CN108156004A - SDN controllers and switch management method - Google Patents

Abstract

This embodiment discloses a software-defined network SDN controller and a switch management method. The SDN controller includes: a simple network management protocol SNMP management unit, which is used to perform information interaction with the switch based on the SNMP protocol. Network topology; the SNMP unit is further configured to read, from the switch, device status information acquired based on the SNMP; wherein the device status information includes port information and/or traffic statistics information. The SDN controller, through the setting of the SNMP management unit, will exchange information with the switch based on SNMP based on the SNMP protocol, so as to obtain network topology and device status information complying with the SNMP protocol, thus solving the internal problem of the switch caused by obtaining the network topology according to the openflow protocol. When the flow table is abnormal, the network topology cannot be obtained normally.

Description

SDN controller and switch management method

technical field

The present invention relates to the field of network technology, in particular to a software defined network (Software Defined Network, SDN) controller and a switch management method.

Background technique

The existing SDN controller will use the OpenFlow protocol to manage the switches. For example, the openflow protocol is used to read the network topology from the switch, and the data packet encapsulated with the network topology based on openflow will be read from the switch. At this time, if the flow table inside the switch is wrong or rewritten, the network topology cannot be correctly received by the SDN controller. Exceptions, openflow can obtain very little switch status information. If the SDN controller needs to further control the switch status information, such as switches, for example, to realize data packet forwarding path control, congestion control or traffic regulation Excellent, these status information cannot meet the control requirements or precise control requirements. Therefore, ensuring that the network topology and/or device status information of the switch is normally reported to the SDN controller is a problem that needs to be further solved in the prior art.

Contents of the invention

In view of this, the embodiments of the present invention expect to provide an SDN controller and a switch management method, which at least partially solve the above problems.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The first aspect of this embodiment provides a software-defined network SDN controller, including:

Simple Network Management Protocol SNMP management unit, used to exchange information with the switch based on the SNMP protocol, and obtain the network topology from the switch;

The SNMP unit is also used to read the device status information obtained based on the SNMP from the switch;

The device status information includes port information and/or traffic statistics information.

Based on the above scheme, the SDN controller also includes:

a processing unit, configured to acquire a path switching policy and/or a congestion control policy, wherein the path switching policy or the congestion control policy is generated based on the port information and/or traffic statistics;

A sending unit, connected to the processing unit, configured to send the forwarding policy and/or the congestion control policy to the switch.

Based on the above solution, the sending unit is a unit supporting the openflow protocol, and is configured to send the path switching policy and/or congestion control policy to the switch by running an openflow plug-in.

Based on the above solution, the processing unit is configured to acquire the path switching strategy and/or the congestion control strategy when the average port bandwidth utilization rate is greater than a preset threshold.

Based on the above solution, the processing unit is specifically configured to receive a congestion alarm formed when the average bandwidth utilization of the port is greater than a preset threshold; when receiving the congestion alarm, automatically generate the path switching strategy and/or A congestion control strategy; or, when the congestion alarm is generated, outputting a switching prompt; and generating the path switching strategy and/or congestion control strategy based on an operation instruction formed by the switching prompt.

Based on the above solution, the SNMP unit is further configured to convert the device state information into display information supported by the presentation layer state RESTful protocol;

The SDN controller also includes:

an output unit, configured to connect with the SNMP unit, and output the display information.

Based on the above solution, the SNMP unit is further configured to convert the device state information into display information supported by the presentation layer state RESTful protocol, and send the display information to the display server; the display information is used for the The server is displayed.

Based on the above solution, the network topology includes connection paths between the switch and other devices;

The connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch.

The second aspect of the embodiment of the present invention provides a switch management method, including:

Exchanging information with the switch based on the simple network management protocol SNMP, so as to obtain the network topology from the switch;

Obtaining device status information from the switch based on the SNMP;

The device status information includes port information and/or traffic statistics information.

Based on the above scheme, the method also includes:

Obtaining a path switching policy and/or a congestion control policy, wherein the path switching policy or the congestion control policy is generated based on the port information and/or traffic statistics;

Sending the path switching policy and/or the congestion control policy to the switch.

Based on the above solution, the sending the path switching policy and/or the congestion control policy to the switch includes:

Send the path switching policy and/or congestion control policy to the switch by running an openflow plug-in supporting the OpenFlow protocol.

Based on the above solution, the sending the path switching policy and/or the congestion control policy to the switch includes:

When the average port bandwidth utilization is greater than a preset threshold, the path switching policy and/or congestion control policy is obtained.

Based on the above solution, when the average port bandwidth utilization is greater than a preset threshold, acquiring the path switching strategy and/or congestion control strategy includes:

receiving a congestion alarm formed when the average bandwidth utilization of the port is greater than a preset threshold;

When receiving the congestion warning, automatically generate the path switching strategy and/or congestion control strategy;

or,

When the congestion warning is generated, a switching prompt is output; and based on an operation instruction formed by the switching prompt, the path switching policy and/or congestion control policy is generated.

Based on the above scheme, the method also includes:

Converting the device status information into display information supported by the presentation layer status RESTful protocol;

Output the displayed information.

Based on the above scheme, the method also includes:

Converting the device status information into display information supported by the presentation layer status RESTful protocol;

Send the display information to a display server; the display information is used for display by the server.

Based on the above solution, the network topology includes connection paths between the switch and other devices;

The connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch.

The embodiment of the present invention is an SDN controller and a switch management method. The SDN controller will exchange information with the switch based on SNMP based on the SNMP protocol through the setting of the SNMP management unit, so as to obtain a network topology that complies with the SNMP protocol, thereby solving the problem of When the network topology is obtained according to the openflow protocol, the internal flow table of the switch is abnormal, and the network topology cannot be obtained normally.

Description of drawings

FIG. 1 is a schematic structural diagram of an SDN controller provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a network topology provided by an embodiment of the present invention;

FIG. 3 is a schematic flowchart of a switch management method provided by an embodiment of the present invention;

FIG. 4 is a schematic flowchart of another switch management method provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of another network topology provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of another network topology provided by an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, this embodiment provides a software-defined network SDN controller, including:

Simple Network Management Protocol SNMP management unit 110, configured to exchange information with the switch based on the SNMP protocol, and obtain the network topology from the switch;

The SNMP unit 110 is further configured to read, from the switch, device status information obtained based on the SNMP; wherein the device status information includes port information and/or traffic statistics information. .

This embodiment provides an SDN controller, and the SDN controller includes an SNMP management unit 110, where the SNMP management unit 110 manages switches based on SNMP. The SNMP management unit 110 can run SNMP plug-ins developed according to SNMP. The SNMP is an abbreviation of Simple Network Management Protocol. SNMP is used to exchange information with the switch, so that the data packets sent from the switch can be received based on SNMP, so as to obtain the network topology. The network topology information here is the connection link information between the switch and other devices. Usually, the switch can run a link layer discovery protocol (Link Layer Discovery Protocol, LLDP) to discover the network topology. In this embodiment, the switch will also run SNMP to exchange information with the SDN controller, so as to send the network topology obtained by using the LLDP protocol to the SDN controller in a data packet supported by SNMP. In this way, the forwarding of the network topology no longer depends on the flow table of the openflow protocol. Even if the flow table fails or is rewritten, the SDN controller can still obtain the network topology, so that the SDN controller can obtain the network topology according to the The network topology performs forwarding control of the switch, etc.

The SNMP management unit 110 can correspond to the processor and the communication port connected to the processor, the processor can run the SNMP plug-in, and the communication port can run the instructions generated by the SNMP plug-in based on the processor , and exchange information with the switch based on SNMP, and at least obtain the network topology.

In a specific implementation, the SDN controller may further include a processing unit, where the processing unit may correspond to a processor. The processor in this embodiment may include various forms of processors such as a central processing unit, a microprocessor, a digital signal processor, a programmable array, or an application processor. The processing circuitry may include an application specific integrated circuit. The processor or the processing circuit can realize the function of the above-mentioned SNMP unit or processing unit through the execution of predetermined instructions. In this embodiment, the processing unit may be used to perform operations such as information analysis and information output control.

The device status information may include: device software version information, device power-on running time, device name and location information, CPU usage rate of the central processing unit, resource usage rate of each process in the CPU, memory usage rate, power supply status, heat dissipation Fan running status and log information, etc., various information that can reflect the history and current running status of the switch device and/or port. Acquisition of such information is beneficial for the SDN controller to perform operations such as routing decisions. In this embodiment, the SNMP unit supported by SNMP obtains device status information based on SNMP. Compared with the device status information obtained by the openflow protocol that focuses on flow table forwarding, it has more types of device status information, and the amount of information is larger and more accurate. Comprehensive features.

Specifically, for example, the device status information includes port information and/or traffic statistics information. The port information may include port status information. The port state information may be used to represent at least one of port states such as whether the corresponding port is in a working state, idle or busy state, and whether it is in a normal state. In addition, the port information may also include port attribute information, and the port attribute information may include information representing port attributes such as Max Translation Unite (MTU) configuration information of the port, port bandwidth, and port transmission rate. The MTU configuration information can be used to limit the maximum packet length transmitted by the port each time.

The traffic statistics information may include statistics on the transmission of the port, may include statistics on the number of packets sent by the port, statistics on the amount of packet data, statistics on the number of packets of different lengths sent, and statistics on the number of packets of different lengths received. Redundancy check (Cyclic Redundancy Check, CRC) error packet statistics, packet loss statistics and other statistical information associated with traffic.

Through the acquisition of the device status information of these information, the SDN controller can determine whether traffic distribution and path switching are required according to the port status and traffic statistics. Therefore, in this embodiment, the SDN controller further includes: a processing unit 120, configured to acquire a path switching strategy and/or a congestion control strategy, wherein the path switching strategy or the congestion control strategy is based on the The port information and/or traffic statistics information is generated; the sending unit 130 is connected to the processing unit and configured to send the forwarding policy and/or the congestion control policy to the switch.

The processing unit 120 here may correspond to a processor or a processing circuit, and may determine at least one of a path switching strategy, a congestion control strategy, and a switching prompt according to port information and/or traffic statistics, and the path switching strategy is used to perform path switching. Switching, through path switching, traffic can be shunted, and some traffic on overly congested paths can be switched to relatively idle paths for forwarding, so as to achieve forwarding load balancing, reduce the phenomenon that some paths are congested, and some paths are idle, thereby improving overall Smooth network transmission and reduced delay. The congestion control strategy may be used for congestion control, and specifically may include a congestion control method, and the congestion control method may include a tail drop method, which relieves congestion by discarding tail data packets in a transmission queue. The congestion control method may also include a weighted random early detected (Weighted Random Early Detected, WRED) method, by adjusting the discarding threshold and packet loss rate of the WRED method, adjustment of congestion control, etc. may be realized.

The sending unit is a unit supporting the openflow protocol, and is used to send the path switching strategy and/or congestion control strategy to the switch by running an openflow plug-in.

The sending unit uses the openflow protocol to send the path switching strategy and/or congestion control strategy, in this case, the path switching strategy and/or congestion control strategy will be carried in the flow table and delivered in the form of flow table To the switch, in this case, when the switch executes the path switching strategy and/or the congestion control strategy, it only needs to query the flow table to perform the corresponding operation, which reduces the types of information that the switch queries, simplifies the work of the switch, and The existing technology has strong compatibility.

The processing unit 120 is configured to obtain the path switching policy and/or congestion control policy when the average port bandwidth utilization rate is greater than a preset threshold. For example, the processing unit 120 may be specifically configured to obtain the average port bandwidth utilization rate according to traffic statistics; and obtain the path switching strategy and/or congestion control strategy when the port bandwidth average utilization rate is greater than a preset threshold .

In this embodiment, the processing unit 120 may obtain the port average bandwidth utilization rate of the port according to traffic statistics. For example, divide the port traffic statistics by the port rate to obtain the port utilization. Then use the time sliding window to calculate the average bandwidth utilization rate within a predetermined period of time. The time sliding window is a time window with a certain time length, and the time window slides in the time dimension according to a preset step size. When the sliding time length reaches the predetermined time length, M port utilization rates will be obtained, and an average value of the M port utilization rates is calculated. The M is equal to dividing the predetermined duration by a preset step.

When the average bandwidth utilization rate of the port is greater than the preset threshold, it indicates that the current port is relatively congested, and it may be necessary to trigger generation of a path switching strategy or a congestion control strategy. In this embodiment, when the average port bandwidth utilization rate is greater than a preset threshold, at least one of the path switching policy and the congestion control policy will be generated.

In some embodiments, the port bandwidth average utilization rate may be automatically calculated and generated by the processing unit 120, or the processing unit 120 may send the port information and/or flow information to other devices, for example The web server is generated by other devices, and the processing unit 120 generates the path switching strategy or congestion control strategy according to the average port bandwidth utilization generated by other devices.

The processing unit 120 is specifically configured to receive a congestion alarm formed when the average port bandwidth utilization is greater than a preset threshold; when receiving the congestion alarm, automatically generate the path switching strategy and/or congestion control strategy , or when the congestion alarm is generated, outputting a switching prompt; and generating the path switching policy and/or congestion control policy based on the operation instruction formed by the switching prompt.

For example, the SDN controller reports the status information to the webpage WEB server, and the WEB server performs data processing, generates a congestion alarm when the average utilization rate of the port bandwidth is greater than a preset threshold, and sends the congestion alarm to The SDN controller, the SDN controller will generate the path switching strategy or the congestion control strategy according to the congestion alarm. In this embodiment, the processing unit 120 does not calculate the average utilization rate of the port bandwidth at all, but only stores it in a device such as a WEB server. There are many ways to generate the path switching strategy and/or congestion control strategy. For example, the SDN controller automatically generates based on built-in instructions; of course, the SDN controller can also output a congestion alarm and receive the administrator's manual The input switching instruction or control instruction, so as to generate the path switching strategy and/or congestion control strategy. Of course, the SDN controller can also locate an alternative path or an optimizable path when determining which path is congested according to the device state information, output a switching prompt, and then receive the information input by the administrator based on the switching prompt. an operation instruction, and finally generate the path switching strategy and/or the congestion control strategy according to the operation instruction.

The switching prompt includes prompting that the switch can forward the data packet on one of the paths through other paths or have other better alternative paths. After the SDN controller outputs the switching prompt, the manager will determine whether to accept the replacement after seeing it, and then input a corresponding operation instruction, so as to generate the path switching strategy or congestion control strategy.

In this embodiment, the SNMP unit 110 can also be used to convert the device state information into display information supported by the presentation layer state RESTful protocol; the SDN controller also includes:

an output unit, configured to connect with the SNMP unit 110, and output the display information.

In this implementation, the output unit may correspond to various display screens, and can display the display information, where the display information may be information that needs to be displayed to managers in the device status information. Specifically, for example, the output unit outputs the display information on a web page. Certainly, the output unit may also output the presentation information in an application interface of predetermined software.

In some implementations, the SNMP unit 110 is further configured to convert the device state information into display information supported by the presentation layer state RESTful protocol, and send the display information to the display server; the display information is used for The server is displayed. In this embodiment, the SDN controller itself does not directly output the presentation information, but sends the presentation information to the presentation server, and the presentation server outputs it. For example, the display server outputs through a webpage, and at this time, the display server may also be called a WEB server. Of course, during specific implementation, the SNMP unit 110 may send all device status information to the presentation server. In addition to displaying by the display server, it can be used to calculate the average utilization rate of the port bandwidth, and can also be used to generate the congestion alarm and other processing.

In some embodiments, the network topology includes connection paths between the switch and other devices;

The connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch.

In this embodiment, the network topology includes two connection ends of any connection, and includes the respective connection ports of the two connection ends. In this way, when locating a fault, the fault can be specifically located to the port and the device, thereby realizing Precise fault location.

In specific implementation, in order to simplify the representation of the network topology, an array may be used for representation. An array represents a connection, and an array includes two elements, and each element includes a device number and a port number.

Figure 2 is a network topology diagram of a local device and multiple other devices. The following is an example of using an array to represent the network topology shown in Figure 2:

[(Local device identification (Identity, ID), local device port number), (peer device ID_1, peer device port number)]

[(local device ID, local device port number), (peer device ID_2, peer device port number)]

[(local device ID, local device port number), (peer device ID_3, peer device port number)]

[(local device ID, local device port number), (peer device ID_4, peer device port number)].

As shown in Figure 3, this embodiment provides a switch management method, including:

Step S110: exchange information with the switch based on the Simple Network Management Protocol SNMP to obtain the network topology from the switch; step S120: obtain device status information from the switch based on the SNMP, wherein the device status information includes port information and/or traffic statistics.

The switch management method provided in this embodiment is an information processing method applied to an SDN controller. In the step S110 in this embodiment, the network topology information can be obtained from the switch based on the SNMP protocol by running the SNMP plug-in. In step S120, information may be exchanged with the switch based on SNMP to obtain device status information.

Here, obtaining the network topology of the id may include: the switch runs SNMP, encapsulates the network topology into a data packet based on SNMP, and sends the data packet to the SDN controller. In this case, the SDN controller will obtain the network topology encapsulated by SNMP , it is not necessary to obtain the network topology based on the openflow protocol, thereby avoiding the phenomenon that the network topology cannot be obtained when the internal flow table of the switch is abnormal.

In this embodiment, there is no certain sequence between step S110 and step S120, step S110 may be executed first as shown in FIG. 3 , and then step S120 may be executed. The step S110 and the step S120 may also be executed synchronously, or the step S120 and the step S110 may be executed first. During specific implementation, in order to reduce information interaction between the SDN controller and the switch, the network topology and the device status information are acquired from the switch together.

In this embodiment, the device status information is obtained from the switch through the SNMP. For details of the device status information here, reference may be made to the foregoing embodiments, and repeated descriptions will not be repeated here.

In a specific implementation process, the network topology and the device state information may be received by the SDN controller from the switch respectively, or may be received at the same time, as shown in Figure 4, in step S120 Synchronously receive the network status and port information and/or traffic statistics information.

Further, as shown in FIG. 4, the method further includes: Step S130: Obtaining a path switching strategy and/or a congestion control strategy, wherein the path switching strategy or the congestion control strategy is based on the port information and / or generated by traffic statistics;

Step S140: Deliver the path switching policy and/or the congestion control policy to the switch.

In this embodiment, the SDN controller can automatically generate a path switching policy or a congestion control policy, and send the path switching policy and/or congestion control policy to the switch, thereby controlling message forwarding and congestion control in the switch.

In some implementations, the step S140 may include:

Send the path switching policy and/or congestion control policy to the switch by running an openflow plug-in supporting the OpenFlow protocol.

In this embodiment, the openflow plug-in is used to issue the path switching strategy and/or congestion control strategy to the switch based on the openflow protocol, for example, in the form of a flow table, thereby reducing the type of information stored by the switch and facilitating the query by the switch The flow table can complete various operations related to forwarding and simplify the query operation of the switch.

In still some embodiments, the step S140 may include:

When the average port bandwidth utilization is greater than a preset threshold, the path switching policy and/or congestion control policy is obtained.

In this embodiment, the path switching policy and/or the congestion control policy are sent when the average port bandwidth utilization rate is greater than a preset threshold. The average port bandwidth utilization here can be obtained by averaging the port bandwidth utilization in multiple small time periods, or can be calculated by using the sliding time window as mentioned in the previous embodiment to improve the performance of port bandwidth utilization. rate accuracy.

In some embodiments, the step S140 may include:

receiving a congestion alarm formed when the average bandwidth utilization of the port is greater than a preset threshold;

When the congestion warning is received, automatically generate the path switching strategy and/or congestion control strategy; or, when the congestion warning is generated, output a switching prompt; and based on the operation instruction formed by the switching prompt, generate the The path switching strategy and/or the congestion control strategy.

In this embodiment, the SDN controller may send the device state information to a device such as a WEB server. The WEB server can calculate the average utilization rate of the port bandwidth, and when the average utilization rate of the port bandwidth is greater than a preset threshold, a congestion alarm is formed; and the congestion alarm is sent to the SDN controller, such SDN control The device can receive the congestion warning. When the SDN controller will automatically generate a path switching strategy and/or congestion control strategy, or output a switching prompt, the output of the switching prompt here will detect the operation instruction input by the manager based on the switching prompt, and based on the operation instruction , the path switching policy and/or congestion control policy may be generated.

In some embodiments, the method also includes:

Converting the device status information into display information supported by the presentation layer status RESTful protocol;

Output the display information.

In this embodiment, the SDN converts the device status information acquired by SNMP into display information supported by the RESTful protocol through protocol conversion, and outputs the display information. The output may be a display output or a voice output. For example, a web page is used to display the display information, which is convenient for managers to view.

In some embodiments, the method also includes:

Converting the device status information into display information supported by the presentation layer status RESTful protocol;

Send the display information to a display server; the display information is used for display by the server.

In this embodiment, the converted display information is sent to the display server, and is output by the display server for viewing by managers. The display server can output the display information through a webpage, so the display server can also be called a WEB server.

In some embodiments, the network topology includes a connection path between the switch and other devices; the connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch .

In this embodiment, the network topology will include: the device identifiers of the two connected devices and the connected port identifiers. In this way, which device is faulty and which port of the device is faulty can be located when fault location is performed. . The equipment here may include the aforementioned switch.

Several specific examples are provided below in conjunction with any of the above-mentioned embodiments:

Example one:

As shown in FIG. 5 , this example provides a network system, including: an openflow switch, an SDN controller connected to the openflow, and a WEB server connected to the SDN controller. The WEB server runs a WEB browser.

The SDN controller runs an openflow plug-in and an SNMP plug-in. The openflow switch runs LLDP and SNMP, thereby obtaining network topology and device status information, and reporting the network topology and device status information to the SNMP plug-in, and the SNMP plug-in implements the SNMP-to-RESTful protocol corresponding to the data conversion, and send the converted data to the WEB server, and the WEB server controls the WEB browser to display corresponding information based on the hypertext transfer protocol http. The SNMP plug-in is connected with the openflow plug-in, and sends the path switching strategy or instruction and the congestion control strategy or instruction to the openflow switch in the form of a flow table according to the openflow protocol.

Example two:

This example proposes a switch management method based on the network system provided in Example 1, including:

The first step: openflow switch network topology implementation

Step 1: Open LLDP and SNMP on the Openflow switch;

Step 2: the SDN controller reads the information of the openflow switch through SNMP, and the read information includes: (1) the local device identification (Identity, ID) of the openflow switch; (2) the port number of the local device; (3) the connection with the local device IDs of all connected peer devices; (4) port numbers of all peer devices; the read information is formed into an array in the format of [(local ID, local port number), (peer ID, peer port number)].

Step 2: Device status information monitoring. Basic device information monitoring is to monitor each device in the topology. The basic device status information obtained from monitoring can include: device software version information, device power-on running time, device name and location information , CPU resource usage of each process, memory usage, switch power module working status, switch cooling fan running status, log information, etc.

The information is passed to the WEB server through the RESTful interface, and finally presented on the WEB page.

The device status information monitoring may also include: device port monitoring and flow analysis. Device port monitoring is to monitor the status and traffic of all ports of all devices in the network topology. The monitored port information includes: port online/offline status, port MTU configuration, statistics on the number of packets of different lengths sent by the port, and different lengths received by the port. Statistics on the number of packets, CRC error packets, and lost packets, etc.

Step 3: Carry out congestion warning and forwarding path switching according to the monitored information.

Congestion alarm and forwarding path switching may include the following steps:

The WEB server obtains the port packet count of the openflow switch through SNMP, and then divides it by the port rate to obtain the port bandwidth utilization:

The WEB server uses the sliding window method to count the average port bandwidth utilization rate for a certain period of time;

Set the bandwidth utilization rate alarm threshold. When the average bandwidth utilization rate exceeds the threshold value, an SNMP alarm is triggered and reported to the SDN controller;

The SDN controller gets an alarm and displays it on the WEB network management interface through the RESTful interface;

At the same time, the SDN controller re-delivers the flow table through the openflow protocol to realize forwarding path switching.

Figure 6 shows a network topology diagram of a switch, including switch 1 to switch 7 in Figure 6, switch 1 is connected to switch 3 to form path A, switch 1 is connected to switch 6 to form path B; switch 3 is connected to switch 4 respectively It is connected with switch 5 to form path C and path D; switch 6 is connected with switch 7, and switch 7 is connected with switch and 2. Wherein, the dotted-line path indicates a busy path, and the solid-line path indicates a non-busy path.

Combined with the network topology shown in Figure 6, an example of path switching is provided:

On switch 1, there are two paths to switch 2, which are path A and path B; on switch 3, there are also two paths to switch 2, which are path C and path D; the flow table on openflow switch 1 There are two matches with different priorities in , for example, path A is higher than path B, and path C is higher than path D.

When the SDN controller obtains that the average bandwidth utilization of a certain link exceeds the set threshold, it triggers an alarm and displays it on the WEB page to notify the user. At the same time, the SDN controller reconfigures the flow table through the openflow plug-in. The configuration and delivery methods of the flow table can include the following two methods:

The flow table is automatically issued: when a congestion alarm occurs on port A of switch 1, a new flow table is automatically configured to switch the traffic to port B without manual confirmation; similarly, when a congestion alarm occurs on port C of switch 3, the forwarding is automatically switched Path to port D. The B port connection here forms the aforementioned path B, the C port connection forms the path C, and the D port connection forms the path D.

Manual distribution of flow tables: When a congestion alarm occurs on a certain path, the SDN controller does not automatically distribute it, but prompts that there is a preferred path or an alternative path, allowing the operation and maintenance personnel to choose whether to switch according to the actual network situation, and download it again. Send flow table.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods may be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or May be integrated into another system, or some features may be ignored, or not implemented. In addition, the coupling, or direct coupling, or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical or other forms of.

The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units; Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention can be integrated into one processing module, or each unit can be used as a single unit, or two or more units can be integrated into one unit; the above-mentioned integration The unit can be realized in the form of hardware or in the form of hardware plus software functional unit.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the Including the steps of the foregoing method embodiments; and the foregoing storage medium includes: a removable storage device, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, etc. A medium on which program code can be stored.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (16)

1. A software-defined network SDN controller, characterized in that, comprising: Simple Network Management Protocol SNMP management unit, used to exchange information with the switch based on the SNMP protocol, and obtain the network topology from the switch; The SNMP unit is further configured to read, from the switch, device status information obtained based on the SNMP; wherein the device status information includes port information and/or traffic statistics information. 2. The SDN controller according to claim 1, characterized in that, The SDN controller also includes: a processing unit, configured to acquire a path switching policy and/or a congestion control policy, wherein the path switching policy or the congestion control policy is generated based on the port information and/or traffic statistics; A sending unit, connected to the processing unit, configured to send the forwarding policy and/or the congestion control policy to the switch. 3. The SDN controller according to claim 2, characterized in that, The sending unit is a unit supporting the openflow protocol, and is used to send the path switching strategy and/or congestion control strategy to the switch by running an openflow plug-in. 4. The SDN controller according to claim 2, characterized in that, The processing unit is configured to obtain the path switching policy and/or congestion control policy when the average port bandwidth utilization rate is greater than a preset threshold. 5. The SDN controller according to claim 4, characterized in that, The processing unit is specifically configured to receive a congestion alarm formed when the average port bandwidth utilization is greater than a preset threshold; when receiving the congestion alarm, automatically generate the path switching strategy and/or congestion control strategy; Or, when the congestion alarm is generated, outputting a switching prompt; and generating the path switching policy and/or congestion control policy based on an operation instruction formed by the switching prompt. 6. The SDN controller according to claim 1, characterized in that, The SNMP unit is also used to convert the device state information into display information supported by the presentation layer state RESTful protocol; The SDN controller also includes: an output unit, configured to connect with the SNMP unit, and output the display information. 7. The SDN controller according to claim 1, characterized in that, The SNMP unit is further configured to convert the device state information into display information supported by the presentation layer state RESTful protocol, and send the display information to a display server; the display information is used for display by the server. 8. The SDN controller according to claim 1, characterized in that, The network topology includes connection paths between the switch and other devices; The connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch. 9. A switch management method, characterized in that, comprising: Exchanging information with the switch based on the simple network management protocol SNMP, so as to obtain the network topology from the switch; Obtain device status information from the switch based on the SNMP, where the device status information includes port information and/or traffic statistics information. 10. The method according to claim 9, further comprising: Obtaining a path switching policy and/or a congestion control policy, wherein the path switching policy or the congestion control policy is generated based on the port information and/or traffic statistics; Sending the path switching policy and/or the congestion control policy to the switch. 11. The method of claim 10, wherein, The sending the path switching policy and/or the congestion control policy to the switch includes: Send the path switching policy and/or congestion control policy to the switch by running an openflow plug-in supporting the OpenFlow protocol. 12. The method of claim 10, wherein, The sending the path switching policy and/or the congestion control policy to the switch includes: When the average port bandwidth utilization is greater than a preset threshold, the path switching policy and/or congestion control policy is obtained. 13. The method of claim 10, wherein, The acquiring the path switching strategy and/or congestion control strategy when the average port bandwidth utilization is greater than a preset threshold includes: receiving a congestion alarm formed when the average bandwidth utilization of the port is greater than a preset threshold; When receiving the congestion warning, automatically generate the path switching strategy and/or congestion control strategy; or, When the congestion warning is generated, a switching prompt is output; and based on an operation instruction formed by the switching prompt, the path switching policy and/or congestion control policy is generated. 14. The method of claim 10, wherein, The method also includes: Converting the device status information into display information supported by the presentation layer status RESTful protocol; Output the displayed information. 15. The method of claim 10, wherein, The method also includes: Converting the device status information into display information supported by the presentation layer status RESTful protocol; Send the display information to a display server; the display information is used for display by the server. 16. The method of claim 9, wherein, The network topology includes connection paths between the switch and other devices; The connection path includes a local device identifier, a local connection port, a peer device identifier, and a peer device port identifier of the switch.