JP6084894B2 - Route search apparatus and program for communication network - Google Patents

Description

  The present invention relates to a route search device that searches for a route of a line connecting two client devices in a communication network in which various multiplexing methods are mixed.

  Patent Document 1 discloses an apparatus for determining a line route in a communication network. In this way, in order to set up a line between two devices that perform communication, first, all possible routes are searched, and one route is finally determined based on a predetermined criterion. Done. For this reason, a line route search device is used. In general, a route search device uses a multiplexing device or the like as a node, a wired or wireless transmission line connecting the devices as an edge or a link, and searches and determines a route by a route search algorithm based on graph theory.

JP 2008-022523 A

  Currently, communication networks include a variety of multiplexing devices such as SDH (synchronous digital hierarchy) and OTN (optical transmission network), and the multiplexing configuration of signals transmitted between communication stations has become complicated. ing. For this reason, the multiplexed path of signals becomes a constraint condition in the path search. For example, as shown in FIG. 10, a station # 1 and a station # 2 are connected by a wavelength multiplexing device (WDM), and each of the station # 1 and the station # 2 has a multiplexing device (OTN and OTN). Notation), a multiplexing device (indicated as SDH) conforming to SDH, and a client device are installed. In addition, the connection relation of each communication apparatus of each station # 1 and # 2 shall be as the line which connects between apparatuses.

  In this case, since there are four multiplexing orders for the stations # 1 and # 2, there are a total of 4 × 4 = 16 paths for connecting the client apparatuses. However, the signal multiplexed in the path of the client apparatus-OTN-WDM in the station # 1 must be separated in the reverse order, that is, in the path of the WDM-OTN-client apparatus in the station # 2. For example, the path cannot be a WDM-SDH-client device path. Therefore, there are actually four possible routes in the configuration of FIG.

  As described above, the route search apparatus performs a route search using the multiplexing order as a constraint condition. However, it is necessary to determine whether or not the constraint condition is satisfied during the route search, and the size of the communication network increases. The route search time increases.

The present invention provides a route search apparatus and program capable of suppressing an increase in route search time even if the size of a communication network increases.

  According to an aspect of the present invention, there is provided a route search apparatus for a line set between two client apparatuses in a communication network, the multiplexed interface of each communication apparatus of the communication network, and the multiplexed interface, Determining means for determining possible multiplexing configurations in the communication network and determining the number of multiplexed configurations of multiplexed signals handled by each interface of each communication device; and each interface of each communication device of the communication network Is defined as the number of nodes of the multiplexing configuration determined by the determination means, and the signal path between the connection configuration of each communication device in each communication station building of the communication network and the interface in each communication device Based on the definition means for defining the link between the nodes and the nodes and links defined by the definition means as a graph, A search means for searching the possible paths between two client devices, characterized in that it comprises.

  It is not necessary to consider the constraint conditions during the route search, and an increase in route search time can be suppressed even if the size of the communication network increases.

1 is a schematic configuration diagram of a route search apparatus according to an embodiment. FIG. The block diagram between the exemplary communication stations for explaining the route search process by one Embodiment, and a communication station building. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the route search process by one Embodiment. Explanatory drawing of the conventional problem.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the following drawings, components that are not necessary for the description of the embodiments are omitted from the drawings.

  FIG. 2 is a configuration diagram of a communication system used for explaining the present embodiment. As shown in FIG. 2, station A and station B are connected by WDMs 1 and 2, respectively, and station B and station C are connected by WDMs 3 and 4, respectively. In addition, SDH 7 and client device 50 are installed in station A, OTN 5 and SDH 8 and 9 are installed in station B, and OTN 6, SDH 10 and 11 and client device are installed in station C. 51 is installed. A square including a number displayed in each communication device represents an interface, and the number is an index indicating a speed. Note that the lower interface shown in each communication device corresponds to a signal to be multiplexed. In the following description, the lower interface is referred to as a multiplexed interface. On the other hand, the interface shown on the upper side of each communication apparatus corresponds to multiplexed signals, and in the following description, the interface shown on the upper side is called a multiplexed interface.

  In the configuration of FIG. 2, the line connecting the interfaces of different communication devices indicates a communication link. A communication link can be set only between interfaces having the same index of different communication devices. Furthermore, a line connecting the communication devices inside the communication device indicates a path that a signal can take in the communication device. Hereinafter, the route search process or method executed by the route search device according to the present embodiment in order to determine the route between the client device 50 and the client device 51 when the configuration of FIG. 2 is assumed will be described.

  First, the route search device defines a WDM in which all the WDMs installed in all stations A, B, and C are combined, that is, the WDM shown in FIG. Note that there is no need to consider the interface connecting the communication stations. Similarly, the route search apparatus is an OTN in which the interfaces of all the OTNs installed in all stations A, B, and C in the route are combined into one, that is, the OTN shown in FIG. Define Further, the route search apparatus combines the SDHs that have the interfaces of all the SDHs installed in all the stations A, B, and C in the route, that is, the SDH shown in FIG. Define. At this time, the multiplexed interface is distinguished from the multiplexed interface.

  Next, as shown in FIG. 4, the route search device defines a link from the interface of the client device to the interface of the communication device defined in FIG. 3 that can be connected to the interface of the client device. In FIG. 4, a link to an interface whose SDH and OTN indexes are 1 is defined. In addition, if there is an interface that can be connected by the multiplexed interface of the communication device defined in FIG. 3 and the multiplexed interface of another communication device, a link from the multiplexed interface to the multiplexed interface is defined. In FIG. 4, links are defined between interfaces with SDH and OTN indexes of 2 and 8, between interfaces with SDH and WDM indexes of 8 and 32, and interfaces with OTN and WDM indexes of 32. . Further, in the communication device, a link from the non-multiplexed interface to the multiplexed interface is defined according to the signal path in each communication device.

  Subsequently, the route search device determines the number of multiplexed configurations in each interface from the definition contents in FIG. Here, the number of multiplexed interfaces is equivalent to the number of paths from the interface of the client device as the starting point to the interface in the configuration defined in FIG. FIG. 5 shows the number of multiplexed configurations of each interface corresponding to the configuration of FIG. For example, since there is only one path to the SDH multiplexed interface or three multiplexed interfaces, the number of multiplexed configurations of each interface of SDH is one. Similarly, the number of multiplexed configurations of the three multiplexed interfaces of OTN is one. On the other hand, since there are paths from each of the three multiplexed interfaces of OTN in the multiplexed interface of OTN, the number of multiplexed configurations of the multiplexed interface of OTN is 3. An interface having a WDM index of 32 includes a path from an OTN multiplexing interface having a multiplexing configuration number of 3 and a single SDH multiplexing interface. The number of multiplexed components is 4.

  Subsequently, the route search apparatus divides each interface in the configuration of FIG. 2 into the number of multiplexed configurations. Specifically, the multiplexing interfaces of OTN 5 of station B and OTN 6 of station C in FIG. 2 are divided into three from FIG. 5, and the multiplexed interfaces of WDM 3 and WDM 4 of station B are as shown in FIG. It is divided into four. FIG. 6 is obtained by adding the number of divisions in parentheses to the interface to be divided in FIG. FIG. 7 shows a state in which each interface in the configuration of FIG. 2 is divided based on the number of multiplexed configurations. At this time, the multiplexing side interfaces of the WDMs 1, 2, 3, and 4 that connect the stations are divided into the same number as the non-multiplexing side interfaces, and the links between the stations are similarly divided for each multiplexing side interface. Defined in Also, the signal path in the communication apparatus is defined as a link according to the signal path of the communication apparatus in each station. At this time, like the OTN 6 in the station C, the non-multiplexing side interface is 2 with respect to the three multiplexing side interfaces. In this case, one of the three multiplexing side interfaces includes a communication device. Internal links are not defined.

8 and 9 show the codes indicating the multiplexing configuration on each interface of FIG. 8 shows the configuration of the station A and the station B, and FIG. 9 shows the configuration of the station B and the station C. 8 and 9, the character “C” indicates the client device, the character “S” indicates SDH, the character “O” indicates OTN, the character “W” indicates WDM, and the subscript of each character is: Indicates the index of the interface. For example, the OTN multiplexing interface of FIG. 4 includes a path (multiplexing configuration C ₁ O ₃₂ ) in which the output of the client device is directly multiplexed, and a path (multiplexing configuration C) via the interface whose SDH index is 2. ₁ S ₂ O ₃₂ ) and three multiplexing configurations of a path (multiplexing configuration C ₁ S ₈ O ₃₂ ) through an interface having an SDH index of 8 exist, and the three divided interfaces are respectively It is classified into a multiplexing configuration C ₁ O ₃₂ , a multiplexing configuration C ₁ S ₂ O _32, and a multiplexing configuration C ₁ S ₈ O ₃₂ . The same applies to other interfaces.

  As shown in FIG. 8 and FIG. 9, the route search device performs route search based on graph theory with each interface obtained by dividing as a node in the graph and using signal paths between and within the communication devices as links. Do. As described above, before searching, a possible multiplexing configuration in the communication network is determined, and the same physical interface is divided based on the determined multiplexing configuration to correspond to one or more nodes. In the graphs shown in FIGS. 8 and 9, the route search can be performed without considering the constraint condition. In other words, a graph with an actual communication device as a node and a signal path between communication devices as a link, an interface as a node after considering the constraints, and a signal path between communication devices and within the communication device as a link By generating a graph, it is not necessary to consider the constraint conditions when searching for a route. Therefore, even when the size of the communication network increases, the time required for route search can be suppressed.

  FIG. 1 is a schematic configuration diagram of a route search apparatus according to the present embodiment. The database unit 104 includes a connection configuration between each communication station in the communication network, a multiplexing device and a client device installed in each communication station, a connection configuration between communication devices in each communication station, It holds information about the interfaces implemented in the multiplexer and the possible paths of signals between the interfaces in the multiplexer. The input / output unit 105 receives an input of a route to be searched or determined from the user and displays the result.

  Based on the information stored in the database unit 104, the determination unit 101 determines the number of multiplexed configurations in the multiplexed signal handled by each interface, as described with reference to FIGS. The definition unit 102 defines each interface as a node of the number of multiplexed configurations determined by the determination unit 101, and defines a link between nodes as described with reference to FIGS. Generate. The search unit 103 searches for possible routes using the search graph defined by the definition unit 102, and outputs all routes searched for display to the user to the input / output unit 105. Alternatively, the search unit 103 is configured to determine one route based on a predetermined selection criterion from all the searched routes and output the determined route to the input / output unit 105 for display to the user. Also good.

  The route search device according to the present invention can be realized by a program that causes a computer to operate as the route search device. These computer programs can be stored in a computer-readable storage medium or distributed via a network.

Claims (4)

A route search device for a line set between two client devices in a communication network,
Based on the multiplexed interface of each communication device of the communication network and the multiplexing interface, the multiplexing configuration that can be taken in the communication network is determined, and the multiplexing signal multiplexed by each interface of the communication device is determined. A determination means for determining the number of data structures,
Each interface of each communication device of the communication network is defined as a node of the number of the multiplexed configurations determined by the determination unit, a connection configuration of each communication device of each communication station of the communication network, and each communication Defining means for defining a link between the nodes based on a signal path between interfaces in the device;
Search means for considering a node and a link defined by the definition means as a graph and searching for a path that can be taken between the two client devices;
A route search device comprising:   The determination means determines a multiplexing configuration that can be taken in the communication network by obtaining communication devices having all the interfaces used by the communication network for each type of each communication device of the communication network. The route search device according to claim 1.   The route search device according to claim 1 or 2, wherein the search means determines one route based on a predetermined condition from the searched possible routes. A program that causes a computer to function as the route search device according to any one of claims 1 to 3.

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