KR102559099B1 - Apparatus and Method for Interconnecting Multiple Linear Protection Domains and Apparatus Thereof - Google Patents

Abstract

The present invention provides a linear protection switching domain connection method comprising the steps of: a working interconnection node monitoring for failures of a working path i, a working path i+1, and a connection path i connected to a paired protection interconnection node, and transmitting the result to the protection interconnection node; determining, generating working path control information and protection path control information according to user traffic transmission/reception path information and protection path failure information, and transmitting the working path control information to the working interconnection node, and the protection interconnection node connecting only two of protection path i, protection path i+1, and connection path i according to the protection path control information.

Description

Apparatus and Method for Interconnecting Multiple Linear Protection Domains and Apparatus Thereof

The present invention relates to an apparatus and method for connecting two domains protected by a linear protection switching method using two interconnection nodes.

A conventional linear protection switching method can protect a physical or logical connection between two end nodes within one protection domain (protected domain or protection domain). One end node is connected to another end node through a working path and a protection path. The protection switching process executed at each end node allows two end nodes to exchange user traffic using the same path by exchanging information necessary for protection switching through a protection path.

The single-node interconnection method has the advantage of realizing traffic protection switching between end nodes by applying each of the two protection domains without changing the conventional linear protection switching method. However, when a failure occurs in the interconnection node I, there is a problem in that traffic transmission between the two end nodes E1 and E2 is cut off.

The present invention provides a linear protection switching domain connection device and method that protects user traffic transmitted and received between both end nodes in case of a network failure by using two interconnection nodes and a path connecting the interconnection nodes when connecting two protection domains, but allows each end node to use the conventional linear protection switching method as it is.

The present invention is a working interconnection node device, comprising: OAM 1 connected to working path i and monitoring the presence or absence of failure of the working path i; OAM 2 connected to working path i+1 and monitoring the presence or absence of failure of the working path i+1; and a species interconnection control unit for transmitting the received working path control information to the working path connection unit, and a working path connection unit for connecting two of the working path i, the working path i+1, and the connection path i according to the working path control information.

The present invention is a protection interconnection node device, comprising: an OAM that monitors whether a connection path i connecting paired working interconnection nodes has a failure, an OAM & P 1 or an OAM & P 2 that is connected to protection path i or protection path i+1 and monitors whether or not there is a failure in protection path i or protection path i+1, and determines a user traffic transmission/reception path based on the failure status information of working path i or working path i+1 and the failure status information of protection path i or protection path i+1, and the determined user A linear protection switching processor i or a linear protection switching processor i+1 transmits traffic transmission/reception path information to a main interconnection control unit, a main interconnection control unit generates working path control information and protection path control information upon receiving the user traffic transmission/reception path information and protection path failure information, and transmits the generated working path control information and protection path control information to the working interconnection node and the protection path connection unit, respectively, and a protection path connection unit that connects only two of protection path i, protection path i+1, and connection path i according to the protection path control information.

The present invention provides a linear protection switching domain connection method comprising the steps of: a working interconnection node monitoring whether a working path i, a working path i+1, and a connection path i connected to a paired protection interconnection node are connected to the protection interconnection node, and transmitting the result to the protection interconnection node; the protection interconnection node monitoring the connection path i, the protection path i, and the protection path i+1; the protection interconnection node generating working path control information and protection path control information according to the user traffic transmission and reception path information and the protection path failure information, the protection interconnection node transmitting the working path control information to the working interconnection node, and the protection interconnection node connecting only two of protection path i, protection path i+1, and connection path i according to the protection path control information.

The present invention has an effect of protecting user traffic flowing between end nodes even when one interconnection node fails by using two interconnection nodes when connecting two protection domains protected by the linear protection switching scheme. In addition, the operation of the interconnection node proposed in the present invention has an advantage in that the existing linear protection switching technology can be used without change by defining additionally necessary new functions and operations without changing the existing linear protection switching functions and operations.

1 is a diagram for explaining a protection domain using linear protection switching.
2 is an internal configuration diagram of an end node for performing linear protection switching.
3 is a diagram for explaining protection domain interconnection using a single node.
4 is a diagram for explaining an interconnection node in a protection domain interconnection using a single node.
5 is a diagram illustrating an embodiment in which two protection domains are connected according to the present invention.
6 is a diagram showing another embodiment in which three protection domains are connected according to the present invention.
7 is a diagram showing another embodiment in which n+1 protection domains are connected according to the present invention.
8 is a structural diagram of a working interconnection node Ii and a protection interconnection node Ii', which are a pair of interconnection nodes connecting protection domains according to an embodiment of the present invention.
9 is a signal flowchart for explaining a linear protection switching domain connection method according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

Terms including ordinal numbers such as second and first may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It should be understood that when an element is referred to as being “connected” or “connected” to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but it should be understood that the presence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof is not excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and are not interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application.

A "path" used in the present invention means a path through which user traffic is transmitted between two nodes, and another node may exist in the middle of the path between the two nodes. One path may exist in one physical link or port, several paths may logically exist in one physical link or port, or several physical links or ports may be configured as one logical path.

In the present invention, a method of protecting user traffic using a detour path according to the occurrence and disappearance of a path failure is described. In general, in protection switching technology, there are various commands such as Forced Switch (FS), Manual Switch (MS), Lockout of Protection, etc. that allow a network operator to divert user traffic to another path as needed in addition to failure. "Failure" used in the present invention includes practical failures such as Signal Fail (SF) or Signal Degrade (SD) as well as the above-mentioned operator commands.

1 is a diagram for explaining a protection domain using linear protection switching.

Referring to FIG. 1 , an end node E1 (10) is connected to an end node (E2) 20 through a working path and a protection path. Intermediate nodes may exist on each path, but since all intermediate nodes only perform a function of forwarding user traffic and do not perform an operation for protection switching, the display of intermediate nodes is omitted for convenience.

The protection switching process executed in each of the end nodes E1 and E2 10 and 20 exchanges information necessary for protection switching through a protection path so that the two end nodes E1 and E2 10 and 20 can exchange user traffic using the same path.

For example, in a normal state, two end nodes E1 and E2 10 and 20 exchange user traffic using a working path, and when a defect in a working path is detected at either end node, the two nodes E1 and E2 10 and 20 may exchange traffic using a protection path through information exchange between protection switching processes.

Conventional linear protection switching methods include ITU-T recommendations G.8031 (Ethernet linear protection switching), G.8131 (MPLS-TP linear protection switching), G.873.1 (OTN linear protection switching), IETF RFC 6378 (MPLS-TP linear protection switching - PSC mode), and RFC 7271 (MPLS-TP linear protection switching - APS mode).

2 is an internal configuration diagram of an end node for performing linear protection switching.

Referring to FIG. 2, each of the end nodes E1 and E2 10 and 20 has an Operations, Administration and Maintenance (OAM) 11 and 21 for detecting a failure of the working path and an OAM & Protection (OAM & P) 12 and 22 for detecting a failure of the protection path and transmitting or receiving a protection switch message through the protection path.

There are various ways to monitor the state of the working path or protection path, and from the point of view of protection switching, protection switching operation can be performed when failure information (normal, signal fail, or signal degrade) of the working path and protection path is provided regardless of which monitoring method is used.

In addition, each end node (E1 and E2) (10, 20) has a bridge for selectively transmitting user traffic flowing into the protection domain to a working or protection path under the control of the Linear Protection Switching Process (14, 24) and a selector for selecting one of the walking or protection paths and sending traffic received therefrom to the outside of the protection domain. 23) shows that bi-directional traffic is transmitted and received through the working path or protection path. The bridge/selector units 13 and 23 select a working or protection path according to the control of the linear protection switching process 14 and 24 (for example, path control information) and forward user traffic.

The linear protection switching processes 14 and 24 in each end node receive the working path failure information, the protection path failure information, and the protection switching message received from the opposite end node, and control the bridge/selector units 13 and 23 by a linear protection switching mechanism. Although not shown in FIG. 2, the protection switching processes 14 and 24 may control the bridge and the selector by a linear protection switching mechanism in consideration of the protection switching command input from the operator.

3 shows a method of connecting two protection domains protected by the linear protection switching method to one interconnecting or interworking node I.

The single node interconnection method shown in FIG. 3 is the simplest method of interconnecting two protection domains, and has the advantage of being able to protect individual protection domains individually by using the conventional linear protection switching method as it is for each protection domain.

For example, even if there is a failure in working path 1 in protection domain 1 and a failure in protection path 2 in protection domain 2, user traffic between end nodes E1 (10) and E2 (20) can be protected by connecting protection path 1 and working path 2 at interconnection node I (30).

4 is an internal structural diagram of an interconnection node I when using the single node interconnection method shown in FIG. 3;

Referring to FIG. 4 , protection switching can be realized by simply connecting bridge/selector units 31 and 32 to each other without changing protection switching-related structures existing in existing end nodes E1 and E2.

The single node interconnection method shown in FIGS. 3 and 4 has the advantage of realizing traffic protection switching between the end nodes 10 and 20 by applying the conventional linear protection switching method to two protection domains without changing the method. However, when a failure occurs in the interconnection node I 30, traffic transmission between the two end nodes E1 10 and E2 20 is disconnected.

The present invention relates to an apparatus and method for preventing traffic disconnection when a failure occurs in such an interconnection node.

A network configuration including the linear protection switching domain connection device according to the present invention is possible in various embodiments. According to one embodiment, as shown in FIG.

According to another embodiment, as shown in FIG. 6, a configuration in which three protection domains are connected using two pairs of interconnection nodes, that is, a pair of I1 (100-1) and I1' (200-1) and a pair of I2 (100-2) and I2' (200-2) is possible. Here, protection domains 1 and 3 are four interconnection nodes I1 (100-1), I1' (200-1), and I2 ( 100-2) and I2' (200-2), it can also be viewed as being connected. Even in this case, user traffic transmitted and received between the end nodes E1 (10) and E2 (20) can be protected according to the present invention.

According to another embodiment, as shown in FIG. 7, it can be extended using several pairs of interconnection nodes (100-1, 100-2, ... 100-n, 200-1, 200-2, ..., 200-n) without limiting the number of protection domains.

5 to 7, the structure and operation of the end nodes E1 (10) and E2 (20) are the same as those of the conventional linear protection switching, but the structure and operation of a pair of interconnection nodes Ii and Ii' are in accordance with the present invention.

8 is a structural diagram of a working interconnection node Ii and a protection interconnection node Ii', which are a pair of interconnection nodes connecting protection domains according to an embodiment of the present invention. When connecting two or more protection domains as shown in FIGS. 5 to 7 , all pairs of interconnection nodes connecting adjacent protection domains have a structure as shown in FIG. 8 .

Referring to FIG. 8, the working interconnection node Ii 100 connects the working path i and the working path i+1, and each working path is connected to the counterpart end node or working interconnection node of each protection domain, and is connected to the protection interconnection node Ii′ 200 through the connection path i.

On the other hand, the protection interconnection node Ii′ (200) connects protection path i and protection path i+1, each protection path is connected to the opposite end node or protection interconnection node of each protection domain, and is connected to the working interconnection node Ii (100) through connection path i.

The working interconnection node Ii 100 includes three OAMs 110, 120, and 130, a species interconnection control unit 140, and a working path connection unit 150. However, this configuration is only one embodiment for explaining the present invention, and the present invention is not limited thereto, that is, several parts may be combined or one part may be divided in detail, and some functions may be transferred to other parts.

The three OAMs 110, 120, and 130 monitor the states of working path i, working path i+1, and connection path i, respectively. As a technology for monitoring the state of a path in the OAM (110, 120, 130), there are various methods such as an international standard or a separate method defined by an equipment developer.

The working path connection unit 150 serves to connect only two of the three paths including working path i, working path i+1, and connection path i, and interconnects two of the three paths under the control of the species interconnection control unit 140. Here, a state in which working path i and working path i+1 are connected to each other is illustrated as an example.

The species interconnection control unit 140 transmits the failure information received from each OAM unit 110, 120, 130 to the primary interconnection control unit 270 of the protection interconnection node Ii' 200, and forwards the working path control information received from the primary interconnection control unit 270 to the working path connection unit 150. However, according to an embodiment, if the working path control information cannot be received from the main interconnection control unit 270 of the protection interconnection node Ii′ (200) due to a failure in the connection path i, the working path control information instructing to connect the working path i and the working path i+1 is generated and transmitted to the working path connection unit 150.

On the other hand, the protection interconnection node Ii' (200) consists of an OAM (210), two OAM & P (220, 230), two linear protection switching processors (240, 250), a protection path connection unit (260) and a main interconnection control unit (270).

OAM 210 is a block for monitoring the state of connection path i. As a technology for monitoring the state of the path in the OAM 210, there are various techniques such as those defined by international standards or separate techniques defined by equipment developers, and in the present invention, when a failure occurs or disappears in a path regardless of a specific technique, it is assumed that the main interconnect control unit 270 is notified of this.

OAM & P (220, 230) is a block for monitoring the status of protection path i or i+1 and transmitting or receiving a linear protection switching message. Here, the protection path i or i+1 and the linear protection switching message, failure information, and connection control information displayed alongside the connection path i are transferred through the protection path and the connection path, respectively, and are indicated by separate arrows for convenience in explaining the present invention.

As a technology for monitoring the state of a path, there are various methods such as those defined by international standards or separate techniques set by equipment developers. In the present invention, regardless of a specific technique, when a failure occurs or disappears in a path, it is assumed that the linear protection switching processor unit 240, 250 informs. Linear protection switching messages are exchanged between both nodes of the protection path of each protection domain, and the OAM & P (220, 230) transmits the linear protection switching message received from the counterpart node of the protection domain to the linear protection switching processors (240, 250), and transmits the linear protection switching message generated by the linear protection switching processors (240, 250) to the counterpart node of the protection domain.

The linear protection switching processor i (or i+1) determines whether to transmit/receive user traffic to working path i (or i+1) or protection path i (or i+1) by receiving the presence or absence of failure of working path i (or i+1) and protection path i (or i+1) according to the conventional linear protection switching method, and then informs the other node of protection domain i (or i+1) of the determined user traffic transmission/reception path information using a linear protection switching message, and the user It plays a role of informing the main interconnection controller of traffic transmission/reception path information.

Conventional linear protection switching methods performed by the linear protection switching processor include ITU-T recommendations G.8031 (Ethernet linear protection switching), G.8131 (MPLS-TP linear protection switching), G.873.1 (OTN linear protection switching), IETF RFC 6378 (MPLS-TP linear protection switching - PSC mode), RFC 7271 (MPLS-TP linear protection switching - APS mode), and the like. It is not limited to a specific linear protection switching method, and it is assumed that a linear protection switching message and user traffic transmission/reception path information are generated according to the existing linear protection switching method.

The protection path connection unit 260 connects only two of three paths, such as protection path i, protection path i+1, and connection path i. FIG. 8 shows a state in which protection path i and protection path i+1 are connected to each other as an example, and under the control of the main interconnection control unit 270, two of the three paths are connected to each other.

The primary interconnection controller 270 forwards the failure information of the working path i received from the species interconnection controller 140 of the working interconnection node Ii 100 to the linear protection switching processor i 240, and the failure information of the working path i+1 to the linear protection switching processor i+1 250.

In addition, the primary interconnection control unit 270 receives the failure occurrence and extinction information of the connection path i from the species interconnection control unit 140 and the OAM unit 210 in the protected interconnection node Ii' 200, and always recognizes whether or not there is a failure in the current connection path i. Even if a failure of the connection path i occurs in one direction and the failure does not occur in the opposite direction, the primary interconnection controller 270 determines that the connection path i has a failure. In addition, the main interconnect control unit 270 receives a report from the linear protection switching processors 240 and 250 as path information when there is a change in the path through which user traffic is transmitted and received in the protection domain managed by each of the linear protection switching processors 240 and 250, and also receives information on occurrence and extinction of failures in the protection path. Based on the input information as above, working path control information and protection path control information are generated and transmitted to the species interconnection control unit 140 of the working interconnection node Ii (100) and the protection path connection unit 260 of the protection interconnection node Ii' (200). If necessary, a virtual failure signal may be input to the linear protection switching processors 240 and 250 to change the user traffic path.

Table 1 below summarizes operations to be performed by the main interconnection control unit 270 according to signals input to the main interconnection control unit 270.

Input signal (transmitter of input signal) Main Interconnect Control Operation Working path i Failure onset and extinction signal (species interconnection control) Pass the input signal to the linear protection switching processor i Failure onset and extinction signals of working path i+1 (species interconnection control) Pass the input signal to the linear protection switching processor i+1 Failure occurrence and extinction signal of protection path i (linear protection transfer processor i) Record protection path i failure
Fault occurrence and extinction signal of protection path i+1 (linear protection transfer processor i+1) Record protection path i+1 failure
Failure occurrence signal of connection path i (OAM part or species interconnection control part) - Recorded as 'connection path i has failure'.
- In <Table 1>, perform the operation corresponding to 'Connection path i failure'. Fault extinction signal of connection path i (OAM part or species interconnection control part) - Recorded as 'no connection path i failure'
- If there is a 'virtual path failure occurrence signal' for a certain path before, a 'virtual path failure extinction signal' canceling the virtual path failure signal is transmitted to the corresponding linear protection transfer processor.
- In <Table 1>, perform the operation corresponding to 'no connection path i failure'. Route information (linear protection transfer processor i or i+1) - Records 'route in use for sending and receiving user traffic' in each protection domain
- Depending on the failure of connection path i, the corresponding operation is performed in <Table 1>

<Table 2> below shows common operations in a separate table for convenience in describing the operations to be performed by the main interconnect control unit in <Table 1>, and specifies operations according to the presence or absence of failures in connection path i.

Action type action content Connection path i has failure - Working path control information instructing to connect working path i and working path i+1 is generated and transmitted to the species interconnection control unit.
- Creates protection path control information instructing protection path i and protection path i+1 to be connected and transmits it to the protection path connection unit.
- If there is a failure in either the protection path i or the protection path i+1, the 'virtual protection path failure occurrence signal' is transmitted to the linear protection transfer processor to which the protection path with no failure belongs.
- If there is no failure in either protection path i or protection path i+1, 'virtual working path i failure occurrence signal' and 'virtual working path i+1 failure occurrence signal' are transmitted to linear protection switching processors i and i+1, respectively. Connection path i no failure - Transmits path control information that can connect 'paths currently used for sending/receiving user traffic' in the two protection domains to the working path connection unit and the protection path connection unit. (For example, if working path i is in use in protection domain i and protection path i+1 is in use in protection domain i+1, working path control information is the content connecting working path i and connection path i, and protection path control information is the content instructing connection path i and protection path i+1 to be connected.)

Since the operations of the main interconnection control unit described in <Table 1> and <Table 2> are self-evident, a separate supplementary explanation is omitted. However, the 'virtual protection (or working) path failure occurrence signal' or 'virtual protection (or working) path failure extinction signal' mentioned in <Table 1> and <Table 2> is a virtual failure occurrence or extinction signal that the main interconnection control unit 270 sends to the linear protection switching processors 240 and 250 for user traffic connection transmitted between each protection domain. , the linear protection switching processors 240 and 250 receiving this signal treat it the same as an existing failure occurrence or extinction signal.

The 'path in use for sending/receiving user traffic' mentioned in <Table 1> and <Table 2> is the same as the active path (or active transport entity), a term used in existing linear protection switching technology.

Failure information and working path control information exchanged between the working interconnection node (Ii) 100 and the protection interconnection node (Ii') 200 are periodically exchanged, and if the information to be transmitted is different from previously transmitted information, the information can be transmitted immediately regardless of the transmission period.

If the working interconnection node (Ii) 100 does not receive the working path control information from the protection interconnection node (Ii') 200 for a certain period of time, the working interconnection node (Ii) 100 determines that the protection interconnection node (Ii') 200 itself is out of order or that the connection path i used to receive the working path control information has failed.

Likewise, if the protection interconnection node (I1') 200 does not receive failure information from the working interconnection node (Ii) 100 for a certain period of time, the protection interconnection node (I1') 200 determines that the working interconnection node (Ii) 100 itself is out of order or a connection path i used to receive failure information has a failure.

<Table 3> shows user traffic paths according to the presence or absence of failures in each path when a pair of interconnection nodes connect two protection domains, that is, when the operations of the interconnection nodes described with reference to FIG. 8 and <Table 1> and <Table 2> are applied to the network as shown in FIG. 5.

Path Status (O: OK, X: Failure) user traffic path V W1 P1 W2 P2 O O O O O W1-W2 O O O O X W1-W2 O O O X O W1-V-P2 O O O X X doesn't exist O O X O O W1-W2 O O X O X W1-W2 O O X X O W1-V-P2 O O X X X doesn't exist O X O O O P1-V-W2 O X O O X P1-V-W2 O X O X O P1-P2 O X O X X doesn't exist O X X O O doesn't exist O X X O X doesn't exist O X X X O doesn't exist O X X X X doesn't exist X O O O O W1-W2 X O O O X W1-W2 X O O X O P1-P2 X O O X X doesn't exist X O X O O W1-W2 X O X O X W1-W2 X O X X O doesn't exist X O X X X doesn't exist X X O O O P1-P2 X X O O X doesn't exist X X O X O P1-P2 X X O X X doesn't exist X X X O O doesn't exist X X X O X doesn't exist X X X X O doesn't exist X X X X X doesn't exist

In <Table 3>, O and X indicate that there is no failure in the corresponding path, respectively, W1 and W2 indicate working path 1 and working path 2, P1 and P2 indicate protection path 1 and protection path 2, and V means a connection path. In <Table 3>, end nodes and interconnection nodes are omitted for convenience in displaying user traffic paths, and only used paths are displayed. For example, if the user traffic path is W1-V-P2, this means that the user traffic uses the path (E1)-working path 1-(I1)-connection path-(I1')-protection path 2-(E2). In <Table 3>, if there is no path through which user traffic can be transmitted between end-to-end devices, the user traffic path is displayed as 'None'.

<Table 4> shows user traffic paths according to the presence or absence of failures in each path when two pairs of interconnection nodes connect three protection domains, that is, when the operations of the interconnection nodes described with reference to FIG. 8 and <Table 1> and <Table 2> are applied to the network as shown in FIG. 6.

Path Status (O: OK, X: Failure) user traffic path V1 V2 W1 P1 W2 P2 W3 P3 O O O O O O O O W1-W2-W3 O O O O O O O X W1-W2-W3 O O O O O O X O W1-W2-V2-P3 O O O O O X O O W1-W2-W3 O O O O O X O X W1-W2-W3 O O O O O X X O W1-W2-V2-P3 O O O O X O O O W1-V1-P2-V2-W3 O O O O X O O X W1-V1-P2-V2-W3 O O O O X O X O W1-V1-P2-P3 O O O X O O O O W1-W2-W3 O O O X O O O X W1-W2-W3 O O O X O O X O W1-W2-V2-P3 O O O X O X O O W1-W2-W3 O O O X O X O X W1-W2-W3 O O O X O X X O W1-W2-V2-P3 O O O X X O O O W1-V1-P2-V2-W3 O O O X X O O X W1-V1-P2-V2-W3 O O O X X O X O W1-V1-P2-P3 O O X O O O O O P1-V1-W2-W3 O O X O O O O X P1-V1-W2-W3 O O X O O O X O P1-V1-W2-V2-P3 O O X O O X O O P1-V1-W2-W3 O O X O O X O X P1-V1-W2-W3 O O X O O X X O P1-V1-W2-V2-P3 O O X O X O O O P1-P2-V2-W3 O O X O X O O X P1-P2-V2-W3 O O X O X O X O P1-P2-P3 O X O O O O O O W1-V1-P2-P3 O X O O O O O X W1-W2-W3 O X O O O O X O W1-V1-P2-P3 O X O O O X O O W1-W2-W3 O X O O O X O X W1-W2-W3 O X O O X O O O W1-V1-P2-P3 O X O O X O X O W1-V1-P2-P3 O X O X O O O O W1-V1-P2-P3 O X O X O O O X W1-W2-W3 O X O X O O X O W1-V1-P2-P3 O X O X O X O O W1-W2-W3 O X O X O X O X W1-W2-W3 O X O X X O O O W1-V1-P2-P3 O X O X X O X O W1-V1-P2-P3 O X X O O O O O P1-P2-P3 O X X O O O O X P1-V1-W2-W3 O X X O O O X O P1-P2-P3 O X X O O X O O P1-V1-W2-W3 O X X O O X O X P1-V1-W2-W3 O X X O X O O O P1-P2-P3 O X X O X O X O P1-P2-P3 X O O O O O O O P1-P2-V2-W3 X O O O O O O X P1-P2-V2-W3 X O O O O O X O P1-P2-P3 X O O O O X O O W1-W2-W3 X O O O O X O X W1-W2-W3 X O O O O X X O W1-W2-V2-P3 X O O O X O O O P1-P2-V2-W3 X O O O X O O X P1-P2-V2-W3 X O O O X O X O P1-P2-P3 X O O X O O O O W1-W2-W3 X O O X O O O X W1-W2-W3 X O O X O O X O W1-W2-V2-P3 X O O X O X O O W1-W2-W3 X O O X O X O X W1-W2-W3 X O O X O X X O W1-W2-V2-P3 X O X O O O O O P1-P2-V2-W3 X O X O O O O X P1-P2-V2-W3 X O X O O O X O P1-P2-P3 X O X O X O O O P1-P2-V2-W3 X O X O X O O X P1-P2-V2-W3 X O X O X O X O P1-P2-P3 X X O O O O O O P1-P2-P3 X X O O O O O X W1-W2-W3 X X O O O O X O P1-P2-P3 X X O O O X O O W1-W2-W3 X X O O O X O X W1-W2-W3 X X O O X O O O P1-P2-P3 X X O O X O X O P1-P2-P3 X X O X O O O O W1-W2-W3 X X O X O O O X W1-W2-W3 X X O X O X O O W1-W2-W3 X X O X O X O X W1-W2-W3 X X X O O O O O P1-P2-P3 X X X O O O X O P1-P2-P3 X X X O X O O O P1-P2-P3 X X X O X O X O P1-P2-P3 In case other than above doesn't exist

In <Table 4>, O and X indicate that there is no failure in the corresponding path, respectively, W1, W2, and W3 indicate working path 1, working path 2, and working path 3, P1, P2, and P3 indicate protection path 1, protection path 2, and protection path 3, and V1 and V2 indicate connection path 1 and connection path 2. In <Table 4>, end nodes and interconnection nodes are omitted for convenience in displaying user traffic routes, and only used routes are displayed. For example, if the user traffic path is W1-V1-P2-V2-P3, this means that the user traffic uses the path of (E1)-working path 1-(I1)-connection path 1-(I1')-protection path 2-(I2')-connection path 2-(I2)-working path 3-(E2). <Table 4> shows the user traffic path only when there is a path through which user traffic can be transmitted between end-to-ends, and the case where there is no user traffic path between end-to-ends due to multiple failures is omitted from the table.

9 is a signal flowchart for explaining a linear protection switching domain connection method according to an embodiment of the present invention.

Referring to FIG. 9 , the working interconnection node monitors whether a connection path i connecting the working interconnection node and the protection interconnection node has a failure, and whether a working path i or a working path i+1 has a failure (S910). The working interconnection node transmits the monitoring result in S910 to the paired protection interconnection node (S915). Although not shown in the drawing, the working interconnection node may periodically transmit failure information to the protection interconnection node, and may immediately transmit failure information when the failure information is changed. At this time, if the protection interconnection node does not receive failure information from the working interconnection node for a certain period of time, it may be determined that the working interconnection node itself is out of order or a connection path i used to receive failure information has a failure.

Meanwhile, the protection interconnection node also monitors whether connection path i has a failure or not and protection path i or i+1 has a failure (S920).

The protection interconnection node determines whether connection path i has a failure based on the failure status information of connection path i received from the working interconnection node and the failure status information of connection path i it has monitored (S930). At this time, even if the failure of the connection path i occurs in only one direction, it is determined that there is a failure in the connection path i.

Next, the protection interconnection node determines whether to transmit/receive user traffic between the working path (i or i+1) or the protection path (i or i+1), that is, the user traffic transmission/reception path, based on the failure information of working path i or working path i+1 and the failure information of protection path i or i+1 (S940).

In addition, the protection interconnection node generates working path control information and protection path control information according to user traffic transmission/reception path information and protection path failure information (S950). Then, the protection interconnection node transmits the working path control information to the working interconnection node (S960).

Then, the working interconnection node connects two of the working path i, the working path i+1, and the connection path i according to the working path control information received from the protection interconnection node (S970). However, when working path control information cannot be received from the protection interconnection node due to a failure in connection path i, the working interconnection node can connect working path i and working path i+1.

Meanwhile, the protection interconnection node connects only two of protection path i, protection path i+1, and connection path i according to the protection path control information (S980). In addition, the protection interconnection node transmits the linear protection switching message in which the determined user traffic transmission/reception path information is recorded to the protection path i or i+1 (S990).

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be understood that it can be changed.

Claims (17)

An OAM (Operations, Administration and Maintenance) 1 that is connected to the working path i and monitors whether the working path i has a failure;
an OAM 2 that is connected to working path i+1 and monitors whether the working path i+1 has a failure;
An OAM 3 that connects paired protection interconnection nodes and monitors whether or not there is a failure of a connection path i that can be used as a path for transmitting and receiving user traffic;
a species interconnection control unit that transmits failure status information received from the OAM 1 to OAM 3 to the protection interconnection node and transmits the working path control information received from the protection interconnection node to the working path connection unit;
and a working path connection unit for connecting two paths among the working path i, the working path i+1 and the connection path i according to the working path control information.
The method of claim 1, wherein the species interconnection control unit
When working path control information cannot be received from the protection interconnection node due to a failure in the connection path i, working path control information instructing to connect working path i and working path i+1 is generated and transmitted to a working path connection unit.
The method of claim 1, wherein the species interconnection control unit
and periodically transmitting the failure information to the protection interconnection node, and transmitting the failure information immediately when the failure information is changed.
OAM (Operations, Administration and Maintenance) that connects the paired working interconnection nodes and monitors the failure of the connection path i that can be used as a user traffic transmission and reception path;
An OAM & P (OAM & Protection) 1 or OAM & P 2 connected to the protection path i or the protection path i+1, respectively, and monitoring the presence or absence of a failure in the protection path i or the protection path i+1;
A linear protection switching processor i or a linear protection switching processor i+1 that determines a user traffic transmission/reception path based on the failure status information of working path i or working path i+1 and the failure status information of protection path i or protection path i+1, and then transmits the determined user traffic transmission/reception path information to the main interconnect control unit;
a main interconnection controller for generating and transmitting working path control information and protection path control information to the working interconnection node and the protection path connection unit, respectively, upon receiving the user traffic transmission/reception path information and protection path failure information;
and a protection path connection unit connecting only two paths among protection path i, protection path i+1, and connection path i according to the protection path control information.
The method of claim 4, wherein the OAM & P 1 or OAM & P 2
sending and receiving linear protection transfer messages through protection path i or protection path i+1;
The linear protection switching processor i or the linear protection switching processor i + 1
and transmitting the linear protection switching message in which the determined user traffic transmission/reception path information is recorded to protection path i or protection path i+1 through the OAM & P 1 or OAM & P 2.
The method of claim 4, wherein the primary interconnection control unit
The protection interconnection node device, characterized in that, by receiving failure information of the connection path i from the working interconnection node and the OAM, recognizing failure of the current connection path i.
The method of claim 4, wherein the primary interconnection control unit
The protection interconnection node device, characterized in that it is determined that there is a failure in the connection path i even if the failure of the connection path i occurs in only one direction.
The method of claim 4, wherein the primary interconnection control unit
The protection interconnection node device, characterized in that the failure status information of the working path i received from the working interconnection node is transmitted to the linear protection switching processor i, and the failure status information of the working path i+1 is transmitted to the linear protection switching processor i+1.
The method of claim 4, wherein the primary interconnection control unit
A protection interconnection node device, characterized by inputting virtual failure information to linear protection switching processors in order to change a user traffic path. 5. The protection interconnection node device according to claim 4 , wherein the main interconnection control unit determines that the working interconnection node itself is out of order or a connection path i used to receive failure information is out of order when failure information is not received from the working interconnection node for a certain period of time. In the linear protection switching domain connection system,
A working interconnection node included in the linear protection switching domain connection system is connected to a paired protection interconnection node device and monitors whether or not a connection path i that can be used as a user traffic transmission/reception path has a failure and a working path i or a working path i+1 has a failure, and transmits the result to the protection interconnection node device;
monitoring, by the protection interconnection node included in the linear protection switching domain connection system, whether or not there is a failure in the connection path i and whether or not there is a failure in the protection path i or the protection path i+1 through OAM;
determining, by the protection interconnection node, a user traffic transmission/reception path based on the failure presence/absence information of working path i or working path i+1 and the failure presence/absence information of protection path i or protection path i+1;
generating, by the protection interconnection node, working path control information and protection path control information according to the user traffic transmission/reception path information and protection path failure information;
sending, by the protection interconnection node, the working path control information to the working interconnection node;
and connecting, by the protection interconnection node, only two paths among protection path i, protection path i+1 and connection path i according to the protection path control information.
According to claim 11,
and transmitting, by the protection interconnection node, a linear protection switching message in which the determined user traffic transmission/reception path information is recorded to protection path i or protection path i+1.
According to claim 11,
Recognizing, by the protection interconnection node, whether or not there is a failure in the connection path i based on the failure status information of the connection path i received from the working interconnection node and the failure status information obtained in the step of monitoring the failure status of the connection path i. Linear protection switching domain connection method, characterized in that it further comprises.
12. The method of claim 11, wherein the step of monitoring whether there is a failure of the connection path i
A linear protection switching domain connection method in a protection interconnection node device, characterized in that determining that connection path i has a failure even if the failure of the connection path i occurs in only one direction.
According to claim 11,
If the protection interconnection node does not receive failure information from the working interconnection node for a predetermined period of time, it is determined that the working interconnection node has failed or the connection path i has failed. Linear protection switching domain connection method, characterized in that it further comprises.
According to claim 11,
The step of connecting, by the working interconnection node, two of the working path i, the working path i+1, and the connection path i according to the working path control information received from the protection interconnection node.
12. The linear protection switching domain connection method of claim 11 , further comprising: connecting, by the working interconnection node, working path i and working path i+1 when a failure occurs in the connection path i and thus cannot receive working path control information from the protection interconnection node.

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