KR100617307B1 - Connection configuration method and connection reconfiguration method in optical network - Google Patents

Abstract

A connection establishment method and a connection reconfiguration method for traffic of a class having priority in an optical network are disclosed. In the optical network, establish an optical path, which is a physical connection path through at least one optical switch from originating clients to receiving clients, and a logical virtual link between the originating and receiving clients based on the established optical path. After configuring the virtual network consisting of the network, the connection path of the traffic is allocated to a direct connection path in the virtual network or a bypass connection path via at least one or more clients based on the required bandwidth of the traffic. This improves the efficiency of network resource usage, and reconfigures new paths through the network configuration of the physical network only when the traffic connection through the preset virtual network is impossible, thereby improving the performance of the connection configuration and at the same time dynamically changing the traffic demand. Can cope with

Optical path, virtual link, virtual network, priority

Description

Connection configuration method and connection reconfiguration method in optical network

1 is a view showing an optical network to which the present invention is applied;

2 illustrates one embodiment of an optical path setup in an optical network;

3 is a diagram illustrating a virtual network configured based on the optical path of FIG. 2;

4A is a flowchart illustrating an embodiment of a method for establishing a connection of traffic according to the present invention;

4B is a flowchart illustrating an embodiment of a method for reconfiguring a connection of traffic according to the present invention, and

4C and 4D illustrate an embodiment of a connection establishment method and a connection reconfiguration method for traffic belonging to each class when two classes of a high priority class and a low priority class exist.

The present invention relates to a connection establishment method and a connection reconfiguration method in an optical network, and more particularly, to a connection establishment method and a connection reconfiguration method for a multi-class traffic having priority in an optical network.

Nodes of a conventional optical network simply provide a connection between nodes at the request of a client node or an operator terminal connected to the optical network, thereby providing a transmission path for the transmission of traffic flowing from the client node to another client. Client nodes use a pre-connected path or require a new path setting to deliver traffic required from a subscriber or a subscriber network through a path connected to another subscriber or subscriber network.

Conventional techniques related to traffic channel connection in an optical transport network include a system and method for establishing a traffic channel connection between a client and an optical transport network in Korean Patent Publication No. 2003-0066917. This is a system and method for establishing a channel connection between a client and an optical transmission network for supplying various multimedia internet services by using a wavelength division multiplexing (WDM) based optical transmission network that provides a large-capacity high-speed Internet service as a backbone network. It is about.

In the operation between a conventional optical network and a client, the optical network nodes only provide the same transmission function for the traffic on the connected path, so that the traffic of several classes having different priorities unless the client provides a separate connection establishment method for the traffic class. Cannot give priority to.

In addition, the connection settings of the conventional optical network, which is set according to the demand of the available traffic in advance, are not able to actively cope with the demand of the traffic changing over time, and to support as many connections as possible within a fixed network resource. There is difficulty.

The technical problem to be achieved by the present invention is to change the connection setting method of each traffic according to the priority for the multi-class traffic having a priority, and to efficiently support the resources of the limited optical network while supporting the transmission characteristics of the required traffic. This paper provides a connection establishment method and connection reconfiguration method for traffic of multiple classes in an optical network.

In order to achieve the above technical problem, an embodiment of the method for establishing a connection of traffic according to the present invention is an optical network that is a physical connection path through at least one optical switch from originating clients to receiving clients in an optical network. Establishing a path; Configuring a virtual network comprising logical virtual links between the originating and receiving clients based on the established optical path; And setting a routing path for the traffic as a direct connection path in the virtual network or a bypass connection path via at least one or more clients based on the priority of the traffic and the required bandwidth of the traffic.

In order to achieve the above technical problem, an embodiment of the connection reconfiguration method of traffic according to the present invention, based on the amount of traffic demands to establish an optical path via at least one optical switch between the clients, and the optical Constructing a virtual network composed of virtual links between clients based on a path; Resetting an optical path and a virtual network when there is no virtual link available as a connection path of traffic among the virtual links of the virtual network; And establishing a connection path of the traffic based on the virtual link of the reset virtual network.

This improves the efficiency of network resource usage, and reestablishes a new path through the physical network configuration only when traffic is established through a preset virtual network and when traffic cannot be connected through the preset virtual network. It can improve performance and cope with dynamic changes in traffic demand.

1 is a view showing an optical network to which the present invention is applied.

Referring to FIG. 1, an optical network 100 is connected to at least one optical switch 110 and an optical network and uses an optical network client node 120 (hereinafter referred to as a 'client') that uses a connection path on the optical network. It consists of

Nodes of the optical switch 110 in the optical network 100 are connected to a Wavelength Division Mutiplexing (WDM) link 130 that transmits several optical wavelengths as one unit. The unit for transmitting data in the WDM link 130 is a wavelength of a predetermined band, which is called a lambda. If each lambda has a bandwidth of 2.5 Gbps, 10 Gbps, etc., the WDM link 130 may deliver a predetermined number of lambdas.

The optical switch 110 node is responsible for the switching function of the lambda unit converting a specific lambda of the input WDM link to the same or different lambda of the output WDM link. A client node includes a router, an ATM switch, a TDM switch, and the like, and is connected to the optical switch by one optical link 140.

Looking at the transmission unit transmitted on the link 140 between the client node (hereinafter referred to as the 'client') and the optical switch node (hereinafter referred to as the 'optical switch'), the client is delivered through the optical link 140 After converting the light electrically, it recognizes and processes data unit in client where router is located, ATM cell unit in client where ATM switch is located, and SONET / SDH frame unit in client where TDM switch is located. The optical switch does not electrically convert light transmitted through the optical link, but converts the whole into a single lambda, which is transmitted to the input of the optical switch and switches in the corresponding path.

As shown in FIG. 1, a connection establishment method and a connection reconfiguration method of traffic according to the present invention based on seven clients and six optical switches will be described in detail below.

FIG. 2 is a diagram illustrating an embodiment of an optical path setting in an optical network, and FIG. 3 is a diagram illustrating a virtual network configured based on the optical path of FIG. 2.

2 and 3, in order to transmit data on the optical network 200, a connection setup from the originating client to the receiving client to which data is to be transmitted is required, which is called an optical path. The optical path is required and connected by a client or a management node of the optical network. Since the optical switch on the optical path converts the input lambda into an output lambda and exchanges them, when one optical path is connected, all data transmitted through the path reaches the destination client, thus connecting between the clients. It is possible to configure a logical virtual network using the optical path as a link.

One of the optical paths 240 configured in the physical network is the path of Client 1 220-> Optical Switch 1 202-> Optical Switch 2 204-> Optical Switch 3 206-> Client 4 226. to be. If this is configured in the virtual network (FIG. 3), it becomes a virtual link 310 connecting the client 1 220 and the client 4 226. The bandwidth of the virtual link is allocated the bandwidth of the connected optical path.

In this way, if the optical path in the physical network shown in FIG. That is, the optical paths 240 to 260 are converted into the virtual links 300 to 340 of FIG. 3, respectively.

A single optical path occupies a large band, such as 2.5 Gbps or 10 Gbps, so that every time a connection is needed for the transmission of traffic in a smaller band, the same optical link is used for the same traffic connection through the same originating and receiving clients as for the optical path. Use a method of assigning to a path. In addition, the present invention discloses a method for efficiently allocating connection settings for high priority traffic and low priority traffic in addition to the general path allocation method.

4A is a flowchart illustrating an embodiment of a method for establishing a connection of traffic according to the present invention.

Referring to FIG. 4A, the network management node requests an optical path setting according to traffic demands between clients in an initial physical network configuration (S400). The optical path is established by selecting the available links from the originating client to the receiving client and connecting the optical switch. The selection and wavelength assignment of optical switch nodes and links used on the optical path use the algorithms of conventional optical networks.

In operation S405, a virtual network having a set optical path with clients is configured as a virtual link. For example, the virtual network may include Client 1 220 and Client 4 226, Client 1 220 and Client 6 230, Client 2 222 and Client 5, as shown in FIGS. 228, client 3 224, client 6 230, client 4 226, client 6 230, and five virtual links are connected. In the case of the client 7 232, there is no physical path but there is no optical path with any client, so the virtual network cannot communicate with any client.

In a virtual network, there may be a plurality of virtual links to be used as connection paths of traffic, and the virtual links may be originated through at least one client in the middle of a direct connection path between the originating client and the receiving client in the virtual network or directly in between. There is a bypass connection path from the client to the client.

After the virtual network configuration is completed, if the connection setup for the traffic is required, the virtual link capable of the required band is selected among the virtual links connectable between the calling client and the receiving client requesting the connection, and the traffic connection is established. (S415). For example, if the traffic is between client 1 220 and client 6 230, the connection is assigned to the virtual link 310.

In order to establish a connection path of the traffic, the priority of the traffic is used as well as the required band (S415). If two traffics with overlapping bandwidths are required on the virtual link, which is the connection path of the traffic, the high-priority traffic is allocated to this virtual link, and the low-priority traffic is allocated to another bypass connection path.

Specifically, the optimal virtual link for the traffic is selected using a conventional shortest distance path selection algorithm among at least one or more virtual links that satisfy the required bandwidth of the traffic. In addition, when a plurality of traffics are connected to the virtual link and each of the required bands overlap some or all, the high priority traffic is allocated to the virtual link and the low priority traffic is allocated to another bypass connection path.

The traffic belongs to any one of the classes identified by at least one or more priorities. Classes may be divided into two classes or two or more classes, and each may be given a priority.

4B is a flowchart illustrating the flow of one embodiment of a method for reconfiguring a connection of traffic according to the present invention.

Referring to FIG. 4B, a virtual network including virtual links between clients is configured based on the optical path set according to the traffic demand (S420). If the connection path of the traffic cannot be established using the virtual link of the virtual network, a new optical path is set and the virtual network is reconfigured based on the newly set optical path (S422).

When the traffic cannot use the virtual link of the virtual network, when there is no virtual link connecting the originating client and the receiving client of the traffic (for example, in FIG. 3, client 1 220 and client 7 ( 232), there may be a virtual link between the originating client and the receiving client, but the virtual link cannot provide the required bandwidth of the traffic.

When the virtual network is reconfigured, traffic is allocated to the virtual link of the reconfigured virtual network (S424).

4C and 4D illustrate an embodiment of a connection establishment method and a connection reconfiguration method for traffic belonging to each class when two classes of a high priority class and a low priority class exist.

Referring to FIG. 4C, in the state where the virtual network configuration is completed, if connection setting for the first traffic belonging to the high priority class is requested (S430), a request among the virtual links established between the originating client and the receiving client of the traffic is requested. If there is a virtual link with the available band, traffic is established through the virtual link (S465).

If there is a virtual link for the first traffic, but there is a second traffic belonging to a lower priority class having a request band of the same range as the required band of the first traffic (S440), the second Another bypass connection path that can accommodate traffic is selected (S455) and a second traffic is assigned to the bypass connection path. In operation S465, the first traffic is connected to the virtual link from which the second traffic is removed.

For example, in FIG. 3, the low priority traffic connection is assigned to the virtual path 310 between the client 1 220 and the client 6 230, and the band used by the low priority traffic connection is client 1. If the available link is available in each of the virtual link 300 connecting the 220 and the client 4 226 and the virtual link 340 connecting the client 4 226 and the client 6 230, the low-priority traffic connection may be applied to the client 4 226. Assigns to the virtual links 300 and 340 via, removes the low priority traffic from the virtual link 310 and then assigns the high priority traffic link to the virtual link 310.

If there is a virtual link for the first traffic but the second traffic having a lower priority than the request band of the same range as the request band of the first traffic does not exist on the virtual link (S440), a new optical path connection is requested. (S455). The virtual network is reconfigured based on the newly set optical path (S450), and the connection of traffic is established through the virtual link of the reconfigured virtual network (S465).

In addition, if the virtual link connecting the originating client and the receiving client of the first traffic does not exist on the virtual network, or the virtual link exists even if the virtual link does not meet the required bandwidth of the traffic, the virtual network may be disconnected. Reconstruct (S450).

For example, in the virtual network of FIG. 3, when there is no low priority traffic connection to bypass the virtual link 310 between the client 1 220 and the client 6 230, a new optical path is established. When a connection between the client 1 220 and the client 7 232 is required, a new optical path is set.

Referring to FIG. 4D, if connection establishment for traffic belonging to a low priority class is required (S470), the connection path of the traffic is searched through a general shortest distance path selection algorithm on the virtual network (S475).

If there is a connection path (virtual link) (S480), low priority traffic is assigned to the selected path. If there is no connection path (S480), that is, if there is no virtual link for traffic in the virtual network, a new optical path connection establishment is requested (S485). After reconstructing the virtual network on the basis of the new optical path (S490), a connection path of traffic is established through the virtual link of the reconstructed virtual network (S495).

For example, in FIG. 3, when establishing a connection of low priority traffic between the client 1 220 and the client 6 230, traffic is allocated to the virtual link 310 or a bypass connection using the virtual link 300 and the virtual link 340. Traffic may be assigned on the path. If neither is possible, set up a new optical path.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

According to the present invention, by managing the connections of classes with different priorities, the traffic of the high priority class can be accommodated through the bypass of the traffic of the low priority class in a given network environment, thereby increasing the efficiency of network resource usage. . By connecting traffic through a preset virtual network and establishing a new path through the network configuration of the physical network only when the traffic cannot be connected through the preset virtual network, it improves the performance of the connection setup and at the same time changes the dynamic demand of the traffic. Can cope

Claims (9)

Establishing an optical path, which is a physical connection path through at least one optical switch from originating clients to receiving clients in an optical network; Configuring a virtual network comprising logical virtual links between the originating and receiving clients based on the established optical path; And Classifying the traffic by priority and assigning the connection path of the traffic to a direct connection path or a bypass connection path via at least one or more clients in the virtual network based on the required bandwidth and priority of the traffic; Method for establishing a connection of traffic, characterized in that. The method of claim 1, And wherein the traffic belongs to any one of at least one class classified by priority. The method of claim 1, The establishing of the connection path may include setting a connection path of traffic lower than the priority of the traffic to another bypass connection path when a request band of the traffic and a request band of traffic lower than the traffic priority overlap in the connection path of the traffic. Method for establishing a connection of traffic, characterized in that it comprises a step. The method of claim 1, The step of establishing a connection path may include setting a connection path of the traffic through a shortest path selection algorithm among at least one or more direct or detour connection paths as the connection path of the traffic. The method of claim 1, Resetting an optical path and a virtual network if the connection path of the traffic does not exist in the virtual network. The method of claim 1, Resetting an optical path and a virtual network if the required band of the traffic overlaps with the required band of the traffic having higher priority than the traffic in the connection path of the traffic, and there is no other bypass connection path for the traffic. Connection establishment method of traffic, characterized in that it comprises a. The method of claim 1, In the connection path of the traffic, if the request band of the traffic and the request band of traffic having a lower priority than the traffic overlap, and there is no other bypass connection path for the low priority traffic, the optical path and the virtual network are reset. And further comprising the step of: establishing a connection of the traffic. Establishing an optical path between at least one optical switch between the clients based on the demand of the traffic, and constructing a virtual network composed of virtual links between the clients based on the optical path; Resetting an optical path and a virtual network when there is no virtual link available as a connection path of traffic among the virtual links of the virtual network; And Establishing a connection path of the traffic based on the virtual link of the reset virtual network. The method of claim 8, The resetting of the virtual network may be performed by using an optical path and a virtual network when there is no virtual link to use as a connection path of the traffic, or when traffic having a higher priority than the traffic uses the required bandwidth of the traffic in the existing virtual link. And resetting the traffic.

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