JP4839287B2 - Communication path communication confirmation test apparatus and computer program - Google Patents

Description

  The present invention relates to a communication path communication confirmation test apparatus and a computer program related to a communication network (hereinafter referred to as “MPLS network”) to which MPLS (Multi Protocol Label Switching) is applied.

  Conventionally, MPLS is known as one of routing techniques in a packet communication network. With MPLS, a virtual path (LSP: Label Switch Path) can be set as a communication path from a certain node (communication base) to another node. When setting LSP, MPLS-TE (Traffic Engeneering) can be used. MPLS-TE is described in Non-Patent Document 1, for example. One of the features of MPLS-TE is fast reroute (FRR). FRR is described in Non-Patent Document 2, for example. The FRR can minimize the influence of the failure by locally bypassing the failure of the link connecting the nodes and the failure of the node in the MPLS network.

FRR is an essential function for providing high-quality services, and is used by many service providers. When FRR is applied with MPLS-TE LSP (“MPLS TE LSP”, hereinafter simply referred to as “LSP”), in addition to normal LSP, FRR backup LSP for local detour (hereinafter referred to as “backup LSP”). Need to be managed and monitored. As a conventional MPLS operation management / monitoring technique, for example, Non-Patent Document 3 discloses an LSP data plane communication confirmation method for checking whether a packet can be actually transmitted by the LSP.
D. Awduche, et al., “RSVP-TE: Extensions to RSVP for LSP Tunnels”, IETF RFC3209, December 2001. P. Pan, G. Swallow and A. Atlas, “Fast Reroute Extensions to RSVP-TE for LSP Tunnels”, IETF RFC4090, May 2005. K. Kompella and G. Swallow, “Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures”, IETF RFC 4379, February 2006.

  However, in the conventional MPLS operation management / monitoring technology described in Non-Patent Document 3 described above, a data plane assuming that a backup LSP (Link Protection LSP, Node Protection LSP: see Non-Patent Document 2) is used during FRR operation. Communication check is impossible. This point will be described with reference to FIG. In the MPLS network shown in FIG. 6, the LSP (R1-R2-R3-R4) from the node R1 to the node R4 and the backup LSP (R2-R5-R3) from the node R2 to the node R3 via the node R5 are set. Yes. As a result, when a link failure or node failure occurs between the node R2 and the node R3, the detour path (R2-R5-R3-R4) using the backup LSP (R2-R5-R3) is changed to the LSP (R1-R2 -R3-R4), and packet transmission from the node R1 to the node R4 is performed by the detour LSP (R1-R2-R5-R3-R4).

  Here, according to the conventional MPLS operation management and monitoring technology, it is possible to check data plane communication confirmation of LSP (R1-R2-R3-R4) alone and data plane communication confirmation of backup LSP (R2-R5-R3) alone. . However, in the conventional MPLS operation management / monitoring technology, when no failure occurs between the node R2 and the node R3 and the detour route (R2-R5-R3-R4) is not used, the detour route (R2 -R5-R3-R4) Data plane communication confirmation cannot be performed. Therefore, there is a problem that the data plane communication confirmation of the detour path (R2-R5-R3-R4) cannot be performed in advance in preparation for the occurrence of a failure.

  In addition, conventionally, the operator has manually performed data plane communication confirmation work for the backup LSP. However, since the number of backup LSPs is generally very large, the workload is large, and automating the data plane communication confirmation task has become an issue.

  The present invention has been made in consideration of such circumstances, and its purpose is to perform data plane communication confirmation of a detour route using a backup LSP in advance in preparation for the occurrence of a failure, data plane communication. An object of the present invention is to provide a communication path communication confirmation test apparatus and a computer program capable of automating the confirmation work.

In order to solve the above-described problem, the communication path communication confirmation test device according to the present invention performs a data plane communication confirmation test on a bypass path using a backup LSP in an MPLS network in which an LSP and a backup LSP are set. A communication path communication confirmation test apparatus that is used when a path is not used, and searches a backup LSP that passes through a start node of a data plane communication confirmation test from the FRR database of the start node, and outputs an output label and the start point for the backup LSP Backup LSP information acquisition means for acquiring output interface information on a node from the FRR database, and searching for an LSP that uses the backup LSP of the search result as a bypass route from the FRR database, and using the backup LSP as a bypass route preparative LSP information to get the LSP information and MP label of the LSP to be LSP unit based on means, communication confirmation information creating means for creating communication confirmation information composed of backup LSP output interface information, backup LSP output label, MP label and LSP information, and LSP information in the communication confirmation information A confirmation packet creating means for creating a confirmation packet for the data plane communication confirmation test, and an MP label in the communication confirmation information is added to the head of the confirmation packet, and further on the MP label, in the communication confirmation information Label adding means for adding a backup LSP output label, and output interface switching means for sending a confirmation packet after the label addition from the start node using the output interface indicated by the backup LSP output interface information in the communication confirmation information And the response packet to the transmitted confirmation packet is the start node A response packet reception determination means for determining whether or not the received, characterized by comprising a.

  In the communication path communication confirmation test device according to the present invention, the data plane communication confirmation of the detour path is sequentially performed for each set of backup LSP output interface information, backup LSP output label, MP label, and LSP information in the communication confirmation information. Control means for controlling to perform the test is provided.

The computer program according to the present invention is a computer program for performing a data plane communication confirmation test on a bypass route using a backup LSP when the bypass route is not used in an MPLS network in which an LSP and a backup LSP are set. The backup LSP passing through the start node of the data plane communication confirmation test is searched from the FRR database of the start node, and the output label and the information of the output interface on the start node regarding the backup LSP are obtained from the FRR database. Backup LSP information acquisition function, and LSP information acquisition that searches the LSP that uses the backup LSP of the search result as a bypass path from the FRR database and acquires LSP information and MP label of the LSP that uses the backup LSP as a bypass path Function and backup LSP Communication confirmation information creation function to create communication confirmation information consisting of the interface information, backup LSP output label, MP label and LSP information, and data plane communication confirmation of LSP alone based on the LSP information in the communication confirmation information A confirmation packet creation function for creating a test confirmation packet, and an MP label in the communication confirmation information is added to the head of the confirmation packet, and a backup LSP output label in the communication confirmation information is further added to the MP label. Using the label addition function to be added, the output interface indicated by the backup LSP output interface information in the communication confirmation information, the output interface switching function for transmitting the confirmation packet after the label addition from the start node, and the transmitted Determine whether a response packet to the confirmation packet has been received by the source node Characterized in that to achieve a response packet reception determination function that, to the computer.

In the computer program according to the present invention, a data plane communication confirmation test of the detour path is sequentially performed for each set of backup LSP output interface information, backup LSP output label, MP label, and LSP information in the communication confirmation information. The control function is further realized by a computer.
As a result, the communication path communication confirmation test apparatus described above can be realized using a computer.

  According to the present invention, there is an effect that it is possible to confirm the data plane communication of the detour path using the backup LSP in advance in preparation for the occurrence of a failure. Moreover, the effect that the data plane communication confirmation work can be automated is obtained.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a communication path communication confirmation test apparatus 1 according to an embodiment of the present invention. The communication path communication confirmation test apparatus 1 according to the present embodiment is provided in a node R2 that is a node (start node) of a data plane communication confirmation test in the MPLS network illustrated in FIG. The node R2 is a router having a PLR (Point of Local Repair) function. Node R2 includes an FRR database. The FRR database is a database that is conventionally held by a router and is a well-known technique.

  The router receives OSPF (Open Shortest Path First) information and RSVP (Resource reSerVation Protocol) information transmitted from other routers, and constructs an FRR database using the received information. The FRR database includes LSP information, backup LSP information, and an MP (Merge Point) label. The LSP information includes information on the LSP itself (LSP information), information on the backup LSP used as a bypass path, and an MP (Merge Point) label. The backup LSP information includes a backup LSP output label and information (backup LSP output interface information) indicating an output interface (backup LSP output interface) of a node used for the backup LSP.

  In FIG. 1, a communication path communication confirmation test apparatus 1 includes a communication confirmation information creation unit 11, a storage unit 12, a control unit 13, a confirmation packet creation unit 14, a label addition unit 15, an output interface switching unit 16, and a response packet reception determination unit. 17.

  When the communication confirmation information creating unit 11 receives an instruction from the control unit 13, the communication confirmation information creating unit 11 starts creating the communication confirmation information. The communication confirmation information creation unit 11 creates communication confirmation information using the FRR database provided in the node R2. The storage unit 12 stores and holds the communication confirmation information.

Here, with reference to FIG. 2, the operation at the time of creating the communication confirmation information according to the present embodiment will be described. FIG. 2 is a flowchart showing a procedure for creating communication confirmation information according to the present embodiment.
In FIG. 2, first, in step S1, a backup LSP passing through the node R2 is searched from the FRR database, and a backup LSP output label and backup LSP output interface information are acquired from the FRR database regarding the backup LSP. In step S1, all backup LSPs passing through the node R2 are extracted.

Next, in step S2, the LSP that uses the backup LSP searched in step S1 as a bypass path is searched from the FRR database, and the LSP information and the MP label are acquired. In step S2, all LSPs that use the backup LSP as a detour path are extracted from all the backup LSPs extracted in step S1.
Note that the extraction target here is the LSP that ends with the router that sends “Local Protection desired flag” (see Non-Patent Documents 1 and 2), and “Local Protection desired flag” and “Node Protection desired flag” ( The router that sends out the non-patent document 2) is the LSP that is the end point. These LSPs are the subject of the test.

  Next, in step S3, communication confirmation information is created using the information acquired in steps S1 and S2. The communication confirmation information is composed of a set of backup LSP output interface information, backup LSP output label, MP label, and LSP information. The communication confirmation information has the set for each LSP. FIG. 3 shows a configuration example of the communication confirmation information according to the present embodiment. As shown in FIG. 3, the communication confirmation information includes backup LSP output interface information, backup LSP output label, MP label, and LSP information for each LSP.

Returning to FIG.
The control unit 13 controls the units 11, 14, 15, 16, and 17 in order to check the data plane communication of the detour route. First, the operator instructs the start of the data plane communication confirmation test of the detour route. The operator performs this test when no failure occurs between the nodes related to the node R2 and the backup LSP passing through the node R2 is not used. When receiving the test start instruction from the operator, the control unit 13 instructs the communication confirmation information creating unit 11 to create the communication confirmation information. As a result, the communication confirmation information creating unit 11 starts the communication confirmation information creating process of FIG. When the creation of the communication confirmation information is finished, the control unit 13 performs a data plane communication confirmation test of the detour route using the communication confirmation information held in the storage unit 12. The control unit 13 sequentially performs a data plane communication confirmation test of the detour path for each set in the communication confirmation information. The control unit 13 controls the units 14, 15, 16, and 17 during the bypass plane data plane communication confirmation test.

  The control unit 13 may check the data plane communication of the detour route regularly or according to a predetermined schedule. However, the control unit 13 confirms that no failure has occurred between the nodes related to the node R2 and the backup LSP passing through the node R2 is not used, and then performs a data plane communication confirmation test of the detour path. Do.

  Here, with reference to FIG. 1 and FIG. 4, an operation during a data plane communication confirmation test of a detour path according to the present embodiment will be described. FIG. 4 is a flowchart showing a procedure of a data plane communication confirmation test of a detour route according to the present embodiment. Here, for convenience of explanation, the test operation will be described by focusing on one set in the communication confirmation information. The control unit 13 sends information on the test target group in the communication confirmation information to the units 14, 15, 16, and 17.

In FIG. 4, first, in step S11, the confirmation packet creation unit 14 creates a confirmation packet (MPLS echo request) for a data plane communication confirmation test for a single LSP based on the LSP information in the communication confirmation information. The confirmation packet creation unit 14 uses the LSP information received from the control unit 13. FIG. 5 shows the format of the confirmation packet according to this embodiment. The part of the original confirmation packet in FIG. 5 is the format of the confirmation packet created in step S11. This original confirmation packet portion is defined in Non-Patent Document 3. The confirmation packet creating unit 14 uses the LSP information in the communication confirmation information to create the data of the original confirmation packet part in FIG. However, “Sub-Type = 3, Length = 20 (RSVP IPv4 LSP)” is set as “Target FEC Stack”.
The confirmation packet created in step S11 is sent to the label adding unit 15.

  Next, in step S12, the label adding unit 15 adds the MP label and the backup LSP output label in the communication confirmation information to the confirmation packet. The label adding unit 15 uses the MP label and the backup LSP output label received from the control unit 13. As shown in FIG. 5, the label adding unit 15 adds an MP label to the head of the original confirmation packet, and further adds a backup LSP output label on the MP label. The confirmation packet after the label addition is sent to the output interface switching unit 16.

  Next, in step S12, the output interface switching unit 16 switches the output interface used in the node R2 to the output interface indicated by the backup LSP output interface information in the communication confirmation information. The output interface switching unit 16 uses the backup LSP output interface information received from the control unit 13. By this step S12, the output interface used in the node R2 is switched to the output interface for the backup LSP even though the backup LSP passing through the node R2 is not used.

  Next, in step S13, the output interface switching unit 16 transmits a confirmation packet after label addition from the node R2 using the switched output interface for the backup LSP. As a result, the confirmation packet after label addition is transmitted from the output interface for the backup LSP of the node R2.

  For example, in FIG. 6, the confirmation packet after label addition for the main test related to the LSP (R1-R2-R3-R4) is transmitted from the output interface for the backup LSP (R2-R5-R3) of the node R2. . Thereby, the confirmation packet after the label is added is sent from the node R2 to the node R3 via the node R5. Then, the node R3 sends the confirmation packet after the label addition to the node R4. Since the node R4 is a node at the end of the LSP (R1-R2-R3-R4), when it receives the confirmation packet after the label addition, it returns a response packet (MPLS echo reply). This response packet is transferred to the node R2.

  Next, in step S15, the response packet reception determination unit 17 determines whether or not a response packet for the confirmation packet transmitted in step S14 has been received by the node R2. When the response packet reception determination unit 17 receives a response packet reception determination from the control unit 13 (corresponding to the transmission time of the confirmation packet after label addition), the response packet is not received by the node R2 within a predetermined period. Is determined not to receive a response packet. On the other hand, if the response packet is received at the node R2 within a predetermined period from the time when the response packet reception determination is instructed by the control unit 13, the response packet reception determination unit 17 determines that the response packet has been received. .

  If the response packet is received as a result of the determination in step S15, the response packet reception determination unit 17 determines that the bypass path is in communication (step S16). On the other hand, if the result of determination in step S15 is that no response packet has been received, the response packet reception determination unit 17 determines that there is no communication of the detour route (step S17).

  According to the above-described embodiment, for example, in FIG. 6, when no failure has occurred between the node R2 and the node R3 and the detour path (R2-R5-R3-R4) is not used. In addition, the data plane communication confirmation of the detour path (R2-R5-R3-R4) can be performed. As a result, there is an effect that the data plane communication confirmation of the detour path (R2-R5-R3-R4) can be performed in advance in preparation for the occurrence of a failure. As a result, it is possible to contribute to stabilization of actual operation of the MPLS network.

  Further, according to the present embodiment, path information (backup LSP output interface information, backup LSP output label, MP label, and LSP information) related to a detour route using the backup LSP is acquired from the FRR database, and the set of the path information Each time, control is performed to sequentially perform a data plane communication confirmation test of the detour path. As a result, the data plane communication confirmation work is automated, and the work load on the operator is greatly reduced. As a result, the operation work time can be reduced and the operation cost can be reduced.

  Note that the bypass plane data plane communication confirmation test according to the present embodiment can be independently performed in each PLR.

Also, a program for realizing each step shown in FIGS. 2 and 4 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, thereby performing communication. A route communication confirmation test process may be performed. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

It is a block diagram which shows the structure of the communication path | route communication confirmation test apparatus 1 which concerns on one Embodiment of this invention. It is a flowchart which shows the procedure of preparation of the communication confirmation information which concerns on the embodiment. It is a structural example of the communication confirmation information which concerns on the same embodiment. It is a flowchart which shows the procedure of the data plane communication confirmation test of the detour route which concerns on the embodiment. It is a figure which shows the format of the confirmation packet after the label addition which concerns on the embodiment. It is a figure which shows an example of an MPLS network.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Communication path | route communication confirmation test apparatus, 11 ... Communication confirmation information preparation part, 12 ... Memory | storage part, 13 ... Control part, 14 ... Confirmation packet preparation part, 15 ... Label addition part, 16 ... Output interface switching part, 17 ... Response Packet reception judgment unit

Claims (4)

In the MPLS network in which the LSP and the backup LSP are set, a communication path communication confirmation test device that performs a data plane communication confirmation test for a bypass path using the backup LSP when the bypass path is not used,
Backup LSP information acquisition that retrieves the backup LSP that passes through the start node of the data plane communication confirmation test from the FRR database of the start node, and acquires the output label and the information of the output interface on the start node with respect to the backup LSP from the FRR database Means,
LSP information acquisition means for searching the LSP using the backup LSP of the search result as a bypass path from the FRR database, and acquiring LSP information and an MP label of the LSP using the backup LSP as a bypass path ;
Communication confirmation information creating means for creating communication confirmation information composed of backup LSP output interface information, backup LSP output label, MP label and LSP information;
Based on the LSP information in the communication confirmation information, confirmation packet creation means for creating a confirmation packet for a data plane communication confirmation test of a single LSP,
A label adding means for adding an MP label in the communication confirmation information to the head of the confirmation packet, and further adding a backup LSP output label in the communication confirmation information on the MP label;
Using the output interface indicated by the backup LSP output interface information in the communication confirmation information, output interface switching means for transmitting the confirmation packet after the label addition from the start point node;
Response packet reception determination means for determining whether or not a response packet for the transmitted confirmation packet is received at the start node;
A communication path communication confirmation test apparatus characterized by comprising:   Control means for controlling to perform the data plane communication confirmation test of the detour path sequentially for each set of backup LSP output interface information, backup LSP output label, MP label and LSP information in the communication confirmation information. The communication path communication confirmation test apparatus according to claim 1, wherein In an MPLS network in which an LSP and a backup LSP are set, a computer program for performing a data plane communication confirmation test for a bypass route using a backup LSP when the bypass route is not used,
Backup LSP information acquisition that retrieves the backup LSP that passes through the start node of the data plane communication confirmation test from the FRR database of the start node, and acquires the output label and the information of the output interface on the start node with respect to the backup LSP from the FRR database Function and
LSP information acquisition function for searching LSP using the backup LSP of the search result as a bypass path from the FRR database, and acquiring LSP information and MP label of the LSP using the backup LSP as a bypass path ;
A communication confirmation information creation function for creating communication confirmation information composed of backup LSP output interface information, backup LSP output label, MP label and LSP information;
Based on the LSP information in the communication confirmation information, a confirmation packet creation function for creating a confirmation packet for a data plane communication confirmation test of a single LSP, and
A label addition function for adding an MP label in the communication confirmation information to the head of the confirmation packet, and further adding a backup LSP output label in the communication confirmation information on the MP label;
Using the output interface indicated by the backup LSP output interface information in the communication confirmation information, an output interface switching function for transmitting a confirmation packet after the label addition from the start point node;
A response packet reception determination function for determining whether or not a response packet for the transmitted confirmation packet has been received at the source node;
A computer program for causing a computer to realize the above.   The computer further realizes a function of controlling to perform a data plane communication confirmation test of the detour path sequentially for each set of backup LSP output interface information, backup LSP output label, MP label, and LSP information in the communication confirmation information. The computer program according to claim 3.

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