KR20140052847A - Method and apparatus for providing quality of service in software defiend neworking network - Google Patents

Abstract

Disclosed are a method for providing a quality of service (QoS) in a software-defined networking based network and an apparatus thereof. The method for providing the QoS comprises the steps of searching for forwarding information and QoS rule information corresponding to a first packet of a received predetermined flow in a forwarding table and a QoS rule table, respectively; transmitting the packet to a controller if the forwarding information and the QoS rule information do not exist in the forwarding table and the QoS rule table; and generating a flow entry corresponding to the packet in a flow learning table based on the forwarding information and the QoS rule information that are received from the controller, thereby efficiently providing the QoS.

Description

[0001] METHOD AND APPARATUS FOR PROVIDING QUALITY OF SERVICE IN SOFTWARE DEFIEND NEWORKING NETWORK [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to software defined networking technology, and more particularly, to a method and apparatus for providing a service quality that can be applied to a software defined networking based network.

In a general network, one device in which the functions of a control plane and a data plane are integrated functions as a network element, and these network devices are distributed to constitute a whole network, The control protocol is exchanged to determine the forwarding of the traffic, so that the complexity of the network device is high. In addition, since the interior of each network device is configured using the proprietary technology of the manufacturer and is mostly not disclosed, There has been a problem in that it is entirely dependent on the manufacturer to improve the function.

OpneFlow technology transforms existing closed networking technologies as described above into open networking technologies, providing a foundation for new network technology advancements. Open flow technology separates the packet forwarding and control functions of a network switch (or router) and provides a standardized protocol for communication between these two functions so that the software driven by the external control device can communicate with the device manufacturer Thereby enabling packet path determination within the switch.

On the other hand, the Open Networking Foundation (ONF), established to facilitate the use and standardization of open-flow technology, has defined software-defined networking (SDN) technology based on open-flow technology.

SDN technology separates the control plane and the data plane, placing most of the intelligence in the control plane of the SDN controller, and network devices such as switches or routers, the rules that the control plane provides in flow units through standardized protocols such as open- It is possible to fundamentally solve the network cost and complexity by having a simple structure for processing packets according to the network and to fundamentally change the hardware and software technology of the existing networking technology.

However, since the SDN network carries out all the control functions in the centralized SDN controller as described above, when the quality of service (QoS) is provided for the packets coming into the network device, all the rules are transmitted from the SDN controller , Which not only increases the traffic between the SDN controller and the network device but also increases the processing load of the SDN controller.

SUMMARY OF THE INVENTION An object of the present invention is to provide a service quality providing method capable of efficiently providing a service quality in a software defined networking-based network.

Another object of the present invention is to provide a service quality providing apparatus for executing the service quality providing method.

Other objects and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which: FIG.

According to an aspect of the present invention, there is provided a method of providing quality of service performed at an arbitrary node in a network, the method comprising: receiving a first packet of a predetermined flow; (QoS) rule corresponding to a packet in a forwarding table and a QoS rule table, and if the forwarding information and the QoS rule information do not exist in the forwarding table and the QoS rule table, And generating a flow entry corresponding to the packet in the flow learning table based on the forwarding information and the QoS rule information received from the controller.

Here, the unit of the forwarding information and the QoS rule information received from the controller and the unit of the flow entry generated in the flow learning table may be configured differently.

Wherein generating the flow entry may generate a microflow entry.

According to another aspect of the present invention, there is provided a method of providing quality of service performed at an arbitrary node in a network, the method comprising the steps of: Searching for forwarding information and QoS rule information corresponding to the packet in the forwarding table and the QoS rule table, if the flow information does not exist in the flow learning table; Obtaining at least one piece of information that does not exist if at least one of the forwarding table and the QoS rule table does not exist from the controller and information obtained from at least one of the forwarding table and the QoS rule table And a controller Using at least one of the information includes the step of learning the learning table flow.

Here, if the forwarding information and the QoS rule information are respectively present in the forwarding table and the QoS rule table, the service quality providing method may include forwarding information and QoS rule information to be applied to the packet from the forwarding table and the QoS rule table, Learning the flow learning table using the acquired forwarding information and the QoS rule information, and processing the packet using the acquired forwarding information and the QoS rule information .

The step of acquiring the at least one non-existent information from the controller includes the step of, when the forwarding information exists in the forwarding table but the QoS rule information does not exist in the QoS rule table, The method comprising the steps of: sending a message requesting update of the QoS rule information provided from the controller, learning the flow learning table using QoS rule information provided from the controller and forwarding information acquired from the forwarding table, And processing the packet based on the forwarding information obtained from the table.

The step of acquiring the at least one non-existent information from the controller includes the step of, when the forwarding information is not present in the forwarding table and the QoS rule information is present in the QoS rule table, Learning the flow learning table using forwarding information provided from the controller and QoS rule information acquired from the QoS rule table, and transmitting the forwarding information and the QoS And processing the packet based on the QoS rule information obtained from the rule table.

The step of acquiring the at least one non-existent information from the controller includes the step of, when the forwarding information is not present in the forwarding table and the QoS rule information is not present in the QoS rule table, Transmitting a message requesting the update of the QoS rules, learning the flow learning table using the forwarding information and the QoS rule information provided from the controller, and transmitting the forwarding information provided from the controller and the QoS rules And processing the packet based on the information.

Here, the service quality providing method may include calculating a packet arrival interval for each packet flowing in each flow, and including the calculated packet arrival interval information in a header of the packet, And forwarding the packet to another node. The step of forwarding a packet including the packet arrival interval information to another node may further include the step of transmitting an SDN (IP) packet between the MAC (Medium Access Control) header of the IP packet and the IP header when the packet is an IP Software Defined Networking) header, and may include the packet arrival interval information in the SDN header.

The method of providing service quality may further include comparing an arrival time of a packet flowing in each flow with an estimated arrival time calculated with respect to a flow of the packet, and if the arrival time of the packet is earlier than the expected arrival time, Transmitting a message indicating that a traffic explosion has occurred in the flow of the packet. The step of comparing the arrival time of the packet flowing in each flow with the estimated arrival time calculated for the flow of the packet may include comparing the arrival time of the packet based on the packet arrival interval information included in the header of the packet, And compare the arrival time of the packet with the expected arrival time.

According to another aspect of the present invention, there is provided a service quality providing apparatus including a forwarding table including packet forwarding information, a QoS rule table including QoS rule information to be applied to the packet, A forwarding table and a flow learning table that is learned based on the QoS rule information; and a packet processing unit for applying QoS to the forwarded packets and the incoming packets based on the information stored in the storage unit .

Here, the packet processor receives the first packet of the predetermined flow, searches the forwarding table and the QoS rule table for the forwarding information and the QoS rule corresponding to the packet, respectively, and transmits the forwarding information and QoS If the rule information does not exist, the packet can be transmitted to the controller, and then the flow entry corresponding to the packet can be generated in the flow learning table based on the forwarding information and the QoS rule information received from the controller.

Here, the packet processor searches for the flow information corresponding to the received packet in the flow learning table, and when the flow information does not exist in the flow study table, the packet processing unit searches forwarding information and QoS rule information corresponding to the received packet A forwarding table and a QoS rule table, and if at least one of the forwarding information and the QoS rule information does not exist in the forwarding table and the QoS rule table, at least one information that does not exist is acquired from the controller The flow learning table can be learned using at least one of information obtained from at least one of the forwarding table and the QoS rule table and information acquired from the controller.

According to the method and apparatus for providing service quality in a software defined networking based network as described above, each node separately manages packet forwarding information and QoS rule information using a flow learning table, a forwarding table, and a QoS rule table, By using the forwarding information and the QoS rule information to learn the flow learning table and using it for packet forwarding and QoS application, it is possible to provide QoS on a microflow basis.

Also, in the present invention, by reducing the number of messages exchanged between each node and the controller using the flow learning table, the overall network performance can be improved and the scalability can be provided to the SDN network.

1 is a conceptual diagram showing a flow processing method of an SDN-based network.
2 is a conceptual diagram for explaining a QoS providing method according to an embodiment of the present invention.
3 is a flowchart illustrating an entry generation process of a flow learning table in an SDN-based network according to an exemplary embodiment of the present invention.
4 is a flowchart illustrating a QoS providing method performed in each node in an SDN-based network according to an embodiment of the present invention.
5 is a flowchart showing a processing method of Case 1 shown in Fig.
6 is a flowchart showing a processing method of Case 2 shown in Fig.
7 is a flowchart showing a processing method of Case 3 shown in Fig.
8 is a flowchart showing a processing method of Case 4 shown in Fig.
9 is a conceptual diagram for explaining a QoS providing method according to an embodiment of the present invention.
10 is a block diagram showing a configuration of an apparatus for executing a method for providing a service quality according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

1 is a conceptual diagram illustrating a flow processing method in an SDN-based network.

Referring to FIG. 1, an SDN-based network may include a controller 110 and a plurality of nodes 130.

Each node 130 may be configured as a network device for substantially forwarding traffic, such as a switch or a router, and may include various kinds of flow tables 131.

Each node 130 searches the flow table corresponding to the first packet to process the first packet for each flow.

When the node 130 is not registered in the flow table in the rule corresponding to the first packet received, the node 130 transmits all or a part of the first packet to the controller 110 in the form of a message, (Rule) for the flow table of the first packet. Here, the flow refers to a set of packets having a Transmission Control Protocol (TCP) connection, a specific Medium Access Control (MAC) or Internet Protocol (IP) address, and the same VLAN (Virtual Local Area Network) value.

(IP source address, IP destination address, protocol, TCP / UDP source port number, TCP / UDP destination port number) of the IP header at the time of processing the IP packet at each node 130 When it is necessary to provide quality of service (QoS) such as bandwidth control for each microflow, the node 130 transmits a packet to the controller 110 for N microflows as shown in Figure 1, N < / RTI > rules for controller < RTI ID = 0.0 > 110. < / RTI > In this case, not only the number of messages transmitted to the controller 110 increases but also the number of rules is increased by the number of microflows.

In order to solve the above problems, the present invention provides a method for effectively providing QoS by using forwarding table, QoS rule table and flow learning table in each node in an SDN-based network.

2 is a conceptual diagram for explaining a QoS providing method according to an embodiment of the present invention.

Referring to FIG. 2, in the QoS providing method according to an embodiment of the present invention, each node 230 constitutes a flow learning table 231, a forwarding table 233, and a QoS rule table 235.

That is, each node 230 separates the forwarding information and the QoS rule information into a forwarding table 233 and a QoS rule table 235 instead of a flow table in which existing forwarding information and QoS information are mixed, and separately manages the forwarding information and the QoS rule information And the flow learning table 231 that learns and maintains the flow forwarding and QoS rule information for each microflow is managed to reduce the number of messages exchanged with the controller 210, Forwarding and QoS can be provided.

The flow learning table 231 generally includes a 5-tuple field (for example, an IP source address, an IP destination address, a protocol, a TCP / UDP source port number, a TCP / UDP destination Port number) based on a hash table (hash table) can be configured to manage each microflow dynamically. However, the method for classifying the microflows in the flow learning table 231 is not limited to the hash table, and other types of tables such as a tree structure can be used. In addition, the information used for classifying the microflows in the flow learning table 231 is not limited to the 5-tuple separator of the IP packet header, and other fields other than the 5-tuple information may be additionally considered, You can also configure the tuple to not use any fields.

In the present invention, each node 230 manages the forwarding information and the QoS rule information by using separate tables 233 and 235, which is an advantage that the forwarding providing unit and the QoS providing unit can be clearly distinguished and applied to provide. In addition, in the present invention, each node 230 separately performs QoS learning for each microflow overcomes the disadvantage that forwarding and QoS information providing units are tightly coupled with QoS management and state management units in the conventional packet processing method And provides an advantage that the unit for providing the forwarding information or the QoS rule information and the unit for the actual QoS and the status management can be provided differently.

For example, according to the embodiment of the present invention, the forwarding information and the QoS rule information are provided in larger units, while the actual QoS and the state management unit can be provided in units of microflows.

FIG. 3 is a flowchart illustrating an entry generation process of a flow learning table in an SDN-based network according to an exemplary embodiment of the present invention. FIG. 3 illustrates an operation performed by a node when a first packet of each flow is input to a node.

Referring to FIG. 3, when a first packet of each flow is inputted to an arbitrary node (S301), the node searches the forwarding table and the QoS rule table to obtain forwarding information and QoS rule information of the first packet (S303 ).

The node searches the forwarding table and the QoS rule table to determine whether the corresponding information exists in the tables. If it is determined that the forwarding information and the QoS rule information do not exist, Th packet (S305).

Thereafter, the node receives the information about the forwarding table and the QoS rule table from the controller (S307), and creates an entry for the corresponding microflow in the flow learning table based on the received information (S309). At this time, as described above, the units of the forwarding information, the units of the QoS rule information, and the units of the flow learning table may be different from each other. For example, the forwarding information may be given in IP destination address units, the QoS rule unit may be given in units of differentiated service code points (DSCP), and the flow learning table may be managed for each microflow.

Therefore, if the IP destination address of the packet is the same but the value of the field other than the IP destination address in the 5-tuple is different, the QoS rule information for the DSCP value can be managed with different microflows. So that the total or DSCP of the traffic can be applied to each individual flow having the same value. For example, the QoS rule information may define a bandwidth limit for the sum of all traffic with DSCP 10 for DSCP 10 or a bandwidth limit for individual microflows for DSCP 10.

On the other hand, the packets included in the same flow after the above process for the first packet of an arbitrary flow are forwarded according to the information because forwarding information and QoS rule information are already learned in the flow learning table.

4 is a flowchart illustrating a QoS providing method performed in each node in an SDN-based network according to an embodiment of the present invention.

Referring to FIG. 4, when a packet is input to the node through the external interface (S401), the node generates a hash value for distinguishing the flow corresponding to the incoming packet (S403). Here, the key value (or hash value) for the hash is generally considered to use the 5-tuple information included in the header of the packet in order to classify the microflow, but the granularity may vary depending on the situation Or a wider unit, and for this purpose, fields of the packet header can be added or deleted. In addition, various functions such as CRC-32 and the like can be used as the hash function, and it is not limited to a specific function. The present invention does not define the use of a particular hash function.

After generating a hash value, the node first searches for a flow corresponding to the incoming packet in the flow learning table using the generated hash value (S405), and determines whether there is a flow corresponding to the incoming packet (S407 ). Here, when the incoming packet is the first packet of an arbitrary flow, there is no flow corresponding to the packet flowing into the flow learning table.

If it is determined in step S407 that there is no flow corresponding to the incoming packet, the node searches the forwarding table and the QoS rule table for the forwarding information and the QoS rule corresponding to the incoming packet, respectively (S409). Or if there is a flow corresponding to the incoming packet in step S407, the node acquires forwarding information and QoS information from the flow and processes the packet according to the obtained information (S415).

Thereafter, the node determines whether the forwarding information and the QoS information corresponding to the incoming packet exist (S411). Here, the following four cases may exist according to the determination result, and the node performs packet processing corresponding thereto (S413).

Case 1) Forwarding information is included in forwarding table, and QoS rule information exists in QoS rule table.

Case 2) The forwarding table contains forwarding information but there is no corresponding QoS rule information in the QoS rules table.

Case 3) There is no forwarding information in forwarding table, but QoS rule information exists in QoS rule table.

4) There is no forwarding information in the forwarding table, and there is no QoS rule information in the QoS rules table.

Hereinafter, a method of processing a node for each of the four cases shown in FIG. 4 will be described with reference to FIGS. 5 to 8. FIG.

5 is a flowchart showing a processing method of Case 1 shown in Fig.

Referring to FIG. 5, Case 1 means that packet forwarding information exists in the forwarding table and QoS rule information of the packet exists in the QoS rule table. Therefore, the node transmits forwarding information of the packet from the forwarding table and the QoS rule table, The QoS rule information is obtained (S501), and the flow learning table is learned based on the acquired forwarding information and QoS rule information (S503).

In addition, the node applies QoS to the incoming packet according to the acquired forwarding information and QoS rule information, and forwards the packet (S505).

5, step S505 is performed after the step S503 is performed. However, the steps S503 and S505 are not limited to those shown in Fig. For example, steps S503 and S505 may be executed simultaneously.

6 is a flowchart showing a processing method of Case 2 shown in Fig.

Referring to FIG. 6, in case 2, there is packet forwarding information in the forwarding table, but there is no QoS rule information of the packet in the QoS rule table. In this case, the node first applies the QoS rule set by default Otherwise, it is determined whether to transmit a QoS rule update request message to the controller (S601). Here, the QoS rule set basically can be, for example, a best effort service or the like. Further, the execution of step S601 can be selectively performed. That is, in case 2, the node may be configured to send a QoS rule update request message directly to the controller without executing step S601.

If it is determined in step S601 that the default QoS rule is not applied, the node transmits a message requesting the controller to update the QoS rule of the packet (S603). Here, the node may transmit to the controller a message including information requesting only the QoS rule of the packet together with all or part of the packet. The controller receiving the QoS rule update request message transmits the QoS rule information to the corresponding node.

The node receives the QoS rule information of the packet from the controller (S605).

In step S607, the node obtains the forwarding information of the packet from the forwarding table, and learns the flow learning table using the obtained forwarding information and the QoS rule information of the packet received from the controller.

In step S609, the node applies QoS to the packet according to the forwarding information and the QoS rule information of the packet, and forwards the packet.

If it is determined in step S601 that the default QoS rule is to be applied, the node processes the packet using the basic QoS rule and the forwarding information acquired from the forwarding table (S611).

7 is a flowchart showing a processing method of Case 3 shown in Fig.

Referring to FIG. 7, in case 3, QoS rule information to be applied to a packet exists in the QoS rule table, but there is no packet forwarding information in the forwarding table. In this case, the node first applies the forwarding path set by default Or to forward the forwarding path update request message to the controller (S701). Here, the execution of step S701 may be selectively performed. That is, in case 3, the node may be configured to send a forwarding route update request message directly to the controller without executing step S701.

If it is determined in step S701 that the forwarding path set in step S701 is not applied, the node sends a message requesting the controller to update the forwarding path of the packet (S703). Here, the node may transmit to the controller a message including information requesting only the forwarding path information of the packet together with all or part of the packet. Upon receiving the forwarding path update request message as described above, the controller transmits forwarding information to the corresponding node.

The node receives the forwarding information of the packet from the controller (S705).

In step S707, the node acquires QoS rule information to be applied to the packet from the QoS rule table, and learns the flow learning table using the acquired QoS rule information and the forwarding information of the packet received from the controller.

Then, the node applies QoS to the packet according to the forwarding information and the QoS rule information of the packet, and forwards the packet (S709).

If it is determined in step S701 that the default forwarding path information is to be applied, the node processes the packet using the basic forwarding path information and the QoS rule information obtained from the QoS rule table (S711).

8 is a flowchart showing a processing method of Case 4 shown in Fig.

Referring to FIG. 8, in case 4, there is no packet forwarding information in the forwarding table and QoS rule information to be applied to the packet does not exist in the QoS rule table. In this case, It is determined whether to apply the QoS rule basically set or to transmit the forwarding path and the QoS rule update request message to the controller (S801). Here, the execution of step S801 can be selectively performed. That is, in case 4, the node may be configured to send the forwarding path and QoS rule update request message directly to the controller without executing step S801.

If it is determined in step S801 that the default forwarding path and the default QoS rule are not applied, the node transmits a message for requesting the forwarding path and the QoS rule update of the packet to the controller (S803). Here, the node may transmit to the controller a message including information requesting both the forwarding information and the QoS rule information of the packet together with all or part of the packet. Upon receiving the forwarding path and the QoS rule update request message as described above, the controller transmits forwarding information and QoS rule information to the corresponding node.

The node receives forwarding information and QoS rule information of the packet from the controller (S805).

Then, the node learns the flow learning table using forwarding information and QoS rule information received from the controller (S807).

Then, the node applies QoS to the packet according to the forwarding information and the QoS rule information of the packet, and forwards the packet (S809).

If it is determined in step S801 that the default forwarding path and the default QoS rule are to be applied, the node processes the packet using the basic forwarding path information and the basic QoS rule (S811).

The QoS processing applied in the service quality providing method according to an embodiment of the present invention may include a service type such as a bandwidth guarantee service and a fairness providing service, and QoS requirements may exist in various types of service types .

The bandwidth guarantee service means a service that ensures that packets can be serviced according to a fixed service time based on a packet length and a requested bandwidth, and the fairness providing service is a service that allows the bandwidth to be divided equally for each flow .

In the present invention, in order to guarantee QoS as described above, when a band is determined for each flow, each node determines a packet arrival interval (t_A) according to a determined bandwidth, and based on the determined packet arrival interval (t_A) Calculate the expected arrival time. Then, the node can guarantee the QoS by a method of determining the acceptance or discard of the next packet based on the previously calculated arrival time, when the next packet actually arrives. Here, the band for each flow may be configured to be variable according to time. In the case of the first packet of each flow, the expected arrival time may be set as the time of the node at which the first packet arrives.

9 is a conceptual diagram for explaining a QoS providing method according to an embodiment of the present invention.

9, in an embodiment of the present invention, to efficiently provide QoS, a node constituting an SDN network is divided into edge nodes 921 and 923 and a core node 925 do. The edge nodes 921 and 923 are located at the border of the SDN network and can be connected to a plurality of subscriber terminals. Also, the core node 925 refers to a node that is located inside the SDN network and connects between the edge nodes, between the edge node and another core node or between core nodes. In FIG. 9, the core node 925 is illustrated as connecting two edge nodes 921 and 923 for the sake of simplicity. In addition, a plurality of edge nodes 921, 923 and core nodes 925 constituting the SDN network are connected to the controller 910.

The edge node 921 calculates the packet arrival interval t_A for each packet flowing in each flow when the bandwidth of each flow is allocated and transmits the calculated packet arrival interval t_A to the header of the packet And forward it to the next node.

9, the edge node 921 defines an SDN header between the MAC header and the IP header, and stores the QoS information in the SDN header in the case where the packet received in the edge node 921 is an Ethernet IP packet (T_?) Information and forward it to the next node (the core node 925 in FIG. 9). Here, the size and the specific format of the SDN header can be variously defined.

The core node 925 compares the arrival time of the received packet with the expected arrival time calculated for the corresponding flow, and transmits the arrival of the received packet to the core node 925 Determine if the time is earlier or later than the expected arrival time.

If it is determined that the packet arrives sooner than the expected arrival time, the core node 925 notifies the controller 910 of a traffic congestion notification message indicating that a traffic explosion has occurred in the flow corresponding to the received packet, . Here, the core node 925 may be configured to send a traffic surge notification message to the controller 910 immediately when a packet arrives earlier than the scheduled arrival time of the packet, or if the packet continues to come quickly even after exceeding a predetermined allowable value To send a traffic spoofing notification message. In addition, the core node 925 may be configured to immediately discard packets associated with traffic spikes, and may be configured to perform DSCP marking on packets associated with traffic spikes. When a traffic explosion occurs, a processing method for the packet may be provided by the controller 925 to each node 921, 923, or 925, and the controller 925 may transmit a processing method to each node .

The core node 925 updates the expected arrival time η for the next packet of the same flow using Equation 1 using the packet arrival interval t_Δ for the accepted packet through the process as described above.

On the other hand, when the controller 910 receives the traffic spoofing notification message from any node through the above-described process, the controller 910 notifies the node where the traffic explosion occurred to the previously located node (for example, , A node that forwarded the packet to the node where the traffic explosion occurred, and a flow rate control message for controlling the flow rate. The flow rate control message may include an appropriate transmission rate for the flow, and the appropriate transmission rate may be set by the controller 910.

The node (edge node 921 in FIG. 9) receiving the flow rate control message from the controller 910 receives the packet arrival interval t_Δ for each packet based on the transmission rate information included in the flow rate control message, .

FIG. 10 is a block diagram showing a configuration of an apparatus for executing a method for providing quality of service according to an embodiment of the present invention, wherein the apparatus executing the QoS providing method may be the node described above.

Referring to FIG. 10, a node 1000 according to an embodiment of the present invention may include a storage unit 1030 and a packet processing unit 1010.

The storage unit 1030 may include a flow learning table 1031, a forwarding table 1033, and a QoS rule table 1035 as shown in FIG. The forwarding table 1033 and the QoS rule table 1035 each include forwarding information and QoS rule information provided from the controller and the flow learning table 1031 includes forwarding table 1033 and information included in the QoS rule table 1035 Or information learned in the node 1000 based on the forwarding information or QoS rule information provided from the controller.

The packet processing unit 1010 performs processing for providing QoS on a microflow basis based on header information of an incoming packet as shown in FIG. 3 to FIG.

Specifically, the packet processing unit 1010 searches the forwarding table 1033 and the QoS rule table 1035 for forwarding information and QoS rules corresponding to incoming packets when the first packet of each flow flows, If it is determined that the packet does not exist, all or part of the first packet is delivered to the controller to receive information about the forwarding table 1033 and the QoS rule table 1035 from the controller, and based on the received information, ) To generate an entry for the corresponding microflow.

In addition, the packet processor 1010 generates a hash value for distinguishing a flow corresponding to an incoming packet when a packet is received, and generates a hash value by using a flow corresponding to the packet received from the flow learning table 1031 If it is determined that there is no flow corresponding to the incoming packet, the forwarding information and the QoS rule corresponding to the incoming packet are searched in the forwarding table 1033 and the QoS rule table 1035, respectively. 4 to 8, the packet processing unit 1010 determines whether or not the forwarding information and the QoS information corresponding to the incoming packet are present. Then, the packet processing unit 1010 performs packet processing .

The packet processing unit 1010 included in the edge node calculates a packet arrival interval t_Δ for each packet flowing in each flow as shown in FIG. 9 when a bandwidth is allocated for each flow, (T_ [Delta]) information is included in the header of the packet and forwarded to the next node.

In addition, when a packet including an SDN header including the packet arrival interval (t_A) information is received, the packet processing unit 1010 included in the core node calculates the packet arrival interval Determines the arrival time, compares the arrival time of the determined packet with the estimated arrival time calculated for the corresponding flow of the packet, determines whether a traffic explosion occurs in the flow corresponding to the received packet, And transmits a Traffic Congestion Notification message to the controller when the determination result is affirmative. In addition, the packet processing unit 1010 may process (e.g., discard or DSCP mark) a packet related to a traffic surge according to a preset policy.

In addition, when receiving the flow rate control message from the controller, the packet processing unit 1010 included in the edge node or the core node performs packet processing based on the transmission rate information included in the received flow rate control message .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

110: controller 130: node
131: Flow table 210: Controller
230: node 231: flow learning table
233: forwarding table 235: QoS rule table
910: Controller 921, 923: Edge node
925: core node 1000: node
1010: Packet processing unit 1030:
1031: Flow learning table 1033: Forwarding table
1035: QoS rule table

Claims (15)

A method for providing quality of service performed at an arbitrary node of a network,
Receiving a first packet of a predetermined flow;
Retrieving forwarding information and QoS (Quality of Service) rules corresponding to the packet from a forwarding table and a QoS rule table, respectively;
Transmitting the packet to the controller when the forwarding information and the QoS rule information do not exist in the forwarding table and the QoS rule table; And
And generating a flow entry corresponding to the packet in the flow learning table based on the forwarding information and QoS rule information received from the controller. The method according to claim 1,
Wherein the unit of the forwarding information and the QoS rule information received from the controller is different from the unit of the flow entry generated in the flow learning table. The method according to claim 1,
Wherein the step of generating the flow entry generates a microflow entry. A method for providing quality of service performed at an arbitrary node of a network,
Searching the flow learning table for flow information corresponding to the received packet;
If the flow information does not exist in the flow learning table, searching for forwarding information and QoS rule information corresponding to the packet in a forwarding table and a QoS rule table, respectively;
If at least one of the forwarding information and the QoS rule information is not present in the forwarding table and the QoS rule table, acquiring at least one information that does not exist from the controller; And
And learning the flow learning table using at least one of information obtained from at least one of the forwarding table and the QoS rule table and information acquired from the controller. 5. The method of claim 4,
If the forwarding information and the QoS rule information are respectively present in the forwarding table and the QoS rule table,
Obtaining forwarding information and QoS rule information to be applied to the packet from the forwarding table and the QoS rule table, respectively;
Learning the flow learning table using the acquired forwarding information and the QoS rule information; And
And processing the packet using the acquired forwarding information and the QoS rule information. In claim 4,
Wherein the obtaining of the at least one non-existent information from the controller comprises:
If the forwarding information is present in the forwarding table but the QoS rule information is not present in the QoS rule table,
Transmitting a message for requesting update of the QoS rule information to the controller;
Learning the flow learning table using QoS rule information provided from the controller and forwarding information acquired from the forwarding table; And
And processing the packet based on QoS rule information provided from the controller and forwarding information obtained from the forwarding table. In claim 4,
Wherein the obtaining of the at least one non-existent information from the controller comprises:
If the forwarding information is not present in the forwarding table and the QoS rule information is present in the QoS rule table,
Transmitting a message requesting update of the forwarding information to the controller;
Learning the flow learning table using forwarding information provided from the controller and QoS rule information acquired from the QoS rule table; And
And processing the packet based on forwarding information provided from the controller and QoS rule information obtained from the QoS rule table. In claim 4,
Wherein the obtaining of the at least one non-existent information from the controller comprises:
If the forwarding information does not exist in the forwarding table and the QoS rule information does not exist in the QoS rule table,
Transmitting the forwarding information and a message requesting update of the QoS rule to the controller;
Learning the flow learning table using forwarding information and QoS rule information provided from the controller; And
And processing the packet based on forwarding information provided from the controller and the QoS rule information. The method of claim 4,
The service quality providing method includes:
Calculating a packet arrival interval for a packet flowing in each flow; And
Further comprising forwarding the packet including the packet arrival interval information to another node after the calculated packet arrival interval information is included in the header of the packet. The method of claim 9,
Wherein the step of forwarding a packet including the packet arrival interval information to another node comprises:
(SDN) header between an MAC (medium access control) header and an IP header of the IP packet when the packet is an Internet Protocol (IP) packet, and includes the packet arrival interval information in the SDN header The quality of service. The method of claim 4,
The service quality providing method includes:
Comparing an arrival time of a packet flowing in each flow with an estimated arrival time calculated for a flow of the packet; And
If the arrival time of the packet is earlier than the expected arrival time, transmitting to the controller a message indicating that a traffic explosion has occurred in the flow of the packet. The method of claim 11,
Wherein comparing the arrival time of the packet flowing in each flow with the estimated arrival time calculated with respect to the flow of the packet,
Determining arrival time of the packet based on packet arrival interval information included in a header of the packet, and comparing the arrival time of the packet with the expected arrival time. A forwarding table including forwarding information of a packet, a QoS rule table including QoS rule information to be applied to the packet, and a flow learning table that is learned based on the forwarding table and the QoS rule information. And
And a packet processing unit for applying forwarding of an incoming packet and QoS to the incoming packet based on information stored in the storage unit. 14. The method of claim 13,
The packet processing unit receives the first packet of the predetermined flow, searches the forwarding table and the QoS rule table for the forwarding information and the QoS rule corresponding to the packet, respectively, and transmits the forwarding information and the QoS rule information And if it does not exist, generates a flow entry corresponding to the packet in the flow learning table based on forwarding information and QoS rule information received from the controller after delivering the packet to the controller . 15. The method of claim 14,
The packet processing unit
Searches the flow learning table for flow information corresponding to a received packet, and if the flow information does not exist in the flow learning table, forwarding information and QoS rule information corresponding to the received packet are transmitted to a forwarding table and a QoS rule table And if at least one of the forwarding information and the QoS rule information does not exist in the forwarding table and the QoS rule table, at least one information that does not exist is acquired from the controller, And the flow learning table is learned using at least one of information obtained from at least one table in the QoS rule table and information acquired from the controller.

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