KR100792207B1 - Apparatus and method of multi-layer restoration applying lcas adaptively - Google Patents

Abstract

A multilayer restoration apparatus for adaptively applying an LCAS(Link Capacity Adjustment Scheme) and a method thereof are provided to minimize the data loss due to an increase in restoration time and previously prevent service interruption in case of failing to secure reserve channels by adaptively applying an LCAS according to the significance of channel-by-channel services. A software restoration part(320) in a multilayer restoration apparatus comprises a service judgement part(321), a dynamic restoration part(324), a pre-planned restoration part(322), and an LCAS(323). The service judgement part(321) previously stores channel-by-channel service priority information in a network. The dynamic restoration part(324) broadcasts a restoration message through a message communication channel between network nodes and execute fault restoration. The pre-planned restoration part(322) executes fault restoration through a pre-appointed restoration route according to the occurrence location of a network fault. The LCAS(323) automatically reduces link capacity by removing a specific node if a fault has occurred from the specific node. If the fault is removed, the LCAS(323) automatically returns the link capacity to normal and executes fault restoration.

Description

[0001] APPARATUS AND METHOD OF MULTI-LAYER RESTORATION APPLICATION [0002] LASER ADAPTIVELY [

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

2 is a flowchart showing a general multi-layer recovery method;

3 is a block diagram illustrating a multi-layer recovery apparatus adaptively applying an LCAS according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a multi-layer recovery method in which an LCAS is adaptively applied according to an embodiment of the present invention. FIG.

The present invention relates to a network restoration method, and more particularly, to a multi-layer restoration apparatus and method in which LCAS is adaptively applied to a mesh network.

Currently, the transmission equipment processes high-speed signals of high-capacity in a high-speed, high-capacity network, so that the hardware is complicated and the amount of software to control the equipment is enormous. Therefore, the network equipment manager should recover the network failure such as the breakdown of the optical line, the failure due to the natural disaster as well as the failure of the transmission equipment itself in an early time to provide stable service.

A general failure recovery method of such a device is divided into a central control method and a distributed control method according to a self-healing control method, and is divided into a line recovery and a path recovery according to the target of signal recovery. Is divided into a 1 + 1 or 1: N recovery method, and a software restoration algorithm can be classified into a pre-planned recovery method and a dynamic recovery method.

Among them, the general recovery method is mainly a dynamic recovery method that can recover in real time after the occurrence of a fault, reflecting the network situation. This is a method in which a recovery message is broadcast using a message communication channel between each line distribution system node. However, this method has a disadvantage in that the message processing load is increased, and the actual recovery performance is significantly degraded.

On the contrary, the pre-planned restoration method can achieve high recovery performance by performing a failover through a designated recovery route according to the location of the failure. However, this method can not specify a recovery route in advance for all failures of the network, and even if designation is made, the amount of memory for storing it is enormous, .

This will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a general multi-layer recovery apparatus, which illustrates a multi-layer recovery apparatus capable of simultaneously operating a hardware recovery method and a software-based recovery method for failover.

1, the general multi-layer recovery apparatus includes a hardware recovery apparatus 110 and a software recovery apparatus 120, and the software recovery apparatus 120 includes a pre-plan recovery unit 121 and a dynamic recovery (Not shown). The hardware recovery apparatus 110 and the software recovery apparatus 120 are as described above.

In the case of a general multi-layered recovery apparatus configured as described above, since it is better to recover the network failure than to recover the network failure in terms of the recovery time and the recovery reliability, Afterwards, it is common to perform software recovery in a secondary way.

In addition, in the software-based recovery, if the two recovery methods are structured in a step-by-step manner and recovery is performed, a certain recovery rate and a quick recovery time obtained through the recovery recovery unit 121 can be obtained. A high recovery rate can be obtained by further applying the dynamic recovery unit 122 to the channel that is not used.

FIG. 2 is a flowchart illustrating a general multi-layer recovery method, which illustrates the operation of the recovery apparatus.

As shown in FIG. 2, if a network failure is detected (S200), hardware recovery is first performed (S205). If the failure recovery is not completed through the hardware recovery (S210), the failure recovery is performed by applying the software recovery method (S215-S225).

However, such a multi-layer recovery method broadcasts a dynamic recovery message, which increases the processing time of the recovery message and increases the recovery time. In addition, there is a problem in that data loss may occur due to the increased recovery time, and the service should be stopped when the spare channel is not secured.

In order to solve this problem, Korean Patent Application No. 2005-0042772 (hereinafter referred to as " Conventional Technology ") discloses a multi-layer recovery method using LCAS, in which hardware recovery is performed when a failure occurs in a network, If the failure is not overcome by the preplanned recovery method, if the failure is not overcome, it is determined that the channels passing through the failed line use LCAS, and then the channels use LCAS A method of applying an LCAS function to channels and restoring a failure through a dynamic recovery method when channels do not use LCAS has been disclosed.

However, since the prior art is applied to all channels uniformly without regard to the importance of the service for each channel, there is a problem in that the service can not be recovered and the service must be stopped when a network failure occurs.

Accordingly, it is an object of the present invention to provide a multi-layer recovery apparatus and method adaptively applying LCAS.

To this end, a multi-layer recovery method adaptively applying LCAS according to an exemplary embodiment of the present invention includes: (a) performing hardware recovery when a failure occurs in a network; (b) if the failure is not overcome through the hardware recovery, determining a service importance of channels passing through the failure path; And (c) recovering the fault using at least one of a method of applying a preplanned recovery method, a dynamic recovery method, or a Link Capacity Adjustment Scheme (LCAS) according to the determination result.

In addition, according to an embodiment of the present invention, a multi-layer recovery apparatus that performs hardware recovery when a network failure is detected, and applies software recovery if the failure recovery is not completed through the hardware recovery, A service determination unit for previously storing the service importance ranking information for each channel; A dynamic recovery unit for broadcasting a recovery message through a message communication channel between the network nodes to perform the failure recovery; A line plan restoring unit for restoring a fault through a predetermined recovery route according to a location of the network fault; And a Link Capacity Adjustment Scheme (LCAS) for automatically reducing a link capacity by removing a specific node in the network in which the failure occurs, and automatically recovering the link capacity when the failure of the node is removed, The dynamic recovery unit, the pre-plan restoring unit, and the LCAS are selectively performed according to the service importance determined by the service determination unit.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments. In the drawings, the same or similar components are denoted by the same reference numerals.

FIG. 3 is a block diagram illustrating a multi-layer recovery apparatus to which an LCAS according to an embodiment of the present invention is adaptively applied.

As shown in FIG. 3, the apparatus mainly includes a hardware restoration unit 310 and a software restoration unit 320. The software restoring unit 320 includes a service importance determining unit 321, a line plan restoring unit 322, an LCAS 323, and a dynamic restoring unit 324. [

1 and 2, the hardware restoring unit 310, the pre-plan restoring unit 322, and the dynamic restoring unit 324 have the same functions as those of the hardware restoring unit 110, 121 and the dynamic restoration unit 122, the description thereof will be omitted.

First, the Link Capacity Adjustment Scheme (LCAS) 323 performs a function of automatically removing and recovering a failure occurring in a virtual connection and a function of increasing / decreasing link capacity without error. All the controls used in this LCAS 323 use control packets defined in ITU-T G.7042.

Particularly, in the present invention, the automatic removal and return function of the fault path of the LCAS 323 is applied. For example, in an SDH / OTN (Synchronous Digital Hierarchy / Optical Transmission Network) network, when a particular member in a VCAT (Virtual Concatenation) group (VCG) is difficult to service due to a failure in the network, Automatically reduce or overcome network failures by automatically returning the link capacity when this member is removed.

In addition, the LCAS 323 defines states required on the source and sink sides to adjust the flexibility of the VCAT signal, and when increasing or decreasing the signal capacity of the VCG in response to a specific application request It provides a control mechanism that can guarantee Hitless.

As described above, when the LCAS 323 is applied to the present invention, the channel can minimize the data loss and minimize the blocking probability for the line. However, when the data is recovered through the LCAS 323, a transmission delay or a data transmission speed may be reduced due to delays.

The service importance determination unit 321 stores the service priority information for each channel in advance. Accordingly, the service priority information of each channel selected by the manager is previously stored, and the multi-layer recovery method is applied differently according to the priority in the network restoration.

FIG. 4 is a flowchart illustrating a multi-layer recovery method adaptively applying LCAS according to an exemplary embodiment of the present invention. That is, if a failure is detected in the network, a multi-layer recovery method is started by the following process.

First, a hardware recovery is performed, and if the failure is not overcome by hardware recovery, software recovery is performed (S405-S410). The time required for hardware recovery is within 50ms.

Software recovery first determines the importance of each channel-based service (S415). As a result of the determination, if the service importance of the channel is the highest (that is, if the service is classified as the highest class), the LCAS 323 is first applied in order to prevent the service interruption (S420).

If the importance of the service of the channel is medium, the pre-plan restoration method is performed first, and if the restoration is not completed by the pre-plan restoration method, the LCAS 323 is applied (S425-S435).

In addition, if the channel service is least important (i.e., classified as the lowest class), the pre-plan recovery method recovery method is performed. If the pre-recovery method is not completed, the dynamic restoration method is performed (S440- S450). However, if recovery is not completed by the dynamic recovery method, the LCAS 323 is applied (S455-S460).

In the case described above, when the LCAS 323 is applied to a failed network, the link capacity of the channels is reduced. However, if the above-mentioned obstacle is removed, the link capacity of these channels is restored.

Meanwhile, the flowchart of FIG. 4 can be implemented as a computer-readable code or a program on a computer-readable recording medium. In addition, the computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present invention.

According to the present invention, in a synchronous network having a mesh structure, LCAS is adaptively applied according to the importance of services per channel, minimizing data loss due to an increase in recovery time that can occur in a conventional multi- It is possible to prevent the extreme situation of service interruption in advance in case of failing to secure.

Claims (7)

(a) performing a hardware recovery if a failure occurs in the network; (b) if the failure is not overcome through the hardware recovery, determining a service importance of channels passing through the failure path; And (c) recovering the fault using at least one of a preplanning recovery scheme, a dynamic recovery scheme, and a Link Capacity Adjustment Scheme (LCAS) scheme according to the determination result. A multi - The method of claim 1, wherein the step (c) If it is determined that the service priority of the channel is classified as the highest class, And the LCAS is applied to the channels to recover the fault. The multi-layer recovery method adaptively applied to the LCAS. The method of claim 1, wherein the step (c) If it is determined that the service priority of the channel is classified as the lowest class, Wherein the channel recovery method is performed on the channels, and if the recovery is not completed by the pre-plan recovery method, the dynamic recovery method is performed. If the recovery is not completed by the dynamic recovery method, A multi - layer recovery method adaptively applying an LCAS characterized by restoring a fault. The method of claim 1, wherein the step (c) As a result of the determination, if the service importance of the channel is not classified into the highest and lowest classes, Wherein the pre-plan restoration method is performed first, and if the restoration is not completed by the pre-plan restoration method, the fault is recovered by applying the LCAS method to the multi-layer restoration method adaptively applied to the LCAS. A multi-layer recovery apparatus for performing a hardware recovery when a network failure is detected and applying software recovery if the failure recovery is not completed through the hardware recovery, A service determination unit for previously storing service priority information of each channel for the network; A dynamic recovery unit for broadcasting a recovery message through a message communication channel between the network nodes to perform the failure recovery; A line plan restoring unit for restoring a fault through a predetermined recovery route according to a location of the network fault; And And an LCAS (Link Capacity Adjustment Scheme) for automatically reducing a link capacity by removing a specific node in the network in which the failure occurs, and automatically recovering the link capacity when the failure of the node is removed, Wherein the dynamic restoration unit, the pre-plan restoration unit, and the LCAS are selectively performed according to the service importance determined by the service determination unit. 6. The apparatus of claim 5, If the service priority of the channel is classified into the highest class, the LCAS is performed on the channels, If the priority of the service of the channel is classified into the lowest class, the preplanned recovery unit is performed on the channels, the dynamic recovery unit is performed if the recovery is not completed, the LCAS is performed if the recovery is not completed, Wherein the LCAS is performed if the service priority of the channel is not classified into the highest and lowest classes, and if the recovery is not completed, the LCAS is performed. A computer-readable recording medium recording a program for performing multi-layer recovery, The program includes: (a) performing a hardware recovery when a failure occurs in the network; (b) if the failure is not overcome through the hardware recovery, determining a service importance of channels passing through the path where the failure occurs; And (c) recovering the fault using at least one of a preplanning recovery scheme, a dynamic recovery scheme, and a Link Capacity Adjustment Scheme (LCAS) scheme according to the determination result. Recording medium.

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