JP5470595B2 - Network control apparatus and path selection method - Google Patents

Description

  The present invention relates to a network control apparatus, and relates to a network control apparatus that controls a communication path by MPLS.

  In recent years, introduction of full IP-Ethernet (registered trademark, the same shall apply hereinafter) has progressed in backbone networks of communication carriers. The IP-Ethernet network is also required to have carrier grade reliability (that is, very high availability).

  As a method for responding to this request, a logical path (LSP: Label Switch Path) is statically allocated on a physical optical transmission line, and a communication state is monitored and controlled (Transport-MPLS). Alternatively, MPLS-TP (MPLS-Transport Profile) or the like is defined. Such a method is defined as MPLS (Multi-Protocol Label Switching) (see, for example, Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3).

  In MPLS, a 1 + 1 protection method and a one-to-one protection method are used to improve reliability. In the 1 + 1 protection method and the one-to-one protection method, two LSPs are statically assigned to different physical transmission lines for connecting End to End. The two assigned LSPs are used as a working LSP and a spare LSP, respectively, and the working LSP and the spare LSP are controlled.

  Here, the allocation of the two LSPs to the working LSP and the backup LSP is called multiplexing. The working LSP and the backup LSP are called a redundant path or a duplex path. The working LSP is an LSP through which traffic passes in a normal state. The spare LSP is an LSP that allows traffic to pass instead of the working LSP when the working LSP is abnormal.

  In a system using MPLS, in order to generate this duplex path, two LSPs with different physical paths are assigned to each end to end logical path. For this reason, when a duplex path is generated in a network having a large number of physical paths, both a working LSP and a backup LSP are mixed in a certain physical path.

  In addition, QoS (Quality of Service) function is defined in MPLS. According to the QoS function in MPLS, a system using MPLS allocates a minimum guaranteed bandwidth to an LSP passing through a physical path in a state where the total traffic amount of the physical path is large and traffic is congested. The minimum guaranteed bandwidth is the minimum guaranteed bandwidth.

  Also, in a system using MPLS, the maximum restricted bandwidth is allocated to the LSP that passes through the physical path when the total traffic amount of the physical path is small. The maximum bandwidth limit is a bandwidth that can be used to the maximum extent within the range of the bandwidth upper limit value of the physical path.

  Since a system using MPLS allocates LSPs on many physical paths as described above, a plurality of LSPs are mixed in one physical path using MPLS. For this reason, in a system using MPLS, it is necessary to design for each physical path so that the total bandwidth of the minimum guaranteed bandwidth of all LSPs passing through the physical path does not exceed the bandwidth of the physical line.

  Further, in the duplex path of the one-to-one protection method in MPLS, the traffic flows through the backup LSP as a result of switching the LSP through which the traffic passes from the working LSP to the backup LSP. At this time, even when the traffic passes through the backup LSP, in order to guarantee the same QoS control as when the traffic passes through the working LSP, the working LSP is also used in the physical path assigned to the backup LSP. It is necessary to design so as to allocate a minimum guaranteed bandwidth equivalent to the guaranteed bandwidth in.

  Note that allocating the working LSP and backup LSP to each physical path is described as system selection, and switching the LSP through which traffic passes is described as changing the system selection.

  However, the traffic passing through the duplex path using the one-to-one protection method normally passes only the working LSP and does not pass the backup LSP. For this reason, when the working LSP is selected for the path through which the traffic flows, the bandwidth for the spare LSP assigned to a certain physical path is not used.

  For this reason, one working LSP multiplexed in a section of one physical path has an unused band and which LSP among the minimum guaranteed bands of other working LSPs allocated to the section of the physical path. In addition, it is possible to share a bandwidth that is not reserved and a bandwidth that is reserved for the backup LSP. This makes it possible to provide the end user with a band that exceeds the minimum guaranteed band and is closer to the maximum limited band.

ITU-T Y.M. 1370.1 ITU-T Y.M. 1382 ITU-T Y.M. 1720

  In a network system using MPLS, when a working LSP and a backup LSP are multiplexed on a section (physical line section) of the same physical route, and traffic flows to one working LSP, the minimum guarantee assigned to the working LSP It is possible to use a band and a band in which no traffic flows in the same physical line section as a band for flowing traffic. Bands in which no traffic flows are an unused band assigned to another active LSP on the same physical line section, an unused band assigned to a backup LSP on the same physical line section, and a physical line section And a band not assigned to any LSP in FIG.

  By using a band in which no traffic flows in the same physical line section, the communication system can provide a throughput exceeding the minimum guaranteed band. When the upper limit physical line speed or the maximum restricted bandwidth is set, a bandwidth close to the maximum restricted bandwidth can be provided to the end user.

  However, for example, when all the redundant paths assigned to a certain physical line section are working LSPs and there is no spare LSP, the above-mentioned “assigned for spare LSP” can be used in the same physical line section. There is no “unused bandwidth”. For this reason, the physical line section is in a state where the band of the working LSP is allocated up to the band upper limit value.

  In this state, when traffic that uses the minimum guaranteed bandwidth of each active LSP flows, it becomes impossible to provide a throughput that exceeds the minimum guaranteed bandwidth to the LSP assigned to the physical line section. As a result, the physical line section may become a bottleneck in the network.

  On the other hand, if all the LSPs assigned to a certain physical line section are backup LSPs, and no traffic actually flows in the same physical line section in a state where no working LSP exists, the The “assigned unused bandwidth” is always an unused bandwidth. As a result, the physical line section is wasted.

  Therefore, in order to design a line so that the bandwidth for flowing traffic can be utilized to the maximum by assigning the bandwidth of the spare LSP assigned to the same physical line section to the working LSP assigned to each physical line section. Therefore, it is necessary to mix the working LSP and the standby LSP as uniformly as possible on each physical line section. Even when traffic flows over a specific physical line section exceeding the minimum guaranteed bandwidth of each active LSP, the physical line section does not become a bottleneck on the network and is wasted in each physical line section. It is necessary to design a logical redundant path that does not generate unused bandwidth.

  Here, in order for a network administrator or the like to perform such a design, it is required to introduce a dedicated design system, and the burden on maintenance and cost is large.

  Also, even if the system is designed once and the working LSP and the spare LSP are mixed evenly on each physical line section of the network, and a system that does not have a bandwidth bottleneck and waste is constructed, a failure occurs in the network. In such a case, a bottleneck may occur due to a change in system selection.

  That is, when the active LSP assigned to the physical line section is simultaneously switched to the backup LSP due to the occurrence of a failure in a certain physical line section, or when the system selection is changed due to a failure in another physical line section, The physical path of each LSP in the network changes. Further, in the recovery of the failure section after the failure occurrence, the physical path allocated to the LSP also changes for each section.

  For this reason, in the event of a failure, the balance between the active LSP and the backup LSP in the physical line section of the network is lost, and traffic flows beyond the minimum guaranteed bandwidth of each active LSP assigned to the physical line section. The circuit section has a problem that becomes a bottleneck in the network.

  The present invention aims to avoid such a network bottleneck, and provides a method for making the working LSP and the standby LSP uniform in the network. Further, the present invention provides a method for effectively using the bandwidth in the network.

According to a typical embodiment of the present invention, a network control device connected to a plurality of communication devices that communicate using MPLS, wherein the plurality of communication devices are connected to each other by a plurality of physical paths, The network control device connects two communication devices of the plurality of communication devices, connects a first logical path accommodated in at least one first physical path, and the two communication devices, A bandwidth of traffic passing through each of the physical paths, holding a table for allocating a second logical path accommodated in a second physical path different from the first physical path to the plurality of communication devices A plurality of first logical paths that hold an upper limit value, hold a maximum restricted bandwidth amount and a minimum guaranteed bandwidth amount of traffic passing through the first logical route, and are accommodated in each first physical route , Calculating an index value based on a sum of the physical paths of the maximum restricted bandwidth amount or the minimum guaranteed bandwidth amount and a bandwidth upper limit value of each physical route, and according to the calculated index value, Of the plurality of first logical paths accommodated in the physical path by assigning the first physical path to the second logical path and assigning the second physical path to the first logical path The candidate of the first logical path whose allocation is to be changed is extracted, the extracted first logical path candidate is stored in the table as a new second logical path, and the extracted first logical path is stored in the table. The second logical path accommodated in the second physical path different from the first physical path in which the logical path is accommodated is stored in the table as a new first logical path.

  According to an embodiment of the present invention, bandwidth in a network can be used effectively.

It is a block diagram which shows the 1st example of the duplex path | pass of the communication system of the 1st Embodiment of this invention. It is a block diagram which shows the 2nd example of the duplex path | pass of the communication system of the 1st Embodiment of this invention. It is a block diagram which shows the 3rd example of the duplex path | pass of the communication system of the 1st Embodiment of this invention. It is a block diagram which shows the 4th example of the duplex path | pass of the communication system of the 1st Embodiment of this invention. It is a block diagram which shows the logical structure of the network control part of the 1st Embodiment of this invention. It is a block diagram which shows the physical structure of the network control part of the 1st Embodiment of this invention. It is a flowchart which shows the whole process for optimizing the duplex path | pass of the 1st Embodiment of this invention. It is explanatory drawing which shows the topology table of the 1st Embodiment of this invention. It is explanatory drawing which shows the LSP table of the 1st Embodiment of this invention. It is explanatory drawing which shows the duplication path | pass table of the 1st Embodiment of this invention. It is explanatory drawing which shows the index value management table of the 1st Embodiment of this invention. It is a flowchart which shows the process which changes the system selection of the duplex path | pass of the 1st Embodiment of this invention. It is a flowchart which shows the process which extracts the duplex path | pass of the 1st Embodiment of this invention. It is explanatory drawing which shows the LSP table of the 2nd Embodiment of this invention. It is explanatory drawing which shows the index value management table of the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating a first example of a duplex path 201 of the communication system according to the first embodiment of this invention.

  The communication system of the present embodiment includes a network control unit 1 and a communication device 10 (10 # 1 to 10 # 7).

  The network control unit 1 is implemented by a computer including a processor and a memory. The network control unit 1 is connected to each communication device 10 via the monitoring control network 30.

  The network control unit 1 controls the route of traffic passing through the communication device 10 and monitors the amount of traffic passing through the communication device 10.

  The communication device 10 is a network device such as a switch or a router, and is implemented by a computer including a processor and a memory. Each communication device 10 of the present embodiment includes a communication interface 101 (101 # 1 to 101 # 4). The communication device 10 is connected to the physical line section 20 via the communication interface 101.

  Note that four communication interfaces 101 of the first embodiment are provided in each communication device 10, but any number of communication interfaces 101 of the present invention may be used.

  Each communication device 10 (10 # 1 to 10 # 7) is connected via a physical line section 20 (20 # 1 to 20 # 9). The physical line section 20 is a physical line (physical route) in the communication system of this embodiment.

  The network control unit 1 can assign a label indicating an LSP to each physical line section 20 by the communication device 10. Also, the LSP 202 that statically connects the two communication devices 10 by peer-to-peer is assigned to the communication device 10. The LSP 202 is a logical path in a system using MPLS. In addition, the network control unit 1 causes the communication device 10 to allocate a duplex path 201 including two LSPs 202.

  The network control unit 1 in FIG. 1 causes the LSP 202 # 1 and the LSP 202 # 2 to be assigned to each communication device 10. The LSP 202 # 1 is assigned to the physical line section 20 # 1 and the physical line section 20 # 5 between the communication device 10 # 1 and the communication device 10 # 6. The LSP 202 # 2 is assigned to the physical line section 20 # 2 and the physical line section 20 # 6 between the communication device 10 # 1 and the communication device 10 # 6.

  The LSP 202 # 1 and LSP 202 # 2 are the duplex path 201 # 1. LSP202 # 1 is a working path, and LSP202 # 2 is a backup path.

  FIG. 2 is a block diagram illustrating a second example of the duplex path 201 of the communication system according to the first embodiment of this invention.

  The network control unit 1, the communication device 10, and the physical line section 20 in FIG. 2 are the same as the network control unit 1, the communication apparatus 10, and the physical line section 20 in FIG.

  The network control unit 1 in FIG. 2 assigns the LSP 202 # 3 and LSP 202 # 4 to each communication device 10. The LSP 202 # 3 is assigned to the physical line section 20 # 1, the physical line section 20 # 5, and the physical line section 20 # 9 between the communication device 10 # 1 and the communication device 10 # 7. The LSP 202 # 4 is assigned to the physical line section 20 # 2 and the physical line section 20 # 7 between the communication device 10 # 1 and the communication device 10 # 6.

  The LSP 202 # 3 and LSP 202 # 4 are the duplex path 201 # 2. LSP202 # 3 is a working path, and LSP202 # 4 is a backup path.

  FIG. 3 is a block diagram illustrating a third example of the duplex path 201 of the communication system according to the first embodiment of this invention.

  The network control unit 1, communication device 10, and physical line section 20 in FIG. 3 are the same as the network control unit 1, communication device 10, and physical line section 20 in FIG.

  The network control unit 1 in FIG. 3 causes the LSPs 202 # 5 and LSP202 # 6 to be assigned to each communication device 10. The LSP 202 # 5 is assigned to the physical line section 20 # 3 and the physical line section 20 # 7 between the communication device 10 # 2 and the communication device 10 # 7. The LSP 202 # 6 is assigned to the physical line section 20 # 4 and the physical line section 20 # 8 between the communication device 10 # 2 and the communication device 10 # 7.

  The LSP 202 # 5 and LSP 202 # 6 are the duplex path 201 # 3. LSP202 # 5 is a working path, and LSP202 # 6 is a backup path.

  FIG. 4 is a block diagram illustrating a fourth example of the duplex path 201 of the communication system according to the first embodiment of this invention.

  The network control unit 1, communication device 10, and physical line section 20 in FIG. 4 are the same as the network control unit 1, communication apparatus 10, and physical line section 20 in FIG.

  The network control unit 1 in FIG. 4 allocates the LSP 202 # 7 and the LSP 202 # 8 to each communication device 10. The LSP 202 # 7 is assigned to the physical line section 20 # 3 and the physical line section 20 # 6 between the communication device 10 # 2 and the communication device 10 # 6. The LSP 202 # 8 is allocated to the physical line section 20 # 4, the physical line section 20 # 8, and the physical line section 20 # 9 between the communication device 10 # 2 and the communication device 10 # 6.

  The LSP 202 # 7 and LSP 202 # 8 are the duplex path 201 # 4. LSP202 # 7 is a working path, and LSP202 # 8 is a backup path.

  The networks shown in FIGS. 1 to 4 are examples of the present embodiment, and any configuration may be used as the physical network topology format. For example, a ring topology, a linear topology, a tree topology, or a mesh topology may be used. The monitoring control network 30 may also use the various topologies described above.

  In the following, a case where the design showing the assignment of the duplex path 201 and the LSP 202 shown in FIGS. 1 to 4 is already designed by a network designer or the like will be described. However, the design of the duplex path 201 or the like is not limited to the design shown in FIGS. Further, the present invention can be applied by treating an LSP that is not multiplexed and has only a single working LSP as an LSP without a spare LSP.

  FIG. 5 is a block diagram illustrating a logical configuration of the network control unit 1 according to the first embodiment of this invention.

  The network control unit 1 is provided in a general computer such as a personal computer or a workstation. The network control unit 1 is implemented by software including a function for managing the duplex path 201 being installed in a computer or the like and being activated by a user or an operator.

  A computer including the network control unit 1 holds an input unit 40, an output unit 41, a calculation unit 42, and a database unit 43.

  The input unit 40 is a function for inputting a value transmitted by an operator or the like to the network control unit 1. The output unit 41 is a function for displaying processing results and the like.

  The calculation unit 42 has a function of executing processing for monitoring the communication device 10, processing for assigning LSP to the communication device 10, and the like. Further, when executing the process, the calculation unit 42 generates an instruction to the communication device 10 by referring to a table held in the database unit 43. In addition, data generated as a result of executing the process is stored in the database unit 43.

  The calculation unit 42 of this embodiment holds a screen display unit 421, a data input processing unit 422, a reserved bandwidth adjustment unit 423, and a device control processing unit 424.

  The screen display unit is a function for causing the output unit 41 to display the processing result in the calculation unit 42. The data input processing unit 422 has a function of inputting a value input from the input unit 40 into processing in the calculation unit 42.

  The reserved bandwidth adjustment unit 423 is a function for extracting the physical line section 20 that needs to equalize the communication bandwidth. The reserved bandwidth adjustment unit 423 holds a redundant path selection unit 4231. The redundant path selection unit 4231 is a function for extracting the duplex path 201 that changes the system selection.

  The device control processing unit 424 is a function for transmitting an instruction to assign an LSP to the communication device 10 based on the processing result by the reserved bandwidth adjustment unit 423.

  The design information (hereinafter referred to as logical path design information) indicating the assignment of the LSP 202 and the duplex path 201 shown in FIGS. 1 to 4 is first calculated by the operator via the input unit 40 and the output unit 41. By inputting logical path design information to 42, the communication apparatus 10 is instructed. Logical path design information input by an operator or the like is stored in the database unit 43 by the calculation unit 42.

  At this time, the arithmetic unit 42 stores the logical path design information in tables (topology table T00, LSP table T10, and duplex path table T20 described later) held by the database unit 43.

  The logical path design information may be directly input to the network control unit 1 by an operator or the like, or may be input via another device.

  FIG. 6 is a block diagram illustrating a physical configuration of the network control unit 1 according to the first embodiment of this invention.

  The network control unit 1 includes a central processing unit (CPU) 50, a main storage device (main memory) 51, a network card (NIC: Network Interface Card) 52, an auxiliary storage device 53, an input / output unit 54, an input unit 55, and an output. Unit 56 and a computer internal transmission path 57.

  The CPU 50 implements the function in the calculation unit 42 by executing a program or the like in the main memory 51. The NIC 52 mounts the communication device 10. The auxiliary storage device 53 is equipped with a database unit 43.

  The input unit 55 is a device such as a keyboard or a mouse, and implements the input unit 40. The output unit 56 is a device such as a display or a printer, and mounts the output unit 41. The input / output unit 54 is a device that transmits data input from the input unit 55 to the main memory 51 and the like, and transmits data to be output to the output unit 56 to the output unit 56.

  The computer internal transmission path 57 is a bus or the like, and connects each part of the network control unit 1.

  FIG. 7 is a flowchart showing an overall process for optimizing the duplex path 201 according to the first embodiment of this invention.

  When the logical path design information is input from an operator or the like or another device, the network control unit 1 starts the optimization process of the duplex path 201 (A01).

  The computing unit 42 of the network control unit 1 stores the input logical path design information in a table described later of the database unit 43 (A02).

  After A02, the reserved bandwidth adjustment unit 423 of the network control unit 1 extracts one duplex path 201 based on the information stored in the database unit 43. Then, each physical line section 20 through which the extracted working LSP of the duplex path 201 is extracted is extracted, and another working LSP that shares the band of the extracted physical line section 20 is extracted. Here, the reserved bandwidth adjustment unit 423 changes the system selection of the extracted duplex path 201 in order to expand the bandwidth that can be accommodated in the other extracted active LSP, and the database is determined by the duplex path 201 after the change. The part 43 is updated (A03).

  Note that the system selection change of the present embodiment is specifically performed by assigning the physical line section 20 assigned to the working LSP to the backup LSP, and changing the physical line section 20 assigned to the backup LSP to the working LSP. Is to assign to.

  Details of the processing of the reserved bandwidth adjustment unit 423 will be described later.

  After A03, the reserved bandwidth adjustment unit 423 determines whether the information stored in the database unit 43 indicates a predetermined condition (A04). If the predetermined condition is satisfied in A04, the optimization process is terminated (A05). If the predetermined condition is not satisfied in A04, A03 is repeated.

  In A04, the reserved bandwidth adjustment unit 423 determines, for example, whether all duplex paths 201 have been optimized. If there is no duplex path 201 to be optimized any more, the optimization process is terminated in A05. If there is another duplex path 201 to be optimized, A03 is repeated.

  In A04, for example, the reserved bandwidth adjustment unit 423 determines whether or not A03 has been executed n times (n is an arbitrary integer value). When A03 is executed n times, the optimization process is terminated at A05. If A03 is not executed n times, A03 is repeated until A03 is executed n times.

  For example, the reserved bandwidth adjustment unit 423 reduces the total sum of the minimum guaranteed bandwidth of the working LSP that passes through each physical line section 20 to less than mMbps (m is an arbitrary value and can be taken as a bandwidth) in A04. Determine whether or not. If the sum of the minimum guaranteed bandwidths of the working LSP passing through all the physical line sections 20 is not more than mMbps, the optimization process is terminated in A05. Further, when the sum of the minimum guaranteed bandwidths of the working LSP passing through all the physical line sections 20 exceeds mMbps, A03 is repeated.

  Note that the optimization of the present embodiment indicates that the communication band is equalized (leveled) in the entire communication system of the present embodiment.

  Each table of the database unit 43 in which the logical path design information input by the operator or the like or other device in A02 is stored is shown below.

  FIG. 8 is an explanatory diagram illustrating the topology table T00 according to the first embodiment of this invention.

  The topology table T00 is held in the database unit 43. The topology table T00 includes a physical line section identification number T01, an A point apparatus identification number T02, a Z point apparatus identification number T03, and a physical line bandwidth upper limit value T04.

  Here, in the present embodiment, of the two communication devices 10 connected by the physical line section 20, the communication device 10 with a small identification number is described as an A point device, and the large communication device 10 is described as a Z point device. In the present embodiment, the identifier of the communication device 10 is indicated by a numerical value after “#” of the communication device 10 # 1. The identifier of this embodiment is indicated by a number, but any identifier may be used as long as it can be uniquely identified.

  Information stored in a topology table T00, LSP table T10, and duplex path table T20, which will be described later, is logical path design information input from an operator or another device in A02 of FIG. The logical path design information is information related to the LSP designed by a network designer or the like in advance. A network designer or the like sends logical path design information to the network control unit 1 via an operator or another device.

  The physical line section identification number T01 indicates an identifier for uniquely identifying the physical line section 20. The physical line section identification number T01 illustrated in FIG. 8 stores an identifier corresponding to the physical line sections 20 # 1 to 20 # 9 illustrated in FIGS.

  The point A device identification number T02 indicates an identifier for uniquely identifying the communication interface 101 of the point A device connected by the physical line section 10. The point A device identification number T02 shown in FIG. 8 corresponds to the identifier corresponding to the communication devices 10 # 1 to 10 # 6 of FIGS. 1 to 4 and the communication interfaces 101 # 1 to 101 # 4 of each communication device 10. Identifier to be stored.

  The Z point device identification number T03 indicates an identifier for uniquely identifying the communication interface 101 of the Z point device connected by the physical line section 10. The Z point device identification number T03 shown in FIG. 8 corresponds to the identifier corresponding to the communication devices 10 # 1 to 10 # 6 of FIGS. 1 to 4 and the communication interfaces 101 # 1 to 101 # 4 of each communication device 10. Identifier to be stored.

  The bandwidth upper limit value T04 of the physical line indicates the bandwidth upper limit value of the physical line connecting the physical line section 20. The unit of the physical line bandwidth upper limit value T04 shown in FIG. 8 is Mbps.

  FIG. 9 is an explanatory diagram illustrating the LSP table T10 according to the first embodiment of this invention.

  The LSP table T10 is held in the database unit 43. The LSP table T10 includes an LSP identification number T11, a minimum guaranteed bandwidth T12, a maximum restricted bandwidth T13, and a passing physical line section T14.

  The LSP identification number T11 indicates an identification number for uniquely identifying the LSP 202. The LSP identification number T11 in FIG. 9 stores an identifier corresponding to the LSPs 202 # 1 to 202 # 8 in FIGS.

  The minimum guaranteed bandwidth T12 indicates the minimum guaranteed bandwidth allocated to the LSP 202. The maximum bandwidth limit T13 indicates the maximum bandwidth limit assigned to the LSP 202. The unit of the minimum guaranteed bandwidth T12 and the maximum restricted bandwidth T13 in FIG. 9 is Mbps.

  The physical line section T14 that passes through indicates an identifier of the physical line section 20 through which each LSP 202 passes. The value stored in the passing physical line section T14 corresponds to the value stored in the physical line section identification number T01 of the topology table T00.

  The value of the minimum guaranteed bandwidth T12 of the first embodiment is designed in advance so that the sum of the minimum guaranteed bandwidth of the LSP 202 passing through each physical line section 20 does not exceed the bandwidth upper limit value of each physical line section 20. Is a value designed by In addition, the value of the maximum restricted bandwidth T13 of the first embodiment is set in advance so that the sum of the maximum restricted bandwidths of the working LSP in the entire communication system is smaller than the sum of the bandwidth upper limit values of all the physical line sections 20. This is a value designed by a designer or the like.

  FIG. 10 is an explanatory diagram illustrating the duplex path table T20 according to the first embodiment of this invention.

  The duplex path table T20 is held in the database unit 43. The duplex path table T20 includes a duplex path identification number T21, a working LSP identification number T22, and a backup LSP identification number T23.

  The duplex path identification number T21 indicates an identifier for uniquely identifying the duplex path 201. The duplex path identification number T21 in FIG. 10 stores an identifier corresponding to the duplex paths 201 # 1 to 201 # 4 in FIGS.

  The working LSP identification number T22 indicates an identifier for uniquely identifying the working LSP included in the duplex path 201. The working LSP identification number T22 in FIG. 10 stores the identifier of the working LSP among the LSPs 202 # 1 to LSP202 # 8 in FIGS.

  The backup LSP identification number T23 indicates an identifier for identifying the backup LSP included in the duplex path 201. The spare LSP identification number T23 in FIG. 10 stores the identifier of the spare LSP among the LSPs 202 # 1 to LSP202 # 8 in FIGS.

  The values stored in the working LSP identification number T22 and the backup LSP identification number T23 correspond to the LSP identification number T11 in the LSP table T10.

  Here, for example, when the sum of the maximum restricted bandwidth T13 of all the working LSPs passing through the physical line section 20 # 1 exceeds the bandwidth upper limit value T04 of the physical line corresponding to the physical line section 20 # 1, the physical line When all the working LSPs passing through the section 20 # 1 accommodate traffic up to each maximum restricted band T13, traffic exceeding the bandwidth upper limit value T04 of the physical line in the physical line section 20 # 1 overflows from the physical line. At this time, the amount of overflow traffic is described as the overflow traffic amount.

  When the total sum of the maximum restricted bandwidths T13 of all the working LSPs in the entire communication system of the first embodiment is smaller than the sum of the bandwidth upper limit values T04 of the physical lines in all the physical line sections 20, all the working LSPs When the traffic indicated by the maximum restricted bandwidth T13 is accommodated in any of the physical line sections 20, there is a margin in the bandwidth for passing traffic.

  For this reason, the network control unit 1 passes the physical line section 20 in which the overflow traffic amount is larger than 0 in the duplex path 201 through the working LSP, and the spare LSP passes the physical line section 20 in which the overflow traffic amount is 0. When the duplicated path 201 via is extracted and the system selection of the extracted duplicated path is changed, there is a possibility that the total amount of overflow traffic of the entire communication system may be reduced.

  Therefore, the network control unit 1 according to the first embodiment calculates the overflow traffic amount for each physical line section 20, and compares the physical line sections 20 using the calculated overflow traffic amount. Based on the comparison result, the physical line section 20 that is the most bottlenecked is extracted from the entire system.

  Here, when comparing the amount of overflow traffic in the communication system, the bandwidth upper limit value T04 of the physical line in each physical line section 20 may be different. For this reason, the result of dividing the overflow traffic amount in each physical line section 20 by the bandwidth upper limit value T04 of the physical line in each physical line section 20 is used as the index value in the first embodiment. By using this index value, the network control unit 1 of the first embodiment can determine which physical line section 20 overflows a lot of traffic.

  By changing the duplex path 201 as described above, the state where all the working LSPs can accommodate traffic up to the maximum restricted bandwidth, that is, the total sum of the overflow traffic amount in the entire system approaches zero. For this reason, the throughput of the entire communication system can be improved beyond the minimum guaranteed bandwidth of each working LSP.

  When determining the increase or decrease of the overflow traffic amount in the entire communication system, the above-described index values are totaled in the entire communication system, and the total value is used as the index value for the entire system of the first embodiment. By using the index value of the entire system according to the first embodiment, the network control unit 1 can determine whether or not the overflow traffic amount of the entire communication system has decreased, and avoid an increase in a part of the overflow traffic amount. can do.

  In FIG. 11, an index value management table generated when the sum of the maximum restricted bandwidths T13 of all working LSPs in the entire system is smaller than the sum of the bandwidth upper limit values T04 of the physical lines in all physical line sections 20. T30 is shown.

  FIG. 11 is an explanatory diagram illustrating an index value management table T30 according to the first embodiment of this invention.

  The index value management table T30 is held in the database unit 43. The index value management table T30 includes a physical line section identification number T31, a physical line bandwidth upper limit value T32, a working LSP identification number T33 passing through the physical line section, a total T34 of the maximum restricted bandwidth of the working LSP, an overflow traffic amount T35, and The ratio T36 between the bandwidth upper limit value and the overflow traffic amount is included.

  The physical line section identification number T31 indicates an identification number for uniquely identifying the physical line section 20. The physical line section identification number T31 corresponds to the physical line section identification number T01 in the topology table T00.

  The bandwidth upper limit value T32 of the physical line is a bandwidth upper limit value of the physical line connecting the physical line section 20. The physical line bandwidth upper limit value T32 corresponds to the physical line bandwidth upper limit value T04 in the topology table T00.

  The working LSP identification number T33 that passes through the physical line section indicates an identifier for uniquely identifying the working LSP that passes through the physical line section 20. The working LSP identification number T33 passing through the physical line section corresponds to the working LSP identification number T22 of the duplex path table T20.

  The sum T34 of the maximum restricted bandwidth of the working LSP indicates the sum of the maximum restricted bandwidth T13 of all the working LSPs that pass through one physical line section 20. The unit of the sum T34 of the maximum restricted bandwidth of the working LSP is Mbps in this embodiment.

  The overflow traffic amount T35 is the amount of traffic overflowing from the physical line section 20 when all the working LSPs passing through the physical line section 20 accommodate traffic up to the maximum restricted bandwidth. The unit of the overflow traffic amount T35 is Mbps in this embodiment.

  The ratio T36 between the bandwidth upper limit value and the overflow traffic amount indicates the ratio of the overflow traffic amount T35 to the bandwidth upper limit value T32 of the physical line. The ratio T36 between the bandwidth upper limit value and the overflow traffic amount is the index value of the first embodiment described above.

  The index value management table T30 stores the index values of the first embodiment calculated for every physical line section 20.

  FIG. 12 is a flowchart illustrating processing for changing the system selection of the duplex path 201 according to the first embodiment of this invention.

  FIG. 12 shows processing of the reserved bandwidth adjustment unit 423 in A03 of FIG. After A02 in FIG. 7, the reserved bandwidth adjustment unit 423 of the network control unit 1 starts the process shown in FIG. 12 (A11).

  After A11, the reserved bandwidth adjustment unit 423 performs the index value management table T30 for each physical line section 20 based on the topology table T00, LSP table T10, and duplex path table T20 in which the logical path design information is stored. Is generated (A12).

  Specifically, in A12, the reserved bandwidth adjustment unit 423 uses the same values as the physical line section identification number T01 and the physical line bandwidth upper limit value T04 in the topology table T00, and the physical line section identification number T31 in the index value management table T30. And the physical line bandwidth upper limit value T32.

  In A12, the reserved bandwidth adjustment unit 423 extracts the LSP identification number T11 in the column of the LSP table T10 that includes the same value as the physical line section identification number T01 in the topology table T00 in the passing physical line section T14. Then, from the extracted LSP identification number T11, the identifier of the working LSP included in the working LSP identification number T22 is extracted. Then, the extracted identifier of the working LSP is stored in the working LSP identification number T33 passing through the physical line section in the column including the corresponding physical line section identification number T31.

  Further, the reserved bandwidth adjustment unit 423, in A12, the value of the maximum restricted bandwidth T13 in the column of the LSP table T10 including the same value as the value stored in the working LSP identification number T33 passing through the physical line section in the LSP identification number T11. To extract. When there are a plurality of identifiers stored in the working LSP identification number T33 passing through the physical line section, the value of the maximum restricted bandwidth T13 is extracted for each identifier. Then, all the values of the extracted maximum restricted bandwidth T13 are summed, and the summed value is added to the sum T34 of the maximum restricted bandwidths of the working LSP in the column including the working LSP identification number T33 passing through the corresponding physical line section. Store.

  Further, in A12, when the value stored in the sum T34 of the maximum restricted bandwidth of the working LSP is equal to or less than the bandwidth upper limit value T32 of the physical line, the reserved bandwidth adjusting unit 423 sets "0" to the corresponding overflow traffic amount T35. Store. When the value stored in the sum T34 of the maximum restricted bandwidth of the working LSP is larger than the bandwidth upper limit value T32 of the physical line, the reserved bandwidth adjusting unit 423 performs physical processing from the value stored in the sum T34 of the maximum restricted bandwidth of the working LSP. The value stored in the line bandwidth upper limit value T32 is subtracted, and the result of the subtraction is stored in the overflow traffic amount T35.

  In A12, the reserved bandwidth adjustment unit 423 divides the value stored in the overflow traffic amount T35 by the value stored in the bandwidth upper limit value T32 of the physical line, and the divided result is the bandwidth upper limit value and the overflow traffic amount. And stored in the ratio T36. As described above, the ratio T36 between the bandwidth upper limit value and the overflow traffic amount is the index value of the first embodiment.

  In A12, the reserved bandwidth adjustment unit 423 includes the sum of the values stored in the sum T34 of the maximum restricted bandwidth of the working LSP in all the columns of the index value management table T30 (that is, all the physical line sections 20), and The sum of the values of the upper limit T32 of the physical line in the physical line section 20 is compared, and the sum of the values stored in the total maximum limit band T34 of the working LSP is the upper limit T32 of the physical line in the physical line section 20. If it is determined that it is less than or equal to the sum of the values, the value may be stored in the overflow traffic volume T35 and the ratio T36 of the bandwidth upper limit value and the overflow traffic volume. And you may continue the process of 1st Embodiment after A12.

  In A12, when it is determined that the sum of the values stored in the maximum limited bandwidth sum T34 of the working LSP is greater than the sum of the bandwidth upper limit values T32 of the physical lines in the physical line section 20, the reserved bandwidth adjustment unit 423 You may perform 2nd Embodiment mentioned later.

  After A12, the reserved bandwidth adjustment unit 423 determines whether there is a physical line section 20 that can be optimized based on a predetermined condition (A13). If there is no physical line section 20 that can be optimized, the reserved bandwidth adjustment unit 423 ends the process shown in FIG. 12 (A18). When there is a physical line section 20 that can be optimized, the process proceeds to A14.

  In A13, the reserved bandwidth adjustment unit 423 determines, for example, whether or not all physical line sections 20 stored in the physical line section identification number T31 are determined to be “no” in A16, and temporarily stores values in A16. Determination is made by referring to a specific storage area (main memory 51). If all the physical line sections 20 are determined to be “no” in A16, the process shown in FIG. 12 is terminated because there is no physical line section 20 that can be optimized (A18). If there is a physical line section 20 that is not determined to be “no” in A16, the process proceeds to A14 because there is a physical line section 20 that can be optimized.

  Further, for example, the reserved bandwidth adjustment unit 423 determines in A13 whether or not “no” is determined n times (n is a positive integer) in A16 by referring to the variable updated in A16. When it is determined “no” n times in A16, there is no physical line section 20 that can be optimized, and the process shown in FIG. 12 is terminated (A18). If the number of times determined as “no” in A16 is smaller than n, the process proceeds to A14 because there is a physical line section 20 that can be optimized.

  In addition, for example, the reserved bandwidth adjustment unit 423 determines whether or not the index value of all the first embodiments, that is, the value of the ratio T36 between the bandwidth upper limit value and the overflow traffic amount is “0” in A13. judge. When the index value of the first embodiment is “0”, there is no optimizable physical line section 20, and the process shown in FIG. 12 is terminated (A18). When there is a physical line section 20 whose index value is not “0” in the first embodiment, the process proceeds to A14 because there is a physical line section 20 that can be optimized.

  The determination of A13 prevents the search for a duplex path that can be optimized from being repeated indefinitely.

  After A13, the reserved bandwidth adjustment unit 423 has the physical line section with the largest index value (that is, the ratio T36 between the bandwidth upper limit value and the overflow traffic amount) of the first embodiment from the index value management table T30. 20 is extracted (A14). When a plurality of physical line sections 20 having the largest value are extracted, the reserved bandwidth adjustment unit 423 extracts a physical line section 20 having a small identification number of the physical line section 20 in order to extract one physical line section 20. May be.

  After A14, the reserved bandwidth adjustment unit 423 inputs the physical line section 20 extracted in A14 to the redundant path selection unit 4231. Then, after receiving the extracted physical line section 20, the redundant path selection unit 4231 extracts a working LSP that passes through the extracted physical line section 20. Then, the duplex path 201 for changing the system selection is extracted from the duplex paths 201 including the extracted current LSP (A15). The duplex path 201 extracted in A15 is a duplex path 201 that can equalize the use band of the physical line section 20 through which the duplex path 201 passes. Details of the processing in A15 will be described later.

  After A15, the reserved bandwidth adjustment unit 423 determines whether the redundant path 201 has been extracted by the redundant path selection unit 4231 (A16). When the duplex path 201 is extracted, the reserved bandwidth adjustment unit 423 proceeds to A17.

  If it is determined in A16 that the duplex path 201 has not been extracted, the reserved bandwidth adjustment unit 423 returns to A13 in order to extract the physical line section 20 that can be further optimized. In A16, the reserved bandwidth adjustment unit 423 stores the identifier indicating the physical line section 20 already extracted in A14 in the temporary storage area (main memory 51) as the physical line section 20 that cannot be optimized. You may return to Alternatively, “1” may be added to the variable n previously stored in the temporary storage area, and the process may return to A13.

  In A16, the reserved bandwidth adjustment unit 423 may determine whether or not the extracted duplex path is stored in the main memory 51 or the database unit 43, for example. If the extracted duplex path is stored in the main memory 51 or the database unit 43, the reserved bandwidth adjustment unit 423 proceeds to A17. If the extracted duplex path is not stored in the main memory 51 or the database unit 43, the reserved bandwidth adjustment unit 423 returns to A13 in order to extract the physical line section 20 that can be further optimized.

  In A16, for example, the reserved bandwidth adjustment unit 423 may determine whether or not the processing result of A15 is “success”. Then, when the processing result of A15 is “success”, the reserved bandwidth adjustment unit 423 proceeds to A17. If the processing result of A15 is not “successful”, the reserved bandwidth adjustment unit 423 returns to A13 in order to extract the physical line section 20 that can be further optimized.

  After A16, the reserved bandwidth adjustment unit 423 extracts a column of the duplex path table T20 including the value of the duplex path identification number T21 that is the same as the identifier indicated by the duplex path 201 extracted in A15. Then, the value stored in the working LSP identification number T22 in the extracted column is exchanged with the value stored in the backup LSP identification number T23. As a result, the reserved bandwidth adjustment unit 423 changes the system selection between the working LSP and the backup LSP of the duplex path 201 and updates the duplex path table T20 (A17).

  After A13 or A17, the reserved bandwidth adjustment unit 423 ends the process shown in FIG. 12 (A18).

  FIG. 13 is a flowchart illustrating processing for extracting the duplex path 201 according to the first embodiment of this invention.

  The process shown in FIG. 13 corresponds to the process A15 in FIG.

The reserved bandwidth adjustment unit 423 inputs the physical line section 20 extracted in A14 to the redundant path selection unit 4231, whereby the redundant path selection unit 4231 is activated (A21).
After A21, the redundant path selection unit 4231 extracts all the duplex paths 201 through which the working LSP passes through the physical line section 20 extracted in A14 based on the LSP table T10 and the duplex path table T20 (A22).

  Specifically, in A22, the redundant path selection unit 4231 includes columns of the LSP table T10 included in the physical line section T14 that passes the same value as the physical line section identification number T31 of the physical line section 20 extracted in A14. To extract all. Then, all the columns of the duplex path table T20 including the same value as the value of the LSP identification number T11 of the column of the extracted LSP table T10 in the working LSP identification number T22 are extracted. Then, all the duplicated path identification numbers T21 included in the extracted duplicated path table T20 are extracted. As a result, all identifiers of the duplex path 201 to which the working LSP is assigned to the physical line section 20 extracted in A14 are extracted.

  After A22, the redundant path selection unit 4231 calculates the index value of the first embodiment when the system selection of each duplex path 201 extracted in A22 is changed (A23).

  Specifically, in A23, the redundant path selection unit 4231 extracts the working LSP identification number T22 and the backup LSP identification number T23 in the column of the duplex path identification number T21 corresponding to the duplex path 201 extracted in A22. Then, a column of the index value management table T30 including the same values as the extracted values of the working LSP identification number T22 and the standby LSP identification number T23 in the working LSP identification number T33 passing through the physical line section is extracted.

  Then, in A23, the redundant path selection unit 4231 extracts the duplicated path extracted in A22, with the value corresponding to the working LSP identification number T22 included in the working LSP identification number T33 passing through the physical line section in the extracted column. An index value management table updated to the value stored in the spare LSP identification number T23 corresponding to 201 is generated in a temporary storage area.

  Further, in A23, the redundant path selection unit 4231, based on the index value management table generated in the temporary storage area and the maximum restricted bandwidth T13 of the LSP table T10, the sum T34 of the maximum restricted bandwidth of the working LSP, overflow The traffic amount T35 and the ratio T36 between the bandwidth upper limit value and the overflow traffic amount are calculated. Then, the calculated total T34 of the maximum restricted bandwidth of the working LSP, the overflow traffic amount T35, and the ratio T36 between the bandwidth upper limit value and the overflow traffic amount are stored in the index value management table generated in the temporary storage area.

  In A23, the redundant path selection unit 4231 performs the above-described processing on each duplex path 201 extracted in A22, and generates different index value management tables in temporary storage areas.

  After A23 or A26, the redundant path selection unit 4231 determines whether there is a duplex path 201 that reduces the overflow traffic amount of the entire communication system by changing the selection.

  Specifically, in A24 after A23, the redundant path selection unit 4231 totals the index values of the first embodiment in each index value management table generated in the temporary storage area. That is, a total value of values corresponding to the ratio T36 between the bandwidth upper limit value and the overflow traffic volume is calculated for each index value management table held in the temporary storage area.

  Thus, the redundant path selection unit 4231 calculates the index value of the entire system of the first embodiment after changing the system selection. Further, the total value of the ratio T36 between the bandwidth upper limit value and the overflow traffic volume in the index value management table T30 held in the database 43 is summed, and the index value of the entire system of the first embodiment before changing the system selection is obtained. calculate.

  Then, the redundant path selection unit 4231 has the entire system of the first embodiment before changing the system selection among index values of the entire system of the first embodiment after changing the system selection in A24 after A23. It is determined whether there is a duplex path 201 that can make the index value of the entire system of the first embodiment smaller than the index value of (A24). Thus, the redundant path selection unit 4231 determines whether there is a duplex path 201 that reduces the overflow traffic amount of the entire communication system by changing the system selection.

  In A24 after A23, for example, the redundant path selection unit 4231 may determine whether or not the index values of the first embodiment all become zero. If all the values are 0, the redundant path selection unit 4231 ends the process of FIG.

  Further, in A24 after A26, for example, the redundant path selection unit 4231 becomes n times (n is an integer) no in the determination in A26 (that is, the index value of the first embodiment after changing the system selection) It may be determined by referring to the variable n updated in A26 whether or not there are n times when there is a duplex path in which the maximum value of A is large. Then, when there are n times when the maximum value of the index value of the first embodiment after the system selection is changed is increased n times, the index value of the entire system of the first embodiment is further exceeded. It is determined that there is no duplex path 201 that can reduce the length of the redundant path 201, and the redundant path selection unit 4231 ends the process of FIG.

  A24 prevents the search for the duplex path for changing the system selection from being repeated indefinitely.

  If there is no duplex path 201 that can reduce the index value of the entire system of the first embodiment among the duplex paths 201 extracted in A22, the redundant path selection unit 4231 ends the process shown in FIG. 13 (A28). ). Also, when there is a duplex path 201 that decreases the index value of the entire system of the first embodiment, the redundant path selection unit 4231 proceeds to A25.

  After A24, the redundant path selection unit 4231 compares the index values of the entire system of the first embodiment calculated in A24, and after changing the system selection from the duplex paths 201 extracted in A22. The redundant path 201 that can reduce the index value of the entire system of the first embodiment is extracted (A25). If the index values of the entire system of the first embodiment after changing the system selection in the plurality of duplex paths 201 are the same, one duplex path 201 is extracted, so that the identifier of the duplex path 201 is The smaller one may be extracted.

  After A25, the redundant path selection unit 4231 corresponds to the index value management table after changing the system selection and the index value management table T30 before changing the system selection, corresponding to the duplex path 201 extracted in A25. After comparing the maximum values of the index values (the ratio T36 between the bandwidth upper limit value and the overflow traffic amount) in the first embodiment and changing the system selection, the maximum value of the index values in the first embodiment increases. It is determined whether there is a duplex path (A26).

  In A26, when the system selection is made and the duplex path 201 determined that the maximum value of the index value of the first embodiment is increased after the system selection, the use bandwidth of the physical line section 20 is increased and the bandwidth amount is increased. It cannot be leveled. For this reason, in A26, when it is determined that the maximum value of the index value of the first embodiment is increased after the system selection, the duplexing is performed in which the maximum value of the index value of the first embodiment is increased after the system selection. The index value management table corresponding to the path 201 is deleted from the temporary storage area.

  As a result, the redundant path selection unit 4231 excludes the duplex path 201 that cannot equalize the used bandwidth of the physical line section 20 from the target to be determined in A24 as the index value of the entire system of the first embodiment. Then, the redundant path selection unit 4231 returns to A24. The redundant path selection unit 4231 generates a variable n in the temporary storage area in advance, and when the maximum value of the index value of the first embodiment is increased after system selection, “1” is set to the variable n. You may add and return to A24.

  In A26, when it is determined that there is no duplex path in which the maximum index value of the first embodiment is large, the redundant path selection unit 4231 proceeds to A27.

  After A26, the redundant path selection unit 4231 stores the duplex path 201 extracted in A25 in the main memory 51, the database unit 43, or the like for output to the reserved bandwidth adjustment unit 423. Further, the redundant path selection unit 4231 may send to the reserved bandwidth adjustment unit 423 that the process shown in FIG. 13 (that is, the process of A15) is successful.

  After A27, the redundant path selection unit 4231 ends the process shown in FIG. 13 (A28).

  As described above, the optimized logical path design information is stored in the database unit 43 by the processing shown in FIG. Therefore, the network control unit 1 assigns a logical path to each communication device 10 via the device control processing unit 424 of the network control unit 1 based on the information in the database unit 43.

  This balances the total bandwidth reserved by all active LSPs in each physical line section 20, the total bandwidth reserved by all spare LSPs, and the free bandwidth. A logical path that can provide the end user with a bandwidth that exceeds the minimum guaranteed bandwidth and is closer to the maximum restricted bandwidth can be constructed on the network.

  Further, in the processing shown in FIG. 7, the logical path design information may be acquired by receiving the path information operated in the communication system from each communication device 10, and thus the communication system in operation can be obtained. Can be optimized. Furthermore, by comparing the path information in operation before and after the execution of the process shown in A11, it is possible to extract the duplex path 201 to which the system selection should be changed, and change the system selection of the extracted duplex path 201. By doing so, it is possible to provide the end user with a band that exceeds the minimum guaranteed band and is closer to the maximum limited band.

  The topology table T00, the LSP table T10, and the duplex path table T20 may have different table configurations as long as they include information necessary for generating the index value management table T30.

(Second Embodiment)
The logical path design according to the second embodiment is a logical path design when the sum of the maximum restricted bandwidths of all the active LSPs is larger than the sum of the bandwidth upper limit values of all the physical line sections 20.

  The topology table T00 and duplex path table T20 of the second embodiment are the same as the topology table T00 and duplex path table T20 of the first embodiment. Also, the values stored in the topology table T00, LSP table T10, and duplex path table T20 of the second embodiment are logical path information generated by a physical line designer, etc. Based on the logical path information transmitted from the device, the value input by the operator or the like in A02 is stored.

  FIG. 14 is an explanatory diagram illustrating an LSP table T10 according to the second embodiment of this invention.

  Similarly to the LSP table T10 of the first embodiment, the LSP table T10 of the second embodiment includes an LSP identification number T11, a minimum guaranteed bandwidth T12, a maximum restricted bandwidth T13, and a physical line section T14. Similarly to the LSP table T10 of the first embodiment, the LSP table T10 of the second embodiment is input by an operator or the like in A02 based on logical path information generated by a physical line designer or another device. Stored values are stored.

  In the minimum guaranteed bandwidth T12 of the second embodiment, a value is stored so that the sum of the minimum guaranteed bandwidth T12 of the working LSP in each physical line section 20 does not exceed the bandwidth upper limit value of each physical line section 20. . Further, in the maximum restricted bandwidth T13 of the second embodiment, the sum of the maximum restricted bandwidth T13 of the working LSP in the entire communication system is the sum of the bandwidth upper limit values of all physical line sections 20 (that is, in the topology table T00). A value that is larger than the sum of the physical line bandwidth upper limit values T04 is stored.

  For example, a case will be described below where each active LSP is assigned the bandwidth limit of the physical line as the maximum bandwidth limit. In this case, in the entire communication system, the sum of the maximum restricted bandwidths of all the working LSPs is larger than the sum of the bandwidth upper limit values of all the physical line sections 20. In addition, in a state where traffic of one working LSP is accommodated in each physical line section 20, when the physical line section 20 accommodates traffic of another working LSP, an overflow traffic amount is always generated. That is, even if the overflow traffic generated in one physical line section 20 is moved to another physical line section 20, the effect of effectively using the bandwidth cannot be obtained.

  Specifically, even if the system selection of the duplex path 201 is changed in the second embodiment, since the overflow traffic amount is simply moved from a certain physical line section 20 to a certain physical line section 20, the physical line The total amount of overflow traffic in the section 20 does not change.

  Therefore, in the second embodiment, that is, when the sum of the maximum restricted bandwidths of all the active LSPs is sufficiently larger than the sum of the bandwidth upper limit values of all the physical line sections 20, the first embodiment Use different index values.

  Further, in the second embodiment, since the amount of overflow traffic in the entire communication system cannot be reduced, the physical line section 20 is obtained by leveling the sum of the minimum guaranteed bandwidths of the working LSP in each physical line section 20. Eliminate bottlenecks.

  Specifically, the reserved bandwidth adjustment unit 423 of the second embodiment calculates the sum of the minimum guaranteed bandwidths of the working LSPs in each physical line section 20, and uses the calculated sum as the bandwidth upper limit value of each physical line section 20. Divide by Thereby, the reserved bandwidth adjustment unit 423 of the second embodiment calculates the index value of the second embodiment of the second embodiment. Note that the index value of the second embodiment is calculated at A12 in FIG. 12 and A23 in FIG.

  In the second embodiment, the overflow traffic amount of the entire communication system cannot be reduced to zero. For this reason, the optimum state of the entire communication system in the second embodiment is such that the ratio of the sum of the minimum guaranteed bandwidth of the working LSP to the bandwidth upper limit value of the physical line section 20 (physical bandwidth limit value T04) is In the line section 20, it is not unevenly high and is leveled in the entire communication system.

  Therefore, the index value of the entire system of the second embodiment (the index value of the entire system of the second embodiment) used in A24 and A25 of FIG. 13 is the same as that of the second embodiment of the entire physical line section 20. The index variance (that is, the value obtained by dividing the sum of the minimum guaranteed bandwidths of the working LSP in each physical line section 20 by the bandwidth upper limit value T04 of the physical line in each physical line section 20) is calculated.

  The reserved bandwidth adjustment unit 423 of the second embodiment performs the processes shown in FIGS. 10, 7, and 12 in the same manner as the reserved bandwidth adjustment unit 423 of the first embodiment. In the following, processing different from the first embodiment in the processing of FIGS. 7 and 12 will be described.

  The reserved bandwidth adjustment unit 423 of the second embodiment starts A11 of FIG. 12, and then generates an index value management table T30 of the second embodiment in A12.

  FIG. 15 is an explanatory diagram illustrating an index value management table T30 according to the second embodiment of this invention.

  Referring to FIG. 15, generated in A12 of FIG. 12 and A23 of FIG. 13 when the sum of the maximum restricted bandwidths of all working LSPs is sufficiently larger than the sum of the bandwidth upper limit values of all physical line sections 20 The index value management table T30 will be described.

  Similar to the index value management table T30 of the first embodiment, the index value management table T30 of the second embodiment passes through the physical line section identification number T31, the physical line bandwidth upper limit T32, and the physical line section. The working LSP identification number T33 is included. In addition, the index value management table T30 of the second embodiment includes the sum T37 of the minimum guaranteed bandwidth of the working LSP and the ratio T38 between the bandwidth upper limit value and the sum of the minimum guaranteed bandwidth of the working LSP.

  The sum T37 of the minimum guaranteed bandwidth of the working LSP is the sum of the minimum guaranteed bandwidth of all the working LSPs passing through each physical line section 20. The ratio T38 between the bandwidth upper limit value and the sum of the minimum guaranteed bandwidth of the working LSP is obtained by dividing the value stored in the sum T37 of the minimum guaranteed bandwidth of the working LSP by the value stored in the bandwidth upper limit value T32 of the physical line. Value.

  The index value management table T30 of the second embodiment also stores the index values of the entire system of the second embodiment for all physical line sections 20. The physical line section identification number T31, the physical line bandwidth upper limit value T32, and the working LSP identification number T33 passing through the physical line section in the second embodiment are the same as those in the first embodiment in A12 of FIG. The value is stored by the same procedure.

  In A12 of FIG. 12, the reserved bandwidth adjustment unit 423 of the second embodiment creates a column of the LSP table T10 that includes the same value as the value included in the working LSP identification number T33 via the physical line section in the LSP identification number T11. All the minimum guaranteed bandwidth T12 of the extracted column is extracted. Then, the sum of the values stored in the extracted minimum guaranteed bandwidth T12 is calculated, and the calculated value is stored in the sum T37 of the minimum guaranteed bandwidth of the working LSP.

  In addition, the reserved bandwidth adjustment unit 423 of the second embodiment calculates a value obtained by dividing the total T37 of the minimum guaranteed bandwidth of the working LSP by the working LSP identification number T33 passing through the physical line section in A12 of FIG. Each zone identification number T31 is stored in the ratio T38 between the band upper limit value and the sum of the minimum guaranteed bands of the working LSP.

  The reserved bandwidth adjustment unit 423 of the second embodiment calculates the sum of all the columns of values stored in the sum T34 of the maximum restricted bandwidth of the working LSP in A12 of the first embodiment and the bandwidth upper limit of the physical line. After comparing the sum of all the columns of the values stored in the value T32 and determining that the sum of all the columns of the values stored in the total T34 of the maximum restricted bandwidth of the working LSP is large, the second embodiment A12 may be executed.

  After A12, the reserved bandwidth adjustment unit 423 of the second embodiment performs A13 as in the first embodiment. After A13, the reserved bandwidth adjustment unit 423 of the second embodiment, in A14, determines the physical line section 20 having the largest index value (the total guaranteed minimum bandwidth T37 of the working LSP) in A14. Extracted from the index value management table T30. The physical line section 20 having the largest index value (the sum of the minimum guaranteed bandwidths of the working LSP T37) of the second embodiment is the physical line section 20 in which the traffic hardly flows.

  In A15 after A14, the reserved bandwidth adjustment unit 423 of the second embodiment activates the redundant path selection unit 4231. After being activated in A15, the redundant path selection unit 4231 of the second embodiment performs A22 of FIG. 13 as in the first embodiment.

  In A23 after A22, the redundant path selection unit 4231 of the second embodiment changes the system selection of the duplex path 201 passing through the physical line section 20 extracted in A14. And the index value of 2nd Embodiment after changing is calculated.

  Then, after A23, the redundant path selection unit 4231 of the second embodiment calculates an index value of the entire system (an index value of the entire system of the second embodiment) in A24.

  The redundant path selection unit 4231 according to the second embodiment calculates the index value of the entire system according to the second embodiment using Equation 1 in A24 and A25 of FIG. Equation 1 is the sample variance of the ratio T38 between the upper limit value of the bandwidth in all physical line sections 20 and the sum of the minimum guaranteed bandwidth of the working LSP.

  The ratio T38 between the bandwidth upper limit value in all the physical line sections 20 and the sum of the minimum guaranteed bandwidths of the working LSP is not limited to Equation 1, and may be calculated by other methods.

  The redundant path selection unit 4231 according to the second embodiment includes a duplex path 201 in A24 where the index value of the entire system according to the second embodiment is reduced before the system selection is changed and after the system selection is changed. It is determined whether or not.

  If the redundant path selection unit 4231 according to the second embodiment determines in A24 that there is a duplex path 201 in which the index value of the entire system according to the second embodiment becomes small, the entire system according to the second embodiment. The duplicated path 201 that can minimize the index value is extracted at A25.

  After A25, the redundant path selection unit 4231 of the second embodiment changes the system selection of the duplex path 201 extracted in A25, and then there is no duplex path in which the index value of the second embodiment increases. Determine whether. When the index value of the second embodiment increases, the traffic of any physical line section 20 becomes difficult to flow, so the system selection of the duplex path 201 extracted in A25 is not changed.

  As described above, the reserved bandwidth adjustment unit 423 and the redundant path selection unit 4231 according to the second embodiment extract the duplex path 201 that can optimize the communication system, and make each communication apparatus 10 change the system selection. 201 is assigned.

  The network control unit 1 according to the second embodiment guarantees the minimum guarantee in each physical line section 20 when the sum of the maximum restricted bandwidths of all the working LSPs is larger than the sum of the upper band limit values of all the physical line sections 20. The total bandwidth is leveled in all communication systems. As a result, in each physical line section 20, the difference between the upper limit of the physical line bandwidth and the sum of the minimum guaranteed bandwidth of each active path is constant, and it is possible to avoid any physical line section 20 becoming a bottleneck. According to the second embodiment, the bandwidth of each physical line section 20 can be used effectively.

DESCRIPTION OF SYMBOLS 1 Network control part 10, 10 # 1-10 # 7 Communication apparatus 30 Monitoring control network 101, 101 # 1-101 # 4 Communication interface 20 Physical line section 40 Input part 41 Output part 42 Calculation part 43 Database part 10 Communication apparatus 421 Screen display unit 422 Data input processing unit 423 Reserved bandwidth adjustment unit 4231 Redundant path selection unit 424 Device control processing unit 202 LSP
201 LSP
T00 Topology table T10 LSP table T20 Redundant path table T30 Index value management table

Claims (10)

A network control device connected to a plurality of communication devices that communicate using MPLS,
The plurality of communication devices are connected to each other by a plurality of physical paths,
The network controller is
Two communication devices of the plurality of communication devices are connected, a first logical path accommodated in at least one first physical route, and the two communication devices are connected, and the first physical route Holding a table for allocating a second logical path accommodated in a second physical path different from the plurality of communication devices,
Holds the bandwidth upper limit value of traffic passing through each physical path,
Holding a maximum bandwidth limit and a minimum guaranteed bandwidth amount of traffic passing through the first logical path;
The sum of the physical paths of the maximum restricted bandwidth amount or the minimum guaranteed bandwidth amount of the plurality of first logical paths accommodated in the first physical routes, and the bandwidth upper limit value of the physical paths , Calculate the index value,
Allocating the first physical path to the second logical path, the candidate of the first logic path for changing the allocation of the physical path by assigning the second physical path to said first logical path , Extracting from the plurality of first logical paths accommodated in each physical path according to the calculated index value ,
The extracted first logical path candidate is stored in the table as a new second logical path, and is different from the first physical path in which the extracted first logical path is accommodated. A network control apparatus , wherein a second logical path accommodated in two physical paths is stored in the table as a new first logical path . A value obtained by subtracting the bandwidth upper limit value of the physical path from the sum of the maximum bandwidth limits of the plurality of first logical paths accommodated in the physical paths is divided by the bandwidth upper limit value of the physical paths. An index value of 1 and
Defining a second index value that is a sum of first index values in the plurality of physical paths;
The network controller is
Extracting the first index value in each physical path and the physical path having the largest first index value;
For each first logical path accommodated in the extracted physical path, the second index value before the physical path allocation change, and the second index value after the physical path allocation change, To calculate
Comparing the calculated second index value before the allocation change with the second index value after the allocation change,
The network control device according to claim 1, wherein when the second index value after the allocation change is small, the first logical path is extracted as a candidate for the allocation change. A third index value that is the sum of the minimum guaranteed bandwidth amounts of a plurality of first logical paths accommodated in each physical path;
A fourth index value that is a dispersion value obtained by dividing a third index value in the plurality of physical paths by the bandwidth upper limit value ;
The network controller is
Extracting a physical path having the largest third index value;
For each first logical path accommodated in the extracted physical path, calculate the fourth index value before the allocation change and the fourth index value after the allocation change,
Comparing the calculated fourth index value before the allocation change with the fourth index value after the allocation change,
2. The network control device according to claim 1, wherein if the fourth index value after the assignment change is small as a result of the comparison, the first logical path is extracted as a candidate for assignment change. The network controller is
Extracting the maximum value of the first index value before the allocation change and the maximum value of the first index value after the allocation change of each first logical path accommodated in the physical path ,
Comparing the maximum value of the first index value before the allocation change with the maximum value of the first index value after the allocation change;
3. The network control according to claim 2, wherein if the maximum value of the first index value after the allocation change is large as a result of the comparison, the respective first logical paths are not extracted as candidates for the allocation change. apparatus. The network controller is
Calculating the sum of the maximum bandwidth limits of the plurality of first logical paths;
Calculate the sum of the bandwidth upper limit values of the plurality of physical paths,
Comparing the calculated sum of the maximum restricted bandwidth amounts of the plurality of first logical paths with the calculated sum of the bandwidth upper limit values of the plurality of physical paths;
The network control device according to claim 2, wherein, as a result of the comparison, the first index value is calculated when a sum of bandwidth upper limit values of the plurality of physical paths is large. A path selection method by a network control device connected to a plurality of communication devices that communicate using MPLS,
The plurality of communication devices are connected to each other by a plurality of physical paths,
The network controller is
Holds the bandwidth upper limit value of traffic passing through each physical path,
Holding a maximum bandwidth limit and a minimum guaranteed bandwidth amount of traffic passing through the first logical path;
The path selection method is:
The network control device connects two communication devices of the plurality of communication devices, connects a first logical path accommodated in at least one first physical path, and the two communication devices; A procedure for allocating a second logical path accommodated in a second physical path different from the first physical path to the plurality of communication devices;
The network control device includes a sum of the physical paths of the maximum restricted bandwidth amount or the minimum guaranteed bandwidth amount of the plurality of first logical paths accommodated in the first physical routes, and the physical paths. To calculate the index value based on the bandwidth upper limit value of
The network controller assigns the first physical path to the second logical path, the first to change the assignment of the physical path by assigning the second physical path to said first logical path A path selection method comprising: extracting a plurality of logical path candidates from a plurality of first logical paths accommodated in each of the physical paths according to the calculated index value . The procedure for calculating the index value is as follows:
A value obtained by subtracting the bandwidth upper limit value of the physical path from the sum of the maximum bandwidth limits of the plurality of first logical paths accommodated in the physical paths is divided by the bandwidth upper limit value of the physical paths. An index value of 1 and a second index value that is the sum of the first index values in the plurality of physical paths are defined;
The procedure for extracting the candidate of the first logical path for changing the allocation of the physical path is as follows:
A procedure in which the network control device extracts the first index value in each of the physical paths and the physical path having the largest first index value;
The network control device assigns, to each first logical path accommodated in the extracted physical path, the second index value before the physical path allocation change and the second logical path after the physical path allocation change. A procedure for calculating an index value of 2,
The network control device comparing the calculated second index value before the allocation change with the second index value after the allocation change;
The path according to claim 6, further comprising: a step of extracting the first logical path as a candidate to be reassigned when the second index value after the assignment change is small. Selection method. The procedure for calculating the index value is as follows:
Said third index value of the the sum of the minimum guaranteed bandwidth of the plurality of first logical path contained in each physical path, the network controller, the third index value in the plurality of physical paths A fourth index value, which is a variance value obtained by dividing by the band upper limit value , is defined,
The procedure for extracting the candidate of the first logical path for changing the allocation of the physical path is as follows:
A procedure for the network control device to extract a physical path having the largest third index value;
The network control device, for each first logical path accommodated in the extracted physical path, the fourth index value before the allocation change, the fourth index value after the allocation change, The procedure for calculating
The network control device compares the calculated fourth index value before the allocation change with the fourth index value after the allocation change;
The network control device includes a procedure for extracting the first logical path as a candidate for reassignment when the fourth index value after the assignment change is small as a result of the comparison. 6. The path selection method according to 6. The procedure for extracting the candidate of the first logical path for changing the allocation of the physical path is as follows:
The network control device has a maximum value of the first index value before the allocation change and a maximum of the first index value after the allocation change of each first logical path accommodated in the physical path. A procedure for extracting values,
The network control device compares the maximum value of the first index value before the allocation change with the maximum value of the first index value after the allocation change;
The network control device does not extract the first logical path as a candidate for reassignment when the maximum value of the first index value after the assignment change is large as a result of the comparison, The path selection method according to claim 7. The procedure for calculating the index value is as follows:
A procedure in which the network control device calculates a sum of maximum limited bandwidth amounts of the plurality of first logical paths;
A procedure in which the network control device calculates a sum of bandwidth upper limit values of the plurality of physical paths;
The network control device compares the calculated sum of the maximum restricted bandwidth amounts of the plurality of first logical paths with the calculated sum of the bandwidth upper limit values of the plurality of physical paths;
The network control device includes a procedure of calculating the first index value when a sum of bandwidth upper limit values of the plurality of physical paths is large as a result of the comparison. Path selection method.

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