KR101977527B1 - Multicasting method and apparatus using multicast group sharing tree in software definition network - Google Patents

Abstract

The present invention relates to a multicasting method and apparatus using a multicast group sharing tree of a software-defined network (SDN). The present invention provides the multicasting method using a multicast group sharing tree of the SDN, which includes multiple switches, comprising the following steps: obtaining a distance of each receiver within a multicast group by each rendezvous point (RP) candidate switch and obtaining the sum of the distances of all the receivers by each RP candidate switch; comparing the distance of each obtained RP candidate to select a switch with the shortest distance as an RP; setting a path to make the distance between the selected RP and a sender shortest; and generating a tree structure for the path between the RP and the receiver, wherein the selection of the RP, the setting of the path between the sender and the RP and the generation of the tree structure between the receiver and the RP occur when the sender or the receiver participates in or leaves the multicast group. The present invention, when the multicast is applied in an environment of the internet of things where the senders and the receivers become more, can reduce resources of network equipment, can reduce the number of flow objects applied to the switch and can reduce the overload of the RP.

Description

TECHNICAL FIELD The present invention relates to a multicast group sharing tree and a multicast group sharing tree,

The present invention relates to multicasting network communication, and more particularly, to a multicasting method and apparatus using a multicast group shared tree of a software defined network (SDN)

Multicast is a communication method that transmits the same traffic to a large number of people at a time from a single sender among network communication methods at once. If the same traffic is repeatedly sent to multiple recipients, the network is overloaded. To reduce this load, a multicast approach has emerged. Multicast has two transmission schemes, source-based tree and group-shared tree.

The source-based tree is a structure in which the sender is centralized and network flows are made to the recipients participating in the group. This tree is useful for networks that can quickly deliver traffic. On the other hand, a group share tree is a tree structure in which multicend communication must pass a rendezvous point. Here, the rendezvous point is responsible for the top layer of the group share tree. This network communication is useful in many senders and networks with many multicast groups.

The disadvantage of the multicast group share tree is the overhead of rendezvous points and the difficulty of multicast tree structure and group management. Overload of rendezvous points is due to the nature of the group share tree in the case of a network with many senders, packets must pass through rendezvous points. In this section, the entire traffic is concentrated, which causes a problem of information loss due to overload of the network. In order to solve the network overload, it is necessary to have a function to view the entire network in the course of modifying the rendezvous point. The existing network should generate packets of the whole network to check the structure of the whole network. This results in a heavy load on the network. If multicast communication is performed without this method, it is difficult to appropriately change the rendezvous point of the group share tree, and it is difficult to control the multicast tree and the group management of the sender and the receiver.

SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus for multicast routing in a software defined network (SDN) based on a proximity receive rendezvous point dynamic selection algorithm capable of distributing rendezvous point (RP) And a multicasting method and apparatus using the group shared tree.

According to an aspect of the present invention, there is provided a multicast method using a multicast group shared tree of a software definition network (SDN), including multicasting using a multicast group shared tree of a software definition network (SDN) The method includes: obtaining a distance of each receiver in a multicast group for each Rendezvous Point (RP) candidate switch and obtaining a sum of distances of all receivers for each Rendezvous candidate switch; Selecting a switch having a shortest distance as a rendezvous point by comparing the obtained rendezvous point candidate distances; Setting a path to be the shortest distance between the selected rendezvous point and the sender; And generating a tree structure between the rendezvous point and the recipient, wherein the rendezvous point selection, the routing between the sender and the rendezvous point, and the tree structure creation between the recipient and the rendezvous point are performed by the sender or the receiver, When a person joins or leaves the group.

 The rendezvous point candidate distance is the number of times that the rendezvous point candidate switch has passed, and is determined as a sum of distances to the receivers for each rendezvous point candidate switch.

 Wherein the control plane in a software defined network (SDN) including the plurality of switches is an SDN multicast controller and a switch connected to the SDN multicast controller is a data plane, the SDN multicast controller includes a rendezvous point ) Is selected, the Flow-Mod message is sent to the switch so that the number of switches passing through the rendezvous point (RP) is the smallest and the route with the shortest distance is formed. In addition, when a control plane in a software defined network (SDN) including the plurality of switches is an SDN multicast controller and a switch connected to the SDN multicast controller is a data plane, the SDN multicast controller is a rendezvous point (RP) is selected, the flow of the recipients at the rendezvous point (RP) is sent to the switch so that the flow-mode message is passed through the path of the shortest tree type.

According to another aspect of the present invention, there is provided a multicast method using a multicast group shared tree of a software defined network (SDN), comprising: transmitting a control plane in a software defined network (SDN) including a plurality of switches to an SDN multicast controller And a switch connected to the SDN multicast controller is a data plane, the multicast traffic is generated at a sender and transmitted to a rendezvous point; And the rendezvous point includes attaching a VLAN (Virtual LAN) header matching a multicast group, and separating the VLAN header from the last switch adjacent to the receiver and transmitting the multicast traffic, Or when a recipient joins or leaves a multicast group, and the rendezvous point selection algorithm for selecting the rendezvous point determines the distance of each recipient in the multicast group for each rendezvous point candidate switch, and calculates the distance The sum of the calculated rendezvous point candidates is compared with the calculated distance of the rendezvous point candidates, and the switch having the shortest distance is selected as a rendezvous point.

The multicast method using a multicast group sharing tree of a software definition network (SDN) according to the present invention includes: sending, by the receiver, an IGMPv3 Report message, which is a group join message, to the switch; The switch sending an IGMPv3 Report message received from the receiver to the SDN multicast controller; Wherein the SDN multicast controller selects a rendezvous point using a group management and a proximity receiver dynamic rendezvous point selection algorithm based on a message received from the switch and calculates a multicast flow; And the SDN multicast controller may include sending a Flow-mod message to install the multicast flow entity to the switch.

In addition, the present invention provides a multicasting method using a multicast group sharing tree of a software defined network (SDN), comprising: sending a multicast message to a switch by a sender; The switch sending a multicast message received from the sender to an SDN multicast controller; The SDN multicast controller 100 selects a rendezvous point (RP) using a group management and a proximity receiver dynamic rendezvous point selection algorithm based on a multicast message received from the switch, and calculates a multicast flow; The SDN multicast controller sending a Flow-mod message for installing a multicast flow entity to the switch; When the Flow object is installed through the Flow-mode message, the sender transmits a multicast message to the switch; And the switch may include transmitting the multicast message to the recipient according to the installed Flow.

According to an aspect of the present invention, there is provided a multicasting apparatus using a multicast group sharing tree of a Software Defined Network (SDN) network, the multicasting apparatus including at least one sender and a plurality of receivers, A plurality of switches comprising multicast traffic and including rendezvous points; And an SDN multicast controller for managing control planes in a software defined network (SDN) comprising the plurality of switches, the SDN multicast controller being responsible for selecting a rendezvous point from the plurality of switches when the sender or the receiver joins or leaves a multicast group Wherein the rendezvous point comprises a switch connected to the SDN multicast controller as a data plane, receives a multicast traffic generated by a sender, and transmits a virtual LAN (VLAN) header corresponding to the multicast group to the multicast packet The SDN multicast controller obtains the distance of each of the recipients in the multicast group for each rendezvous point candidate switch, and transmits the multicast traffic to the Rendezvous point candidate switch, after For each switch, obtain the distance sum of the entire receiver compares the determined rendezvous point candidate by the distance to the short distance that the switch is characterized in that selected as rendezvous points.

According to the multicasting method and apparatus using the multicast group sharing tree of the Software Defined Network (SDN) according to the present invention, when multicast is applied in the object Internet environment where there are many senders and receivers, , And the number of flow objects applied to the switch can be reduced. In addition, due to the software defined network, it is possible to easily reduce the load of the rendezvous point, thereby reducing the packet loss due to the distribution balancing effect of the packet.

FIG. 1 is a block diagram illustrating a configuration of a multicast device in a software defined network (SDN) to which a multicasting method using a multicast group shared tree of a software definition network (SDN) according to the present invention is applied. Road.
2 is a flow chart illustrating the operation of the recipient multicast group.
3 is a flow chart illustrating the operation of the sender multicast group.
FIG. 4 is a flowchart illustrating an embodiment of a multicasting method using a multicast group shared tree of a software definition network (SDN) according to the present invention.
FIG. 5 illustrates an example of a pseudo code for a near-receiver dynamic RP algorithm according to the present invention.

The techniques disclosed herein can be applied to multicasting of software defined networks (SDN). However, the technology disclosed in this specification is not limited thereto, and can be applied to all electronic devices and methods to which the technical idea of the above-described technology can be applied.

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the scope of the technology disclosed herein. Also, the technical terms used herein should be interpreted as being generally understood by those skilled in the art to which the presently disclosed subject matter belongs, unless the context clearly dictates otherwise in this specification, Should not be construed in a broader sense, or interpreted in an oversimplified sense. It is also to be understood that the technical terms used herein are erroneous technical terms that do not accurately represent the spirit of the technology disclosed herein, it is to be understood that the technical terms used herein may be understood by those of ordinary skill in the art to which this disclosure belongs And it should be understood. Also, the general terms used in the present specification should be interpreted in accordance with the predefined or prior context, and should not be construed as being excessively reduced in meaning.

As used herein, terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements 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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals denote like or similar elements, and redundant description thereof will be omitted.

Further, in the description of the technology disclosed in this specification, a detailed description of related arts will be omitted if it is determined that the gist of the technology disclosed in this specification may be obscured. It is to be noted that the attached drawings are only for the purpose of easily understanding the concept of the technology disclosed in the present specification, and should not be construed as limiting the spirit of the technology by the attached drawings.

The present invention provides the ability to view the entire network because of the software defined network structure that separates the entire network from the data plane and control plane. The ability to view the entire network makes it easy to manage multicast trees and groups, can easily modify the rendezvous point location, and can easily select the rendezvous point location through the proximity receive rendezvous point dynamic selection algorithm.

The proximity receiving rendezvous point dynamic selection algorithm selects a rendezvous candidate switch located at the shortest distance among the results of the distance between the receivers of the same multicast group and each rendezvous candidate switch as a rendezvous switch. The algorithm is called and executed whenever a member of a multicast group joins or leaves.

FIG. 1 is a block diagram illustrating a configuration of a multicast device in a software defined network (SDN) to which a multicasting method using a multicast group shared tree of a software definition network (SDN) according to the present invention is applied. Road.

A multicast device in a software defined network (SDN) according to the present invention comprises a plurality of switches 151, 152, 153, 154, 155, 156 and an SDN multicast controller 100.

The plurality of switches 151, 152, 153, 154, 155, 156 are present between at least one sender and a plurality of receivers, and comprise multicast traffic from a sender to a plurality of receivers, including rendezvous points 153 do.

SDN multicast controller 100 is responsible for a control plane in a software defined network (SDN) comprising the plurality of switches, and when the sender or the receiver joins or leaves a multicast group, Select a point. When selecting the rendezvous point among the plurality of switches, the SDN multicast controller 100 obtains the distance of each of the receivers in the multicast group for each rendezvous point candidate switch, obtains the sum of distances of all the receivers for each rendezvous candidate switch, Select the rendezvous point as the shortest distance switch by comparing the rendezvous point candidate distances.

The rendezvous point 153 receives the multicast traffic generated by the sender and transmits the multicast group to the multicast group when the switches 151, 152, 153, 154, 155, and 156 connected to the SDN multicast controller 100 are data planes. To the multicast packet and removes the VLAN header from the multicast packet from the last switch adjacent to the receiver and transmits the multicast traffic.

1, the control plane in a software defined network (SDN) is an SDN multicast controller 100, and the switches 151, 152, 153, 154, 155, 156 connected to the SDN multicast controller 100 ) Is the data plane. The multicast traffic is generated at the senders 160 and 170 and is transmitted to the rendezvous point 153. The rendezvous point 153 attaches a virtual LAN (VLAN) header suited to the multicast group, And the switch 155 and 156, which are adjacent to each other, remove the VLAN header and transmit the multicast traffic.

The SDN multicast controller 100 may have six modules. A topology discovery module 110, a flow installation module 115 and a traffic monitor module 120 are basically provided as a module. The modules include a tree management module 135, a group manager Manager 140, and the RP selection module 145 is an extension module 130.

First, a topology discovery module (Topology Discovery) 110 is a module for discovering a current network structure. Through a LLDP (Link Layer Discovery Protocol) message, the topology discovery module 110 determines where a switch is located, Check the information.

A flow installation module 115 is a module for installing a flow for forwarding a packet, and sends a message to the switch to install a multicast flow object to send a multicast packet.

A traffic monitor (120) is a module that can check the amount of packets transmitted through the entire network. To monitor the amount of traffic of the entire network, the traffic monitor (120) .

Next, the extension module 130 will be described. The tree management module 135 is a module for managing a tree of multicast, and determines how to construct a tree by referring to group management and packet monitoring.

The group management module 140 manages the multicast group, and manages the sender and the receiver of the multicast group using the IGMPv3 Report packet of the receiver and the multicast packets of the sender.

The RP selection module (RP Selection 145) is a module for selecting the location of the rendezvous point (RP) of the group share tree, and selects the rendezvous point location using the algorithm of the proximity receiver dynamic rendezvous point.

2 is a flow chart illustrating the operation of the recipient multicast group. First, the receiver sends an IGMPv3 Report message, which is a group join message, to the switch. (210) The switch sends an IGMPv3 Report message received from the receiver to the SDN multicast controller 100. (220) A rendezvous point is selected 230 and a multicast flow is calculated using the group management and proximity receiver dynamic rendezvous point selection algorithm based on the message received from the SDN multicast controller 100) sends a Flow-mod message to install the multicast flow object to the switch (250)

3 is a flow chart illustrating the operation of the sender multicast group. First, the sender sends a multicast message to the switch. (310) The switch sends the multicast message received from the sender to the SDN multicast controller 100. (320) The SDN multicast controller 100 selects (330) the rendezvous point (RP) using the group management and proximity receiver dynamic rendezvous point selection algorithm based on the multicast message received from the switch (330) (340) The SDN multicast controller 100 sends a Flow-mod message for installing the multicast flow object to the switch 350. When the Flow object is installed through the Flow-mod message, The switch transmits a multicast message to the receiver according to the installed flow at step 350. At step 360,

FIG. 4 is a flowchart illustrating an embodiment of a multicasting method using a multicast group shared tree of a software definition network (SDN) according to the present invention. Referring to FIG. 4, in a multicasting method using a multicast group shared tree of a software defined network (SDN) including a plurality of switches, a distance of each receiver in a multicast group is calculated for each Rendezvous Point (RP) candidate switch In step S420, the sum of the total Rendezvous point candidates is calculated as the sum of the distances to the receivers by the Rendezvous point candidate switches. . ≪ / RTI >

In step S430, the route is set to a shortest distance between the selected rendezvous point and the sender in step S440. In step S440, the rendezvous points And the recipient is created in a tree structure (step S450)

The selection of the rendezvous point, the routing between the sender and the rendezvous point, and the creation of a tree structure between the recipient and the rendezvous point occur when the sender or the recipient joins or leaves the multicast group.

After the rendezvous point (RP) is selected, the SDN multicast controller sends a Flow-Mod message to the switch to create a route with the least number of switches via the sender's device and the rendezvous point (RP).

In addition, the SDN multicast controller sends a Flow-Mod message to the switch at the rendezvous point (RP) after the rendezvous point (RP) is selected, so that the path of the recipient passes through the path of the shortest tree.

FIG. 5 illustrates an example of a pseudo code for a near-receiver dynamic RP algorithm according to the present invention. The Nearest Receive Dynamic RP algorithm according to the present invention is an algorithm used for setting a rendezvous point when a group shared tree needs to be created or changed. The algorithm includes a receiver of the same multicast group and a rendezvous point candidate And then selects the rendezvous point as the switch having the shortest distance among the switches. And constructs a multicast tree around the selected switch.

More specifically, the input parameters of the proximity receiving rendezvous point dynamic selection algorithm are S, N, C. N is the topology of the network that the current group has, and S is an array containing information about all the switches in the network topology of the multicast group. And C is an array having location information of receivers registered through the IGMP Report message. And utilizes the input to return the location information of the selected switch in the proximity receive rendezvous point dynamic selection algorithm.

The algorithm operates on the RP candidate switch to determine the distance to the receivers of the same multicast group. The distance obtained here is defined as the number of times the switch has passed. The sum of the distances to the receivers for each switch is obtained. Next, the distance between the candidates of the RP is compared, the switch having the shortest distance is selected, and the position information is returned. After the RP is selected, the controller sends a Flow Mod message to make the router the shortest distance between the sender and the rendezvous point (RP), that is, the switch oversuced, and the path of the recipients on the RP to the shortest path Sends a Flow Mod message. This action occurs when joining or leaving a multicast group of a sender or a receiver.

In the foregoing, preferred embodiments of the present invention have been described with reference to the accompanying drawings. Here, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and should be construed in a sense and concept consistent with the technical idea of the present invention.

The scope of the present invention is not limited to the embodiments disclosed herein, and the present invention can be modified, changed, or improved in various forms within the scope of the present invention and the claims.

100: SDN multicast controller 110: Topology discovery module
115: Flow Install module 120: Traffic monitor
130: Expansion module 135: Tree management module
140: Group Manager 145: Rendezvous point selection module
151, 152, 153, 154, 155, 156: switch 153: rendezvous point
160, 170: Source 180, 190: Receiver,

Claims (8)

A multicast method using a multicast group share tree of a software defined network (SDN) comprising a plurality of receivers and a plurality of switches,
Obtaining respective distances between the rendezvous point candidate switch and the plurality of receivers in the multicast group for each rendezvous point (RP) candidate switch, and obtaining a sum of distances of all the plurality of receivers for each rendezvous point candidate switch;
Selecting a switch having a shortest total sum of the plurality of receivers as a rendezvous point by comparing the total sum of the plurality of receivers for each of the rendezvous point candidate switches obtained;
Setting a path between the rendezvous point and the sender to be the shortest distance between the selected rendezvous point and the sender; And
Generating a path between the rendezvous point and the recipient in a tree structure,
The tree structure creation between the rendezvous point selection and the rendezvous point occurs whenever a new recipient joins a multicast group or an existing recipient leaves a multicast group.
Wherein the rendezvous point is a switch through which all packets transmitted in the multicast communication are routed. The method of multicasting using a multicast group shared tree of a software defined network (SDN). 2. The method of claim 1, wherein the sum of the total of the plurality of receivers for each rendezvous point candidate switch is
Wherein the rendezvous point candidate switch is determined as a sum of the distances to the plurality of receivers by the rendezvous point candidate switch and the sum of the distances to the plurality of receivers by the rendezvous point candidate switch. Way. The method as claimed in claim 1, wherein when a control plane in a software defined network (SDN) including the plurality of switches is an SDN multicast controller and a switch connected to the SDN multicast controller is a data plane, The controller
Defined network (SDN), characterized in that after the rendezvous point (RP) is selected, a Flow-Mod message is sent to the switch so as to create the path with the smallest number of switches via the rendezvous point (RP) A multicasting method using a multicast group shared tree. The method as claimed in claim 1, wherein when a control plane in a software defined network (SDN) including the plurality of switches is an SDN multicast controller and a switch connected to the SDN multicast controller is a data plane, The controller
Characterized in that after the rendezvous point (RP) is selected, the flow of the recipients at the rendezvous point (RP) is sent to the switch so that the flow- Multicasting method using group shared tree. When a control plane in a software defined network (SDN) including a plurality of receivers and a plurality of switches is an SDN multicast controller and a switch connected to the SDN multicast controller is a data plane, the multicast traffic is generated at a sender To a rendezvous point; And
The rendezvous point includes attaching a VLAN (Virtual LAN) header suitable for a multicast group, and separating the VLAN header from the last switch adjacent to the receiver and transmitting the multicast traffic,
The selection of the rendezvous point occurs every time a new recipient joins a multicast group or an existing recipient leaves a multicast group, and a rendezvous point selection algorithm for selecting the rendezvous point is performed for each rendezvous point candidate switch A distance sum between the rendezvous point candidate switch and the plurality of receivers is obtained and a sum of distances of all of the plurality of receivers is obtained for each rendezvous point candidate switch to compare the sum of distances of all the plurality of receivers for each rendezvous point candidate switch, Wherein a rendezvous point candidate switch having a shortest total sum of a plurality of receivers is selected as a rendezvous point, characterized in that the rendezvous point is a switch through which all packets transmitted in the multicast communication go through A multicasting method using a multicast group shared tree of a software definition network (SDN). 6. The method of claim 5,
Sending the IGMPv3 Report message, which is the group join message, to the switch by the receiver;
The switch sending an IGMPv3 Report message received from the receiver to the SDN multicast controller;
Wherein the SDN multicast controller selects a rendezvous point using a group management and a proximity receiver dynamic rendezvous point selection algorithm based on a message received from the switch and calculates a multicast flow; And
Wherein the SDN multicast controller includes a step of sending a Flow-mod message for installing a multicast flow entity to the switch. ≪ RTI ID = 0.0 > 8. < / RTI > 6. The method of claim 5,
The sender sending a multicast message to a switch;
The switch sending a multicast message received from the sender to an SDN multicast controller;
The SDN multicast controller selects a rendezvous point (RP) using a group management and a nearest neighbor dynamic rendezvous point selection algorithm based on a multicast message received from the switch, and calculates a multicast flow;
The SDN multicast controller sending a Flow-mod message for installing a multicast flow entity to the switch;
When the Flow object is installed through the Flow-mode message, the sender transmits a multicast message to the switch; And
Wherein the switch comprises sending a multicast message to a recipient according to the installed flow. ≪ Desc / Clms Page number 19 > A plurality of switches residing between at least one sender and a plurality of receivers, the plurality of switches comprising multicast traffic from a sender to a plurality of receivers and including rendezvous points; And
(SDN), comprising a plurality of switches, wherein each time a new recipient joins a multicast group or an existing recipient leaves a multicast group, a rendezvous point Select < / RTI > SDN multicast controller,
When the switch connected to the SDN multicast controller is a data plane, the rendezvous point receives the multicast traffic generated by the sender, attaches a VLAN (Virtual LAN) header matching the multicast group to the multicast packet, Removes the VLAN header from the multicast packet from an adjacent switch, transmits multicast traffic,
Wherein the SDN multicast controller obtains a distance between the rendezvous point candidate switch and the plurality of receivers in the multicast group for each rendezvous point candidate switch and obtains a sum of distances of the plurality of receivers for each rendezvous point candidate switch, Point candidates, and selects a rendezvous point candidate switch having a shortest total sum of the plurality of receivers as a whole, by comparing the total sum of all of the plurality of receivers for each of the point candidate switches, wherein the rendez- (SDN) multicast group shared tree, characterized in that the multicast group shared tree is a switch through which all packets going through the multicast group are transmitted.

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