CN105656799A - Scheduling method based on business features in SDN network - Google Patents

Abstract

The invention discloses a scheduling method based on business features in an SDN network, and belongs to the technical field of communication. Balancing the loads of communication links is taken as a target; forwarding paths are adjusted through comparing the bandwidth utilization rates of the links; the target of rationally using the network resources is realized; rational priorities are designed for the business requests according to the QoS features of the business requests; high utilization rates of the system resources are ensured; moreover, better experience degrees are provided for a user; and the quality of service of the user is improved.

Description

A scheduling method based on service characteristics in SDN network

technical field

The invention discloses a scheduling method based on service characteristics under an SDN network, belonging to the technical field of communication.

Background technique

SDN, Software Defined Networking, software-defined network, is a new network innovation architecture of Emulex network and a way to realize network virtualization. Its core technology, OpenFlow, realizes network traffic by separating the control plane and data plane of network equipment. The flexible control of the network makes the network more intelligent as a pipeline. SDN mainly includes SDN controllers and OverFlow switches. As an operating system of the network, the SDN controller is responsible for management, policy formulation, etc., so as to ensure the intelligence of the network. The OverFlow switch is responsible for reporting link status and forwarding service data packets. However, the traffic transmission between the networks is very large, and the utilization rate of the links connecting the switches is often unbalanced. Improper system scheduling will bring serious pressure on link bandwidth expansion. The existing resource allocation methods mainly use the network Use optimization theory to analyze the overall situation, such as minimizing the communication link load and maximizing resource utilization as the goal. However, from the user's point of view, different services have different service quality requirements. However, the present invention provides a scheduling method based on service characteristics under an SDN network, aiming at balancing the communication link load, adjusting the forwarding path by comparing the bandwidth utilization rate of the link, and achieving the goal of rationally using network resources. QoS features, design a reasonable priority for it, ensure high utilization of system resources, and provide users with better experience and improve user service quality.

Contents of the invention

The present invention provides a scheduling method based on service characteristics in an SDN network. According to the QoS requirements of different services, a reasonable priority is designed for user service requests, so as to provide better user experience; at the same time, the link bandwidth load in the system Balanced as the goal, by comparing the utilization rate of the link bandwidth, while considering the switching delay, dynamically adjust the forwarding path, to achieve the purpose of rational use of network resources.

The concrete scheme that the present invention proposes is:

A scheduling method based on service characteristics in an SDN network:

According to the QoS characteristics of user service requests, classify them and set priorities for different types of services;

Arrange user service requests in order of priority and submit them to SDN network switches for processing;

The switch reports service queue information and link state information to the SDN controller in real time. The SDN controller weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission link for each service. Develop a distribution flow table;

According to the flow table issued by the SDN controller, the switch finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet.

According to the QoS characteristics of user service requests, it is classified, and priorities are established for different types of services. The priorities are used to represent the weight of each type of service, which is affected by the dynamic adjustment factor and is performed by increasing or decreasing the dynamic adjustment factor. Scheduling for sending business requests.

According to the delay constraints in the QoS characteristics of user service requests, classify them, and formulate priorities for different types of services, then the weight of each type of service is expressed as the priority is proportional to the dynamic adjustment factor, and is proportional to the maximum value of each type of service Latency is inversely proportional.

The specific process for the SDN controller to formulate and deliver the flow table is: the SDN controller first formulates forwarding strategies for it according to the level of business priority, and then selects multiple transmission paths for it according to the requirements of the destination address of the business data packet, satisfying If the average link bandwidth utilization rate in the selected path is less than the set threshold, the path with the least number of exchanges in the path is selected to determine the delivery of the flow table.

If the forwarding of the corresponding service data packet is unsuccessful, the switch will feed back the information to the SDN controller, request a new forwarding flow table, and apply for a new forwarding path.

After the forwarding of the corresponding service data packets is successful, the cache information of the service queue is updated, and at the same time, the switch reports the utilization rate of the specific link to the SDN controller.

A scheduling system based on service characteristics under an SDN network, applied to the method, including a service management module, a service queue, a switch module, and an SDN controller module,

The service management module classifies user service requests according to their QoS characteristics, and sets priorities for different types of services;

The service queue arranges user service requests in order of priority and submits them to the SDN network switch module for processing;

The switch module reports service queue information and link state information to the SDN controller module in real time. The SDN controller module weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission for each service. link, formulate the delivery flow table;

The switch module sends the flow table according to the SDN controller module, finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet.

The benefits of the present invention are:

The present invention provides a scheduling method based on service characteristics under an SDN network, aiming at balancing the communication link load, adjusting the forwarding path by comparing the bandwidth utilization rate of the link, and achieving the goal of rationally using network resources. The QoS feature is designed with a reasonable priority to ensure high utilization of system resources while providing users with better experience and improving user service quality.

Description of drawings

Fig. 1 schematic diagram of system framework of the present invention;

Fig. 2 schematic flow chart of the method of the present invention.

detailed description

A scheduling system based on service characteristics under an SDN network, applied to the method, including a service management module, a service queue, a switch module, and an SDN controller module,

The service management module classifies user service requests according to their QoS characteristics, and sets priorities for different types of services;

The service queue arranges user service requests in order of priority and submits them to the SDN network switch module for processing;

The switch module reports service queue information and link state information to the SDN controller module in real time. The SDN controller module weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission for each service. link, formulate the delivery flow table;

The switch module sends the flow table according to the SDN controller module, finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet.

A scheduling method based on service characteristics in an SDN network:

According to the QoS characteristics of user service requests, classify them and set priorities for different types of services;

Arrange user service requests in order of priority and submit them to SDN network switches for processing;

The switch reports service queue information and link state information to the SDN controller in real time. The SDN controller weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission link for each service. Develop a distribution flow table;

According to the flow table issued by the SDN controller, the switch finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet.

The present invention will be further described by using the above-mentioned system, method and content of the invention in conjunction with the accompanying drawings.

(1) The service management module divides the service requests currently waiting for processing into K categories according to the delay constraints in the QoS characteristics, and sets the priority ω _k for each category, and T _k,max represents the tolerable service of the kth category The maximum delay, the weight of each type of business is expressed as ω _k = α/T _k,max , where α represents the dynamic adjustment factor;

If the link is congested, reduce the value of α to reduce the priority of the business submitted later, and let the data in the front of the business queue be transmitted first, so as to avoid too long waiting time;

Since the maximum delay of the business is preset, if a certain type of business needs to increase the transmission within a certain period of time, the value of α can be increased for flexible scheduling;

(2) The business queue uses the proportional fairness algorithm to report the user request to the switch module according to the reported business priority, for example, the average waiting delay in the statistical time slot t Then the transmission priority of the corresponding service is expressed as ${\mathrm{\ω}}_t={\mathrm{\ω}}_t/\stackrel{\‾}{T};$

(3) The switch module submits the collected business queue information to the SDN controller module, and at the same time obtains the bandwidth utilization γ _i,t-1 of the i-th link in the last time slot t-1 through network traffic sampling, and reports it to SDN controller;

(4) The SDN control module aims at balancing the link bandwidth, and formulates a forwarding flow table, wherein;

According to the level of business priority, formulate forwarding strategies for them in turn, and select N forwarding paths for each business request according to the requirements of the destination address of the business data packet. If the path n contains M switch nodes, and the link bandwidth can The upper limit of the average utilization rate to bear is γ _th , then the selected path needs to satisfy Where γ _i,t-1 represents the bandwidth utilization rate of link i in the last time slot t-1;

If the bandwidth utilization rate of the link connected to the switch m is higher than the set threshold γ _th in the t-1 time slot, avoid the switch m when selecting the forwarding path;

In order to reduce the switching delay, a scheme with a small number of switches in the transmission path is selected when formulating the flow table;

(5) The switch module forwards the corresponding service data packet according to the issued flow table, wherein;

If the requirements of the flow table can be met, the service data packet is forwarded to the corresponding switch; if the forwarding is unsuccessful, an error message is fed back to the SDN controller and the type of error occurs, and a new forwarding path is applied for;

After the service data packet is successfully forwarded, the service queue is notified to update the cache information, and at the same time, the utilization rate γ _i,t of the i-th link in the time slot t is reported to the SDN controller.

Using the above method, according to the QoS characteristics of the service request, design a reasonable priority for it, aim at balancing the communication link load, and adjust the forwarding path by comparing the bandwidth utilization rate of the link, so as to achieve the goal of rational use of network resources and improve Quality of service for users.

Claims (7)

1. A scheduling method based on service characteristics under an SDN network, characterized in that According to the QoS characteristics of user service requests, classify them and set priorities for different types of services; Arrange user service requests in order of priority and submit them to SDN network switches for processing; The switch reports service queue information and link state information to the SDN controller in real time. The SDN controller weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission link for each service. Develop a distribution flow table; According to the flow table issued by the SDN controller, the switch finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet. 2. The method according to claim 1, characterized in that according to the QoS characteristics of user service requests, it is classified, and priorities are formulated for different types of services, and the priorities are used to represent the weight of each type of service, subject to dynamic adjustment factors Influence, by increasing or decreasing the dynamic adjustment factor to schedule the sending of service requests. 3. The method according to claim 2, wherein it is characterized in that it is classified according to the delay constraint in the QoS characteristic of the user service request, and the priority is formulated for different types of services, and then the weight of each type of service is expressed as priority and dynamic The adjustment factor is directly proportional to and inversely proportional to the maximum delay of each type of business. 4. The method according to any one of claims 1-3, characterized in that the specific process of the SDN controller formulating the delivery flow table is: the SDN controller first formulates forwarding strategies for it according to the level of business priority , and then select multiple transmission paths for it according to the requirements of the destination address of the service data packet, satisfying that the average link bandwidth utilization rate in the selected path is less than the set threshold, select the path with the least number of exchanges in the path, and determine the delivery flow surface. 5. The method according to claim 4, characterized in that if the corresponding service data packets are not sent successfully, then the switch feeds back information to the SDN controller, and requests a new forwarding flow table, and applies for a new forwarding path. 6. The method according to claim 5, characterized in that after the forwarding of the corresponding service data packet is successful, the service queue buffer information is updated, and the switch reports the utilization rate of the specific link to the SDN controller at the same time. 7. A scheduling system based on service characteristics under an SDN network, characterized in that it is applied to the method described in any one of 1-6, including a service management module, a service queue, a switch module, an SDN controller module, The service management module classifies user service requests according to their QoS characteristics, and sets priorities for different types of services; The service queue arranges user service requests in order of priority and submits them to the SDN network switch module for processing; The switch module reports service queue information and link state information to the SDN controller module in real time. The SDN controller module weighs the priority of service requests and link state information based on the goal of network bandwidth load balancing, and selects the optimal transmission for each service. link, formulate the delivery flow table; The switch module sends the flow table according to the SDN controller module, finds a switch that meets the scheduling target in the available switching network, and forwards the corresponding service data packet.