KR100428778B1 - method for CR-LSP path protection in Multi Protocol Label Switching system and the recorded media thereof - Google Patents

Abstract

According to the present invention, a path protection method for a CONTRAINT-based routing Label switched Path (CR-LSP) may include an alternative path due to a failure of the CR-LSP when performing the path protection of the CR-LSP in a multi-protocol label switching system. Creating a profile by receiving information for management, setting a CR-LSP based on the profile, and index information about the profile to manage the state of the corresponding CR-LSP for each set CR-LSP. Generating a CR-LSP state management table; and if a failure of a predetermined CR-LSP is detected, the linked profile is searched for by referring to each index information of the state management table of the corresponding CR-LSP, and the profile By performing the path protection procedure step of forwarding the service traffic to the alternate path according to the setting in the above, a high level of network is provided by providing a plurality of alternate paths on one primary path. It can provide services having sex.

Description

Method for CR-LSP path protection in Multi Protocol Label Switching system and the recorded media etc.

The present invention relates to a path protection method of a Constraint-based routing Label switched Path (CR-LSP) provided by a Multi Protocol Label Switching (MPLS) system, and a recording medium therefor.

As the traffic and services using the Internet have increased since the late 90s, the survivability of the network, which was not important before, has emerged as a major challenge, as it is not just a data network but a public network. In particular, from the following point of view, the viability of the network is emerging as an indispensable part of the ISP (Internet Service Provider).

First of all, it is possible to take the role of public network that delivers important information such as VoIP or VPN, away from simple information exchange or entertainment-oriented use, so that it is impossible to provide long-term service due to network failure. Loss of money and damage to the ISP due to the loss of reliability of the service.

Second, as the internet network becomes faster and larger, a single network failure can make many users' services uncomfortable and lose a huge amount of information.

Due to the importance of such network survivability, MPLS is attracting attention as a means to compensate for the weakness of IP routing in the construction of next generation internet network. Traffic engineering function, an important function of MPLS, can select explicit path considering traffic information and network resources through the constraint-based routing method. To this end, MPLS uses CR-LDP and RSVP-TE as signaling protocols, and can use this signaling protocol to set up alternate paths for network recovery. Here, the constraint-based routing method refers to a routing method by an explicit protocol (designated path, bandwidth, etc.). CR-LDP stands for Constraint Routed (or Based) Label Distribution Protocol. It refers to a signaling protocol for distributing a label to establish a route according to an explicit protocol. RSVP-TE is an abbreviation of Resource Reservation Protocol for Traffic Engineering. It refers to a signaling protocol that distributes remble to reserve and route resources required for a service.

When MPLS technology is expected to be adopted in most backbone networks in the future, the support of network recovery function in MPLS network is expected to be a very important issue for vendors developing MPLS LER / LSR. Here, LER is an abbreviation of Label Edge Router, which is located at the boundary of the MPLS network and refers to the starting point and end point of the path using MPLS, and LSR is an abbreviation of Label Switch Router, which is an intermediate node located on the MPLS path between LERs.

Currently, the Internet is in charge of network recovery at the IP layer. The network recovery function in the IP layer does not have a separate function and uses a connectionless hop-to-hop routing method. That is, routing information is delivered to each node in the event of a node or link failure, and traffic is forwarded by the changed routing information.

However, this type of recovery has a weak point that it takes a long time to recover the network because it takes a long time to detect a failure. In addition, the IP layer has a problem in that the protection path cannot be set in advance because the path cannot be determined explicitly.

The path protection model for network recovery used in the MPLS layer is divided into rerouting and protection-switching models.

The path protection scheme by rerouting establishes a new path segment or path for retransmission of service traffic in case of network failure. The new path is determined through fault information, policy elements that operate the network, preset configuration information and network structure. This method takes longer than the protection switching method because it takes time to find and recover from a fault and defines the new path and involves all the work required for routing.

The path protection method by protection switching method sets the recovery path in advance based on the explicit routing policy. If a failure occurs in the work path, it immediately replaces the traffic with the recovery path. Therefore, this method enables faster path recovery than the rerouting method.

As the network recovery algorithm used in MPLS, a recovery algorithm using Haskins method and RNT (Reverse Notification Tree) has been proposed.

Haskins recovery algorithm is a kind of protection switching method that sets a reverse path for the main path in one main path and one alternative path in case of a main path failure. If a failure occurs in a path between nodes in the main path, the node that detects the failure sends traffic to the reverse path of the main path and sends it to the start node that has established the main path. Receiving traffic transmitted in the reverse direction, the start node determines that the main path has failed, and transmits the traffic to the end node through the predetermined alternative path.

Figure 1 shows a network recovery process of the conventional Haskins method.

In FIG. 1 the labels 1/3-3/5-5/7 are set as the main path and the labels 7/5-5/3-3/1 are set in the reverse direction. The labels 1/2-2/4-4/6-6/7 are alternative routes to the main route. If the link between nodes 5 and 7 on the primary path fails, the upper node 5 detects the failure and forwards the service traffic to switch 1 on the reverse path. Switch 1 sends the service traffic delivered through the reverse path to the predetermined alternative path. The reverse path to the primary path can be used so that the primary path uses all bandwidth when the primary path preempts resources and there is no traffic flowing in the reverse direction.

However, when the Haskins recovery algorithm is applied, there is a problem that a reverse path to the main path must be set in order to detect a path failure. In FIG. 1, if a failure occurs in the alternate paths 1/2-2/4-4/6-6/7, there is no way for the switch 1 to detect the service traffic. If you want to detect faults on the alternate paths 1/2-2/4-4/6-6/7, you must set up reverse paths of 7/6-6/4-4/2-2/1. You must also set the reverse path when setting the path. This is likely to complicate path management in the network.

The recovery algorithm of the RNT method has a problem that all devices applied to the entire network support the corresponding algorithm, that is, each node must remember a higher node. If a node on the main path does not have the ability to identify and remember its parent, then the RNT cannot be configured. In this case, an existing ISP that is configuring a network with equipment from multiple vendors or wants to provide a new network recovery service has a high cost to provide a network recovery service.

The recovery algorithm using Reverse Notification Tree (RNT) is a method for providing a reverse path for failure notification as a starting path for performing routing, and is effective in a network in which a plurality of paths cause label merging via one node.

The RNT is created by the nodes located on each path remembering the parent node. The RNT starts from a path merge node (PMN) where several paths are merged from one node and ends at a path switch node (PSN). When a failure occurs in a path between nodes, the parent node of the path sends a failure notification to the parent node that it remembers, and the parent node that receives the failure notification checks whether it is the PSN of the LSP. Otherwise, it sends fault notification to its parent. Figure 2 shows a failure recovery algorithm of the conventional RNT method.

The recovery algorithm of the RNT method has a problem that all devices applied to the entire network support the corresponding algorithm, that is, each node must remember a higher node. In other words, if traffic is transmitted through nodes 1-2-3-4 and 8-9-3-4, and if node 4 has a problem, It should have information about the upper node of 3-2-1 about the traffic forwarded and reverse about the traffic forwarded through node 8-9-3-4 on the higher node of 3-9-8. You must have information.

Thus, for each node, the RNT cannot be configured if the node on the primary path lacks the ability to identify and store its parent. In this case, an existing ISP that is configuring a network with equipment from multiple vendors or wants to provide a new network recovery service has a high cost to provide a network recovery service.

The present invention has been made to solve this conventional problem, CR that can perform the following functions so that ISPs can easily provide a path service for path recovery to their subscribers and easily control the alternative path The object of the present invention is to provide a path protection method of -LSP and a recording medium therefor.

First, it should be possible to detect faults by utilizing existing signal protocol without any specification change.

Second, the main route and the alternative route should be easily managed in the Ingress LSR of the MPLS network.

In addition, second and third alternative routes should be established to maximize network viability.

Third, both protection switching and rerouting should be supported to increase ISP revenue.

Fourth, when interworking with other vendor's equipment, path protection service should be provided smoothly without additional specification change of equipment.

1 is a conceptual diagram showing a network recovery process of the conventional Haskins method.

2 is a conceptual diagram showing a failure recovery algorithm of a conventional RNT method.

3 is a schematic structural diagram of a system for performing path protection of a CR-LSP in a multi-protocol label exchange system according to the present invention;

4 is a schematic flowchart of a procedure for creating a profile according to the present invention;

5 is a structural diagram of a CR-LSP state management table according to the present invention;

6 is a conceptual diagram illustrating an association between such a profile and a CR-LSP state table.

7 is a conceptual diagram illustrating a relationship between the path information managed in the subscriber profile and the CR-LSP state management table.

8 is a change diagram of a CR-LSP state table for each CR-LSP setting step.

9 is a flowchart illustrating a procedure for path protection when a failure occurs in a primary CR-LSP preset by the path protection method when a failure of the CR-LSP occurs according to the present invention.

FIG. 10 is a conceptual diagram illustrating path protection when a failure of a CR-LSP according to the present invention shown in FIG. 9 occurs. FIG.

11A and 11B are table state variation diagrams when performing the procedure shown in FIG. 9;

<Description of Symbols for Main Parts of Drawings>

10: traffic engineering unit (TE) 20: signal protocol unit

30: Forwarding Engineering Division (FE)

Path protection method of the CR-LSP according to an embodiment of the present invention for achieving this object, in the method of protecting the path of the CR-LSP in a multi-protocol label exchange system, the alternative path according to the failure of the CR-LSP Creating a profile by receiving information for management, setting a CR-LSP based on the profile, and index information about the profile to manage the state of the corresponding CR-LSP for each set CR-LSP. Generating a CR-LSP state management table; and if a failure of a predetermined CR-LSP is detected, the linked profile is searched for by referring to each index information of the state management table of the corresponding CR-LSP, and the profile A path protection procedure step of forwarding service traffic to an alternate path is performed according to the settings in.

In addition, the recording medium for performing the path protection method of the CR-LSP according to an embodiment of the present invention, is executed by the digital processing apparatus, to perform the path protection method of the CR-LSP in a multi-protocol label exchange system. In the recording medium that can be read by the digital processing device is implemented programmatically, the step of generating a profile by receiving the information for the alternative path management according to the failure of the CR-LSP; Setting a CR-LSP based on the profile, generating a CR-LSP state management table having index information for the profile to manage the state of the corresponding CR-LSP for each set CR-LSP; When a failure of the configured CR-LSP is detected, the linked profile is searched for by referring to the index information of the state management table of the corresponding CR-LSP. The path protection procedure step of forwarding service traffic to an alternate path is performed according to the settings in the file.

As described above, in the CR-LSP path protection method according to the present invention, in order to control the main path and the alternative path, the CR-LSP state management table manages it through an internal structure. The CR-LSP state management table is used to cross-reference profile information associated with a predetermined CR-LSP ID.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic structural diagram of a system for performing path protection of a CR-LSP in a multi-protocol label exchange system according to the present invention.

As shown, the multi-protocol label exchange system generates a profile for setting the CR-LSP and a table for managing the CR-LSP status for each subscriber, so that if an abnormality occurs in the CR-LSP, the protocol and the table are replaced. Traffic engineering unit 10 which is responsible for overall traffic engineering by forwarding traffic to the path, signal protocol unit 20 for setting CR-LSP according to the request of traffic engineering unit 10, and signal protocol unit And a forwarding engineering unit 30 for forwarding traffic according to the CR-LSP set value set by 20.

The traffic engineering unit 10 receives the information for the alternative path management according to the failure of the CR-LSP, generates a profile, and requests the signal protocol unit 20 to set the CR-LSP based on the profile. In response to the request, the signal protocol unit 20 generates a CR-LSP state management table having index information for the profile to manage the state of the corresponding CR-LSP for each set CR-LSP.

When the release signal for the predetermined ID of the CR-LSP is received from the signal protocol unit 20, it is determined whether the failure is a failure, and when the failure is detected, each index information of the state management table of the corresponding CR-LSP. Reference to the search for the linked profile, and transmits the information for forwarding the service traffic to the alternative path to the forwarding engineering unit 30 in accordance with the details set in the profile.

On the other hand, when the signal protocol unit 20 requests the setting of the CR-LSP from the traffic engineering unit 10, the signal protocol unit 20 sets the CR-LSP based on the profile and sets the ID of the set CR-LSP to the traffic engineering unit 10. To pass).

The forwarding engineering unit 30 receives the information on the alternative route from the traffic engineering unit 10 and receives the information for performing the current forwarding operation, and forwards the route if the route is required to replace the corresponding traffic.

In the system that performs the path protection of the CR-LSP configured as described above, a profile is generated by receiving the information for the alternative path management according to the occurrence of the failure of the CR-LSP, and the CR-LSP is set based on the profile. To manage the state of the CR-LSP for each CR-LSP, create a CR-LSP state management table with index information for the profile, and if the failure of the preset CR-LSP is detected, the state of the corresponding CR-LSP The linked profile is searched by referring to each index information of the management table, and a path protection procedure for forwarding service traffic to an alternate path is performed according to the information set in the profile.

First, let's look at the process of creating a profile.

4 schematically illustrates a procedure for creating a profile. Referring to FIG. 4, first, a subscriber profile for performing a path protection service for each subscriber is generated by setting a plurality of alternative routes in one main path by receiving the subscriber's information (S1).

Then, receiving node information for specifying a route for service traffic to pass through, create a route profile such that CR-LSP is set by the node information (S2), and create a QoS profile for defining QoS parameters for service traffic. It generates (S3).

When each profile is generated as described above, each profile is linked to each other to perform a path protection service for each subscriber (S4).

Generating the subscriber profile (S1) is a procedure for registering the information of the TE subscriber to the profile from the operator to register the type of service, FEC information, whether to provide a path protection service. If a failure occurs in the CR-LSP after the path protection service type registered in this step, a procedure for the path protection service is performed. Here, FEC stands for Fowarding Equivalence Class and represents a group of destination addresses having the same route.

Generating the route profile (S2) is a procedure for registering a route profile for specifying a route from which the service traffic will go out from the operator. That is, the IP address, netmask, and strict / loose mode of each node to the destination are registered. CR-LSP is set through each registered node.

In the step S3 of generating a QoS profile, when a CR-LSP is set, a Quality Of Service (QoS) profile is registered to define QoS parameters for service traffic. ATM QoS parameters such as PCR (Peak Cell Rate), SCR (Sustained Cell Rate), MBS (Maximum Burst Size), and CDVT (Cell Delay Variance Tolerance) values are defined.

Linking each profile (S4) is a step of linking each of the registered profiles with each other to form a mutual relationship. In this case, when providing a path protection service for a corresponding subscriber, up to four path profile entries may be stored in one service subscriber profile. You can register at

Next, let's look at the creation of the CR-LSP state management table.

An entry in the CR-LSP state management table is constructed upon CR-LSP configuration. That is, after the traffic engineering unit 10 generates a profile and requests the signal protocol unit 20 to set the CR-LSP based on the profile, the signal protocol unit 20 sets the CR-LSP and sets The ID of the CR-LSP is transmitted to the traffic engineering unit 10. The traffic engineering unit 10 generates a CR-LSP state management table having index information on the profile to manage the state of the corresponding CR-LSP for each set CR-LSP.

The CR-LSP state management table includes an entry index of a subscriber profile that manages the service information of a TE subscriber by setting the ID of the CR-LSP set in the LER as a key index, an entry index of a path profile having the corresponding CR-LSP path information, QoS profile entry index containing information about QoS applied to the CR-LSP, the type of signaling protocol used when setting up the CR-LSP, the status of the current CR-LSP, and information about the previous backup path and the next backup path. Have

5 shows the structure of such a CR-LSP state management table.

The CR-LSP ID identifies the CR-LSP set by the CR-LDP or RSVP-TE and plays a key role in the CR-LSP state management table.

ProtoType indicates the type of signaling protocol used in CR-LSP configuration and is set to CR-LDP or RSVP-TE.

SubsName represents the name of a subscriber receiving preferential services through the CR-LSP.

SubsId can be assigned up to 999 as an ID of a subscriber. SubsId has the same meaning as the subscriber ID of the subscriber profile.

SubsPrfIdx is an index of a service profile entry that manages service information provided to a subscriber, and up to four services are provided per subscriber. SubsPrfIdx also has the same meaning as the service profile index of the subscriber profile.

PathIndex is an entry index of a path profile that manages information of each node through which a set CR-LSP passes and can be assigned up to 15999.

QoSIndex is an index of a QoS profile entry that manages QoS parameters applied to the set CR-LSP.

Active indicates the current state of the CR-LSP. ACT means that the label is assigned for CR-LSP and related FEC information is set in MPLS system's forwarding engine, so that actual traffic is being forwarded. STBY (Stand-by) is assigned label for LDP mapping. Since the relevant FEC information is not set in the forwarding engine, the actual service traffic is not forwarded. DEACT indicates that only the CR-LSP setting is required and no label assignment and FEC setting are made. Performs actual path protection service of CR-LSP with reference to Acitve field.

PrevLspId represents the ID value of the previous backup CR-LSP.

NextLspId represents the ID of the next backup CR-LSP.

If the CR-LSP provided to the subscriber is not subject to the path protection service, these two fields are meaningless.

The operator can refer to the profile information using the SubsId, SubsPrfIdx, PathIndex, and QoSIndex values shown in the CR-LSP state management table.

That is, it is possible to search the information of the subscriber using the currently set CR-LSP, the information on the path that the CR-LSP is passing, and the information of the QoS parameters applied to the CR-LSP. 6 shows an association between this profile and the CR-LSP state table.

On the other hand, the subscriber profile may specify a plurality of alternative paths, for example four. The alternate path is defined by four path profile entries when defining the association between each profile entry. In the present invention, the path of the first (zero) path profile entry defined in the alternative path list is defined as the main path, and the information of the path profile entry defined in the rest is defined as the alternative path.

7 shows the relationship between the path information managed in the subscriber profile and the CR-LSP state management table. In each alternative route list, the ID of the set CR-LSP is registered. An entry in the CR-LSP state management table is constructed upon CR-LSP configuration.

When the CR-LSP setting request is made, an entry of the CR-LSP status management table is generated, and if the ID of the CR-LSP is notified to the traffic engineering unit 10 by the signaling protocol, the traffic engineering unit 10 converts the corresponding CR-LSP ID into a CR. -Register in the LSP status management table and manage the status of the entry in STBY (Stand-by) status, but if FEC information is registered in FE normally, it becomes ACT (Active) status. It means a state that can be.

8 shows changes in the CR-LSP state table for each CR-LSP setting step.

In step S11, the CR-LSP state management table is not generated without a CR-LSP setting request.

In the step S12, an entry of the CR-LSP table is generated and initialized with a CR-LSP setting request entered as a signal protocol by the TE block. At this time, the signal protocol transmits the ID of the CR-LSP set to TE after performing the procedure for CR-LSP configuration. The ID of the received CR-LSP becomes an index of the CR-LSP state management table.

Step S13 is a mapping event for the CR-LSP setup request, which means that the setup request for the corresponding CR-LSP reaches an egress LSR and the signaling protocol receives the response. In this step, the label and channel information of the CR-LSP are allocated, and the Active field of the CR-LSP state management table is changed to STBY state.

Step S14 registers the FEC information associated with the set CR-LSP to the FE. If the FEC is normally registered in the FE, the Active field of the CR-LSP state management table becomes ACT.

Step S15 shows a state in which both the main route and the alternate route are set.

Next, when using the CR-LSP state management table, let's look at the procedure for the path protection of the CR-LSP.

The path protection method of CR-LSP is classified into two types: protection switching method and rerouting method. The protection switching method sets up a plurality of CR-LSPs to back up one primary CR-LSP, and in case of failure of the primary CR-LSP, the channel information of the primary backup CR-LSP and the FEC information for the primary CR-LSP are set. It forwards service traffic to the path of backup CR-LSP immediately upon failure detection by forwarding to forwarding engine.

In case of a failure in the CR-LSP through which current service traffic flows, the re-routing method resets the CR-LSP with a preset ER-Hop and sends the corresponding service traffic to the reset CR-LSP. In case of a failure of the CR-LSP, the rerouting method can avoid packet loss during the time of forwarding service traffic by resetting the backup path replacing the existing CR-LSP. Therefore, the rerouting method is a lower priority path protection service method than the protection switching method.

9 is a flowchart illustrating a procedure for path protection when a failure occurs in a set primary CR-LSP.

First, when the keep alive timer or hello timer for the set CR-LSP is released, the signal protocol unit 20 notifies the traffic engineering unit 10 that the corresponding CR-LSP is released. Accordingly, the CR-LSP release event is received from the signaling protocol (S21). Here, the keep-alive timer is a S / W device that manages time for maintaining sessions between two adjacent routers (or nodes), and the hello timer periodically sends a Hello message sent to find neighboring neighboring routers (or nodes). It is a S / W device for sending and managing data.

The traffic engineering unit 10 determines whether the self-request has been requested by referring to the ID of the de-configured CR-LSP (S22). To judge.

If it is determined that the CR-LSP is broken, the traffic engineering unit 10 searches for an associated subscriber profile entry with reference to the received ID of the corresponding CR-LSP (S23). It is determined whether the path protection service is registered in the subscriber profile associated with the failed CR-LSP (S24).

If the subscriber is not provided with the path protection service, the operator is notified that a failure has occurred and the LSP ID information and Ex-FEC information for the CR-LSP are deleted from the FE and the operation is terminated (S25). Here, Ex-FEC is an abbreviation of Extened Fowarding Equivalence Class and indicates source address or additional information (port information, etc.) for a destination address.

On the other hand, if the path protection service is registered, the entry for the next backup CR-LSP of the failed CR-LSP is found in the CR-LSP state management table (S26). If the subscriber receives the path protection service by rerouting, refer to the list of path profiles associated with the subscriber profile in the subscriber profile associated with the failed CR-LSP. Find the index of the next backup path profile entry.

It is determined whether the alternative CR-LSP is set (S27), and if the next backup CR-LSP is not set, the operator is notified that the backup CR-LSP is no longer set, and the information of the failed CR-LSP and the associated FEC are determined. Delete the information from the FE.

On the other hand, when the next backup CR-LSP is set, the channel information and the FEC for the failed CR-LSP are deleted (S28).

At this time, as the protection procedures are distinguished according to the type of protection method, first, it is determined whether the protection method is a protection switching re-routing method (S29).

In the case of the protection switching scheme, the channel information and the Ex-FEC information of the backup CR-LSP are transmitted to the FE so that service traffic forwarded through the failed CR-LSP is forwarded through the backup CR-LSP (S30).

On the other hand, in the case of the repath setting method, the signal protocol unit 20 is requested to set the alternative CR-LSP (S31). The signal protocol unit 20 receiving the new CR-LSP setting request sets the CR-LSP according to the general CR-LSP setting procedure and then notifies the traffic engineering unit 10 of the result.

The TE block receiving the CR-LSP setting notification from the signal protocol unit 20 transmits the channel information and Ex-FEC information of the newly set CR-LSP to the forwarding engineering unit 30 to replace the CR-LSP that has failed. Forward the service traffic through (S32).

FIG. 10 is a conceptual diagram of performing path protection when a CR-LSP failure occurs according to the present invention shown in FIG. 9, and FIGS. 11A and 11B are table state change diagrams when performing the procedure of FIG. 9.

As shown in the figure, there may be three kinds of paths from LER1 to LER2. That is, there may be an A path consisting of LER1-LSR1-LER2, a B path consisting of LER1- LSR2-LSR4-LER2, and a C path consisting of LER1-LSR3-LSR5-LSR6-LER2. In the drawing, the solid line represents the main path, and each dotted line represents the alternate path. That is, when a failure occurs in the path between LSR1 and LER2, the Keep Alive Timer or Hello Timer for Path A is released and the signal protocol unit 20 notifies the traffic engineering unit 10 that the corresponding CR-LSP is released. As a result, a CR-LSP release event is received from the signaling protocol, and traffic is transferred through an alternate path with reference to the CR-LSP state management table through the process illustrated in FIG. 9.

11A and 11B are set to use the A path as the main path, when there is a problem in the A path, then use the B path as an alternative path, and use the C path when there is a problem in the B path.

FIG. 11A illustrates a case where the A path is used, and the state management table corresponding to the A path is in the ACT state, and the state management tables corresponding to the B and C paths are set to the STBY state. .

On the other hand, Figure 11b shows that there is a problem in the path A is using the path B, the state management table corresponding to the path A is deleted, the state management table corresponding to the path B is in the ACT state, It can be seen that the state management table corresponding to the C path is set to STBY.

Through the present invention can be expected the following effects.

First, by using the timer of the existing signaling protocol and the CR-LSP control function of the Ingress LSR, it is possible to detect a failure by utilizing without changing any protocol specification. Because of this, it is possible to provide path protection service without additional S / W and H / W when interworking with other devices.

Second, in the ingress LSR, the main route and alternate route can be set in advance, and the route can be easily managed by linking with specific service subscribers.

Third, by supporting both the protection switching method and the rerouting method, it is possible to increase the profitability of the ISP by providing various classes of path protection services.

Fourth, by providing a plurality of alternative paths to one main path can provide a service having a high level of network survivability to improve the profit of the ISP.

Claims (15)

In the CR-LSP path protection method in a multi-protocol label exchange system, Generating a profile by receiving information for alternative path management according to a CR-LSP failure; Setting a CR-LSP based on the profile; Generating a CR-LSP state management table having index information for the profile to manage the state of the corresponding CR-LSP for each set CR-LSP; When a failure of a predetermined CR-LSP is detected, the linked profile is searched by referring to each index information of the state management table of the corresponding CR-LSP, and the service traffic is forwarded to an alternate path according to the setting in the profile. Path protection method of CR-LSP that performs the path protection procedure step. The method of claim 1, wherein generating the profile comprises: Generating a subscriber profile for performing path protection service for each subscriber by receiving a subscriber's information and setting a plurality of alternative routes in one main path; Generating a route profile to receive node information for designating a route through which service traffic is to be routed and to establish a CR-LSP based on the node information; Creating a QoS profile for defining QoS parameters for service traffic; Linking each profile with each other to perform a path protection service for each subscriber. 3. The method of claim 2, wherein in generating the subscriber profile, The subscriber profile, the path protection service path protection method of the CR-LSP including at least one of the information, whether the service method, FEC information, alternative route list. The method of claim 3, wherein the service method is one of a protection switching method and a rerouting method. The method of claim 2, wherein in the step of generating the route profile, The route profile, CR-LSP path protection method comprising at least one of the IP address, Netmask, Strict / Loose mode of each node to the destination. The method of claim 2, wherein in generating the QoS profile: A method of protecting a path of a CR-LSP that defines at least one of a PCR, SCR, MBS, CDVT value, and QoS category. The method of claim 2, wherein linking the profiles to each other, Linking one or more of the path profile entries to the subscriber profile to establish a sequential alternate path. The method of claim 1, wherein the CR-LSP state management table, The entry index of the subscriber profile that manages the service information of the TE subscriber with the ID of the CR-LSP as the key index, the entry index of the route profile having the route information of the corresponding CR-LSP, and the QoS applied to the CR-LSP. QoS profile entry index with at least one of the following information: the type of signaling protocol used to configure the corresponding CR-LSP, the status of the current CR-LSP, the information of the previous backup path and the next backup path. Way. The method of claim 1, wherein generating the CR-LSP state management table, Creating and initializing an entry of a CR-LSP state management table according to a CR-LSP setting request; If the CR-LSP is set, registering the ID of the set CR-LSP in the CR-LSP ID index field of the state management table; Displaying a standby status in a current status field of a status management table when a label and channel information for a CR-LSP are allocated; If an alternate route is assigned, register the alternate route assigned to the alternate route field of the state management table, display an active state in the current state field of the state management table corresponding to the main route, and manage the state corresponding to the alternate route. A method of protecting a CR-LSP path, comprising the step of displaying a standby state in a current state field of a table. The method of claim 1, wherein the performing of the path protection procedure, Determining whether a failure of the CR-LSP occurs by referring to the ID of the received CR-LSP when a release event of the predetermined CR-LSP is received; Searching for a related subscriber profile entry based on the received ID of the CR-LSP and retrieving whether or not the subscriber's path protection service is registered in the searched related subscriber profile; When the path protection service is registered, information for setting a CR-LSP to be replaced by referring to the CR-LSP state management table linked to the searched related subscriber profile for each path protection service and forwarding service traffic to an alternative path. CR-LSP path protection method comprising the step of registering in the forwarding list. The method of claim 10, wherein the determining whether the failure is, If the ID of the received CR-LSP is a CR-LSP for which it has not requested release, determining that the CR-LSP is broken. The method of claim 10, wherein in the step of registering information for forwarding to an alternate path in a forwarding list, If you are a subscriber who is receiving route protection services through rerouting, Refer to the list of path profiles associated with the subscriber profile in the subscriber profile associated with the failed CR-LSP, and obtain the index of the next backup path profile entry of the path profile entry index constituting the failed CR-LSP. Requesting setting of a CR-LSP; Receiving the newly set information of the CR-LSP from the signaling protocol and registering in the forwarding list to forward the service traffic through the replacement CR-LSP of the failed CR-LSP. The method of claim 12, wherein registering with the forwarding list comprises: The newly set information of the CR-LSP includes at least one of channel information and Ex-FEC information of the CR-LSP. The method of claim 10, wherein performing forwarding to an alternate path, If you are a subscriber with path protection services with protection switching, The CR-LSP path protection method of registering the channel information and Ex-FEC information of the designated backup CR-LSP in the forwarding list so that service traffic forwarded through the failed CR-LSP is forwarded through the backup CR-LSP. In order to perform the path protection method of the CR-LSP in a multi-protocol label exchange system, a program of instructions that can be executed by a digital processing apparatus is tangibly implemented, and in a recording medium that can be read by the digital processing apparatus. , Generating a profile by receiving information for alternative path management according to a CR-LSP failure; Setting a CR-LSP based on the profile; When a failure of a predetermined CR-LSP is detected, the linked profile is searched by referring to the index information of the state management table of the corresponding CR-LSP, and the service traffic is forwarded to an alternate path according to the information set in the profile. Recording medium storing program for performing the path protection procedure step.