JP5611999B2 - Network design method and network design apparatus for realizing cut-through configuration - Google Patents

Description

  The present invention relates to a network design method and apparatus using cut-through in which a transfer process of an L2 apparatus is omitted in a communication network constituted by an L2 apparatus and a transmission apparatus.

  The wide area Ethernet (registered trademark) service is a service that provides a user with a closed network in which multipoint connection is possible for each user. Therefore, in order to efficiently provide a multipoint connection, a relay network used when providing a wide area Ethernet (registered trademark) service may be constructed by connecting a plurality of L2 switches. However, when such a construction form is used, it has been a problem to consume L2 processing resources of the L2 device even at a simple relay point that does not involve branching.

  On the other hand, in a wide area Ethernet (registered trademark) relay network, transmission devices such as ROADM and MC are arranged between switches as a transmission means for connecting a remote L2 switch. Transmission has been realized. However, in recent years, transmission techniques that have been used only as transmission means so far have been remarkably developed, and as a result, the setting granularity and path control capability of transmission paths set in the transmission apparatus have improved. For example, WSON, an all-optical transport technology that performs path control in units of wavelengths without electrically converting optical signals, has been realized with the advent of WSS devices. Also, standardization of OTN, which is a standardization technique for handling both the optical layer wavelength path and the electrical layer TDM path in multiple layers, has progressed, and it becomes possible to form a TDM path smaller than the wavelength called ODU, and ODU Circuit switching-like switching called cross-connect is now possible. Furthermore, standardization of MPLS-TP, which is a packet transport technology, is progressing. In MPLS-TP, a packet path is set by a label, and logical separation of users and services and flexible switching are possible.

  Recently, an integrated transmission apparatus that can control three layers of a wavelength path, a TDM path, and a packet path in an integrated manner has appeared. It is expected that an economical transport network can be realized by appropriately using three layers according to the network scale, and these transmission technologies and transmission devices will be applied to wide area Ethernet (registered trademark) relay networks in the future. It is expected to be done.

  Conventionally, relay transfer control of user frames in a wide area Ethernet (registered trademark) network has been realized by L2 processing that performs frame forwarding by MAC learning. However, due to the development of the transmission technology described above, L1 that is a lower layer than L2 is controlled. By performing transfer control of user frames using transmission technology, the applicability of cut-through omitting the L2 processing of the L2 device has increased. FIGS. 18A to 18C show the form of cut-through. FIG. 18A shows an example of a communication network. The communication network includes L2 devices 311 to 313, L2 ports 311-1 and 2, 312-1 and 2, 313-1 and 2, transmission devices 411 to 413, Long-distance transmission ports 411-2, 412-1, 412-4, 413-1 and client signal accommodation ports 411-1, 412-2, 412-3-3, 413-2 are configured. FIG. 18B shows the arrangement of communication paths and L2 processing functions when cut-through is not applied. Focusing on the L2 device 312 and the transmission device 412, if cut-through is not applied, the transmission device once sends it to the L2 device, performs the L2 processing in the L2 device, returns to the transmission device, and performs transfer. Recognize. FIG. 18C shows the arrangement of communication paths and L2 processing functions when cut-through is applied. Similarly, when attention is paid to the L2 device 312 and the transmission device 412, when applying cut-through, the transmission device 412 is previously set in the transmission device 412 with the above-described path control by wavelength and ODU cross-connect. It becomes a form to switch the route. By taking this form, there is an advantage that the L2 relay transfer control function of the L2 device 312 is not wasted. By applying cut-through that eliminates the transfer processing of the L2 device, it is possible to efficiently handle network resources by replacing expensive and complicated transfer control by L2 with broadband, inexpensive, and simple transfer control by L1. Therefore, a method for realizing a wide-area Ethernet (registered trademark) service provision form to which cut-through is applied is desired.

  One technique using cut-through is Ethernet (registered trademark) over MPLS (Non-Patent Document 1). The configuration of Non-Patent Document 1 performs communication by allocating a data frame to an MPLS path on the edge side, performing relay transfer processing by label switching, and extracting the data frame on the edge side. In this configuration, cut-through can be applied simply, but only 1: 1 point-to-point connection is possible, and multipoint connection, which is a necessary function of the wide area Ethernet (registered trademark) service, is possible. There was a problem that could not be realized.

  As a method for providing wide-area Ethernet (registered trademark) service by cut-through, there is VPLS (Non-patent Document 2). In the configuration of Non-Patent Document 2, MAC learning of a user frame is performed by an edge device, and the user frame is assigned to the MPLS-TP packet path according to the learning result. Therefore, it is possible to realize a multipoint connection to which cut-through is applied by performing relay transfer processing using a packet path or lower layer path switching technology. However, since VPLS essentially takes the form of configuring multipoint connections by preparing multiple point-to-point connections, it is necessary to set transmission paths on the mesh at all sites, and the number of transmission paths is an exponential number. It increases functionally. Further, since flooding of multicast and unlearned frames is copied at the edge portion, there is a problem that extra network bandwidth is consumed. Therefore, VPLS is not a solution for realizing a wide-area Ethernet (registered trademark) service provision form to which cut-through is applied.

JP 2011-49643 A

IETF RFC4448 "Encapsulation Methods for Transport of Ethernet (R) over MPLS Networks" Matsumoto et al., “Broadband optical network technology supporting high-reliability and large-volume data communication services”, Hitachi review, May 2010, pp. 52-55

  As described so far, network resources can be handled efficiently by applying cut-through that eliminates the transfer process of the L2 device, so wide area Ethernet (registered trademark) to which cut-through is applied. Although it is desired to realize a service provision form, it is difficult to realize multipoint connection with existing technology, and even if multipoint connection is enabled by VPLS, transmission paths and network bandwidth are increased accordingly. There was a problem of consumption.

  Therefore, in order to solve the above-described problem, the present invention provides a network design method capable of designing a data transfer path that uses a cut-through that omits transfer processing of an L2 device as a part of a communication path in a wide area L2 network. And a network design device is proposed.

  In order to solve the above-described problem, the network design method and the network design apparatus according to the present invention design a data transfer path so that the transfer process of the L2 apparatus can be omitted in a part of the communication path. It is characterized by realizing cut-through capable of multipoint connection without wasting power.

  Specifically, the network design method according to the present invention designs a data transfer path that uses a cut-through that omits the transfer process of the L2 device as a part of the communication path in the L2 network configured by the transmission device and the L2 device. A method of multicasting a user device using network configuration information including a connection destination and connection state of each port of the L2 device, and an access accommodation point information including the L2 device connected to the user device and the port of the L2 device. A cut-through L2 device design procedure for generating VLAN design information in which an L2 device in which a VLAN constituting a closed network to be connected is set is determined, and determining an L2 device to perform cut-through based on the VLAN design information; In order for the L2 device determined by the cut-through L2 device design procedure to be cut-through, A transmission path design procedure for designing a transmission path based on the serial VLAN design information, and having in sequence.

  In the network design method according to the present invention, the VLAN design information further includes a port in which a VLAN is set, and the cut-through L2 device design procedure is performed on a VLAN for the L2 device described in the VLAN design information. If the set number of ports is 2, the cut-through device that performs the cut-through may be determined.

  In the network design method according to the present invention, the VLAN design information indicates whether the connection destination of the port of the L2 device is cascade-connected, connected to a transmission device, or connected to a user device. The cut-through L2 device design procedure further includes a port connected to the transmission device or the user device for each L2 device described in the VLAN design information, or is cascade-connected. And when the connection destination of a cascade connection is a several user apparatus, you may determine to the L2 processing apparatus which does not perform a cut-through.

  In the network design method according to the present invention, the transmission path design procedure includes determining a transmission device that connects between L2 devices determined as L2 processing devices that do not perform cut-through, and a connection transmission port of the transmission device. A transmission path may be designed.

  In the network design method according to the present invention, in the cut-through L2 device design procedure, the redundant region information indicating the device ID of the L2 device existing in the partially completed redundant region, the redundant domain ID, and the redundant domain Redundant design information for defining a redundant region used by the closed network designed by the VLAN design information is used using redundant configuration information composed of redundant domain information including a redundant region ID having a redundant configuration and a device ID of an L2 device. In the transmission path design procedure, the redundancy domain information may be used to determine the redundancy domain of the L2 device existing in the redundancy area defined by the design information.

  In the network design method according to the present invention, in the transmission path design procedure, an L2 device that does not perform cut-through determined by the cut-through L2 device design procedure from among a plurality of redundant domains set in the redundancy region. The redundant domain may be determined by comparing the set with a set of L2 devices belonging to the redundant domain, and selecting one of the redundant domains including the set of L2 devices that completely match.

  Specifically, the network design apparatus according to the present invention designs a data transfer path that uses a cut-through that omits L2 apparatus transfer processing as part of a communication path in a wide area L2 network configured by a transmission apparatus and an L2 apparatus. Network design device, and the device ID and port ID of the L2 device to which each port of the L2 device is connected and the network configuration information including the connection state and the device ID and port ID of the L2 device connected to the user device L2 that generates VLAN design information in which an L2 device in which a VLAN that configures a closed network that multicast-connects user devices is connected is defined using the access accommodation point information that includes the information, and performs cut-through based on the VLAN design information Cut-through design unit to determine the device, and determined by the cut-through design unit As second device is cut through, and a transfer path route design unit for designing a transmission path based on the VLAN design information.

  Specifically, the network design program according to the present invention designs a data transfer path that uses a cut-through that omits the transfer process of the L2 device as a part of the communication route in the wide area L2 network configured by the transmission device and the L2 device. A network design program for causing a computer to execute a method for performing the method, wherein the cut-through design unit includes network configuration information and user information including a device ID and a port ID of the L2 device to which each port of the L2 device is connected and a connection state A VLAN design in which an L2 device in which a VLAN constituting a closed network for multicast connection of user devices is set is defined using access accommodation point information including a device ID, a port ID, and a VLAN ID of an L2 device connected to the device Information is generated, and the cuts are generated based on the VLAN design information. The cut-through L2 device design procedure for determining the L2 device to be performed and the transmission path route design unit based on the VLAN design information so that the L2 device determined by the cut-through L2 device design procedure is cut-through And a transmission path design procedure for designing a transmission path in order.

  The above inventions can be combined as much as possible.

  According to the present invention, a data transfer path that uses cut-through that omits the transfer process of the L2 device as a part of the communication path is designed, and a service that does not consume an extra transmission path or network bandwidth while realizing multipoint connection. It is possible to provide a network design method and a network design apparatus capable of realizing the provision form.

2 shows an example of a configuration of a communication network according to the first embodiment. 2 shows an example of a base configuration of a communication network according to the first embodiment. An example of the logical connection structure in L2 in Embodiment 1 is shown. 1 illustrates an example of an embodiment of a network design device, an L2 network control device, and a transmission control device according to a first embodiment. An example of the network design procedure by the network design apparatus 500 is shown. An example of the network design procedure by the network design apparatus 500 is shown. An example of the network design procedure by the network design apparatus 500 is shown. 4 shows an example of network configuration information in the first embodiment. An example of the access accommodation point information in Embodiment 1 is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information at the time of finishing step S103 in the first embodiment is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information at the time of completing steps S104 to S111 in the first embodiment is shown. An example of VLAN design information, L2 device design information, and transmission path design information during the processing of steps S201 to S214 in the first embodiment is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information when the processes of steps S201 to S214 in Embodiment 1 are completed is shown. An example of VLAN design information after performing the process of step S301 in Embodiment 1, L2 apparatus design information, and transmission path design information is shown. An example of the structure of the communication network in Embodiment 2 is shown. An example of the base configuration of the communication network in Embodiment 2 is shown. An example of the logical connection structure in L2 in Embodiment 2 is shown. An example of embodiment of the network design apparatus, L2 network control apparatus, and transmission control apparatus in Embodiment 2 is shown. An example of the network design procedure by the network design apparatus 500 in Embodiment 2 is shown. An example of the network design procedure by the network design apparatus 500 in Embodiment 2 is shown. An example of the network design procedure by the network design apparatus 500 in Embodiment 2 is shown. An example of redundant configuration information is shown. An example of the network configuration information in Embodiment 2 is shown. An example of the access accommodation point information in Embodiment 2 is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information when the process up to step S134 in the second embodiment is completed is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information when the process up to step S142 in Embodiment 2 is completed is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information when the process up to step S244 in the second embodiment is completed is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information when the process up to step S333 in Embodiment 2 is completed is shown. An example of VLAN design information, L2 apparatus design information, and transmission path design information after finishing all operations in Embodiment 2 is shown. It is a form of the conventional cut-through and shows an example of a communication network. This is a conventional cut-through configuration, and shows the arrangement of communication paths and L2 processing functions when cut-through is not applied. This is a conventional cut-through configuration, and shows the arrangement of communication paths and L2 processing functions when cut-through is applied.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
FIG. 1 shows a configuration of a communication network in the first embodiment.
The communication network shown in FIG. 1 includes base buildings 101 to 109, L2 devices 301 to 310, L2 ports 301-1 to 302, 302-1 to 4, 303-1 to 4, ... 310-1 to 4, transmission. Devices 401-407, long-distance transmission ports 401-1-4, 402-1, 403-1, 404-1, 404-5, 404-6, 405-1, 406-1, 407-1, client signal accommodation Ports 401-5 to 8, 402-2, 403-2, 404-2 to 4, 405-2, 406-2, 407-2, network design device 500, L2 network control device 600, and transmission control device 700 Is done. FIG. 2 shows a base configuration of the communication network shown in FIG. 1, and FIG. 3 shows a logical connection configuration at L2 in the communication network shown in FIG.

  FIG. 4 shows an example of the network design apparatus of this embodiment. The network design apparatus according to the embodiment includes a network design apparatus 500, an L2 network control apparatus 600, and a transmission control apparatus 700. The network design device 500 includes an access accommodation point information input unit 501, an access accommodation point information management unit 502, a VLAN design unit 503, a network configuration information management unit 504, a cut-through design unit 505, an L2 device design information storage unit 506, and VLAN design information. The storage unit 507 and the transmission path design information storage unit 508 are configured. The L2 network control device 600 includes a VLAN setting unit 601, and the transmission control device 700 includes a transmission path route design unit 701 and a transmission path setting unit 702.

  The access accommodation point information input unit 501 is an input unit for inputting information on the L2 device that accommodates connection from the user base and its port when configuring a closed network that connects the user bases to multiple points. The access accommodation point information management unit 502 also stores information about the L2 device that accommodates the connection from the user base and the port input by the access accommodation point information input unit 501, the L2 device as the user accommodation device, and the port as the user accommodation. As a port, it is stored and held in access accommodation point information for each closed network. FIG. 7 shows an example of access accommodation point information stored and held in the access accommodation point information management unit 502.

  The VLAN design unit 503 is a closed network that connects user bases to multiple points from the access accommodation point information stored by the access accommodation point information management unit 502 and the network configuration information stored by the network configuration information management unit 505. Are designed, VLAN design information and L2 device design information, which will be described later, are generated and stored and held in the L2 device design information management unit 506 and the VLAN design information management unit 507, respectively. Any method for realizing the function of designing the VLAN may be used. For example, the configuration disclosed in Patent Document 1 may be used, or the operator may manually design the function.

  The network configuration information management unit 504 stores and holds network configuration information representing the configuration of the communication network. FIG. 6 shows an example of network configuration information stored and held in the network configuration information management unit 504. As shown in FIG. 6, the network configuration information includes L2 port configuration information and L2 device configuration information, and the L2 port configuration information indicates the L2 port, its port attribute, and the transmission device connected to the L2 port. The connection transmission device ID and the connection transmission port ID indicating the accommodation port, the opposite device ID indicating the opposite L2 device connected to the L2 port and the opposite port ID indicating the opposite L2 port are stored and held as a table. ing. Here, the port attributes include whether the L2 port is a cascade connection port that is directly connected without passing through a transmission device, a transmission device connection port that is connected via a transmission device, or an access port that accommodates access. Any information is recorded. In the L2 device configuration information in the network configuration information, the L2 device ID and the base ID indicating the base where the device is located are stored and held as a table.

  The cut-through design unit 505 designs a form for realizing cut-through from the network configuration information, the L2 device design information, and the VLAN design information, reflects the design contents in the VLAN design information and the L2 device design information, and transmits the transmission path design information. Is generated. Specific operations will be described later.

  The L2 device design information management unit 506 stores and holds the L2 device design information shown in FIG. 8A for each closed network. The L2 device design information includes a device ID and a device attribute. The device ID records the ID of the L2 device that has set the VLAN when configuring the closed network, and the device attribute cuts through the device. The attribute indicating whether or not is generated by the cut-through design unit 505 and stored / held.

  The VLAN design information management unit 507 stores and holds the VLAN design information shown in FIG. 8A for each closed network. Here, the VLAN design information includes the device ID indicating the L2 device having the port, the port ID of the port, the VLAN ID designed for the port, the port attribute of the port referenced from the network configuration information, and the network design time. It consists of processing flags to be used.

  The transmission path design information management unit 508 stores and holds the transmission path design information shown in FIG. 10A for each closed network. Here, the transmission path design information includes a point 1 transmission device indicating a transmission device at one end of the transmission path and a point 1 accommodation port indicating a port accommodating an L2 connection in the transmission device at one end of the transmission path. Point 1 path identification VLAN ID indicating the VLAN set in the connection, point 2 transmission device indicating the transmission device at the other end point, and point 2 accommodation port and accommodation indicating the port accommodating the L2 connection in the transmission device at the other end point The point 2 path identification VLANID indicating the VLAN set in the L2 connection is generated, and this information is generated by the cut-through design unit 505 and stored and held by the transmission path design information management unit 508.

The VLAN setting unit 601 in the L2 network control device 600 has a function of setting a VLAN in an L2 device and a port on the L2 network based on the VLAN design information held in the VLAN design information management unit 507 of the network design device 500. Have.
A transmission path design unit 701 in the transmission control apparatus 700 designs a path and band of the transmission path based on the transmission path design information held in the transmission path design information management unit 508 of the network design apparatus 500. The route and bandwidth can be designed by any method. If there are multiple routes, the two ends of the transmission path can be connected by the shortest route, or the route can be designed in consideration of load distribution. Also good. The transmission path setting unit 702 sets a transmission path in the transmission apparatus according to the route and band designed by the transmission path route design unit 701.

5A to 5C show an example of a network design method by the network design apparatus 500 in the present embodiment.
In the procedure shown in FIG. 5A, a cut-through L2 device design procedure for determining a L2 device capable of cut-through based on VLAN design and VLAN design information is performed.
When the access accommodation point information is input from the access accommodation point information input unit 501 (step S101), the VLAN design unit 503 designs the VLAN that connects the access accommodation points based on the input access accommodation point information and the network configuration information. Is performed (step S102). The design information is stored and held in the L2 device design information storage unit 506 and the VLAN design information storage unit 507 as L2 device design information and VLAN design information, respectively (step S103).

Here, the cut-through design unit 505 performs the following processing on the L2 device in the L2 design information (step S104).
First, in the VLAN design information, it is determined whether there is an port whose port attribute is an access port among the ports for which the VLAN related to the L2 device being processed is set (step 105). If there is even one, the process proceeds to step S109, and the L2 device being processed and the L2 device at the same base as the L2 device being processed are recorded in the table as “L2 process setting device”. Here, even if the device attribute is set for the L2 device at the same site, it is assumed that recording is performed by overwriting the already set attribute. If there is none, the process proceeds to step S106.
In step S <b> 106, it is determined whether there is a port whose port attribute is cascade connection among the ports for which the VLAN is set. If even one of them is a cascade connection, the process proceeds to step S107, and if none is present, the process proceeds to step S108.
In step S107, it is determined using the network configuration information whether there is an opposite device of a port whose port attribute is cascade connection, and if there is an opposite device of a different base, the process proceeds to step S109. If not, the process proceeds to step S108.
In step S108, it is determined using the VLAN design information whether there are three or more ports including the logical ports in the device being processed. If it is 3 or more, the process proceeds to step S109. If it is 3 or less, the process proceeds to step S110. In step S110, since the number of ports for which the VLAN is set is 2, the device attribute of the L2 device being processed is recorded in the table as “cut-through device”. Here, it returns to step S104 and repeats the same operation with respect to the next L2 apparatus (step S111).

In the procedure shown in FIGS. 5B to 5C, a transmission path design procedure is performed.
In the L2 device design information managed by the L2 device design information management unit 506, the cut-through design unit 505 performs processing for the device attribute “L2 processing device” (step S201). In addition, the cut-through design unit 505 sequentially performs the following processing for all the ports in the “L2 processing device” that do not have the processing end flag registered in the VLAN design information (steps). S202).

First, it is determined whether the attribute of the port is access (step S203). If the determination result is true, a process end flag is set for the port being processed (step S212), and the next port is processed (step S213). When all ports have been processed, the next “L2 processing device” is processed (step S214). If the determination result of step S204 is false, the process proceeds to step S204.
In step S204, it is determined whether the port attribute of the port is cascade connection. If the determination result is true, the process proceeds to step S212 and subsequent steps. If the determination result is false, the process proceeds to step S205. In step S205, the L2 device opposite to the L2 port opposite to the port being processed is taken out. Here, the opposite L2 port and L2 device are extracted from the network configuration information managed by the network configuration information management unit 504.

Next, it is determined whether or not the extracted L2 device is “L2 processing device” in the L2 device design information (step S206).
If the determination result is true, a transmission path is designed between the L2 devices. The connection transmission device and connection transmission port of the port being processed are extracted from the network configuration information, and the set VLAN ID is extracted from the VLAN design information, and these are extracted as the point 1 transmission device, the point 1 accommodation port, and the point 1 path identification VLAN ID. The transmission path design information management unit 508 records the transmission path design information managed by the transmission path design information management unit 508 (step S209). Next, the connection transmission device, connection transmission port, and set VLAN ID of the currently extracted port are extracted in the same manner as in step S209, and this is transmitted as the point 2 transmission device, the point 2 accommodating port, and the point 2 path identification VLAN ID. The transmission path design information managed by the path design information management unit 508 is recorded (step S210). That is, the operations in steps S209 and S210 define the start point and end point of the transmission path to be set. Finally, a process end flag is set for the port being processed and the extracted port (step S211), and the processes after step S213 are performed.
If the determination result in step S206 is false, first, a process end flag in the VLAN design information is set for all VLAN setting ports in the extracted L2 device (step S207). Next, out of the VLAN setting ports in the extracted L2 device, the other L2 port that is not the extracted L2 port is extracted from the VLAN design information, and the opposite L2 port of the L2 port is referred to the network configuration information. Take out. Further, the L2 device having the taken out L2 port is taken out, and the process returns to the operation of step S206 (step S208). When the operations of S201 to S214 are completed, the operation proceeds to the operation shown in FIG.

FIG. 5C shows an example of a network setting procedure by the network design device 500, the L2 network control device 600, and the transmission control device 700 in the present embodiment.
The cut-through design unit 505 deletes the VLAN information having the attribute “cut-through device” in the L2 device design information from the VLAN design information (step S301).
Next, the VLAN setting unit 601 of the L2 network control device 600 sets a VLAN in the L2 device based on the VLAN design information (step S302).
Finally, the transmission path route design unit 701 of the transmission control apparatus 700 designs a path route connecting the point 1 and the point 2 of the transmission path design information based on the transmission path design information, and the transmission path setting unit 702 transmits the transmission path. Is set for the transmission apparatus (step 303).

  Next, as an example, how the network is designed when the access accommodation point information shown in FIG. 7 is input to the network design device 500 will be described with reference to FIGS. FIG. 8A shows VLAN design information, L2 device design information, and transmission path design information when step S103 in FIG. 5A is finished. Here, the port attribute of the VLAN design information is entered by referring to the network configuration information from the device ID and the port ID.

  FIG. 8B shows the VLAN design information, the L2 device design information, and the transmission path design information when steps S104 to S111 in FIG. 5A are completed. It can be seen that the device attribute of the L2 device is determined to be either “L2 processing device” or “cut-through device” by the processing from steps S104 to S111. For example, in the case of the L2 device 301, referring to the VLAN design information, it can be seen that there are three or more ports to which the VLAN is set. On the other hand, in the case of the L2 device 305, none of the ports set with the VLAN have cascade connection or access, and there are only two ports with the VLAN set. Cut-through device ".

FIG. 8C shows VLAN design information, L2 device design information, and transmission path design information being processed in steps S201 to S214. In this example, processing is performed from the L2 device 301, but processing may be performed from any device or port.
Since the port 301-1 of the L2 device 301 is true with respect to the determination in step S204, the process proceeds to step S212, and a processing end flag is set in the port 301-1.
Next, when processing of the port 301-2 of the L2 device 301 is performed, first, the opposing L2 port 305-1 and the opposing L2 device 305 are taken out from step S205. Since the extracted L2 device 305 is a “cut-through device” from step S206, a processing end flag is set for all VLAN setting ports of the L2 device 305 from step S207.
Next, in step S208, the L2 port 306-1 opposite to the L2 port 305-2 that is not the extracted L2 port in the extracted L2 device 305 and the L2 device 306 are extracted. Since the L2 device 306 is an “L2 processing device”, the process proceeds from step S206 to step S209, and the connection transmission device, connection transmission port, and set VLAN ID of the port being processed are changed to the point 1 transmission device and the point, respectively. It is recorded in the transmission path design information as 1 accommodation port and point 1 path identification VLAN ID. Here, the point 1 transmission device is the transmission device 401, the point 1 accommodation port ID is the port 401-7, and the point 1 path identification VLAN ID is 200.
Next, from step S210, the transmission path design is performed using the connection transmission device, connection transmission port, and set VLAN ID of the currently extracted port as the point 2 transmission device, point 2 accommodation port, and point 2 path identification VLAN ID, respectively. Record in information. Here, the point 2 transmission device is the transmission device 405, the point 1 accommodation port ID is the port 405-2, and the point 1 path identification VLAN ID is 200.

  FIG. 8D shows VLAN design information, L2 device design information, and transmission path design information when the processing of steps S201 to S214 is completed. When the process is completed, the process end flag of the VLAN design information is recorded for all VLAN setting ports.

  FIG. 8E shows VLAN design information, L2 device design information, and transmission path design information after the processing in step S301. Here, the VLAN information in the shaded portion that is the VLAN design information of the L2 device 305 that is the “cut-through device” is deleted.

  Based on the VLAN design information, L2 device design information, and transmission path design information created by the procedure so far, network settings are performed as shown in steps S302 and S303.

  As described above, the network design method according to the present embodiment determines to cut through L2 devices that do not affect connectivity from the VLAN design that realizes multipoint connection, as in steps S102 to S111. Therefore, multipoint connection can be realized. Note that the network design apparatus of the present embodiment can also be configured by a program for causing a computer to execute each procedure of the network design method according to the present embodiment.

  Here, in the network design method according to the present embodiment, an L2 device that can be cut-through is determined by the procedure of steps S101 to 111, and the L2 device that can be cut-through by the procedure of steps S201 to S214 based on the determination information. Since the transmission path is set so as not to perform this process, it is not necessary to set the path to the access mesh point at the full mesh. Thereby, since the number of transmission paths does not increase exponentially, excess consumption of transmission paths can be prevented.

  In addition, the network design method according to the present embodiment, as in steps S102 to S111, determines that the L2 device that does not affect connectivity is to be cut through from the VLAN design that realizes multipoint connection, so that multicast Will be copied inside the network, not at the edge. This can prevent excessive consumption of the network bandwidth.

(Embodiment 2)
FIG. 9 shows a configuration of a communication network including a redundant configuration in the present embodiment. The communication network shown in FIG. 9 includes base buildings 111 to 109, L2 switches 331 to 339, L2 ports 331-1 to 4, 332-1 to 4, ... 339-1 to 4, transmission devices 431 to 438, and long. Distance transmission port 431-4-6, 432-3-4, 4333-3-4, 434-2, 3, 6, 435-3-4, 436-1, 436-2, 438-3-4, client Signal accommodating ports 431-1 to 43, 432-1 to 2, 433-1 to 2, 434-1, 4, 5, 435-1 to 2, 436-2, 437-1, 438-1 to 2, network It comprises a design device 500, an L2 network control device 600, and a transmission control device 700.

FIG. 10 shows the base configuration of the communication network shown in FIG. 9, and FIG. 11 shows the L2 logical topology of the communication network shown in FIG. The communication network shown in FIGS. 9 to 11 is a Recommendation ITU-T G.264. 8032 / Y. 1344, "Ethernet (R) Ring Protection Switching (2010/03)", Appendix XI. 3, it is assumed that a ring protection technology represented by “Access Resiliency” is used as a redundancy means, but the redundancy technology to be targeted in this embodiment is not limited to the ring protection technology, Any redundant technology that can have a plurality of redundant domains with different types of devices constituting redundancy in a redundant region completed within a certain range may be used. Examples of such redundant technologies include IEEE 802.1s "
"Multiple Spanning Tree Protocol".

  FIG. 12 shows an example of the network design apparatus of this embodiment. The network design apparatus according to the embodiment includes a network design apparatus 500, an L2 network control apparatus 600, and a transmission control apparatus 700. The network design device 500 includes an access accommodation point information input unit 501, an access accommodation point information management unit 502, a VLAN design unit 503, a network configuration information management unit 504, a cut-through design unit 505, an L2 device design information storage unit 506, and VLAN design information. The storage unit 507 includes a transmission path design information storage unit 508, a redundant configuration information management unit 509, and a redundant design information management unit 510. The L2 network control device 600 includes a VLAN setting unit 601 and a redundant function setting unit 602. The transmission control device 700 includes a transmission path route design unit 701 and a transmission path setting unit 702. Here, the function units 501 to 504 and 506 to 508 of the network design device 500 are equivalent to the functions of the first embodiment described above.

  The cut-through design unit 505 is realized by an algorithm as shown in FIGS. 13A to 13C described later, and realizes cut-through from network configuration information, L2 device design information, VLAN design information, and redundant configuration information. In addition to reflecting the design contents in the VLAN design information and the L2 device design information, redundant design information and transmission path design information are generated.

  The redundant configuration information management unit 509 holds and stores the redundant configuration information shown in FIG. The redundant configuration information is made up of redundant domain information and redundant area information. The redundant domain information is information indicating a redundant domain ID, a redundant area ID indicating a network range in which the redundant domain has a redundant configuration, and a property of the redundant domain. And the belonging device ID indicating the device group constituting the redundant domain. Here, since ring protection is assumed, information indicating the initial block port is stored as information indicating the nature of the redundant domain, but may be changed according to the redundant configuration. The redundant area information includes a redundant area ID indicating a network range having a redundant configuration and all apparatus IDs indicating all apparatuses in the redundant area. An example of redundant design information is shown in FIG. Record the redundancy area ID in which the closed network constitutes redundancy, the redundant domain to which the VLAN of the closed network belongs in the redundant area, and the ID of the L2 processing apparatus having “L2 processing apparatus” as the device attribute in the redundant area. It consists of the L2 processing device ID.

  The VLAN setting unit 601 in the L2 network control device 600 is equivalent to the function of the first embodiment described above. The redundancy function setting unit 602 has a function of performing redundancy setting for the L2 device in the L2 network based on the redundancy design information stored / held by the redundancy design information management unit 510. The transmission control device 700, and the transmission path route design unit 701 and transmission path setting unit 702, which are functional units thereof, are equivalent to the functions of the first embodiment described above.

FIGS. 13A to 13C show an example of a network design method by the network design apparatus 500 in this embodiment.
In the procedure shown in FIG. 13A, a cut-through L2 device design procedure is performed for determining an L2 device capable of cut-through based on VLAN design, redundant design, and VLAN design information.
Steps S131 to 133 are equivalent to the operations from Steps 101 to 103 of the first embodiment.
Next, based on the VLAN design information, a redundant area used by the closed network is designed and stored as redundant design information (step S134). For example, in the communication network shown in FIG. 9 to FIG. 11, if the user accommodation base is the L2 device 338, 337, the upper ring is not necessary, so only the redundant area 902 indicating the lower ring is the redundant area of the redundant design information. If the user accommodation base is L2 devices 332, 335, and 337, the redundant areas 901 and 902 are recorded in the redundant area ID of the redundant design information because both the upper and lower rings pass.
Steps S135 to S142 are equivalent to steps S104 to S111 of the first embodiment.

In the procedure shown in FIGS. 13B to 13C, a transmission path design procedure is performed.
Steps S231 to S244 shown in FIG. 13B are equivalent to the operations in steps S201 to 214 in the first embodiment.
Steps S332 to S333 are processed for all redundant areas recorded in the redundant area ID of the redundant design information (step S331).
In step S332, the device ID having the device attribute “L2 processing device” in the L2 device design information is extracted from the L2 devices in the redundant area being processed. At this time, referring to the redundant area information in the redundant configuration information stored in the redundant configuration information management unit 509, all device IDs in the redundant area may be acquired and extracted.
In step S333, one of the redundant domains in which the device ID group extracted in step S332 and the belonging device ID group completely match from the redundant domain information in the redundant configuration information is selected, and the redundant domain is set in the redundant area being processed As a table. Here, the selection method when there are a plurality of redundant domains that completely match may be any method, and may be selected from a random selection method or from the viewpoint of load distribution.
In step S334, the next redundant area is processed.

Steps S335 to S336 shown in FIG. 13C are equivalent to the operations of steps S301 and S303 of the first embodiment.
Next, based on the redundant design information, settings are made for each L2 device so that the redundant function operates in the designed redundant domain in the redundant area (step S337). As a specific setting operation, for example, an operation for allocating a VLAN of the closed network to a redundant domain can be considered. Step S338 is equivalent to the operation of step S303 of the first embodiment.

  FIG. 15 shows network configuration information stored and held in the network configuration information management unit 504 in the communication network shown in FIGS. The meanings and roles shown in each figure are the same as those in FIG. 7 described in the first embodiment.

  Next, as an example, how the network is designed when the access location information shown in FIG. 17 is input to the network design device 500 will be described with reference to FIGS. FIG. 17A shows the state of VLAN design information, L2 device design information, transmission path design information, and redundant design information when the processing up to step S134 shown in FIG. Next, FIG. 17B shows the state of VLAN design information, L2 device design information, transmission path design information, and redundant design information when the processing up to step S142 shown in FIG. . In the figure, the device attribute is determined in the L2 device design information. The device attribute is determined in the same manner as in the first embodiment. FIG. 17C shows the state of VLAN design information, L2 device design information, transmission path design information, and redundant design information when the processing up to step S244 shown in FIG. In the figure, information on the designed transmission path is recorded and held in the transmission path design information. The transmission path is designed in the same manner as in the first embodiment. FIG. 17D shows the state of VLAN design information, L2 device design information, transmission path design information, and redundant design information when the processing up to step S333 shown in FIG.

  First, in step S332, the ID of the L2 processing device in the redundant area 901 is recorded as the L2 processing device ID. In this example, the L2 devices in the redundant area 901 are 331 to 335 and 339, and those having the device attribute “L2 processing device” are 331, 332, 334, and 335. Record. Next, a redundant domain including 331, 332, 334, and 335 as a belonging device is collated with redundant domain information in the redundant configuration information. As a result, it can be seen that the redundant domain 1004 and the redundant domain 1005 are candidates. This time, the redundant domain 1005 is selected, and the selection result is recorded in the redundant domain of the redundant design information. FIG. 17E shows the state of VLAN design information, L2 device design information, transmission path design information, and redundant design information after all operations are completed.

  As described above, the network design method according to the present embodiment can be applied to a network design that realizes cut-through by appropriately selecting a redundant domain from L2 device information that is not cut-through according to the procedures of steps S331 to S332. It is possible to provide a network having fault tolerance. Note that the network design apparatus of the present embodiment can also be configured by a program for causing a computer to execute each procedure of the network design method according to the present embodiment.

  The present invention can be applied to the information communication industry.

101-109, 111-109: Base buildings 301-310, 331-339: L2 devices 301-1-3, 302-1-4, 303-1-4, ... 310-1-4, 331-1 -4, 332-1-4,... 339-1-4: L2 ports 401-407, 431-438: transmission devices 401-1-4, 402-1, 403-1, 404-1, 404- 5, 404-6, 405-1, 406-1, 407-1, 431-4-6, 432-3-4, 4333-3, 434-2, 3, 6, 435-3-4, 436-1, 436-2, 438-3-4: long-distance transmission ports 401-5-8, 402-2, 403-2, 404-2-4, 405-2, 406-2, 407-2, 431-1 to 43, 432-1 to 2, 433-1 to 2, 434-1, 4, 5, 35-1-2, 436-2, 437-1, 438-1-2: Client signal accommodation port 500: Network design device 501: Access accommodation point information input unit 502: Access accommodation point information management unit 503: VLAN design unit 504: Network configuration information management unit 505: Cut-through design unit 506: L2 device design information storage unit 507: VLAN design information storage unit 508: Transmission path design information storage unit 509: Redundant configuration information management unit 510: Redundant design information management unit 600: L2 network control device 601: VLAN setting unit 602: Redundancy function setting unit 700: Transmission control device 701: Transmission path route design unit 702: Transmission path setting unit

Claims (8)

A method for designing a data transfer path that uses a cut-through that omits a transfer process of an L2 device in a part of a communication path in an L2 network configured by a transmission device and an L2 device,
A closed network for multicast connection of user devices using network configuration information including the connection destination and connection state of each port of the L2 device, L2 device connected to the user device, and access accommodation point information including the port of the L2 device. A cut-through L2 device design procedure for generating VLAN design information in which an L2 device in which a VLAN to be configured is set is determined, and determining an L2 device to perform cut-through based on the VLAN design information;
A transmission path design procedure for designing a transmission path based on the VLAN design information so that the L2 device determined by the cut-through L2 device design procedure is cut through;
A network design method characterized by comprising in order. The VLAN design information further includes a port where the VLAN is set,
The cut-through L2 device design procedure is to determine a cut-through device for performing a cut-through when the number of ports set for the VLAN is 2 with respect to the L2 device described in the VLAN design information. The network design method according to claim 1. The VLAN design information further includes a port attribute indicating whether the connection destination of the port of the L2 device is cascade-connected, connected to a transmission device, or connected to a user device,
In the cut-through L2 device design procedure, each L2 device described in the VLAN design information has a port connected to a transmission device or a user device, or is connected in cascade and connected in cascade connection. 3. The network design method according to claim 1 or 2, wherein when a plurality of user apparatuses are determined, an L2 processing apparatus that does not perform cut-through is determined.   The transmission path design procedure is characterized in that a transmission path is designed by determining a transmission apparatus that connects between L2 apparatuses determined as L2 processing apparatuses that do not perform cut-through and a connection transmission port of the transmission apparatus. The network design method according to any one of claims 1 to 3. In the cut-through L2 device design procedure, a redundant domain including redundant region information and a redundant domain indicating a L2 device existing in a partially completed redundant region, a redundant region in which the redundant domain has a redundant configuration, and a redundant domain Using the redundant configuration information configured by information, generating redundant design information that defines a redundant area used by the closed network designed by the VLAN design information,
5. The network according to claim 1, wherein, in the transmission path design procedure, a redundant domain of an L2 device existing in the redundant area defined by the design information is determined using the redundant domain information. Design method.   In the transmission path design procedure, among a plurality of redundancy domains set in the redundancy area, a set of L2 devices that do not perform cut-through determined by the cut-through L2 device design procedure, and L2 devices that belong to the redundancy domain 6. The network design method according to claim 5, wherein the redundant domain is determined by comparing the sets of the two and selecting any one of the redundant domains including the set of L2 devices that completely match. A network design device for designing a data transfer path that uses a cut-through that omits transfer processing of an L2 device as a part of a communication route in a wide area L2 network configured by a transmission device and an L2 device,
Using network configuration information including the device ID and port ID of the L2 device to which each port of the L2 device is connected and the connection status, and access accommodation point information including the device ID and port ID of the L2 device connected to the user device A cut-through design unit that generates VLAN design information in which an L2 device in which a VLAN configuring a closed network for multicast connection of user devices is set is determined, and determines an L2 device to perform cut-through based on the VLAN design information When,
A transmission path route design unit that designs a transmission path based on the VLAN design information so that the L2 device determined by the cut through design unit is cut through;
A network design apparatus comprising: A network design program for causing a computer to execute a method of designing a data transfer path that uses a cut-through that omits transfer processing of an L2 apparatus as a part of a communication path in a wide area L2 network configured by a transmission apparatus and an L2 apparatus. And
The cut-through design unit uses the device ID and port ID of the L2 device to which each port of the L2 device is connected and the network configuration information including the connection state and the device ID and port ID and VLAN of the L2 device connected to the user device. Using the access accommodation point information including the ID, the VLAN design information in which the L2 device configuring the VLAN configuring the closed network for multicast connection of the user device is defined is generated, and cut-through is performed based on the VLAN design information Cut-through L2 device design procedure to determine L2 device;
A transmission path design procedure in which a transmission path route design unit designs a transmission path based on the VLAN design information so that the L2 device determined by the cut-through L2 device design procedure is cut through;
Network design program for causing computers to execute in order.

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