KR101595160B1 - Methods for managing transaction in software defined networking network - Google Patents

Abstract

A method for managing transactions in a software defined networking network is disclosed. The transaction management method performed by the controller generates a group message for changing the state of the associated one of the flow tables stored in the switch, and transmits the group message to the switch. The switch verifies the group message and reports it to the controller. The controller instructs the execution of the group message if there is no error in the group message. Thus, the concurrency, consistency, and atomicity of transactions for a single switch or a plurality of switches can be guaranteed.

Description

{METHODS FOR MANAGING TRANSACTION IN SOFTWARE DEFINED NETWORKING NETWORK}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to software defined networking technologies, and more particularly, to a transaction management method in a software defined networking network.

Since a network composed of a general router or a switch is configured based on a complicated protocol and functions, and each equipment company operates a device or a user interface, a network operator or a researcher develops a new network protocol and applies it to the network There is a problem that it is difficult to extend the network or to interwork the network equipment with each other. In order to solve such a problem, a switch or router technology having an open interface has been studied, but network technologies providing an open interface have been difficult to commercialize because of high performance price.

OpenFlow technology has emerged to provide an open standard interface to users or developers while addressing costly problems.

Open flow technology separates the packet forwarding and control functions of a network switch and provides a standardized protocol for communication between these two functions. Therefore, using open-flow technology, the software running on the external control device can determine the packet path in the switch regardless of the equipment manufacturer and manage the traffic more precisely than before.

The Open Networking Foundation (ONF) has defined Software Defined Networking (SDN) technology that makes it easier to program networks based on open flows.

The open-flow-based SDN architecture includes an OpenFlow Switch and a Controller, and the open-flow switch and controller are interconnected by an open-flow protocol.

In an open-flow-based SDN network, a controller provides flow table information to a switch, and the switch processes the packet by changing the attributes of the packet using the provided flow table information or controlling the flow of the packet.

In addition to ONF, standardization organizations such as Internet Engineering Task Force (IETF), European Telecommunications Standards Institute (ETSI), and International Telecommunications Union Telecommunication (ITU-T) are also standardizing SDN-based networks. For example, IETF's Interface to Router System (I2RS) Working Group provides an open interface between an external client (client) and an agent (agent) located in the router so that traditional router equipment can be externally monitored and controlled. Standardization of the structure is underway.

As described above, various standardization organizations such as ONF and IETF are standardizing for SDN, but there is no concrete method for ensuring consistency in transaction between controller and switch or between client and agent It is not.

It is an object of the present invention to provide a transaction management method capable of ensuring consistency of transactions between a controller and a switch in an SDN network.

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 transaction management method performed by a controller, the transaction management method comprising: generating a group message for changing a status of associated ones among flow tables stored in a switch; And sending a group message to the switch.

Here, the group message may be a message including a plurality of messages for simultaneously changing tables having mutually related states among a plurality of flow tables in the switch. In addition, the plurality of messages have the same structure and may be included in the group message repeatedly.

Here, the group message may include at least one of a message type, a number of messages, a length of a message, and an identifier of a group message.

Here, the transaction management method may include receiving an acknowledgment message indicating whether an error occurs in the group message from the switch, and transmitting a message instructing execution or cancellation of the group message to the switch based on the acknowledgment message Step < / RTI >

Here, the confirmation message may include an error code when an error occurs in the group message.

The step of transmitting a message instructing execution or cancellation of the group message to the switch may include receiving a confirmation message indicating that an error has occurred in at least one of the plurality of messages included in the group message , And may transmit a message instructing the switch to cancel the group message.

According to another aspect of the present invention, there is provided a transaction management method performed by a controller, the method comprising: receiving, from a plurality of switches, And transmitting the group message to the plurality of switches.

The group message may be a message including a plurality of messages for simultaneously changing a plurality of flow tables associated with each other among the flow tables stored in the plurality of switches.

Here, the transaction management method may further include: receiving an acknowledgment message indicating whether an error occurs in the group message from the plurality of switches, respectively, and transmitting a message instructing execution or cancellation of the group message to the plurality To the switch of FIG.

The step of transmitting a message instructing execution or cancellation of the group message to the plurality of switches comprises the steps of receiving an acknowledgment message indicating an error occurrence of the group message from at least one of the plurality of switches, And may transmit a message instructing cancellation of the group message to the plurality of switches.

According to another aspect of the present invention, there is provided a transaction management method comprising: receiving, from a controller, a group message for changing a state of an associated state among flow tables stored in a transaction management method performed in a switch; And verifying the error of the group message and transmitting an acknowledgment message including the error information of the group message to the controller.

The step of receiving the group message from the controller may include storing the received group message in a temporary storage area.

Here, in the step of verifying the error of the group message, it is possible to determine whether at least one of the grammar and the precondition of the group message is valid.

Here, in the step of verifying the error of the group message, the resource availability of the switch can be determined.

Here, the confirmation message may include an error code if there is an error in the group message.

Here, the transaction management method may further include receiving an execution message indicating execution of the group message from the controller, and changing a flow table based on the contents of the group message stored in the temporary storage area.

Here, the transaction management method may further include receiving a cancellation message for canceling the group message from the controller, and deleting the group message stored in the temporary storage area.

According to the transaction management method in the SDN network according to the embodiment of the present invention, in the process of changing the flow table of the switch, the controller generates the group message in consideration of the states associated with the flow tables or the states requiring sequential operations, To the switch. The switch verifies the received group message and sends the verification result to the controller. The controller instructs the corresponding switch to execute the group message when no error occurs in the group message, and instructs the switch to cancel the group message if an error occurs in the group message.

Accordingly, mutually related states of flow tables stored in a single switch or a plurality of switches can be simultaneously changed, thereby ensuring concurrency.

In addition, it is possible to synchronize changes between a plurality of switches and to ensure consistency by simultaneously changing a plurality of related tables.

1 is a block diagram showing a configuration of an SDN system.
2 shows the structure of the flow entries included in the flow table.
3 is a flowchart illustrating a transaction management method according to an embodiment of the present invention.
4 is a flowchart illustrating a transaction management method according to another embodiment of the present invention.
5 is a conceptual diagram showing an application example of a transaction management method according to an embodiment of the present invention.
6 is a conceptual diagram illustrating an application example of a transaction management method according to another embodiment of the present invention.
FIG. 7 illustrates an example of a group message structure applied to embodiments of the present invention.
8 shows an example of a configuration of a controller and a switch for executing a transaction management method according to the embodiments 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 terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

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, a 'controller' referred to in the present invention refers to a functional entity that controls related components (eg, switches, routers, etc.) to control the flow of traffic. Shape, implementation position, and the like. For example, the controller may refer to a controller functional entity defined in ONF, IETF, ETSI, and / or ITU-T. A 'switch' referred to in the present invention means a functional element for substantially forwarding, switching, or routing traffic (or packet). It may be a switch defined by ONF, IETF, ETSI and / or ITU- , A switch element, a router element, a forwarding element, and the like.

In addition, the embodiments of the present invention described below can be supported by standard documents prepared by ONF, IETF, ETSI, and ITU-T, which are performing standardization of SDN technology. That is, those of the embodiments of the present invention that are not specifically described in order to clearly illustrate the technical idea of the present invention can be supported by the standard documents prepared by the above standardization bodies. In addition, all terms used in the present invention can be described by the standard document.

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 block diagram showing a configuration of an SDN system. 2 shows the structure of the flow entries included in the flow table.

Referring to FIG. 1, the SDN system may include a plurality of switches and controllers, and a plurality of switches and controllers may communicate with each other using an open flow protocol. Although only one controller 110 and one switch 120 are shown in FIG. 1 for the sake of convenience, the controller 110 and the switches 120 may be constituted of a plurality of controllers 110 and 120, respectively.

The switch 120 includes one or more flow tables 121 and group tables 123 for use in lookup and forwarding of packets and includes an open flow channel 125).

Each flow table 121 included in the switch is a set of flow entries, and each flow entry includes match fields 201, a priority 202, Counters 203, instructions 204, timeouts 205, and cookies 206 fields, as shown in FIG.

The match field 201 is information for matching a packet, and may include an ingress port, packet header information, and optionally, metadata specified in a previous flow table. The priority 202 indicates the matching priority of the flow entry. The counter 203 is a value that is updated when a packet is matched. The instruction 204 is used to change action sets or pipeline processing. The timeout 205 indicates the maximum time or idle time before the flow is expired by the switch. The cookie 206 may be used by the controller to filter flow statistics, flow changes, flow deletions, etc. with an opaque data value selected by the controller.

The matching for the processing of the packet may start from the first of the plurality of flow tables 121 included in the switch 120 and may continue in subsequent flow tables.

The switch 120 executes the command associated with the particular flow entry matched if a matching flow entry is found. Or a matching entry is not found in the flow table, the switch 120 may forward or drop the packet to the controller 110 via the open flow channel 125 and may perform matching processing in the following flow table You can continue.

The instructions associated with each flow entry include an action or an instruction to modify the pipeline processing within the switch.

The actions included in the command describe packet forwarding, packet modification, and processing of the group table. For example, an action may specify that a packet be directed to a group that defines additional processing. Here, the group represents a set of actions for handling flooding and more complex forwarding. The group can efficiently change common output actions of packets associated with a plurality of flow entries.

The pipeline processing instructions send packets to the next flow table for subsequent processing, and exchange metadata-type information between the flow tables. The pipeline processing for the flow tables is stopped if the set of instructions associated with the matching flow entry does not specify the next flow table. At this point, the packet is usually modified or forwarded.

The flow entry may also forward packets to the port. Here, the port may denote a general physical port or a logical port defined by the switch 120. In addition, the port may mean a predefined reserved port. The reservation port may forward the packet to the controller 110, or may specify a comprehensive forwarding process, such as flooding, or packet forwarding via a conventional method rather than an open flow. On the other hand, the logical port defined by the switch 120 may specify a link aggregation group, tunnels, or a loopback interface.

The group table includes a plurality of group entries. Each group entry may contain an action buckets list having specific semantics associated with the type of group. Here, an action bucket refers to a set of actions and associated parameters. Actions included in one or more action buckets may forward packets to a group.

The controller 110 may add, modify, or delete flow entries to the flow table 121 of each switch 120 using an open flow protocol.

The open flow protocol supports three message types: controller-to-switch, asynchronous, and symmetric, and each message type includes a plurality of subtype messages.

The controller-to-switch message is a message generated by the controller 110, used to directly manage the switch 120 or to retrieve the status of the switch 120. An asynchronous message is a message generated by switch 120 that is used to update information stored in controller 110 in response to a network event and a change in state of switch 120. The symmetric message is a message generated by the switch 120 or the controller 110, and is transmitted in both directions without a separate request.

The controller-to-switch message includes a Modify-State message and a Barrier message. The status change message is a message sent by the controller 110 to the switch 120 to manage the state of the switch 120 and may be added or deleted for flow or group entries in the open flow table 121 of the switch 120. [ And to change or set the port characteristics of the switch 120. The barrier message consists of a barrier request and a barrier response message and is used by the controller 110 to notify the controller 110 of the dependency between the messages sent by the controller 110 to the switch 120 and the completion of the execution of the messages by the switch 120 Is used.

Asynchronous messages may include Flow-Removed, Port-status messages, and the like. The flow delete message is used by the switch 120 to notify the switch 120 that the flow entry has been deleted from the flow table. The port status message is used by the switch 120 to notify the change of the port.

The symmetric message may include a Hello, an Echo, an Error message, and the like. The hello message is a message exchanged when the connection between the controller 110 and the switch 120 is created. The echo message is composed of an echo request and an echo reply message, and may be transmitted by the switch 120 or the controller 110. A device that has received an echo request message MUST send an echo reply message. The error message is used to notify the connection partner that a problem has occurred with the message used by the switch 120 or the controller 110. [

Generally, when the controller 110 changes the flow table of the switch 120, the controller 120 designates a change type to the command classification information of the above-described Modify-State message and transmits the command to the switch 120. The controller 110 may additionally change or delete the flow entry in the flow table of the switch 120 by using the status change message.

On the other hand, the switch 120 does not immediately respond to the controller 110 for each status change message for a plurality of status change messages for instructing a change to a plurality of flow entries, and sends an error message only when an error occurs To the controller (110).

In addition, the controller 110 may use a Barrier message to ensure the order of execution of the commands to send to the switch 120. For example, if the controller 110 sends a barrier message to the switch 120 at a particular point in time, the switch 120 executes all the commands it has received before receiving the barrier message, . That is, the controller 110 may control a command or a task execution order of the switch 120 using a barrier message when a series of commands or operations must be sequentially executed.

As described above, in the general flow table changing method, the switch 120 transmits an error message to the controller 110 only when an error occurs without immediately responding to the status change message received from the controller 110 on a change-by-change basis. Therefore, even when the switch 120 fails to deliver an error message to the controller 110 due to a network failure or a communication failure of the switch 120 despite an error actually occurring in the process of changing the flow table, 110 may consider that the change of the flow table has been normally executed and perform the subsequent control.

In addition, the controller 110 is using a barrier message to ensure sequential instruction execution order of the switch 120. [ However, with the barrier message alone, the controller 110 can not accurately determine whether to change the flow entries (or states) associated with each other in one or more flow tables.

In addition, in the flow table changing method described above, since a single state change message is transmitted to each flow table change item to change the flow table, a plurality of flow table changes (or a plurality of state changes) It can not guarantee the atomicity that it should not.

Hereinafter, a transaction management method according to embodiments of the present invention for solving the above-mentioned problems will be described.

3 is a flowchart illustrating a transaction management method according to an embodiment of the present invention.

FIG. 3 illustrates a process of changing a flow table in consideration of states associated with a plurality of flow tables stored in one switch 330 or states requiring a series of sequential operations.

Referring to FIG. 3, the controller 310 determines whether or not there is a correlation between the flow entries (or states) included in the flow tables within the switch 330, Or a flow entry) (S301). Here, the group message may include a plurality of messages for simultaneously changing flow entries associated with each other among the flow entries included in the plurality of flow tables stored in the switch 330. [ Also, the plurality of messages included in the group message may be configured such that the flow entry change commands having the same structure are repeatedly included in the array for collective change of a plurality of flow entries (or states).

Then, the controller 310 transmits a Group Modify Prepare message including a group message to the switch 330 (S302).

The switch 330 receives the group change preparation message from the controller 310 and verifies the validity of the received group message (S303). Here, the switch 330 may determine whether a precondition for executing a grammar or group message is valid for each message included in the received group message or group message. Also, the switch 330 may optionally determine whether resources are available for applying the group message.

Thereafter, the switch 330 transmits an acknowledgment (ACK) message including a result of validation of the group message to the controller 310 (S304). Here, the acknowledgment message may include information on whether or not an error occurs in the group message. The switch 330 includes an error code corresponding to an error generated when an error occurs in any one of a plurality of messages included in the group message as a result of validation of the group message, and transmits the error code to the controller 310 .

In addition, when the switch 330 receives the group message from the controller 310, the switch 330 may store the received group message in the temporary storage area. Here, the switch 330 may delete the group message stored in the temporary storage area if an error occurs after verifying the validity of the group message.

The controller 310 waits until it receives an acknowledgment message for the group message from the switch 330. When the acknowledgment message is received, the controller 310 checks whether the acknowledgment message contains information indicating an error (S305).

If the received acknowledgment message includes an error code indicating that an error has occurred in the group message, the controller 310 transmits a group change cancel message to the switch 330, which instructs the switch 330 to cancel the group message (S306).

If the switch 330 receives the group change cancel message from the controller 310, the switch 330 may delete the group message stored in the temporary storage area without executing the received group message (S307).

Alternatively, if it is determined that an error does not occur in the group message through the confirmation message, the controller 310 transmits a Group Modify Execute message instructing execution of the group message to the switch 330 (S308 ).

When receiving the group change execution message from the controller 310, the switch 330 changes the corresponding flow entry (or state) of the flow table based on the group message (S309). Here, the switch 330 may add, delete or change the flow entry according to the command indicated by the group message.

4 is a flowchart illustrating a transaction management method according to another embodiment of the present invention.

FIG. 4 illustrates a process of changing a flow table in consideration of mutually related states for a plurality of flow tables stored in a plurality of switches. For convenience of explanation, two switches 330a and 330b of the plurality of switches are illustrated, Respectively. However, the flow table changing method shown in FIG. 4 can be applied to the case where the number of switches is two or more.

Referring to FIG. 4, the controller 310 determines whether the association of the flow entries (or states) included in the flow tables stored in the first switch 330a and the second switch 330b, respectively (Or flow entries), in step S401, a group message for changing states (or flow entries) associated with each other. Here, the group message may include a plurality of messages for simultaneously changing flow entries associated with one another among the flow entries included in the plurality of flow tables stored in the first switch 330a and the second switch 330b. Also, the plurality of messages included in the group message may be configured such that the flow entry change commands having the same structure are repeatedly included in the array for collective change of a plurality of flow entries (or states).

Thereafter, the controller 310 transmits a group change preparation message including a group message to the first switch 330a and the second switch 330b (S402).

The first switch 330a and the second switch 330b respectively receive the group change preparation message from the controller 310 and verify the validity of the received group message (S403). Here, the first switch 330a and the second switch 330b may determine whether a precondition for executing a grammar or group message is valid for each message included in the received group message or group message. In addition, the first switch 330a and the second switch 330b may selectively determine whether resources for applying the group message are available.

Thereafter, the first switch 330a and the second switch 330b transmit an acknowledgment message including a result of the validity verification of the group message to the controller 310 (S404). Here, the acknowledgment message may include information on whether or not an error occurs in the group message. The first switch 330a and the second switch 330b may transmit an error code corresponding to an error generated when an error occurs in any one of a plurality of messages included in the group message as a result of validation of the group message, To the controller 310.

In addition, the first switch 330a and the second switch 330b can receive the group message from the controller 310 and store the received group message in the temporary storage area. Here, the first switch 330a and the second switch 330b may delete the group message stored in the temporary storage area if an error occurs after verifying the validity of the group message.

The controller 310 waits until it receives an acknowledgment message for the group message from the first switch 330a and the second switch 330b. When the controller 310 receives the acknowledgment message, the controller 310 transmits information indicating an error to the received acknowledgment message It is confirmed whether it is included (S405).

If the confirmation message received from any one of the first switch 330a and the second switch 330b includes an error code indicating that an error has occurred in the group message, And transmits a group change cancel message instructing the first switch 330a and the second switch 330b to cancel the group message (S406).

When receiving the group change cancel message from the controller 310, the first switch 330a and the second switch 330b may delete the group message stored in the temporary storage area without executing the received group message (S407 ).

Alternatively, when the controller 310 indicates that all of the acknowledgment messages received from the first switch 330a and the second switch 330b have not occurred, all the switches, that is, the first switch 330a and the second switch 330b, And transmits a group change execution message instructing execution of the group message to the group change execution message 330b (S408).

When receiving the group change execution message from the controller 310, the first switch 330a and the second switch 330b change the corresponding flow entry (or state) of the flow table based on the group message (S409). Here, the first switch 330a and the second switch 330b may add, delete, or change the flow entry according to a command indicated by the group message.

As described with reference to FIG. 4, in the present invention, a group message is defined in consideration of association (or states in which sequential operations are required) to a flow table stored in a plurality of switches, and a plurality of switches If an error occurs in a group message on some of the switches, be sure to cancel the group message execution on all switches. Therefore, it is possible to ensure consistency of the state change of the plurality of switches.

5 is a conceptual diagram showing an application example of a transaction management method according to an embodiment of the present invention.

FIG. 5 illustrates a process of changing a flow table through a group message to three flow tables having mutually related states among a plurality of flow tables stored in one switch 330 as an application example of the transaction management method. The ingress port, output port 1 and output port 2 of the switch 330 shown in FIG. 4 may be a physical port or a logical port defined by the switch 330 It is possible.

First, the condition for changing the flow table, which should be consistent in the example shown in Fig. 5, is as follows.

First, a packet matching the match field TCP_SRC1 of the flow table 1 among the packets input to the ingress port of the switch 330 should be forwarded to the output port 1. Here, the action for packet forwarding to the output port 1 can be expressed as " Output port1 ", and when the action is defined in the flow table 2, the action corresponding to the match field TCP_SRC1 of the flow table 1 is " Goto- &Quot;

Second, a packet matching the match field TCP_SRC2 of the flow table 1 among the packets input to the incoming port of the switch 330 should be forwarded to the output port 2. Here, the action for packet forwarding to the output port 2 can be expressed as " Output port2 ", and when the action is defined in the flow table 3, the action corresponding to the match field TCP_SRC2 of the flow table 1 is " Goto- &Quot;

The above two flow table changing conditions must be applied at the same time. If only one of the above two flow table changing conditions is applied, there may be a problem in packet flow control or a packet may be discarded.

For example, since the first condition is not changed, the packet matching the match field TCP_SRC1 of the flow table 1 is maintained to be forwarded to the output port 2, and when only the second condition is changed, the TCP_SRC1 and the TCP_SRC2 May be forwarded to the output port 2, resulting in a packet collision inside the switch 330.

Therefore, the first flow table change condition and the second flow table change condition must be satisfied at the same time, and corresponding flow entries of the flow tables 1, 2, and 3 must be changed at the same time.

In the present invention, as described with reference to FIG. 3, the controller defines a group message for simultaneously changing a plurality of flow entries associated with each other, transmits the group message to the switch 330, It is possible to consistently perform the change of the associated Flow Table in one switch 330 by executing the change command.

6 is a conceptual diagram illustrating an application example of a transaction management method according to another embodiment of the present invention.

6 illustrates a process of changing a flow table through a group message to two flow tables having mutually related states among a plurality of flow tables stored in a plurality of switches, respectively, as an application example of the transaction management method. 6, the output port of the first switch 330a among the plurality of switches is connected to the input port of the second switch 330b. However, for the two or more switches, It is obvious that the transaction management method according to another embodiment can be applied equally. In addition, the incoming and outgoing ports of each switch 330a, 330b may be a physical port or a logical port defined by each switch 330a, 330b.

First, the change condition of the flow table, which should be kept consistent in the example shown in Fig. 6, is as follows.

First, among the packets input to the ingress port of the first switch 330a, the packet matching the match field TCP_DST1 of the flow table must be tagged to VLAN1 and forwarded to the output port 1 do. Here, the action for instructing tagging to VLAN1 can be expressed as " push VLAN1 ", and the action for packet forwarding to output port 1 can be expressed as " Output port1 ".

Second, among the packets input to the entry port of the second switch 330b, the packet matching the match field of the tagging with the match field TCP_DST1 of the flow table and the VLAN1 is separated from the VLAN1 tagging and output to the output port 2 Be forwarded. Here, an action for separating VLAN 1 tagging can be expressed as "Pop VLAN 1", and an action for packet forwarding to output port 2 can be expressed as "Output port 2".

The above two flow table changing conditions must be applied at the same time. If only one of the above two flow table changing conditions is applied, the flow control of the packet may cause a problem or the packet may be discarded.

For example, when only the first condition is changed and the second condition is not changed, a problem is that a packet output through the output port 1 of the first switch 330a is not output to the output port 2 of the second switch 330b May occur.

Therefore, the first flow table change condition and the second flow table change condition must be satisfied at the same time, and corresponding flow entries of the flow tables stored respectively in the first switch 330a and the second switch 330b must be simultaneously changed do.

In the present invention, as described with reference to FIG. 4, the controller defines a group message for simultaneously changing a plurality of flow entries associated with a plurality of switches, transmits the group message to a plurality of switches, So that it is possible to consistently perform the change of the related Flow Table between a plurality of switches.

FIG. 7 illustrates an example of a group message structure applied to embodiments of the present invention.

Referring to FIG. 7, the group message structure according to an exemplary embodiment of the present invention may include a header part and a message part.

The header portion may be composed of a protocol header 610 and a group message header 620. The protocol header 610 may be composed of, for example, an open flow protocol header and may be composed of 8 bytes.

The group message header 620 may include a type, a count, a length, and a group id.

The type information may be composed of two bytes and may indicate the type of group message. The type of group message may include a Group Modify Prepare, an acknowledgment (ACK), a Group Modify Cancel, and a Group Modify Execute message as described above.

The count information may be composed of 4 bytes and may mean the number of messages included in the group message.

The length information may be composed of 2 bytes and may mean the length of the group message.

The group ID information may be composed of one byte and may mean a unique identifier of the group message.

The message unit 630 may include a table_id, a command, a priority, an output port, an OFP_MATCH, and an err_code information.

The flow table ID (table_id) information may be composed of one byte and may mean a unique identifier for identifying a flow table.

The command information may consist of one byte and may mean a change command of the flow table. The command may include an Add command for instructing addition of a flow entry to the flow table, a Modify command for instructing a change of the flow entry, and a Delete command for instructing deletion of the flow entry.

The priority information can be composed of two bytes and can indicate the priority of the flow entry.

The out port information may be composed of 4 bytes and may mean an output port.

The OFP_MATCH information may be composed of 8 bytes and may mean structure information defining a match field.

The error code (err_code) information may consist of two bytes and may indicate the type of error.

8 shows an example of a configuration of a controller and a switch for executing a transaction management method according to the embodiments of the present invention.

Although only one controller 310 and one switch 330 are shown in FIG. 8, this is for convenience of explanation. In an actual SDN network, a plurality of switches may be connected to one or more controllers 310, The configurations of the controller 310 and the switch 330 illustrated in FIG. 8 can be applied equally.

Referring to FIG. 8, the controller 310 may include a control unit 311 and a communication unit 314.

The control unit 311 may include a general command control module 312 and a group command control module 313. [ Here, the general command control module 312 and the group command control module 313 may be configured as separate physical hardware (for example, a processor), and a logical software module .

The general command control module 312 is a module for handling general management of the switch 330, and can perform control for changing the flow table other than the flow table change using the group message or managing the switch 330.

The group command control module 313 is a module for performing control for changing the flow table using the group message as described above. The module command control module 313 determines the association between the flow tables in the single switch 330 or the association between the flow tables of the plurality of switches Generates a group message for changing the state of association according to the determination result, and transmits the generated group message to the switch 330 or the switches through the communication unit 314 by including the generated group message in the group change preparation message Function.

In addition, the group command control module 313 receives a confirmation message for the group message from the switch 330 or the switches through the communication unit 314, and forwards the group message to the group And transmits a change cancel message to the corresponding switch or switches that transmitted the group message through the communication unit 314. [

Alternatively, if an error does not occur in the group message, the group command control module 313 transmits a group change execution message instructing execution of the group message to the corresponding switch or switches that transmitted the group message.

The communication unit 314 transmits the messages (for example, a group change preparation message, a group change cancel message, a group change execution message, etc.) provided from the control unit 311 to a specific switch or a plurality of switches under the control of the control unit 311 And provides a control unit 311 with a message (for example, a confirmation message) received from the switch. Here, the communication unit 314 can send and receive messages with the switches or switches based on a predefined protocol.

The switch 330 may include a communication unit 331, a processing unit 332, and a storage unit 335.

The communication unit 331 transmits a message (for example, a confirmation message) to the controller 310 via the network under the control of the processing unit 332 or receives a message (for example, A group change cancel message, a group change execution message, and the like) to the processing unit 332. Here, the communication unit 331 can transmit / receive a message to / from the processing unit 332 according to a predefined protocol.

The processing unit 332 may include a general command processing module 333 and a group command processing module 334. [ Here, the general command processing module 333 and the group command processing module 334 may be constituted by separate physical hardware (for example, a processor), or a logical software module .

The general command processing module 333 is a module for processing a general control command provided from the controller 310 and is capable of handling a flow table change other than the change of the flow table using the group message or a command for management.

The group command processing module 334 performs processing for changing the flow table using the group message as described above. Upon reception of the group message from the controller 310, the group command processing module 334 stores the received group message in the temporary storage area 337 of the storage unit 335 and stores the received message in the temporary storage area 337, . Here, the group command processing module 334 transmits to the controller 310 via the communication unit 331 a confirmation message including the result of the validity check of the group message. If the validation of the group message fails, the switch 330 transmits an error code corresponding to the error content to the controller 310 in the confirmation message.

In addition, when receiving the group change cancel message from the controller 310, the group command processing module 334 deletes the group message stored in the temporary storage area 337 according to the received group change cancel message and changes the flow table I never do that. Alternatively, when receiving the group change execution message from the controller 310, the group command processing module 334 changes the flow table stored in the flow table storage area 336 according to the contents indicated by the group message stored in the temporary storage area do.

The storage unit 335 may include a flow table storage area 336 and a temporary storage area 337. Here, the flow table storage area 336 and the temporary storage area 337 may be constituted by physically separated independent storage devices, and a flow table storage area 336 and a temporary storage area 337 may be configured in a logically assigned form.

The flow table storage area 336 is an area in which a plurality of flow tables are stored, and the temporary storage area 337 is an area in which a group message received from the controller 310 is temporarily stored. When the group message stored in the temporary storage area 337 fails to validate the group message or receives the group change cancel message from the controller 310 or receives the group change execution message from the controller 310 and changes the flow table May be deleted under the control of the group command processing module 334.

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 120: switch
121: Flow table 123: Group table
125: Open flow channel 201: Match field
202: Priority 203: Counter
204: Instruction 205: Timeout
206: Cookie 310: Controller
311: Control section 312: General command control module
312: Group command control module 314:
330: switch 330a: first switch
330b: second switch 331:
332: Processing section 333: General command processing module
334: Group command processing module 335:
336: Flow table storage area 337: Temporary storage area
610: Protocol header 620: Group message header
630:

Claims (18)

As a transaction management method performed on the controller,
Generating a group message for a change of an associated state among the flow tables stored in the switch;
Sending the group message to the switch;
Receiving an acknowledgment message indicating whether an error has occurred in the group message from the switch; And
And sending a message to the switch instructing execution or cancellation of the group message based on the confirmation message,
Wherein the step of transmitting a message instructing execution or cancellation of the group message to the switch comprises the steps of: when receiving an acknowledgment message indicating that an error has occurred in at least one of the plurality of messages included in the group message, And sending a message instructing the switch to cancel the group message. In claim 1,
Wherein the group message is a message including a plurality of messages for simultaneously changing tables having mutually related states among a plurality of flow tables in the switch. In claim 2,
Wherein the plurality of messages have the same structure and are repeatedly included in the group message. In claim 1,
Wherein the group message includes at least one of a type of a message, a number of messages, a length of a message, and an identifier of a group message. delete In claim 1,
Wherein the acknowledgment message includes an error code when an error occurs in the group message. delete As a transaction management method performed on the controller,
The method comprising: generating a group message for changing states of associated ones among flow tables stored in a plurality of switches, respectively;
Transmitting the group message to the plurality of switches;
Receiving an acknowledgment message indicating whether an error has occurred in the group message from the plurality of switches; And
And transmitting a message instructing execution or cancellation of the group message to the plurality of switches based on the confirmation message,
Wherein the step of transmitting a message instructing execution or cancellation of the group message to the plurality of switches comprises the steps of: when receiving an acknowledgment message indicating an error occurrence of the group message from at least one of the plurality of switches, And a message indicating the cancellation of the group message is transmitted to the switch of the group management apparatus. In claim 8,
Wherein the group message is a message including a plurality of messages for simultaneously changing a plurality of flow tables associated with each other among flow tables stored in the plurality of switches. delete delete As a transaction management method performed on a switch,
Receiving a group message from a controller for a mutual state change among stored flow tables;
Verifying an error of the group message; And
And transmitting an acknowledgment message including the error information of the group message to the controller,
Receiving an execution message instructing execution of the group message or a cancel message instructing cancellation of the group message from the controller, and based on the contents of the group message stored in the temporary storage area corresponding to the execution message or the cancel message, The flow table is changed or the group message stored in the temporary storage area is deleted. The method of claim 12,
Wherein the receiving the group message from the controller comprises:
And storing the received group message in a temporary storage area. The method of claim 12,
The step of verifying the error of the group message comprises:
And determining whether at least one of a grammar and a pre-condition of the group message is valid. The method of claim 12,
The step of verifying the error of the group message comprises:
Wherein the resource availability of the switch is determined. The method of claim 12,
Wherein the acknowledgment message includes an error code if there is an error in the group message. delete delete

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