link, and only downlink broadcast traffic (source MAC is MAC corresponding to DC) is on the link, when a broadcast message sent out by the P4 port of the device SE4 reaches the P6 port of the device SE5 through the link, because the device SE5 has configured the MAC corresponding to the static management table entry of the MAC corresponding to DC, and the MAC address of the static VLAN management table is not under the action of the static VLAN 7, downlink broadcast messages received by the port P6 are discarded and cannot be continuously broadcast to the L25 link, and similarly, broadcast messages sent by the port P6 of the device SE5 are discarded under the effect of the non-mobility management function of the static MAC address when reaching the port P4 of the device SE4 through the link L45; in summary, the broadcast storm is completely eliminated due to the presence of the leaf-leaf link L45 in the loop.

The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.

Claims

1. An SPTN network S-SCN implementation method is characterized by comprising the following steps:

after the equipment is electrified and the initialization of the exchange chip is completed, a management VLAN is established, and an input port filtering table entry is configured for the output direction of each member port of the VLAN domain; configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a port after forwarding and searching, if an input port of the message is enabled in an input port filtering table item of the port, the message is transmitted; if the message is not enabled, discarding the message;

configuring a static table entry for the equipment management MAC address in an MAC address table of a management VLAN, and discarding a message when the message with a source MAC address equal to the static MAC address is received from an unexpected port;

the forwarding mode of the management VLAN comprises a relay forwarding mode and a non-relay forwarding mode, and the forwarding mode of the management VLAN is configured to be the non-relay forwarding mode after the equipment is started; and after the OpenFlow connection is established, changing the forwarding mode of the management VLAN from a non-relay forwarding mode to a relay forwarding mode.

2. An SPTN network S-SCN implementing method according to claim 1, characterized in that: the step of configuring the forwarding mode of the management VLAN to be the non-relay forwarding mode after the device is started comprises the following steps:

configuring an input port filtering table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled;

and configuring an input port filter table entry of a member port corresponding to the external physical port, wherein the CPU port is enabled, and all other ports are disabled.

3. The SPTN network S-SCN implementing method of claim 2, wherein after configuring the management VLAN to be in the non-relay forwarding mode, further including:

the DHCP client module selects one port from the ports which receive the DHCP message as an uplink port of the equipment;

after an upper connection port of the equipment is appointed, a DHCP client module is used for acquiring an MAC address corresponding to a domain controller in a DHCP session process;

configuring a static table entry for an MAC address corresponding to a domain controller in an MAC address table of a management VLAN;

a DHCP client applies for an equipment management IP address;

the DHCP client configures the device management IP address to a TCP/IP protocol stack and Netconf and OpenFlow protocol modules.

4. The SPTN network S-SCN implementing method of claim 1, wherein the changing the forwarding mode of the management VLAN from a non-trunk forwarding mode to a trunk forwarding mode includes:

modifying an input port filter table item of a CPU port, setting an upper connection port as enabled, and setting all other ports as disabled;

modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled;

and modifying the input port filtering table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.

5. The method of implementing an SPTN network S-SCN as recited in claim 1, wherein the step of creating a management VLAN and configuring input port filter rules further comprises:

creating a new VLAN field, configuring the VLAN value of the VLAN field to be 4094, and naming the VLAN field as a management VLAN;

adding all physical ports of a device network side and a client side into a management VLAN;

adding a CPU port of a switching chip into a management VLAN;

when each physical port with the receiving direction is configured to receive the tag message with the VLAN4094, the tag message enters a corresponding member port of a management VLAN in a classified mode, and then is forwarded through the management VLAN; all messages sent out by each member port of the management VLAN with the configured sending direction carry the label of the VLAN 4094.

6. An SPTN network S-SCN implementation system, characterized by comprising:

the domain controller comprises a DHCP service module, an OpenFlow module and a netconf module;

at least two SPTN apparatuses connected by a link, each SPTN apparatus including at least two ports, a DHCP client module, and a management VLAN module, wherein,

the management VLAN module is used for configuring a forwarding mode of the management VLAN into a non-relay forwarding mode after the equipment is powered on and the initialization of the switching chip is completed, and changing the forwarding mode of the management VLAN from the non-relay forwarding mode into a relay forwarding mode after the OpenFlow connection is established; configuring a static table entry for the equipment management MAC address in an MAC address table of the management VLAN, and discarding a message when the message with a source MAC address equal to the static MAC address is received from an unexpected port;

and the DHCP client module is used for selecting one port from the ports which receive the DHCP message as an uplink port of the equipment, and using the uplink port to perform subsequent DHCP interaction, Netconf and OpenFlow protocol communication.

7. The SPTN network S-SCN implementation system of claim 6, wherein the manage VLAN module is further to:

configuring an input port filtering table entry for the output direction of each member port of the VLAN domain;

and configuring the following judgment flows for the message forwarding flow of each member port: when a message is transmitted from a port after forwarding and searching, if an input port of the message is enabled in an input port filtering table item of the port, the message is transmitted; if not, the message is discarded.

8. The SPTN network S-SCN implementation system of claim 6, wherein the management VLAN module is further to:

after the SPTN equipment is started, configuring an input port filter table entry of a CPU port, wherein the CPU port is not enabled, and all other ports are enabled; configuring an input port filter table entry of a member port corresponding to an external physical port, wherein a CPU port is enabled, and all other ports are disabled;

after the OpenFlow connection is established, modifying an input port filtering table item of a CPU port, setting an upper connection port as enabled, and setting all other ports as not enabled; modifying an input port filter table item of an upper connection port, setting the upper connection port as disabled, and setting all other ports as enabled; and modifying the input port filter table items of other external ports, setting the uplink port enable, and enabling all other ports to be disabled.