KR101405459B1 - Protection switching method in optical transport network - Google Patents

Abstract

In an optical transmission network for transmitting a packet, at least one tunnel for providing an end-to-end connection between nodes is formed, and the tunnel is composed of at least one optical wavelength. A plurality of optical channels are allocated to each optical wavelength, and one optical channel is set as a protection switching optical channel for the tunnel. When a failure occurs in the optical channel through which the packet is transmitted, the packet is transmitted through the protection switching optical channel set for the corresponding tunnel.

Description

[0001] The present invention relates to a protection switching method in an optical transmission network,

The present invention relates to a protection switching method in an optical transmission network for transmitting a packet.

The optical transport network has broad bandwidth, high reliability, well-developed protection switching and Operation, Administration, Maintenance (OAM) technology. Accordingly, studies are actively conducted to transmit packet data, which is currently exploding, through an optical transmission network.

Packet transmission using a conventional optical transmission network has a disadvantage in that it can not provide an effective protection switching function for packet data by multiplexing packet data with a time division multiplexing (TDM) signal having a high data rate.

A problem to be solved by the present invention is to provide a method for performing a protection switching function differentiated for each optical channel in an optical transmission network.

A protection switching method according to an aspect of the present invention is a protection switching method in a optical transmission network in which packets corresponding to at least one service group are transmitted and received between a plurality of nodes, Providing at least one tunnel for one service group to form an end-to-end connection, the tunnel comprising at least one optical wavelength; Assigning a plurality of optical channels to the optical wavelength; And setting at least one of the plurality of optical channels as a protection switching optical channel for the service group.

Here, one tunnel is provided for one service group, and the tunnel may include a plurality of optical wavelengths. In this case, the setting step sets one optical channel among a plurality of optical channels for each optical wavelength as a protection switching optical channel for the service group.

Also, one tunnel may be provided for the one service group, and the tunnel may include a plurality of optical wavelengths. In this case, the setting step sets all of the plurality of optical channels corresponding to one optical wavelength among the plurality of optical wavelengths corresponding to the tunnel to optical switching channels for protection switching for the service group.

Further, a plurality of tunnels are provided for the one service group, and the plurality of tunnels may each include a different optical wavelength. In this case, the setting step sets one optical channel among a plurality of optical channels corresponding to the optical wavelength as a protection switching optical channel for the service group, for each tunnel.

A protection switching method according to another aspect of the present invention is a protection switching method in an optical transmission network including a plurality of nodes and in which packets corresponding to at least one service group are transmitted and received between nodes, Providing one tunnel each to form an end-to-end connection, wherein the tunnels of the different service groups comprise the same optical wavelength; Allocating a plurality of optical channels to the one optical wavelength; And selecting one of the plurality of optical channels as a protection channel optical channel for each service group, respectively.

According to an embodiment of the present invention, when a packet is transmitted through an optical transmission network, an end-to-end connection is established through a tunnel, and a protection switching function is performed for a plurality of optical channels or optical wavelengths constituting a tunnel , A more effective protection switching function and differentiated packet transmission quality can be guaranteed for each service.

In addition, since the protection switching optical channel is set in advance, the differentiated bandwidth can be allocated to each optical channel, and as a result, the traffic transmitted through the allocated bandwidth can be differentially controlled according to the policy of the operator, Quality can be guaranteed.

1 is a diagram illustrating a method of configuring a tunnel in an optical transmission network according to an embodiment of the present invention.
2 is a diagram illustrating a structure of an optical transmission network having a protection switching function according to an embodiment of the present invention.
3 is a diagram illustrating a mapping relationship between a service group and a tunnel in an optical transmission network according to an embodiment of the present invention.
4 is a flowchart illustrating a protection switching method in the optical transmission network according to the first embodiment of the present invention.
5 is a diagram illustrating an example of applying the protection switching method according to the first embodiment of the present invention.
6 is a flowchart illustrating a protection switching method in an optical transmission network according to a second embodiment of the present invention.
FIG. 7 is an exemplary diagram illustrating the application of the protection switching method according to the second embodiment of the present invention.
8 is a flowchart illustrating a protection switching method in an optical transmission network according to a third embodiment of the present invention.
FIG. 9 is a diagram illustrating an application of the protection switching method according to the third embodiment of the present invention.
10 is a flowchart illustrating a protection switching method in an optical transmission network according to a fourth embodiment of the present invention.
11 is a diagram illustrating an example of applying the protection switching method according to the fourth embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order that those skilled in the art can easily carry out the present invention. In the following detailed description of the preferred embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In the drawings, like reference numerals are used throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

Hereinafter, a method and apparatus for protection switching in an optical transmission network according to an embodiment of the present invention will be described with reference to the drawings.

1 is a diagram illustrating a method of configuring a tunnel in an optical transmission network according to an embodiment of the present invention.

As shown in FIG. 1, the optical transport network 100 is made up of a plurality of tunnels. Each tunnel represents a logical connection path that provides end-to-end connectivity.

These tunnels can be configured in the following three ways.

1. One tunnel consists of one optical wavelength.

2. One tunnel consists of a plurality of optical wavelengths.

3. A plurality of tunnels are composed of one optical wavelength.

One optical wavelength is composed of at least one optical channels. The optical channel can be configured as an optical channel data unit (ODU), a virtual container (VC), a virtual concatenation group (VCG), or an IP / service flow depending on which physical link is used. And can be variously configured according to the type. In the embodiment of the present invention, the bandwidth allocation and the protection switching function can be applied differently for each optical channel.

2 is a diagram illustrating a structure of an optical transmission network having a protection switching function according to an embodiment of the present invention. In FIG. 2, four nodes, three service groups, and four tunnels are used in the optical transmission network 100, but the present invention is not limited thereto.

In the optical transmission network 100 according to the embodiment of the present invention, a plurality of nodes 10 to 40 are connected through at least one tunnel, and each node represents an optical transmission network apparatus. The tunnels T1 to T4 provide an end-to-end connection between each node. For example, a tunnel T1 and a tunnel T2 provide a virtual private network (VPN) A, a tunnel T3 provides a VPN B, and a tunnel T4 provides a VPN C.

The optical transmission network device, that is, each node 10 to 40 can transmit and receive packets corresponding to at least one service group SG1 to SG3. The service groups SG1 to SG3 provide packets corresponding to one of all kinds of services, such as a VPN service or a leased network service, regardless of the type of service.

3 is a diagram illustrating a mapping relationship between a service group and a tunnel in an optical transmission network according to an embodiment of the present invention.

As illustrated in FIG. 3, the first service group SG1 is connected to the tunnel T1 and the tunnel T2 through the optical transmission network interface 101. The first and second service groups SG1 to SG3 may be mapped to at least one tunnel, And the second service group SG2 may be mapped to the tunnel T3 through the optical transport network interface 101. [

Next, a protection switching method in the optical transmission network according to the first embodiment of the present invention will be described.

In the optical transmission network according to the first embodiment of the present invention, one tunnel is composed of one optical wavelength, and optical wavelengths constituting the tunnels are different from each other.

FIG. 4 is a flowchart illustrating a protection switching method in an optical transmission network according to a first embodiment of the present invention, and FIG. 5 is an exemplary view illustrating a protection switching method according to the first embodiment of the present invention. Here, as shown in FIG. 5, a plurality of tunnels are mapped to one service group, and a protection switching method according to an embodiment of the present invention will be described taking the first service group SG1 as an example.

A plurality of tunnels T1 and T2 are mapped to the first service group SG1 as illustrated in FIG. 2, the node 10 is connected to the node 20 and the node 30 through two tunnels T1 and T2 to transmit and receive packets corresponding to the first service group SG1, can do. The packets included in the first service group SG1 are classified by service level agreement (SLA), then mapped to a corresponding optical channel, and transmitted to a destination.

In this manner, a plurality of tunnels are provided in one service group (for example, SG1), each tunnel includes one optical wavelength, and the corresponding optical wavelength includes a corresponding plurality of optical channels (S100, S110). Here, one of the plurality of optical channels corresponding to each tunnel is set as a protection switching optical channel (S120). 5, the tunnel T1 mapped to the first service group SG1 includes one optical wavelength? 1 and a plurality of optical channels 1-1 and 1-2 1, ..., 1-n are assigned to one optical channel 1-n among the plurality of optical channels 1-1, 1-2, ..., 1-n. The other tunnels T2 mapped to the first service group SG1 include one optical wavelength λ2 and a plurality of optical channels 2-1, 2-2, ..., 2-n at the optical wavelength λ2. And one optical channel 2-n out of the plurality of optical channels 2-1, 2-2, ..., 2-n is set as a protection switching optical channel. Therefore, one protection switching optical channel (1-n, 2-n) is set for each of the tunnels for the first service group G1.

2, packets corresponding to the first service group SG1 between the node 10 and the node 20 are transmitted through the optical channels 1-1, 1-2, ..., 1-n-1 through the optical channels 2-1, 2-2, ..., and 2-n-1 corresponding to the tunnels T2 in step S130.

At this time, when a failure occurs in the optical channel through which the packet is transmitted (S140), the packets transmitted through the failed optical channel are transmitted through a predetermined optical switch for protection switching (S150).

More specifically, packets corresponding to the first service group SG1 between the node 10 and the node 20 are transmitted to the optical channels 1-1, 1-2, ..., 1- (1-i, where i is an integer) during transmission through a failed optical channel (1-i) while being transmitted through the optical channel (1-i) And is transmitted through the optical channel 1-n. While the packets corresponding to the first service group SG1 are being transmitted through the optical channels 2-1, 2-2, ..., 2-n-1 constituting the tunnel T2, (2-i, where i is an integer), packets that were transmitted through the failed optical channel (2-i) are transmitted through a predetermined protection switching optical channel (2-n).

Therefore, even when a failure occurs in the optical channel in the optical transmission network, the packets are transmitted through the protection switching optical channel, thereby ensuring the improved packet transmission quality.

In addition, since the protection switching optical channel is set in advance, the differentiated bandwidth can be allocated to each optical channel, and as a result, the traffic transmitted through the allocated bandwidth can be differentially controlled according to the policy of the operator, Quality can be guaranteed.

In the embodiment of the present invention, the failure occurring in the optical channel is a path failure (path degrade) in which the quality of the connection state falls below the set level although there is no problem in path failure and path connectivity, ). The detection of such a fault is a technique known in the art, and a detailed description thereof will be omitted here.

Next, a protection switching method in the optical transmission network according to the second embodiment of the present invention will be described.

In the optical transmission network according to the second embodiment of the present invention, a plurality of tunnels have one optical wavelength.

FIG. 6 is a flowchart illustrating a protection switching method in an optical transmission network according to a second embodiment of the present invention, and FIG. 7 is a diagram illustrating a protection switching method according to a second embodiment of the present invention. Here, the protection switching method according to the second embodiment of the present invention will be described taking the first service group SG1 and the second service group SG2 shown in FIG. 2 as an example. Here, one tunnel is mapped to each service group, and a plurality of tunnels mapped to each service group use one optical wavelength.

2 and 7, a tunnel T2 is mapped to the first service group SG1 and a tunnel T3 is mapped to the second service group SG2. For example, And the node 30, packets corresponding to the first service group SG1 and the second service group SG2 are transmitted. Here, packets corresponding to the first service group SG1 are transmitted through the tunnel T2, and packets corresponding to the second service group SG2 are transmitted through the tunnel T3.

When one tunnel is mapped to each service group (S200), the tunnel T2 to be mapped to the first service group SG1 and the tunnel T3 to be mapped to the second service group SG2 are one 2 of the same wavelength of the light. That is, the tunnel T 2 and the tunnel T 3 share the same optical wavelength λ 2. A plurality of optical channels 2-1, 2-2, ..., 2-n are formed with respect to one optical wavelength lambda 2 corresponding to the tunnels T2 and T3 (S210) (2-1, 2-2,..., 2-n) (S220). That is, one optical channel 2-m among the optical channels 2-1, 2-2, ..., 2-n corresponding to one optical wavelength? And sets the other optical channel 2-n to a protection switching optical channel for the second service group SG2.

Packets corresponding to the first service group SG1 and the second service group SG2 are classified by SLA and then protected among the optical channels 2-1, 2-2, ..., 2-n. And is transmitted to the destination via the remaining optical channels except for the optical fibers 2-m and 2-n for switching (S230).

When packets corresponding to the first service group SG1 are being transmitted / received through the remaining optical channels except for the protection switching optical channel through the tunnel T2, if a failure occurs in the optical channel in which the packet is being transmitted (S240) The packet transmitted through the channel is transmitted through the protection switching optical channel 2-m for the first service group SG1 (S250). In a state where packets corresponding to the second service group SG2 are being transmitted and received through the remaining optical channels except for the protection switching optical channel through the tunnel T3 and a failure occurs in the optical channel in which the packet is being transmitted, Is transmitted through the optical switch 2-n for protection switching to the second service group SG2.

Next, a protection switching method in the optical transmission network according to the third embodiment of the present invention will be described.

In the optical transmission network according to the third embodiment of the present invention, one tunnel is composed of a plurality of optical wavelengths.

FIG. 8 is a flowchart illustrating a protection switching method in an optical transmission network according to a third embodiment of the present invention, and FIG. 9 is an exemplary view illustrating a protection switching method according to a third embodiment of the present invention. Here, the protection switching method according to the third embodiment of the present invention will be described taking the third service group SG3 shown in FIG. 2 as an example.

As shown in FIGS. 2 and 9, packets corresponding to the third service group SG3 are transmitted between the node 10 and the node 40. FIG. Here, the tunnel T4 is mapped to the third service group SG3, and the packets corresponding to the third service group SG3 are transmitted and received through the tunnel T4.

Here, a plurality of optical wavelengths? 3 and? 4 are assigned to a tunnel T4 mapped to the third service group SG3, and a plurality of optical channels are allocated to each optical wavelength. A plurality of optical channels 3-1, 3-2, ..., 3-n are assigned to the optical wavelength? 3 of the tunnel T4, Channels 4-1, 4-2, ..., 4-n are allocated (S300, S310). Hereinafter, for convenience of description, a plurality of optical channels 3-1, 3-2, ..., 3-n assigned to the optical wavelength? 3 of the tunnel T4 is referred to as a "first optical channel group" A plurality of optical channels 4-1, 4-2, ..., 4-n allocated to the optical wavelength? 4 of the first optical channel group 4 is referred to as a "second optical channel group".

In the case where one tunnel T4 is composed of a plurality of optical wavelengths? 3 and? 4, one optical channel among the optical channels corresponding to the respective optical wavelengths is set as a protection switching optical channel. In other words, one of the first optical channel group 3-1, 3-2, ..., 3-n of the first optical channel group 3 of the optical wavelength? 3 constituting the tunnel T4 of the third service group SG3, n is set as a first protection switching optical channel for the third service group SG3 in S320 and the second optical channel group 4-1, 4-2, (4-n) out of the first to third protection groups SG1, ..., and 4-n to the second protection switching optical channel for the third service group SG3 at step S330.

In this manner, optical transmission channels for protection switching for the corresponding service group are respectively set for each wavelength of light. Then, packets corresponding to the third service group SG3 are classified by SLA, and then, Through the optical channels 4-1, 4-2, ..., 4-n-1 of the first optical channel group and the optical channels 3-1, 3-2, ..., (S340).

When a failure occurs in the optical channel in which the packet is being transmitted, the packets transmitted through the failed optical channel are transmitted through a predetermined optical switch for protection switching (S350). That is, when a failure occurs in one of the first optical channel groups 3-1, 3-2, ..., 3-n-1 of the optical wavelength λ3 constituting the tunnel T4, Through the first protection switching optical channel 3-n set for the first optical channel group (S360, S370). When a failure occurs in one of the optical channels 4-1, 4-2, ..., 4-n-1 of the second optical channel group of the wavelength? 4, packets transmitted through the optical channel are transmitted to the second optical channel group Through the optical switch 4-n for the second protection switching (step S380).

Next, a protection switching method in the optical transmission network according to the fourth embodiment of the present invention will be described.

In the optical transmission network according to the fourth embodiment of the present invention, one tunnel is composed of a plurality of optical wavelengths as in the third embodiment. Unlike the third embodiment, all the optical channels corresponding to one optical wavelength, Respectively.

FIG. 10 is a flowchart illustrating a protection switching method in an optical transmission network according to a fourth exemplary embodiment of the present invention, and FIG. 11 is an exemplary view illustrating a protection switching method according to a fourth exemplary embodiment of the present invention. Here, the protection switching method according to the fourth embodiment of the present invention will be described taking the third service group SG3 shown in FIG. 2 as an example.

In the optical transmission network according to the fourth embodiment of the present invention, one tunnel is composed of a plurality of optical wavelengths. As described in the third embodiment above, when one tunnel is composed of a plurality of optical wavelengths and a plurality of optical channels are assigned to each optical wavelength, as described above, for each optical wavelength, The optical wavelength of one of the plurality of optical wavelengths constituting one tunnel can be set for protective switching without setting a channel. That is, a plurality of optical channels corresponding to one optical wavelength are set as protection-use optical channels.

In the fourth embodiment of the present invention, as in the third embodiment, when one tunnel is mapped to one service group as shown in FIGS. 10 and 11, the tunnel is divided into a plurality of optical wavelengths And a plurality of optical channels are allocated to each optical wavelength. That is, a plurality of optical wavelengths? 3 and? 4 are assigned to the tunnel T4 mapped to the third service group SG3, and the first optical channel group 3-1, 3- 2, ..., 3-n, and the second optical channel group 4-1, 4-2, ..., 4-n is assigned to the optical wavelength 4 of the tunnel T4 (S400, S410 ).

However, unlike the third embodiment, one optical wavelength among the light wavelengths? 43 and? 4 of the tunnel T4 is set for protection switching (S420), and a plurality of optical channels corresponding to the set optical wavelength are set for protection switching And sets them as optical channels (S430). That is, as shown in FIG. 10, the optical wavelength? 4 constituting the tunnel T4 of the third service group SG3 is selected and the corresponding second optical channel group 4-1, 4-2, ..., 4-n is selected. Is set as a protection switching optical channel for the third service group (SG3).

Therefore, the packets corresponding to the third service group SG3 are classified by the SLA, and then the optical packets of the other optical wavelengths (here, the first optical channel group 3-1, 3-2, ..., 3-n) to the destination (S440).

In this case, if a failure occurs in the optical channel of the first optical channel group in which packets are being transmitted, the packets transmitted through the failed optical channel are transmitted through the optical channel in the protection switching optical channel, that is, the optical channel in the second optical channel group (S450, S460).

The embodiments of the present invention described above are not only implemented by means of apparatuses and methods but may be implemented by a program capable of executing functions corresponding to the configuration of the protection switching method according to the embodiment of the present invention, Readable recording medium. The present invention can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (9)

delete A protection switching method in an optical transmission network including a plurality of nodes, wherein packets corresponding to at least one service group are transmitted and received between the nodes,
Providing at least one tunnel for one service group to form an end-to-end connection, the tunnel comprising at least one optical wavelength;
Assigning a plurality of optical channels to the optical wavelength; And
Setting at least one of the plurality of optical channels as a protection channel optical channel for the service group
Lt; / RTI >
Wherein one tunnel is provided for the one service group, the tunnel comprises a plurality of optical wavelengths,
Wherein the setting step sets one optical channel among a plurality of optical channels for each wavelength of light as a protection switching optical channel for the service group. A protection switching method in an optical transmission network including a plurality of nodes, wherein packets corresponding to at least one service group are transmitted and received between the nodes,
Providing at least one tunnel for one service group to form an end-to-end connection, the tunnel comprising at least one optical wavelength;
Assigning a plurality of optical channels to the optical wavelength; And
Setting at least one of the plurality of optical channels as a protection channel optical channel for the service group
Lt; / RTI >
Wherein one tunnel is provided for the one service group, the tunnel comprises a plurality of optical wavelengths,
Wherein the setting step sets all of the plurality of optical channels corresponding to one optical wavelength among a plurality of optical wavelengths corresponding to the tunnel to optical switching channels for protection switching for the service group. A protection switching method in an optical transmission network including a plurality of nodes, wherein packets corresponding to at least one service group are transmitted and received between the nodes,
Providing at least one tunnel for one service group to form an end-to-end connection, the tunnel comprising at least one optical wavelength;
Assigning a plurality of optical channels to the optical wavelength; And
Setting at least one of the plurality of optical channels as a protection channel optical channel for the service group
Lt; / RTI >
Wherein a plurality of tunnels are provided for the one service group, each of the plurality of tunnels includes a different optical wavelength,
Wherein the setting step sets one optical channel among a plurality of optical channels corresponding to the optical wavelength as a protection switching optical channel for the service group for each tunnel. A protection switching method in an optical transmission network including a plurality of nodes, wherein packets corresponding to at least one service group are transmitted and received between the nodes,
Providing one tunnel for each of the different service groups to form an end-to-end connection, wherein the tunnels of the different service groups include the same optical wavelength;
Allocating a plurality of optical channels to the one optical wavelength; And
Selecting one optical channel among the plurality of optical channels and setting them as optical channels for protection switching for each service group
. ≪ / RTI > The method according to any one of claims 2 to 5, wherein
A packet is transmitted through the remaining optical channels except for the protection switching optical channel among the optical channels corresponding to one tunnel; And
When a failure occurs in an optical channel through which the packet is transmitted, the packet is transmitted through a protection switching optical channel set corresponding to the tunnel
Further comprising the steps of: The method according to any one of claims 2 to 5, wherein
Wherein packets in the service group are classified by service level agreement (SLA), and then transmitted to a destination through an optical channel of a tunnel mapped to the service group. The method according to any one of claims 2 to 5, wherein
Wherein bandwidths are allocated differently for the optical channels. The method according to any one of claims 2 to 5, wherein
Wherein the optical channel is configured by any one of an optical channel data unit (ODU), a virtual container (VC), a virtual concatenation group (VCG), and an IP / service flow depending on which physical link is used.

Images