CN1929479A - Method and system for protecting label exchanging path - Google Patents

Abstract

The present invention proposes a method and system for protecting a label switching path. When a signal SF event occurs at a line port, the multiplex section protocol processing unit of the switching site notifies other sites on the multiplex section ring of the fault information, and at the same time notifies the site The data forwarding table processing unit; the data forwarding table processing unit notifies the label processing module of the site that needs to be switched to complete the switch; when the multiplex section protocol is processed to other sites on the multiplex section ring, the multiplex section protocol processing unit of the site The data forwarding table processing unit of the station is notified, and the data forwarding table processing unit notifies the label processing module of the station to complete the punch-through. By adopting the invention, the protection of the label switching path can be realized by using the multiplexing section protocol.

Description

A method and system for protecting a label switching path

technical field

The invention relates to the technical field of data transmission, in particular to a method and system for protecting a label switching path.

Background technique

The ITU-T G.841 proposal stipulates the types and characteristics of Synchronous digital hierarchy (SDH) network protection. The proposal specifies the type of SDH network protection and the multiplex section protection protocol. The multiplex section protection protocol utilizes SDH K bytes in the segment overhead, complete SDH network protection, specific protocol details can refer to ITU-T G.841.

As shown in Figure 1, the ITU-T G.841 recommendation stipulates that in the SDH network multiplex section protection ring, under normal conditions, a customer circuit goes from point A to point D, and the working path of the multiplex section ring is point A- Point B-Point C-Point D. But as shown in Figure 2, when the optical fiber between point B and point C is interrupted, point B and point C detect the link failure, and then use the K bytes in the overhead to pass through another path of the multiplex section ring ( It can be described as point B-point A-point F-point E-point D-point C) to notify all sites on the ring of the fault information, and then point B switches the service from the working path to the protection path, and transmits the service to the Point A, point A, point F, point E, and point D correspondingly pass through the services of the protection path, and finally point C switches the services of the protection path back to the working path, and transmits the services to point D, thus completing the entire switchover .

But this multiplex section protection method is to utilize, and can only utilize time slot crossover to realize, can only support the protection in the time division multiplexing switching plane, can't utilize data in the Multiprotocol Label Switching (Multiprotocol LabelSwitch, MPLS) network Packet switching plane to implement multiplex section protection.

Contents of the invention

The object of the present invention is to propose a method and system for protecting a label switching path, which can realize the protection of the label switching path by using a multiplexing section protocol in a multi-protocol label switching network.

For this reason, the present invention adopts following technical scheme:

A method for protecting a label switching path, which is applicable to a multi-protocol label switching network, is characterized in that it comprises the following steps:

A. When a signal loss or frame loss event occurs at the line port, the multiplex section protocol processing unit of the site that needs to be switched will notify other sites on the multiplex section ring of the fault information, and at the same time notify the data forwarding table processing unit of the site;

B. The data forwarding table processing unit notifies the label processing module of the site that needs to be switched, and switches the data packet service on the current working path to the protection path;

C. When the multiplex section protocol is processed to other sites on the multiplex section ring, the multiplex section protocol processing unit of the site notifies the data forwarding table processing unit of the site, and the data forwarding table processing unit notifies the label of the site The processing module converts the protection path into a working path, and sends the data packet changes to the converted working path to complete the pass-through processing;

D. When the multiplex section protocol is processed to another site that needs to be switched, the multiplex section protocol processing unit of the site notifies the data forwarding table processing unit of the site, and the data forwarding table processing unit notifies the label processing module of the site to switch the data packet service on the current working path to the protection path.

In the step A, the multiplex section protocol processing unit of the site to be switched uses K bytes to notify other sites on the multiplex section ring of the fault information.

In the data forwarding table processing unit described in step A, there are two paths for each working channel label, one is a working path and the other is a protection path, and different weight values are assigned to the working path and the protection path.

The switching of the data packet service on the current working path to the protection path described in step B or step D further includes the following steps:

Swap the weight values of the working path and the protection path to complete the swap between the current working path and the protection path.

The converting the protection path into the working path described in the step C further includes the following steps:

Change the weight value of the protection path to the weight value of the working path.

The weight value of the working path may be 1, and the weight value of the protection path may be 0.

In the data forwarding table processing unit described in the step A, there are 2 paths for each kind of working channel label, one is a working path, and the other is a protection path, switches are set for these two paths, and the working path is in a connected state. The protection path is disconnected.

The switching of the data packet service on the current working path to the protection path described in step B or step D further includes the following steps:

The switch is converted, the working path is turned into a disconnected state, and the protection path is turned into a connected state.

The data forwarding table can be manually configured, or automatically configured according to the label distribution protocol.

A system for protecting a label switching path method, comprising a data forwarding table processing unit, a multiplex section protocol processing unit, a data crossover unit, and a data line processing unit, wherein the data line processing unit includes a synchronous digital system layer processing module and a virtual container encapsulation And label processing module, it is characterized in that:

The data line processing unit includes a working path and a protection path, the multiplex section protocol processing unit notifies the data forwarding table processing unit, and the data forwarding table processing unit notifies the label processing module to complete the working path and the protection path protection between.

The data forwarding table processing unit is provided with a path setting unit for setting connection paths between data line processing units.

The path processing unit is a weight value setting unit, which is used to set the weight values of the working path and the protection path, so as to identify the currently connected path.

The path processing unit is a switch setting unit, which is used to set the switch states of the working path and the protection path.

By adopting the technical scheme of the present invention, in the multi-protocol label switching network, the protection of the label switching path can be realized by using the multiplex section protocol, and the protection switching time can be realized within 50 milliseconds, and in the multiplex section protocol module of the original SDH product With a few changes, this functionality can be achieved.

Description of drawings

Fig. 1 is a schematic diagram of a client circuit in a normal state in an SDH network;

Fig. 2 is a schematic diagram of a client circuit in a fault state in an SDH network;

Fig. 3 is a schematic structural diagram of network transmission equipment in an MPLS network;

Fig. 4 is a flow chart of label switched path protection in the present invention;

FIG. 5 is a schematic structural diagram of a switching path at a switching site in the present invention;

FIG. 6 is a schematic structural diagram of punch-through processing of the punch-through station in the present invention.

Detailed ways

The specific implementation manner of the present invention will be described below in conjunction with the accompanying drawings.

As shown in Figure 3, in the data network transmission device, the optical port connected between the transmission devices is called a line port, and the interface connected between the transmission device and the client device is called a tributary port.

The transmission equipment includes the following units: data crossover unit, data line processing unit, data branch processing unit, multiplex section protocol processing unit, and data forwarding table processing unit. The data line processing unit is further divided into SDH layer processing module and virtual Container (virtual container, VC) encapsulation and label processing module, data branch processing unit is divided into interface processing module and label processing module.

The main function of the data line processing unit is to process the business of the line port, demap the data packet in the VC, find the destination port number and destination board position according to the MPLS label in the data packet, and compare the data forwarding table, and then transfer the destination port number to and destination board position information are added to the data packet and sent to the data cross unit.

The main function of the data branch processing unit is to process the business of the client. According to the MPLS label in the client data packet, compare the data forwarding table, find the destination port number and destination board position, and then add the destination port number and destination board position information to the data In the packet, it is sent to the data interleaving unit.

The main function of the data forwarding table processing unit is to store the forwarding information of each single board in the system, which contains the processing measures for each MPLS label, and the processing measures include destination board position, destination port, destination channel, next-hop label, etc.; This data forwarding table can be manually configured or automatically generated according to the LDP protocol.

In this solution, the data forwarding table processing unit is provided with a path setting unit, which is used to set the connection path between the data line processing units.

The design of the present invention requires that there are two paths for each working channel label in the data forwarding table, one is the working path, and the other is the protection path, and the data forwarding table changes the path of the label by changing the weights of the two paths, for example, it can be set The weight of the working path is "1", and the weight of the protection path is "0". At this time, the destination board position, destination port, and destination channel of the working path will be added to each label. When the weight of the working path is changed to "0", the weight of the protection path When it is changed to "1", the current working path becomes the protection path, and the current protection path becomes the working path. For each label, the destination board position, destination port, and destination channel of the switched working path will be added. Corresponding to this solution, the path setting unit can be designed as a weight value setting unit for setting the weight values of the working path and the protection path to identify the currently connected path.

For each data packet of the protection channel, there is only one pass-through path. When the weight of this path is "0", it means no pass-through, and when the weight of this path is "1", it means pass-through.

There is another method of distinguishing the working path and the protection path, that is, setting switches on the working path and the protection path respectively, the working path is in the connected state, and the protection path is in the disconnected state. The connected state is equivalent to a weight of 1, and the disconnected state is equivalent to a weight of 0. If switching and punch-through are to occur, the switch of the current working path is turned into a disconnected state, and the switch of the current protection path is turned into a connected state. Correspondingly, the path setting unit can be designed as a switch setting unit for setting the switch states of the working path and the protection path.

The main function of the data cross-connect unit is to forward to the corresponding board position and port according to the destination board position and destination port information in the data packet sent by each service board.

The main function of the multiplex section protocol processing unit is to process the multiplex section protocol, process the multiplex section protocol according to the information related to the multiplex section reported by each circuit board, and issue the corresponding switching configuration. The multiplex section protocol conforms to the G.841 recommendation .

Technical scheme of the present invention is as shown in Figure 4, and as can be seen from the figure, it mainly comprises the following steps:

S1. The line port is faulty.

When it is judged that a fault occurs at the line port, follow-up steps are performed.

S2. The multiplex section protocol processing unit of the switching site uses K bytes to notify other sites of the fault information.

When a signal loss or frame loss fault occurs at the line port, the multiplex section protocol processing unit of the site to be switched uses K bytes to notify other sites on the multiplex section ring of the fault information.

S3. The multiplex section protocol processing unit of each station notifies the label processing module to change the weight values of the working path and the protection path.

The multiplex section protocol processing unit of each site notifies the label processing module of the site to modify the weight values of the currently set working path and protection path.

S4. The data packet change at the switching site is sent to the protection path; the pass-through site performs pass-through processing on the data packet of the protection path.

Among them, for the switching site, the weight value of the working path and the weight value of the protection path are exchanged, so that the working path and the protection path are exchanged, and the data packet changes at the switching site are sent to the original protection path and the exchanged path. The work path is up. For the pass-through site, the weight value of the protection path is changed to the weight value of the working path, so that the protection path is changed into a working path to realize pass-through processing.

The switching site and the pass-through site will be described respectively below.

As shown in Figure 5, when a signal loss or frame loss failure occurs at the line port, the site needs to switch sites, the multiplex section protocol processing unit will notify the data forwarding table processing unit, and the data forwarding table processing unit will notify the label processing module, To change the weight value of the working path and the protection path, change the weight value of the working path from 1 to 0, and change the weight value of the protection path from 0 to 1, so that the protection path and the working path have been swapped, and it becomes the post-swap The data interface board will add the destination board position, destination port and destination channel of the switched working path to the label processing of each MPLS by the data interface board. At this time, the data packet will be processed according to the destination board position, destination port and destination channel It is forwarded to the switched working path to realize switching.

As shown in Figure 6, when the multiplex section protocol processing requires that the site needs to perform a pass-through action, the site becomes a pass-through site, and the multiplex section protocol processing unit will notify the data forwarding table processing unit, and the data forwarding table processing unit will notify the label processing The module changes the weight value of the protection path from 0 to 1, and the data packet is transmitted through the protection path with the modified weight value, that is, the converted working path, thereby realizing the pass-through action.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person familiar with the technology can easily think of changes or replacements within the technical scope disclosed in the present invention. , should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (13)

1, a kind of method of protecting label switched path is applicable to it is characterized in that in the multi-protocol label switching network, may further comprise the steps:

A, when circuit mouth generation dropout or LOF incident, the multiplex section protocol processing unit of the website that need switch is notified other websites on the multiplex section ring with fault message, notifies the data forwarding list processing unit of this website simultaneously;

The label processing module of the website that B, described data forwarding list processing unit notice need be switched is switched to the data packet traffic on the work at present path on the protection path;

C, when other websites to the multiplex section ring of multiplex section protocol processes, the multiplex section protocol processing unit of this website is notified the data forwarding list processing unit of this website, the label processing module of this website is notified in described data forwarding list processing unit, to protect the path to convert operating path to, packet change sends on the operating path after the conversion, finishes punch-through process;

D, when multiplex section protocol processes during to another website that need switch; the multiplex section protocol processing unit of this website is notified the data forwarding list processing unit of this website; the label processing module of this website is notified in described data forwarding list processing unit, and the data packet traffic on the work at present path is switched on the protection path.

2, the method for protection label switched path as claimed in claim 1 is characterized in that, the multiplex section protocol processing unit of the website that the needs described in the described steps A are switched utilizes the K byte to notify other websites on the multiplex section ring with fault message.

3, the method for protection label switched path as claimed in claim 1; it is characterized in that; for every kind of service aisle label 2 paths are arranged in the data forwarding list processing unit described in the described steps A; one is operating path; one is the protection path, gives different weighted values with the protection path for operating path.

4, the method for protection label switched path as claimed in claim 3 is characterized in that, the data packet traffic with on the work at present path described in described step B or the step D is switched on the protection path and further may further comprise the steps:

The weighted value in operating path and protection path is changed, finished the transposing between current operating path and the protection path.

5, the method for protection label switched path as claimed in claim 3 is characterized in that, will protect the path to convert operating path to further to may further comprise the steps described in the described step C:

The weighted value in protection path is changed into the weighted value of operating path.

6, the method for protection label switched path as claimed in claim 3 is characterized in that, the weighted value of described operating path can be 1, and the weighted value in described protection path can be 0.

7, the method for protection label switched path as claimed in claim 1; it is characterized in that; for every kind of service aisle label 2 paths are arranged in the data forwarding list processing unit described in the described steps A; one is operating path; one is the protection path; for these two paths are provided with switch, operating path is a connected state, and the protection path is an off-state.

8, the method for protection label switched path as claimed in claim 7 is characterized in that, the data packet traffic with on the work at present path described in described step B or the step D is switched on the protection path and further may further comprise the steps:

Switch transition, operating path transfers off-state to, and the protection path transfers connected state to.

9, the method for protection label switched path as claimed in claim 1 is characterized in that, described data forwarding table can manual configuration, also can dispose automatically according to tag distribution protocol.

10, a kind of system that realizes the described protection tag changeable path of claim 1 routing method; comprise data forwarding list processing unit, multiplex section protocol processing unit, data cross unit, data circuit processing unit; described data circuit processing unit comprises SDH (Synchronous Digital Hierarchy) layer processing module and virtual container encapsulation and label processing module, it is characterized in that:

Comprise operating path and protection path between the described data circuit processing unit; described multiplex section protocol processing unit notification data is transmitted processing unit; described data forwarding list processing unit notified tag processing module is with the protection of finishing the work between path and the protection path.

11, system as claimed in claim 10 is characterized in that, described data forwarding list processing unit is provided with path setting element, is used to be provided with the access path between the data circuit processing unit.

12, system as claimed in claim 11 is characterized in that, described path processing unit for weighted value is provided with the unit, is used to be provided with the weighted value in operating path and protection path, to identify the path of current connection.

13, system as claimed in claim 11 is characterized in that, described path processing unit for switch is provided with the unit, is used to be provided with the on off state in operating path and protection path.

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