JP2004140451A - Optical switch application node and optical network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical switch application node wherein an optical switch is inserted among interfaces connected to other nodes, settings of the interfaces connection is changed toefficiently utilize the interface in response to a traffic volume of the interfaces, and the interfaces in use can be shared with the other nodes, and to provide an optical network system. <P>SOLUTION: A traffic monitor section 12 monitors the traffic of each interface and informs an interface switching processing section 11 about an interface switching request when the traffic volume of low speed interfaces IF11 to IF1n exceeds an upper limit value x1 of the low speed interfaces or the traffic volume of high speed interfaces IF11 to IF10m reaches a lower limit value x2 or below of the high speed interfaces, and the interface switching processing section 11 switches connections of an electric switch 13 and an optical switch 14 in response to the switching notice. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical switch application node composed of an electric switch and an optical switch, and an optical network system.
[0002]
[Prior art]
The spread of the Internet since the 1990s has been remarkable. Therefore, even in the process, the communication speed has been increased to a level that is incomparable with 64 kbps ISDN, such as 8 Mbps ADSL and FTTH. The so-called broadband access lines have become widespread, and metro networks that cover the area of urban areas have been developed.
[0003]
In the metro network, communication using IP (Internet Protocol) communication has been rapidly spreading recently. Therefore, high-speed and large-capacity processing is realized by connecting each node forming a network with an optical fiber. However, since the band is not basically guaranteed in the IP communication, the fluctuation of the band in the network becomes large.
[0004]
In order to improve such a problem, a network system that dynamically sets an optical path that achieves the maximum throughput in response to the fluctuation of the communication band has been considered.
[0005]
FIG. 15 shows a configuration of an optical network system using a conventional optical cross connect. In an optical network using a conventional optical cross-connect, four nodes 100 a to 100 d are connected by an optical fiber 200. The nodes 100a to 100d are connected to the packet switch 111 of the packet switch 100 and the interface 121 of the optical cross-connect 120, and input / output between the terminal 300 accommodated in the packet switch 111 and the optical network through the packet switch 111. Do. Further, a network management center 400 that collects band information of the nodes 100a to 100d and manages the optical network is installed. In this optical network, the packet switch 111 performs communication from the connected terminal 300 without requiring a declaration of a band.
[0006]
Here, it is assumed that the bandwidth sharply increases in an optical path between adjacent nodes, for example, in an optical path between the nodes 100a and 100b. That is, it is assumed that the traffic of the optical path between the node 100a and the node 100b sharply increases. The network management center 400 polls the packet switches 111 of the nodes 100a to 100d, and detects that the traffic on the optical path between the nodes 100a and 100b has sharply increased. Then, while referring to the traffic table and the optical path arrangement table on the network, the optical path is dynamically set using the path arrangement algorithm so as to maximize the network throughput. (For example, see Patent Document 1).
[0007]
[Patent Document 1]
JP 2000-232483 A
[0008]
[Problems to be solved by the invention]
In the related art, for example, when traffic between the node 100a and the node 100b sharply increases, an optical path connecting the node 100a and the node 100c is switched to a connection between the node 100a and the node 100c. As a result, two optical paths are set between the node 100a and the node 100b. However, since there is no optical path between the node 100a and the node 100c, there is a problem that when the node 100a and the node 100c perform communication, they have to go through the node 100b and the node 100d. That is, when the traffic between certain nodes increases rapidly, there is a problem that the optical path between the other nodes is deleted and the number of relay nodes increases in order to cope with the increase in the traffic. As the number of relay nodes increases, there is also a problem that the operation cost of the nodes increases.
[0009]
Further, in an optical network, it is required to set an optical path according to the transmission speed of a plurality of interfaces having different transmission speeds, to use the interfaces efficiently, and to reduce the node operation cost.
[0010]
Specifically, if a high-speed interface, for example, 10 Gbit / s Ethernet (registered trademark) is installed between nodes that exchange a large amount of traffic, a large amount of traffic can be efficiently transferred, and the operation cost of the nodes can be reduced. Is done. However, in this case, the number of high-speed interfaces must be prepared by the number of connected nodes, and there is a problem that the cost increases. In addition, since traffic greatly fluctuates with time, there is a problem in that the use efficiency is reduced even when the traffic is connected through a high-speed interface.
[0011]
The present invention has been made in view of the above, and an optical switch is inserted between interfaces connecting nodes, and the setting of the interface connection is changed according to the traffic volume of the interface to efficiently utilize and use the interface. It is an object to obtain an optical switch application node and an optical network system that can share an interface.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an optical switch application node according to the present invention has m (m> 0, m is an integer) first optical interfaces and an optical interface having the first optical speed. An electrical switch having an optical interface having a second transmission rate of n (n> 1, n is an integer) which is an optical interface having a low transmission rate, and an optical switch having (m + n) × (m + n) ports In an optical switch application node connected by an optical fiber, a traffic monitoring unit that monitors traffic of the optical interface of the first transmission rate and the optical interface of the second transmission rate in the electric switch, and a monitoring result of the traffic. An interface for changing the setting of the optical switch so as to switch the connection between the electrical switch and the optical switch based on the Characterized in that it comprises a switching unit.
[0013]
According to the present invention, the traffic monitoring unit monitors the traffic of the optical interface connecting the electrical switch and the optical switch, and the interface switching processing unit monitors the traffic based on the traffic monitoring result, that is, the traffic amount of the optical interface. By changing the setting of the switch, the connection between the electric switch and the optical switch is switched from the low-speed optical interface to the high-speed optical interface, or from the high-speed optical interface to the low-speed optical interface.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of an optical switch application node and an optical network system according to the present invention will be described below in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is a block diagram showing a basic configuration of an optical switch application node according to the present invention. The optical switch application node 10 according to the present invention includes an interface switching processing unit 11, a traffic monitoring unit 12, an electric switch 13, an optical switch 14, and optical fiber lines OF1 to OFa.
[0016]
The optical fiber lines OF1 to OFa connect two optical fibers for transmission and reception, for example, the optical fiber lines OF1 and OF2 to another optical switch applicable node 10 for performing communication between the optical switch applicable nodes 10. They are connected to form an interface IF1 between the optical switch application nodes 10. Hereinafter, the connection between the optical switch application nodes 10 will be described based on the interface of the two optical fiber lines.
[0017]
The optical switch 14 uses, for example, an optical cross connect. The optical switch 14 has ports of the optical fibers OF1 to OFa × a, and converts a signal to a predetermined output port without converting an optical signal input to an input port into an electric signal based on the setting of each port. Output.
[0018]
The electric switch 13 converts an optical signal input from the optical switch 14 into an electric signal handled by the electric switch 13, analyzes the signal, and determines an output interface. Then, the data is transferred to the determined output destination interface, converted from an electric signal to an optical signal, and transferred to the output destination interface. The electric switch 13 may be any switch having an optical interface such as an Ethernet bridge, an IP switch, and an IP router.
[0019]
The traffic monitoring unit 12 monitors traffic flowing through each port of the electrical switch 13 during communication with an adjacent optical switch application node.
[0020]
The interface switching processing unit 11 switches the connection interface between the electric switch 13 and the optical switch 14 based on the notification from the traffic monitoring unit 12.
[0021]
Examples of the optical interface include POS (PPP Over SDH / SONET or Packet Over SDH / SONET), SONET (Synchronous Optical Network), and Gigabit Ethernet (registered trademark). Since a switch is used, the type of interface is not limited to the transmission speed, and it is sufficient if interfaces having different transmission speeds can be shared.
[0022]
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 2 shows an optical network using the optical switch application node 10 according to the first embodiment. In the optical network using the optical switch application node 10 according to the first embodiment, the electrical switch 13 and the optical switch 14 can be connected by n low-speed interfaces IF11 to IF1n and m high-speed interfaces IF101 to IF10m. The optical switch application nodes 10a to 10n are connected by low-speed interfaces IF11 to IF1n.
[0023]
The interface switching processing unit 11 has a basic function of switching the connection interface between the electric switch 13 and the optical switch 14 based on the notification from the traffic monitoring unit 12, and has a low-speed interface with the adjacent optical switch application node during communication. It has an interface table that stores a communication state of whether the interface is an interface or a high-speed interface.
[0024]
The traffic monitoring unit 12 serves as a reference value for switching an interface between the electric switch 13 and the optical switch 14 in addition to a basic function of monitoring traffic flowing through each port of the electric switch 13 during communication with an adjacent optical switch application node. The upper limit value x1 of the traffic of the low-speed interface and the lower limit value x2 of the traffic of the high-speed interface are set so that the relationship of x1> x2 holds. Further, it has a table for storing the communication state of each interface similar to the interface table of the interface switching processing unit 11. This table is changed by the notification of the interface switching processing unit 11, and stores the same information as the interface table of the interface switching processing unit 11.
[0025]
Next, the switching operation of the interface between the optical switch application node 10a and the optical switch application node 10b will be described with reference to the optical switch application node 10a with reference to the flowchart of FIG. 3 and the sequence diagram of FIG.
[0026]
The optical switch application node 10a and the optical switch application node 10b start communication using the low-speed interface IF1. At this time, the interface switching processing unit 11 stores in the interface table that the optical switch application node 10a and the optical switch application node 10b are communicating with each other via the low-speed interface IF11, and also stores in the traffic monitoring unit 12 the optical switch application node. The low-speed interface IF11 notifies that the optical switch 10a and the optical switch application node 10b are communicating with each other. Upon receiving the notification, the traffic monitoring unit 12 stores in the table that the optical switch application node 10a and the optical switch application node 10b are performing communication via the low-speed interface IF11.
[0027]
The traffic monitoring unit 12 monitors the traffic of the low-speed interfaces IF11 to IF1n and the high-speed interfaces IF101 to IF10m (Step S100). Specifically, the number of packets existing in the input queue and output queue of each interface in the electric switch 13 is periodically acquired using polling, and the traffic amount x is calculated from the number of packets.
[0028]
After calculating the traffic volume x, the traffic monitoring unit 12 refers to the table and checks whether the current communication interface is a low-speed interface or a high-speed interface (step S110).
[0029]
If the communication interface between the optical switch application node 10a and the optical switch application node 10b is a low speed interface, the traffic monitoring unit 12 compares the calculated traffic amount x with the upper limit value x1 of the low speed interface (step S120). When the calculated traffic amount x is equal to or smaller than the upper limit value x1 of the low-speed interface, the traffic monitoring unit 12 continues monitoring the interface. When the calculated traffic amount x exceeds the upper limit value x1 of the low-speed interface, the traffic monitoring unit 12 notifies the interface switching processing unit 11 of the high-speed interface switching (Step S130).
[0030]
Upon receiving the notification of the high-speed interface switching, the interface switching processing unit 11 performs an interface switching process (Step S140).
[0031]
The interface switching processing will be described with reference to the sequence diagram of FIG. First, the switching start node (in this case, the optical switch application node 10a) switches the switching passive node (in this case, the optical switch application node 10b) to the switching confirmation message 21 for confirming whether switching to the high-speed interface is possible. Send
[0032]
Upon receiving the switching confirmation message 21, the switching passive node checks whether switching to the high-speed interface is possible. Specifically, the interface table is read, and it is confirmed whether one or more high-speed interfaces IF101 to IF10m are not connected. Upon confirming that the switching to the high-speed interface is possible, the switching passive node transmits a switching acceptance message 22 to the switching activation node.
[0033]
Upon receiving the switching acceptance message 22, the switching activation node transmits a switching start message 23 for notifying the switching passive node of the start of switching to the high-speed interface. Then, the settings of the electric switch 13 and the optical switch 14 are changed so that the signal flowing through the low-speed interface (in this case, the low-speed interface IF11) flows through the high-speed interface (in this case, the high-speed interface IF101). To store the communication. The interface switching processing unit 11 notifies the traffic monitoring unit 12 that the communication state of the interface table has been changed. The traffic monitoring unit 12 changes the table according to the notified change content. The switching activation node transmits a continuity confirmation message 24 for confirming whether or not the setting of the interface switching has been completed to the switching reception node until receiving the switching acceptance message 25.
[0034]
Upon receiving the switching start message 23, the switching passive node changes the settings of the electric switch 13 and the optical switch 14 so that the signal flowing through the low-speed interface flows through the high-speed interface. Then, it confirms that the communication with the switching start node has been conducted through the high-speed interface, and transmits the switching acceptance message 25.
[0035]
In this way, the optical switch application node 10a and the optical switch application node 10b switch the interface from the low-speed interface IF11 to the high-speed interface IF101 as shown in FIG.
[0036]
Since the communication is continued, the traffic monitoring unit 12 continues to monitor the traffic of each interface. Since the fact that communication is being performed through the high-speed interface is stored, the traffic monitoring unit 12 compares the traffic amount x calculated by monitoring the traffic with the lower limit value x2 of the high-speed interface (step S150). When the calculated traffic amount x is equal to or larger than the lower limit value x2 of the high-speed interface, the traffic monitoring unit 12 continues to monitor the interface. When the calculated traffic amount x is smaller than the lower limit value x2 of the high-speed interface, the traffic monitoring unit 12 notifies the interface switching processing unit 11 of the interface switching (Step S160).
[0037]
Upon receiving the notification of the low-speed interface switching, the interface switching processing unit 11 performs an interface switching process (Step S140). Specifically, the switching message for switching to the low-speed interface is transmitted to the switching passive node in accordance with the interface switching processing of the sequence diagram of FIG. 4, and the interface between the optical switch application node 10a and the optical switch application node 10b is changed to the high-speed interface. To low-speed interface.
[0038]
As described above, in the first embodiment, the traffic monitoring unit 12 monitors the traffic of each interface, and when the traffic volume of the low-speed interfaces IF11 to IF1n exceeds the upper limit x1 of the low-speed interfaces, or when the high-speed interfaces IF101 to When the traffic volume of the IF 10m becomes equal to or less than the lower limit value x2 of the high-speed interface, the interface switching processing unit 11 is notified of an interface switching request, and the interface switching processing unit 11 transmits the electric switch 13 and the optical switch in accordance with the switching notification. 14 connections are switched. That is, the interface connecting the electric switch 13 and the optical switch 14 is switched to a low-speed or high-speed interface according to the traffic amount. As a result, the interface can be used efficiently, and the cost of the optical switch application node can be reduced.
[0039]
Embodiment 2 FIG.
Second Embodiment A second embodiment of the present invention will be described with reference to FIGS. FIG. 6 shows an optical network using the optical switch application node 10 according to the second embodiment. In the optical network using the optical switch application node 10 of the second embodiment, n electrical switches 13 and 14 can be connected by k (k> 1, k is an integer) interfaces IF11 to IF1k. Optical switch application nodes 10a to 10n are connected. The interfaces IF11 to IF1k have unused interfaces (in this case, the interfaces IF11 and IFk-1) so that they can be added when the traffic fluctuates. That is, the number k of interfaces is prepared to be larger than the number n of adjacent optical switch application nodes. The interfaces IF11 to IF1k, for example, the interface IF12 is not fixedly connected to the optical switch application node 10b, but can be connected to other optical switch application nodes 10b to 10n by setting the optical switch 14. is there.
[0040]
The interface switching processing unit 11 has a basic function of switching the connection interface between the electric switch 13 and the optical switch 14 based on the notification from the traffic monitoring unit 12, and has a low-speed interface with the adjacent optical switch application node during communication. It has an interface table that stores a communication state of whether the interface is an interface or a high-speed interface.
[0041]
The traffic monitoring unit 12 has a basic function of monitoring traffic flowing through each port of the electric switch 13 during communication with an adjacent optical switch application node, and also has an upper limit y1 for adding an interface and reducing the number of interfaces. Is set so that the relationship of y1> y2 holds.
[0042]
Next, with reference to the flowchart of FIG. 7, the switching operation of the interface between the optical switch application node 10a and the optical switch application node 10b will be described focusing on the optical switch application node 10a.
[0043]
The optical switch application node 10a and the optical switch application node 10b start communication using the interface IF12.
[0044]
The traffic monitoring unit 12 monitors the traffic of the interfaces IF11 to IF1k (step S100). Specifically, the number of packets existing in the input queue and output queue of each interface in the electric switch 13 is periodically acquired using polling, and the traffic amount x is calculated from the number of packets.
[0045]
After calculating the traffic volume x, the traffic monitoring unit 12 compares the calculated traffic volume x with the upper limit y1 for adding an interface (step S210). When the calculated traffic amount x is equal to or smaller than the upper limit value y1 for adding an interface, the traffic monitoring unit 12 continues to monitor the interface. When the calculated traffic amount x exceeds the upper limit y1 for adding an interface, the traffic monitoring unit 12 notifies the interface switching processing unit 11 of the interface addition (Step S220).
[0046]
Upon receiving the notification of the interface addition, the interface switching processing unit 11 performs an interface switching process (Step S230).
[0047]
The interface switching processing will be described with reference to the sequence diagram of FIG. First, the switching start node (in this case, the optical switch application node 10a) transmits a switching confirmation message 21 to the switching passive node (in this case, the optical switch application node 10b) to confirm whether or not an interface can be added. I do.
[0048]
Upon receiving the switching confirmation message 21, the switching passive node confirms whether or not it is possible to add an interface. Specifically, the interface table is read, and it is confirmed whether one or more interfaces IF1 to IF1k are not connected. After confirming that the addition of the interface is possible, the switching passive node transmits a switching acceptance message 22 to the switching activation node.
[0049]
Upon receiving the switching acceptance message 22, the switching start node transmits a switching start message 23 for notifying the switching passive node of the start of the addition of the interface. Then, the settings of the electric switch 13 and the optical switch 14 are changed so that the signal flows to the unused interface IF11, and the fact that the interface IF11 is used is stored in the interface table. The switching activation node transmits a continuity confirmation message 24 for confirming whether the setting of the interface addition has been completed to the switching reception node until receiving the switching acceptance message 25.
[0050]
Upon receiving the switching start message 23, the switching passive node changes the settings of the electric switch 13 and the optical switch 14 so that the signal flows to the unused interface IF11. Then, it confirms that the communication with the switching start node has been conducted through the added interface IF11, and transmits the switching acceptance message 25.
[0051]
Thus, the optical switch application node 10a and the optical switch application node 10b continue communication using the unused interface IF as shown in FIG.
[0052]
Since the communication is continued, the traffic monitoring unit 12 continues to monitor the traffic of each interface. The traffic monitoring unit 12 compares the traffic amount x calculated by monitoring the traffic with the lower limit value y2 for reducing the number of interfaces (step S240). When the calculated traffic amount x is equal to or larger than the lower limit value y2 for reducing the number of interfaces, the traffic monitoring unit 12 continues monitoring the interfaces. If the calculated traffic amount x is smaller than the lower limit value y2 for interface reduction, the traffic monitoring unit 12 notifies the interface switching processing unit 11 of the interface reduction (step S250). However, when only one interface is connected to the same optical switch application node, notification of interface reduction is not performed.
[0053]
Upon receiving the notification of the interface reduction, the interface switching processing unit 11 performs an interface switching process (Step S230).
[0054]
The interface switching processing will be described with reference to the sequence diagram of FIG. First, the switching start node (in this case, the optical switch application node 10a) transmits a switching confirmation message 21 for notifying the switching passive node (in this case, the optical switch application node 10b) of the disconnection of the interface.
[0055]
Upon receiving the switching confirmation message 21, the switching passive node transmits a switching acceptance message 22 to the switching activation node.
[0056]
Upon receiving the switching acceptance message 22, the switching start node transmits a switching start message 23 for notifying the switching passive node of the start of interface reduction. Then, the setting of the electric switch 13 and the optical switch 14 is changed to disconnect the interface IF11, and the fact that the interface IF11 is unused is stored in the interface table. The switching activation node transmits a continuity confirmation message 24 for confirming whether the setting of the interface addition has been completed to the switching reception node until receiving the switching acceptance message 25.
[0057]
Upon receiving the switching start message 23, the switching passive node changes the settings of the electric switch 13 and the optical switch 14 and disconnects the interface IF11. Then, it confirms that the connection has been disconnected, and transmits a switch acceptance message 25.
[0058]
In this way, the optical switch application node 10a and the optical switch application node 10b disconnect the interface IF11 used.
[0059]
As described above, in the second embodiment, an upper limit y1 for adding an interface and a lower limit y2 for reducing an interface are set in the traffic monitoring unit 12 so that the relationship of y1> y2 holds. deep. The traffic monitoring unit 12 periodically monitors the traffic of each interface. If the traffic volume exceeds the upper limit y1, the traffic monitoring unit 12 adds an interface to the interface switching processing unit 11, and if the traffic volume is equal to or less than the lower limit y2. The interface switching processing unit 11 is notified of the interface reduction. The interface switching processing unit 11 performs switching processing for adding or reducing interfaces based on the notification from the traffic monitoring unit 12. That is, the number of interfaces connecting the adjacent optical switch application nodes is increased or decreased according to the traffic volume. Thereby, the interface of the optical switch application node can be used efficiently, and the cost can be reduced.
[0060]
Embodiment 3 FIG.
Embodiment 3 of the present invention will be described with reference to FIGS. In the second embodiment, when the traffic volume exceeds the upper limit y1 for adding an interface, the interface is added. In the third embodiment, when an interface is added, an interface that can be reduced is searched from the interfaces being used, and one interface is shared by the optical switch applicable nodes.
[0061]
The optical network using the optical switch application node 10 according to the third embodiment is the same as that shown in FIG. 6, and thus the description thereof is omitted here.
[0062]
The traffic monitoring unit 12 has a function of monitoring traffic flowing through each port of the electrical switch 13 during communication with an adjacent optical switch application node, and also has an upper limit value y1 for increasing an interface and reducing an interface. The lower limit y2 is set so that the relationship of y1> y2 holds.
[0063]
Next, referring to the flowchart of FIG. 9 and the sequence diagram of FIG. 10, the traffic of each interface is monitored, and when the traffic volume is equal to or less than the lower limit value y2, steps S200 to S250 and S230 for reducing the interface; Is greater than the upper limit y1, and there are no other interfaces to be shared. S200, S220, and S230 for adding an interface are the same as the operations in the second embodiment, and the description of the operations is omitted here.
[0064]
As shown in FIG. 8, the optical switch application node 10a and the optical switch application node 10b communicate using the interfaces IF11 and IF12, and the optical switch application node 10a and the optical switch application node 10b communicate using the interfaces IF13 and IF14. Is performed, and the optical switch application node 10a and the optical switch application node 10n perform communication using the interface IF1k. A spare interface IF1k-1 is connected to the optical switch application node 10a and the optical switch application node 10n in case traffic increases.
[0065]
In such a network state, the traffic monitoring unit 12 monitors the traffic of the interfaces IF11 to IF1k and calculates the traffic amount x (step S200). The traffic monitoring unit 12 compares the calculated traffic amount of the interface IF1k with the upper limit value y1 for adding an interface (step S210). When the traffic volume of the interface IF1k exceeds the upper limit value y1 for adding an interface, the traffic monitoring unit 12 sets the traffic volume of the other interfaces IF11 to IF1k-1 to the lower limit value y2 for reducing the interface. A comparison is made (step S300). When there is an interface having a lower limit y2 or less for reducing the number of interfaces (here, it is assumed that the interface IF11 connected to the optical switch application node 10b during communication is less than or equal to the lower limit y2 for reducing the number of interfaces. ), The traffic monitoring unit 12 notifies the interface switching processing unit 11 of interface addition and reduction (step S310). Upon receiving the notification of the interface addition, the interface switching processing unit 11 performs an interface switching process (Step S230).
[0066]
The interface switching processing will be described with reference to the sequence diagram of FIG. First, the switching start node (in this case, the optical switch application node 10a) transmits the switching confirmation message 21a that confirms the disconnection of the interface to the switching passive node 1 (in this case, the optical switch application node 10a) that reduces the interface. Then, the switch confirmation message 21b for confirming whether or not the interface can be added is transmitted to the switching passive node 2 (in this case, the optical switch application node 10n) for adding the interface.
[0067]
Upon receiving the switching confirmation message 21a, the switching passive node 1 confirms whether or not an interface can be added, and transmits a switching acceptance message 22a to the switching activation node. Further, the switching passive node 2 that has received the switching confirmation message 21b transmits a switching accepting message 22b to the switching activation node.
[0068]
Upon receiving the switching acceptance messages 22a and 22b, the switching start node sends a switching start message 23a notifying the switching passive node 1 of the start of disconnection of the interface and a switching start message 23b notifying the switching passive node 2 of the start of adding an interface. Send. Then, the settings of the electric switch 13 and the optical switch 14 are changed so that the interface IF 11 switches from the optical switch application node 10a to the optical switch application node 10n. The switching start node issues a continuity confirmation message 24a to the switching reception node 1 to confirm whether or not the disconnection of the interface has been completed, and a continuity confirmation message 24b to confirm to the switching reception node 2 whether or not the setting of the interface increase has been completed. Send
[0069]
Upon receiving the switching start message 23a, the switching passive node 1 changes the settings of the electric switch 13 and the optical switch 14 and disconnects the interface IF11. Then, it confirms that the connection has been disconnected, and transmits a switch acceptance message 25.
[0070]
Upon receiving the switching start message 23b, the switching passive node 2 changes the settings of the electric switch 13 and the optical switch 14 so that a signal flows to the unused interface IF11. Then, it confirms that the communication with the switching start node has been conducted through the added interface IF11, and transmits the switching acceptance message 25b.
[0071]
In this way, as shown in FIG. 11, the interface IF11 connecting the optical switch application node 10a and the optical switch application node 10b is connected so as to connect the optical switch application node 10a and the optical switch application node 10n. Frog.
[0072]
As described above, according to the third embodiment, when an interface is increased due to an increase in traffic, a disconnectable interface is detected from other interfaces in communication, and a disconnectable interface is detected. In, the interface is disconnected and the disconnected interface is used for an interface to be added. As a result, one interface can be shared by the optical switch application nodes, and the cost of the optical switch application node can be reduced.
[0073]
The interface to be switched may be an interface having a different transmission speed. In this case, efficient transmission of traffic can also be realized.
[0074]
Embodiment 4 FIG.
Embodiment 4 of the present invention will be described with reference to FIGS. In the first to third embodiments, each optical switch application node performs interface switching processing autonomously and decentralized. In the fourth embodiment, a management center for managing an optical switch application node connected to an optical network is provided, and the management center switches an interface for each optical switch application node by supporting an interface switching process. It is.
[0075]
FIG. 12 shows an optical network using the optical switch application node 10 according to the fourth embodiment. The optical network using the optical switch application node 10 of the fourth embodiment is connected to the optical network shown in FIG. 2 and via a management network 30 different from the optical network to which the optical switch application nodes 10a to 10n are connected. , The management center 40 and the optical switch application nodes 10a to 10n are connected.
[0076]
In the optical switch application nodes 10a to 10n, an information communication unit 15 having a function of communicating with the management center 40 in the optical switch application node 10 shown in FIG. Components having the same functions as those of the basic configuration of the optical switch application node 10 are denoted by the same reference numerals, and redundant description will be omitted.
[0077]
The interface switching processing unit 11 switches the connection interface between the electric switch 13 and the optical switch 14 based on the setting information of the optical switch from the management center 40, and operates at a low speed with the interface with the adjacent optical switch application node in communication. It has an interface table that stores a communication state of whether the interface is an interface or a high-speed interface.
[0078]
The traffic monitoring unit 12 has a basic function of monitoring traffic flowing through each port of the electric switch 13 during communication with an adjacent optical switch application node, and also requests the management center 40 to relocate an interface. The upper limit value z1 of the traffic and the lower limit value z2 of the traffic are set such that the relationship z1> z2 holds.
[0079]
The management center 40 includes an information communication unit 41, a traffic optimal distribution unit 42, an interface table 43, and a traffic information table 44.
[0080]
The information communication unit 41 communicates with the optical switch application nodes 10a to 10n via the management network 30.
[0081]
The interface table 43 stores the settings of the optical switches 14 of the optical switch application nodes 10a to 10n, that is, the connection between the electric switch 13 and the optical switch 14 and whether the connection interface is a low-speed interface or a high-speed interface. .
[0082]
The traffic information table 44 stores traffic information of the optical switch application nodes 10a to 10n.
[0083]
The traffic optimal distribution unit 42 optimally distributes the traffic of the optical switch application nodes 10a to 10n based on the interface table 43 and the traffic information table 44.
[0084]
Referring to the flowchart of FIG. 13, the case where the traffic of the low-speed interface IF11 of the optical switch application node 10a and the optical switch application node 10b exceeds the upper limit value z1 of the traffic for requesting the preset relocation of the interface. The operation of the fourth embodiment will be described by way of example.
[0085]
The traffic monitoring unit 12 of each of the optical switch application nodes 10a to 10n monitors the traffic of the communicating low-speed interfaces IF11 to IF1n and the communicating high-speed interfaces IF101 to IF10m and calculates the respective traffic amounts. The traffic amount of the low-speed interfaces IF11 to IF1n is the upper limit value z1 of the traffic for requesting the interface relocation, and the traffic amount of the high speed interfaces IF101 to IF10m is the lower limit value z2 of the traffic for requesting the interface relocation. Compare with Here, when the traffic monitoring unit 12 of the optical switch application node 10a and the optical switch application node 10b detects that the traffic volume of the low-speed interface IF11 exceeds the upper limit z1, the traffic monitoring unit 12 sends the information to the management center 40 via the information communication unit 41. An interface relocation request for notifying that the traffic volume of the low-speed interface IF11 has exceeded the upper limit z1 is transmitted.
[0086]
When receiving the interface relocation request from the optical switch application nodes 10a and 10b, the information communication unit 41 transmits the interface relocation request to the traffic optimal allocation unit 42.
[0087]
The traffic optimum distribution unit 42 requests the optical switch application nodes 10a to 10n constituting the network for traffic information (the traffic amounts of the low-speed interfaces IF11 to IF1n and the high-speed interfaces IF101 to IF10m), and the optical switch application node 10a The traffic information is acquired from the traffic monitoring units 12 to 10n (step S410).
[0088]
When the traffic information of the optical switch application nodes 10a to 10n is acquired, the traffic optimal distribution unit 42 stores the acquired traffic information in the traffic information table 44. Then, a traffic optimal distribution process is performed (step S420). Specifically, based on the interface table 43 and the traffic information table 44, a calculation process for optimally allocating traffic is performed, and an optimum interface arrangement is determined while comparing the calculation result with the interface table 33.
[0089]
As a result of the determined arrangement, when switching the low-speed interface IF11 between the optical switch application node 10a and the optical switch application node 10b (step S430), the traffic optimal distribution unit 42 transmits the information via the information communication unit 41 to the optical switch application node 10a, The setting information for changing the setting of the optical switch 14 and the arrangement information of the interface are transmitted to 10b (step S440).
[0090]
Upon receiving the setting information for changing the setting of the optical switch 14 from the management center 40, the interface switching processing unit 11 of the optical switch application nodes 10a and 10b communicates with the electric switch 13 and the optical switch 13 according to the interface switching processing in the sequence of FIG. The setting of the switch 14 is updated. At this time, since the arrangement information of the interface has been notified from the management center 40, the transmission may be started from the transmission of the switching start message 23.
[0091]
In this way, as shown in FIG. 14, the connection between the optical switch application node 10a and the optical switch application node 10b is switched from the low speed interface IF11 to the high speed interface IF101.
[0092]
If the connection is made by any of the high-speed interfaces IF101 to IF10m and the traffic volume becomes equal to or less than the lower limit value z2 of the traffic for requesting the relocation of the interface, the management center 40 and the optical switch application node 10a Since the operations of 10 to 10n are the same, the description is omitted here.
[0093]
As described above, in the fourth embodiment, the traffic monitoring unit 12 of the optical switch application nodes 10a to 10n monitors the traffic and compares the traffic with the upper limit z1 or the lower limit z2 of the traffic for requesting the relocation of the interface. When it is determined that the interface needs to be switched, an interface relocation request is transmitted to the management center 40. Upon receiving the interface relocation request, the traffic optimal distribution unit 42 of the management center 40 acquires the traffic information from the optical switch application nodes 10a to 10n, and based on the traffic information and the communication state of the optical switch application nodes 10a to 10n. Then, the setting information for changing the setting of the optical switch 14 is transmitted to the optical switch application node to be switched to the interface by allocating the traffic so as to optimize the traffic. The interface switching processing unit 11 of the optical switch applicable node that has received the setting information switches the interface based on the setting information. That is, the interface of the entire network is managed by the management center 40, and the interface is switched between the optical switch applicable nodes in conjunction with the traffic. Thus, the number of interfaces can be reduced by using the network efficiently, and the cost of the optical switch application node can be reduced.
[0094]
In the fourth embodiment, the case where the interface connecting the electric switch 13 and the optical switch 14 is switched to the low-speed or high-speed interface according to the traffic volume has been described. In the case where the number of interfaces connecting the optical switch is increased or decreased, the management center 40 manages the interface of the entire network even if one interface is shared by each optical switch application node, and the number of interfaces between the optical switch application nodes linked with the traffic is increased. Can be switched.
[0095]
【The invention's effect】
As described above, according to the optical switch application node according to the present invention, the traffic monitoring unit monitors the traffic of the optical interface connecting the electrical switch and the optical switch, and the interface switching processing unit monitors the traffic monitoring result. That is, the setting of the optical switch is changed based on the traffic volume of the optical interface, and the connection between the electric switch and the optical switch is changed from the low-speed optical interface to the high-speed optical interface, or from the high-speed optical interface to the low-speed optical interface. , The interface can be used efficiently, and the cost of the optical switch application node can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration of an optical switch application node according to the present invention.
FIG. 2 is a diagram illustrating a configuration of an optical network using an optical switch application node according to the first embodiment.
FIG. 3 is a flowchart illustrating an operation of the optical switch application node according to the first embodiment;
FIG. 4 is a sequence diagram illustrating an interface switching process.
FIG. 5 is a diagram illustrating a configuration of an optical network after an interface switching process according to the first embodiment.
FIG. 6 is a diagram illustrating a configuration of an optical network using an optical switch application node according to a second embodiment.
FIG. 7 is a flowchart illustrating an operation of an optical switch application node according to the second embodiment;
FIG. 8 is a diagram illustrating a configuration of an optical network after an interface switching process according to the second embodiment.
FIG. 9 is a flowchart illustrating an operation of an optical switch application node according to the third embodiment;
FIG. 10 is a sequence diagram illustrating an interface switching process according to the third embodiment;
FIG. 11 is a diagram illustrating a configuration of an optical network after an interface switching process according to a third embodiment.
FIG. 12 is a diagram illustrating a configuration of an optical network according to a fourth embodiment.
FIG. 13 is a flowchart illustrating an operation of the optical switch application node according to the fourth embodiment.
FIG. 14 is a diagram illustrating a configuration of an optical network after an interface switching process according to a fourth embodiment.
FIG. 15 is a diagram illustrating a configuration of an optical network system using a conventional optical cross connect.
[Explanation of symbols]
10, 10a, 10b, 10c, 10d Optical switch application node, 11 interface switching processing unit, 12 traffic monitoring unit, 13 electric switch, 14 optical switch, 21, 21a, 21b Switching confirmation message, 22, 25, 25a, 25b Switching Reception message, 23, 23a, 23b switching start message, 24, 24a, 25b continuity confirmation message, 30 management network, 40 management center, 41 information communication unit, 42 traffic optimal distribution unit, 43 interface table, 44 traffic information table, 100a, 100b, 100c, 100d nodes, 111 packet switches, 112 switch controllers, 120 optical cross-connects, 121 interfaces, 300 terminals, 200 optical fibers, 400 network management centers.

Claims (14)

m (m> 1, m is an integer) optical interfaces of the first transmission rate and n (n> 1, n is an integer) an optical interface of a transmission rate lower than the optical interface of the first transmission rate A) an optical switch having an optical interface having a second transmission rate and an optical switch having an optical switch having (m + n) × (m + n) ports connected by an optical fiber.
A traffic monitoring unit that monitors traffic of the optical interface of the first transmission rate and the optical interface of the second transmission rate in the electrical switch;
An interface switching processing unit that changes a setting of the optical switch so as to switch a connection between the electric switch and the optical switch based on a result of monitoring the traffic,
An optical switch application node, comprising: The traffic monitoring unit,
An upper limit of traffic is set in advance for each of the n optical interfaces of the second transmission rate, and the result of monitoring the traffic of the optical interface of the second transmission rate is compared with the upper limit of the traffic. When the traffic monitoring result exceeds the upper limit value of the traffic, the interface switch processing unit connects the electrical switch and the optical switch with each other from the optical interface of the second transmission rate to the optical transmission of the first transmission rate. Notify the request to switch to the interface,
The interface switching processing unit,
Setting the optical switch based on the request to switch the connection between the electrical switch and the optical switch from the optical interface at the second transmission rate to the optical interface at the first transmission rate; The optical switch application node according to claim 1, wherein the setting of the optical switch is changed so as to switch from an interface to an optical interface of the first transmission rate. The traffic monitoring unit,
A lower limit of traffic is set in advance for each of the m optical interfaces of the first transmission rate, and the result of monitoring the traffic of the optical interface of the first transmission rate is compared with the lower limit of the traffic. When the traffic monitoring result falls below the lower limit value of the traffic, the interface switch processing unit switches the connection between the electric switch and the optical switch from the optical interface having the first transmission rate to the second transmission rate. Notify the request to switch to the optical interface,
The interface switching processing unit,
Setting the optical switch based on the request to switch the connection between the electrical switch and the optical switch from the optical interface at the first transmission rate to the optical interface at the second transmission rate; The optical switch application node according to claim 1, wherein the setting of the optical switch is changed so as to switch from an interface to an optical interface of the second transmission rate. The traffic monitoring unit,
A lower limit value of traffic for each of the m optical interfaces of the first transmission rate and an upper limit value of traffic for each of the n optical interfaces of the second transmission rate; Comparing the traffic monitoring result of the optical interface with the upper limit value of the traffic, and if the monitoring result exceeds the upper limit value of the traffic, the traffic monitoring result of the optical interface at the first transmission rate indicates the lower limit of the traffic. An optical interface of the first transmission rate which is lower than the value is detected, and the interface switching processing unit transmits an optical interface of the first transmission rate from the optical interface of the second transmission rate exceeding the upper limit of the traffic. A request for switching to an interface and the detected optical interface of the first transmission rate from the optical interface of the second transmission rate. Notifies the request to switch to the face,
The interface switching processing unit,
Changing the setting of the optical switch so that the connection of the optical interface of the second transmission rate whose monitoring result of the traffic exceeds the upper limit value and the connection of the detected optical interface of the first transmission rate are switched. The optical switch application node according to claim 1, wherein: In an optical switch application node in which k (k> 1, k is an integer) optical switches having optical interfaces of the same transmission rate and optical switches having k × k ports are connected by optical fibers,
A traffic monitoring unit that monitors traffic of the optical interface in the electric switch;
An interface switching processing unit that adds and / or reduces the connection between the electric switch and the optical switch based on a result of monitoring the traffic;
An optical switch application node, comprising: The traffic monitoring unit,
An upper limit of traffic is set in advance for each of the k optical interfaces, and a result of monitoring the traffic of the optical interface is compared with the upper limit of the traffic, and the result of monitoring the traffic sets the upper limit of the traffic. If exceeded, notify the interface switching processing unit of a request to increase the connection between the electrical switch and the optical switch,
The interface switching processing unit,
The optical switch application node according to claim 5, wherein the setting of the optical switch is changed based on a request for increasing the connection between the electric switch and the optical switch. The traffic monitoring unit,
A lower limit value of traffic is set in advance for each of the k optical interfaces, and the monitoring result of the traffic of the optical interface is compared with the lower limit value of the traffic so that the monitoring result of the traffic is lower than the lower limit value of the traffic. If the number has decreased, and if two or more optical interfaces are connected to the same connection destination on the network by the optical switch, the interface switching processing unit reduces the connection between the electric switch and the optical switch. Notify the request,
The interface switching processing unit,
The optical switch application node according to claim 5, wherein a setting of the optical switch is changed based on a request to reduce a connection between the electric switch and the optical switch. The traffic monitoring unit,
An upper limit value and a lower limit value of the traffic are preset for each of the k optical interfaces, and the monitoring result of the optical interface is compared with the upper limit value of the traffic, and the monitoring result is the upper limit value of the traffic. Exceeds the lower limit, the traffic monitoring results of the optical interfaces other than the optical interface that was compared with the upper limit are lower than the lower limit of the traffic, and two switches are connected to the same connection destination on the network by the optical switch. The optical interface to which the above optical interface is connected is detected, and a request to reduce the detected optical interface and a request to add an optical interface exceeding the upper limit of the traffic are notified to the interface switching processing unit,
The interface switching processing unit,
Setting the optical switch to switch an optical interface required to reduce the connection between the electrical switch and the optical switch to an interface required to increase the connection between the electrical switch and the optical switch; The optical switch application node according to claim 5, wherein the node is changed. An optical network to which a plurality of optical switch application nodes are connected, and an optical network in which the plurality of optical switch application nodes are connected to a management center in a management network different from the optical network to which the plurality of optical switch application nodes are connected In network systems,
The optical switch application node,
m (m> 1, m is an integer) optical interfaces of the first transmission rate and n (n> 1, n is an integer) an optical interface of a transmission rate lower than the optical interface of the first transmission rate A) an electrical switch having an optical interface of a second transmission rate;
An optical switch having (m + n) × (m + n) ports and outputting an optical signal from an input port to an output port;
A traffic monitoring unit that monitors traffic of the optical interface of the first transmission rate and the optical interface of the second transmission rate in the electric switch and requests the management center to optimally distribute traffic based on the result;
An interface switching processing unit that changes the setting of the optical switch so as to switch the connection between the electric switch and the optical switch based on the notification of the optimal distribution result from the monitoring center,
With
The management center,
When a request for optimal distribution of traffic is received from the optical switch application node, the traffic state of all the optical switch application nodes connected to the optical network is obtained and the traffic is optimally distributed. A traffic optimal distribution unit that notifies the optical switch application node of an optimal distribution result when changing to node connection;
An optical network system comprising: The traffic monitoring unit,
An upper limit of traffic is set in advance for each of the n optical interfaces of the second transmission rate, and the result of monitoring the traffic of the optical interface of the second transmission rate is compared with the upper limit of the traffic. When the traffic monitoring result exceeds the upper limit value of the traffic, a request for optimal distribution of traffic is made to the monitoring center,
The traffic optimal distribution unit,
The interface switch processing unit sets the optical switch based on a request to switch a connection between the electric switch and the optical switch from the optical interface at the second transmission rate to the optical interface at the first transmission rate. 10. The optical network system according to claim 9, wherein an optimum allocation result for changing a setting of the optical switch is switched so as to switch from the optical interface having the second transmission rate to the optical interface having the first transmission rate. The traffic monitoring unit,
A lower limit of traffic is set in advance for each of the m optical interfaces of the first transmission rate, and the result of monitoring the traffic of the optical interface of the first transmission rate is compared with the lower limit of the traffic. When the traffic monitoring result falls below the lower limit of the traffic, the monitoring center issues a request for optimal distribution of traffic,
The traffic optimal distribution unit,
Setting the optical switch based on a request to switch the connection between the electrical switch and the optical switch from the optical interface at the first transmission rate to the optical interface at the second transmission rate in the interface switching processing unit; The optical network according to claim 9 or 10, wherein an optimal allocation result for changing a setting of the optical switch so as to switch from an optical interface having the first transmission rate to an optical interface having the second transmission rate is notified. system. An optical network to which a plurality of optical switch application nodes are connected, and an optical network in which the plurality of optical switch application nodes and a management center are connected in a management network different from an optical fiber to which the plurality of optical switch application nodes are connected. In network systems,
k (k> 1, k is an integer) optical switches having optical interfaces of the same transmission rate;
an optical switch that has k × k ports and outputs an optical signal from an input port to an output port;
A traffic monitoring unit that monitors traffic of an optical interface in the electric switch and requests the management center for optimal distribution of traffic based on a result of the monitoring;
An interface switching processing unit that changes the setting of the optical switch so as to switch the connection between the electric switch and the optical switch based on the notification of the optimal distribution result from the monitoring center,
With
The management center,
When the interface switching processing unit receives a request for optimal distribution of traffic from the optical switch application node, the traffic state of all the optical switch application nodes connected to the optical network is obtained and traffic is optimally distributed. As a result, when changing to the connection of the optical switch application node, a traffic optimal allocation unit that notifies the optical switch application node of an optimal allocation result,
An optical network system comprising: The traffic monitoring unit,
An upper limit of traffic is set in advance for each of the k optical interfaces, and a result of monitoring the traffic of the optical interface is compared with the upper limit of the traffic, and the result of monitoring the traffic sets the upper limit of the traffic. If it exceeds, a request is made to the monitoring center for optimal distribution of traffic,
The traffic optimal distribution unit,
13. The optical network system according to claim 12, wherein an optimum distribution result for increasing the connection between the electric switch and the optical switch is notified. The traffic monitoring unit,
A lower limit of traffic is set in advance for each of the k optical interfaces, and a result of monitoring the traffic of the optical interface is compared with the lower limit of the traffic, and the result of monitoring the traffic is lower than the lower limit of the traffic. If the number has dropped, and if two or more optical interfaces are connected to the same connection destination on the network by the optical switch, the monitoring center issues a request for optimal distribution of traffic,
The traffic optimal distribution unit,
14. The optical network system according to claim 12, wherein the interface switching processing unit is notified of an optimal distribution result for reducing the connection between the electric switch and the optical switch.

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