JP2005323185A - Optical network and its controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical network capable of easily configuring and extending a network at a low cost. <P>SOLUTION: In the optical IP network, a main router 20a and a plurality of general routers 22a are coupled annularly by optical fibers 24, and the main network is coupled with an upper network through the main router 20a. In the optical IP network, the main router 20a has an upper optical interface 204 and a main optical interface 201a connected to the upper network and the main network respectively and mutually converting a light signal and an electric signal, and a main-layer 3 switch 202a controlling the transmission and reception of the electric signal between the upper optical interface 204 and the main optical interface 201a. In the optical IP network, the general router 22a has a general optical interface 201a being connected to the main network and mutually converting the light signal and the electric signal, and the main-layer 3 switch 202a conducts the routing of a packet on the basis of a static routing information. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical network and a control device thereof.

  In order to advance IT, a wide range of optical fiber networks are expected to be introduced, and a method for constructing such an optical network is being studied. For example, Patent Document 1 discloses a ring-type optical network for flexibly responding to system expansion and change.

  As shown in FIG. 37, the optical network 60 includes a plurality of ring networks 64 in which a plurality of collection nodes 62 are connected in a ring shape, and the ring networks 64 are connected by a connection node 66. As a specific configuration of the collection node 62, an ADM (multiplexer) connected to a transmission device (TDM, router, PBX) to an individual network is provided, and the connection node 66 can be replaced with the collection node 62. Configured.

The optical network 60 configured as described above is configured so that each collection node 62 can cope with multiplexed optical signals by using a WDM (Wavelength Division Multiplexing) technique, that is, a technique for multiplexing and transmitting optical signals having different wavelengths. It is possible to collect an optical signal having a wavelength to be selected.
JP 2001-230794 A (page 4-7, FIG. 4)

  According to the above-described conventional optical network, the wavelength of the optical signal corresponding to each collection node 62 must be different between the different ring networks 64. Therefore, as the network is expanded, the ADM included in each collection node 62 is provided. It is necessary to improve the wavelength separation accuracy. However, when such a high-precision ADM is used, the cost for constructing the network is high, which may hinder the widening of the optical network.

  For example, in the case of the CWDM (Coarse WDM) system, the set wavelength interval is as wide as 20 nm, and eight wavelengths of 1470 to 1610 nm are generally used in the 1500 nm band, so the number of collection nodes 62 that can be installed is limited. However, in the case of the DWDM (Dense WDM) method, which has a narrower wavelength interval than the CWDM method, it is difficult to introduce a wide range of optical networks. Although it is possible to set it as the above, installation cost becomes high significantly.

  The present invention has been made to solve such problems, and aims to provide an optical network capable of easily and inexpensively constructing and expanding a network. Further, the present invention provides communication quality in the optical network. It is an object of the present invention to provide a control device that can prevent deterioration.

  The object of the present invention is an optical IP network in which a main router and a plurality of general routers are coupled in a ring shape by optical fibers to form a main network, and the main network is coupled to an upper network through the main router. The main router is connected to the upper network and the main network, respectively, and converts an optical signal and an electric signal between the upper optical interface and the main optical interface, and an electric signal between the upper optical interface and the main optical interface. A main layer 3 switch that controls transmission and reception, the general router includes a general optical interface that is connected to the main network and converts between an optical signal and an electrical signal, and the main layer 3 switch is a static Based on routing information It is achieved by an optical network for routing packets Te.

In addition, the object of the present invention is to form a main network by connecting a main router and a plurality of general routers in a ring shape by at least double optical fibers including a service ring and a control ring, and the main network is the main network. An optical IP network coupled to an upper network through a router,
The main router and the general router include a layer 3 switch and a wavelength-designated optical transceiver connected to a port of the layer 3 switch, and a wavelength multiplexed optical signal is carried in the service ring, and the control The ring includes a control device connected to the main router or a general router in an optical network in which a wavelength control signal is carried, the wavelength included in the wavelength multiplexed optical signal carried in the service ring, and the wavelength Each layer 3 based on the WDM table indicating the correspondence with the ports of the main router or the general router in which communication is performed according to the routing information collected from the routing table provided in the layer 3 switch and the information in the WDM table. A port base that indicates the link state between the switch ports by the specified wavelength. It is achieved by a control device and a logical link information generation unit for generating a logical link matrix information.

  According to the optical network of the present invention, it is possible to easily and inexpensively construct and expand the network. Also, according to the control device of the present invention, it is possible to prevent the deterioration of communication quality in this optical network.

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

(Basic configuration)
FIG. 1 is a schematic diagram for explaining a basic configuration of an optical network according to the present invention. As shown in FIG. 1, this optical network includes a node router 10 as a main switching device and edge routers 12 and 12 as a plurality of sub-switching devices coupled in a ring shape by a single mode (SM) optical fiber. Distribution ring D provided.

  The node router 10 is connected to a feeder ring F that is an optical ring higher than the distribution ring D, and each edge router 12 is connected to an access ring A that is an optical ring lower than the distribution ring D. It is connected. A plurality of user IFs (user interfaces) 14 are connected to the access ring A. The feeder ring F, the distribution ring D, and the access ring A are all configured by 0-system and 1-system double optical fiber rings, and each ring length is, for example, 100 to 300 km, 10 to 100 km, 30 km or less.

  FIG. 2 is a partial configuration diagram of the optical network shown in FIG. As shown in FIG. 2, a main router 20 and a plurality of general routers 22, 22,..., 22 are connected to 0-system and 1-system duplex optical fiber rings 24,. The main router 20 corresponds to the node router 10 or the edge router 12 in the configuration shown in FIG. 1. When the main router 20 is the node router 10, the general router 22 corresponds to the edge router 12, while the main router 20 When 20 is the edge router 12, the general router 22 corresponds to the user IF 14.

  As shown in FIG. 2, each of the main router 20 and the general router 22 includes optical IFs (optical interfaces) 201-0 and 201-1 and layer 3 switches 202-0 and 202-1 each having a double optical ring. 24 and 26 are provided. Transmission of the optical signal in the optical rings 24 and 26 is performed between the optical IFs 201-0 mainly using the 0 system, and the third layer of the OSI (Open System Interconnection) reference model by the layer 3 switch 202-0. Is routed at the network layer. The optical IF 201-0 is a product that mutually converts an electrical signal and an optical signal. For example, a 1000Base-LX standard optical transceiver (OTR: Optical Transceiver) or a coupler or splitter that multiplexes and demultiplexes light of different wavelengths. Combinations can be used. The operation of the layer 3 switches 202-0 and 202-1 of the main router 20 and the general router 22 is controlled by the controller 30. Control of the controller 30 will be described later.

  In the above-described optical network, traffic for which a direct link is established at one wavelength by wavelength multiplexing is classified. That is, the traffic inside the optical rings 24 and 26 is classified into hub traffic, all-to-all traffic, and one-by-one traffic as shown in FIG. The hubd traffic is traffic that communicates with an upper optical ring (for example, feeder ring F when the main router 20 is the node router 10 shown in FIG. 1) via the main router 20. All-To-All traffic is traffic communicated between the general routers 22. One-By-One traffic is traffic that communicates between the main router 20 and the adjacent general router 22 or between the two adjacent general routers 22 and 22. Therefore, the traffic between the main router 20 and the general router 22 adjacent to the main router 20 becomes both hubd traffic and one-by-one traffic. Also, since One-By-One traffic can be transmitted with one wavelength, this wavelength is referred to as an All-By-One wavelength.

(First embodiment: WDS1 network)
FIG. 4 is a partial configuration diagram showing an optical network (WDS1 network) according to the first embodiment of the present invention (WDS is an abbreviation for WDM with Distributed Switching). The configuration shown in FIG. 4 corresponds to FIG. 2 of the basic configuration described above, and corresponds to either distribution ring D or access ring A in FIG. This also applies to the following embodiments.

  As shown in FIG. 4, the main router 20a and the plurality of general routers 22a, 22a,..., 22a are connected to the optical ring 24 (only the 0-system optical ring is shown in FIG. 4). The main network is configured.

  The main router 20a and the general router 22a include an OTR (optical transceiver) 201a and a layer 3 switch 202a, which are optical IFs, respectively. The OTR 201a of the main router 20a is a main optical interface connected to the main network, and the OTR 201a of the general router 22a is a general optical interface connected to the main network.

  The main router 20a is connected to the upper optical ring (for example, feeder ring F when the main router 20a is the node router 10 in FIG. 1) via the upper optical interface 204. A layer 3 switch (main layer 3 switch) 202a is interposed between the OTR 201a and the OTR 201a. Each general router 22a is connected to a lower optical ring (for example, access ring A when the general router 22a is the edge router 12 in FIG. 1) via the lower optical interface 205.

  The configuration of the layer 3 switch 202a in the main router 20a or the general router 22a is shown in FIG. The layer 3 switch 202a includes an upper port 2021a and a lower port 2022a, and further includes a routing table 2023a, an ARP (Address Resolution Protocol) table 2024a, and a MAC (Media Access Control) address table 2025a. In the case of a layer 3 switch installed in the main router, the upper port 2021a is connected to the upper optical interface 204, and the lower port 2022a is connected to an OTR (main optical interface) 201a. When installed in the general router 22a, the upper port 2021a is connected to the OTR 201a, and the lower port 2022a is connected to the lower optical interface 205.

  The routing table 2023a is a table for determining an address (next hop) as a next destination of a packet based on a destination network address (D-NA). The specific contents differ depending on whether the router in which the routing table 2023a is installed is the node router 10, the edge router 12, or the user IF 14. An example of the routing table 2023a is shown in FIG.

  Information for transmitting a packet to a transmission destination determined based on the routing table 2023a is set in the ARP table 2024a and the MAC address table 2025a. The ARP table 2024a is a table showing the correspondence between IP (Internet Protocol) addresses and MAC addresses, and the MAC address table 2025a is a table showing the correspondence between MAC addresses and output ports. The specific contents of the ARP table 2024a and the MAC address table 2025a also differ depending on whether the router in which they are installed is the node router 10, the edge router 12, or the user IF 14. An example of the ARP table 2024a and the MAC address table 2025a is shown in FIGS. 7 and 8, respectively.

  In the present embodiment, the administrator himself / herself stores routing information to nodes located at lower levels in each node (node router 10, edge router 12 or user IF 14) in the routing table 2023a, ARP table 2024a, and MAC address table 2025a. It is explicitly set in advance, and static routing is performed in which packets are transmitted according to this routing information. For IP addresses other than those described above, dynamic routing is performed based on ARP (Address Resolution Protocol) and an address learning function.

  According to the optical network configured as described above, an optical signal input from the upper optical ring to the main router 20 is converted into an electrical signal in the upper optical interface 204, and then routed in the layer 3 switch 202a. It is transported toward the upper optical ring or optical ring 24. The signal directed to the optical ring 24 is converted again into an optical signal in the OTR 201a, and flows through the optical ring 24 in one direction.

In the general router 22a, the passing optical signal is converted into an electric signal in the OTR 201a, and the destination network address (D-NA) given to the header of each packet is extracted in the layer 3 switch 202a. The D-NA is compared with the network address described in the routing table 2023a, and if there is a match, the IP address as the corresponding next hop in the table can be obtained. In the example of FIG. 5, D−NA = NA _k . Thereafter, the MAC address corresponding to the IP address can be acquired from the ARP table 2024a, and the corresponding port information can be acquired from the MAC address table 2025a. In the case of FIG. 5, the port 2022a corresponds to this. If the D-NA of the extracted packet does not match the network address described in the routing table 2023a, the MAC address of the destination specified as the default route is acquired as shown in FIG. Sent to the specified port. In this manner, all packets can be routed from the data described in the three tables 2023a, 2024a, and 2025a.

  In this way, if the transmitted packet is directed to the corresponding lower ring, it is conveyed to the lower ring, whereas if it is not directed to the corresponding lower ring, it is converted again to an optical signal in the OTR 201a. , Transmitted to the adjacent general router 22a on the optical ring 24. The transmission of traffic can be performed using a single wavelength (All-By-One wavelength) for all transmission destinations in the optical ring 24.

  As described above, the information shown in FIG. 6 is static routing explicitly described by the administrator. 7 and 8, the administrator explicitly describes the item described as static in the section, and packet transfer between routers is possible according to this content as described above. On the other hand, for items other than the above described as dynamic in the category column, data is automatically acquired by the ARP and address learning function, which are well-known functions implemented in the layer 3 switch.

  The optical network according to the present embodiment can be easily constructed with a simple configuration, and is suitable for transmission of One-By-One traffic (see FIG. 3) when the number of users is small. The provision of broadband communication by optical fiber is a problem of high cost, and the cost per user is high particularly in a region where the number of users is small. The WDS1 network is the simplest configuration in which a plurality of users share one optical ring, and can provide an extremely economical solution. For example, if 1000Base-LX is used for the OTR, a single optical fiber ring can guarantee a bandwidth of 100 Mbps for 10 users and a bandwidth of 10 Mbps for 100 users.

(Second embodiment: WCS network)
FIG. 9 is a partial configuration diagram showing an optical network (WCS network) according to the second embodiment of the present invention (WCS is an abbreviation of WDM with Central Switching). As in the first embodiment, FIG. A router 20 b and a plurality of general routers 22 b, 22 b,..., 22 b are connected to the optical ring 24. The main router 20b is connected to the upper optical ring via the upper optical interface 204, and each general router 22b is connected to the lower optical ring via the lower optical interface 205, respectively.

Different wavelengths λ _{1 to} λ _n are assigned to the respective general routers 22b in the present embodiment. In this way, the wavelength allocated so as to establish a direct link between each general router and the main router is called a hubd wavelength. The hubded wavelengths λ _{1 to} λ _n have different wavelengths from, for example, 8 waves (1470, 1490, 1510, 1530, 1550, 1570, 1590, and 1610 nm) at 20 nm intervals specified in low density wavelength division multiplexing (CWDM). You can select and set.

The general router 22b includes an ADM (Add / Drop Module) 210b that is an optical IF and a wavelength designation OTR 211b. The ADM 210b adds / drops one of the optical signals of the hub wavelengths λ _{1 to} λ _n individually set for each general router 22b, and uses, for example, an existing product having a wavelength-dependent optical filter. can do. The wavelength designation OTR 211b is an OTR that mutually converts an optical signal having a predetermined wavelength and an electrical signal, and matches each designated wavelength with the hubred wavelengths λ _{1 to} λ _n of each general router 22b. .

The main router 20b includes a signal conversion device 220b that is an optical IF and a layer 3 switch 202b. The signal conversion device 220b includes a plurality of wavelength designation OTRs 221b corresponding to the hubded wavelengths λ _{1 to} λ _n of each general router 22b, a coupler 222b that multiplexes optical signals of a plurality of different wavelengths, and a wavelength multiplexed optical signal. Splitter 223b. For the coupler 222b and the splitter 223b, for example, an existing product having a wavelength-dependent optical filter can be used.

  As shown in FIG. 10, the layer 3 switch 202b included in the main router 20b includes an upper port 2021b and a lower port 2022b, and further includes a routing table 2023b, an ARP table 2024b, and a MAC address table 2025b. The contents of the routing table 2023b, the ARP table 2024b, and the MAC address table 2025b differ depending on whether the router in which they are installed is the node router 10 or the edge router 12, and the administrator explicitly sets in advance. Examples of the routing table 2023b, the ARP table 2024b, and the MAC address table 2025b are shown in FIGS. 11, 12, and 13, respectively.

FIG. 10 shows the layer 3 switch 202b provided in the edge router. When there is a user IF _{k in the} connected access ring and the network address of this user is NA _u-IFk , the layer 3 switch 202b sequentially determines whether the destination of the packet is NA _u-IFk , If applicable, the data is transferred to the lower port 2022b corresponding to the wavelength. On the other hand, if all of them are not applicable, the data is transferred to the upper port 2021b. The routing table 2023b, ARP table 2024b, and MAC address table 2025b are set so that such a determination can be made. The details are the same as described for FIGS. 6-8 for the WDS1 network. However, in the case of the WCS network shown in FIG. 9, since the layer 3 switch is installed only in the main router, there is no user IF. Therefore, in the case of the layer 3 switch of the edge router, in _order to transfer to the network address NA _u-IFk of the corresponding user, the next hop is the address of the user-owned router or the direct routing directly transferred to the user terminal. .

When the layer 3 switch 202b is installed in the node router, the above procedure is established as it is if NA _u-IFk is changed to NA _ARk in FIG. Here, NA _ARk indicates the network addresses of all users on the access ring connected to the edge router k on the ring. When forwarding to NA _ARk , the user-owned router is directly set as the next hop, or the edge router is set as the next hop. In the latter case, the transfer from the edge router to the user is left to the edge router. As described above, also in the present embodiment, as in the first embodiment, routing of packets is performed by static routing.

According to the optical network configured as described above, an optical signal input from the upper optical ring to the main router 20b is converted into an electrical signal by the upper optical interface 204, and then passes through the layer 3 switch 202b to be a signal conversion device. In 220b, it becomes a wavelength multiplexed optical signal and is conveyed to the optical ring 24. That is, in the layer 3 switch 202b, the electrical signal relayed to any one of the wavelength designation OTRs 221b that is the destination is converted into an optical signal having the same wavelength as the designated wavelengths λ _{1 to} λ _{n of the} wavelength designation OTR 221b, The optical signal from the designated OTR 221b and the coupler 222b are combined.

When a wavelength multiplexed optical signal carried in one direction through the optical ring 24 is input to the ADM 210b in the general router 22b, an optical signal having a designated wavelength among the wavelengths λ _{1 to} λ _n is taken in and the corresponding wavelength is received. Optical signals of other wavelengths are input to the designated OTR 211b and pass through. The wavelength designation OTR 211b converts the input optical signal into an electrical signal and transmits it to the lower ring or directly to the user.

The packet transfer in the main router 20b is performed based on the routing table 2023b, the ARP table 2024b, and the MAC address table 2025b in the layer 3 switch 202b, and only the packet signal addressed to the lower network via the main router 20b is transmitted. The optical ring 24 is conveyed. Therefore, since the hubed wavelengths λ _{1 to} λ _n having the same wavelength as described above can be used for the subordinate network to the other main router 20b, the expandability of the optical network can be improved.

On the other hand, the electrical signal input to the wavelength designation OTR 211b in any one of the general routers 22 is converted into an optical signal having the designated wavelengths λ _{1 to} λ _n and transmitted onto the optical ring 24 via the ADM 210b. The splitter 223b demultiplexes the wavelength multiplexed signal input from the optical ring 24 into a plurality of designated wavelengths λ _{1 to} λ _n and inputs the demultiplexed signals to the corresponding wavelength designation OTR 221b.

  The optical network according to the present embodiment can cope with an increase in the number of users with the addition of a small number of parts, and has high expandability, compared to the configuration of the first embodiment (see FIG. 4). Yes. That is, the bandwidth can be increased significantly by simply adding optical components and OTR without changing the optical ring in the first embodiment. For example, if eight wavelengths are employed, it is possible to guarantee a band eight times that of the configuration of the first embodiment.

Since the configuration of the present embodiment uses a hubd wavelength (designated wavelengths λ _{1 to} λ _n ) that allows direct communication between the main router 20b and the general router 22b, hubd traffic (see FIG. 3) is used. It can be transmitted in the shortest time. All-to-all traffic or One-By-One traffic can be performed via the main router 20b.

(Third embodiment: WDS2 network)
FIG. 14 is a partial configuration diagram showing an optical network (WDS2 network) according to the third embodiment of the present invention. Similar to the first embodiment, FIG. 14 shows a main router 20c and a plurality of general routers 22c, 22c, .., 22c are connected to the optical ring 24. The main router 20c is connected to the upper optical ring via the upper optical interface 204, and each general router 22c is connected to the lower optical ring via the lower optical interface 205, respectively. Different wavelengths λ _{1 to} λ _n are assigned to the general routers 22 c in this embodiment, as in the second embodiment.

The general router 22c includes an ADM (Add / Drop Module) 210c that is an optical IF, a wavelength designation OTR 211c, and a layer 3 switch 202c. The ADM 210c adds / drops a plurality of wavelengths. For example, an optical signal having an All-By-One wavelength λ ₀ set identically between the general routers 22c and an optical signal having a hubd wavelength λ _{1 to} λ _n individually set for each general router 22c are added / added. For example, different wavelengths can be selected and set from the eight waves shown in the second embodiment. The wavelength designation OTR 211c is an OTR that mutually converts an optical signal having a predetermined wavelength and an electrical signal, and has the same designated wavelength as the All-By-One wavelength λ ₀ for one general router 22c. And a wavelength designation OTR 211c having the same designated wavelength as the corresponding hubped wavelengths λ _{1 to} λ _n .

The main router 20c includes a signal conversion device 220c that is an optical IF and a layer 3 switch 202c. The signal conversion device 220c includes a plurality of wavelength designation OTRs 221c corresponding to all wavelengths added / dropped by each general router 22c, for example, All-By-One wavelength λ ₀ and hubped wavelengths λ _{1 to} λ _n , Are provided with a coupler 222c for multiplexing optical signals of different wavelengths and a splitter 223c for demultiplexing wavelength-multiplexed optical signals.

  The configuration of the layer 3 switch 202c is shown in FIGS. FIG. 15 is a configuration diagram of the layer 3 switch 202c provided in the user IF 14 when the optical ring is an access ring and the general router corresponds to the user IF 14 shown in FIG. FIG. 16 is a configuration diagram of the layer 3 switch 202c provided in the edge router 12 shown in FIG. As shown in FIGS. 15 and 16, the layer 3 switch 202c includes an upper port 2021c and a lower port 2022c, and further includes a routing table 2023c, an ARP table 2024c, and a MAC address table 2025c.

  The contents of the routing table 2023c, the ARP table 2024c, and the MAC address table 2025c are the same as those in the second embodiment, and are explicitly set in advance by an administrator or the like. Examples of the routing table 2023c, the ARP table 2024c, and the MAC address table 2025c are shown in FIGS. 17, 18 and 19, respectively. In the routing table 2023c shown in FIG. 17, the portion described as “Follow the flow” is determined according to the flowchart shown in FIG.

FIG. 15 is a layer 3 switch of the user IF _k , and determines whether there is a packet addressed to the network address NA _{k of the} user, and if it is addressed to NA _k , the user is connected to the lower level via the lower port 2022c. Forward. If it is not addressed to NA _k , it is determined whether it is addressed to the network address NA _AR of another user on the connected access ring 24. If it is addressed to the NA _AR , it is transferred to the all-by-One wavelength λ ₀ . If it is not destined for the NA _AR , it is not a user on the ring, so it is transferred to the hubded wavelength λ _k .

FIG. 16 is a configuration example of a layer 3 switch in the edge router. As in the previous example, if the destination network address D-NA of the received packet matches the network address NA _{u-IFk of the} user connected to the lower access ring, the packet is transferred to the port. Since each user IF has one hubd wavelength, transfer is possible using this wavelength. If it does not match any NA _u-IFk , if it matches the address NA _{DR of the} user connected to the higher distribution ring, it is transferred to the higher λ _abo . If it does not match, and transfers it to the λ _k. In this example, the all-by-One wavelength λ ₀ exists in the lower access ring. If used for traffic within the access ring, forwarding at the edge router is not required. In this case, it is also possible to transfer the optical signal as it is to the access ring 24 without performing optical / electrical conversion at the edge router, and FIG. 16 shows this state. The network corresponding to this is as shown in FIG.

  Also in this embodiment, the band can be increased only by adding and changing the optical components and OTR without changing the optical ring. That is, in an area where the number of users is small, it is possible to accommodate an increased number of users without changing the optical ring even when only the necessary services are initially provided by the WDS1 network, and a network with excellent expandability. It is.

According to the optical network configured as described above, two types of wavelengths are set for the packet, one wavelength is set to the all-by-one wavelength λ ₀ and the other wavelength is set to the hubed wavelengths λ _{1 to} λ _n . By allocating, all-by-One wavelength and hubd wavelength can be multiplexed on one optical ring, and the packet transmission according to the first embodiment and the second embodiment described above can be made with the same configuration. Can be realized. According to the optical network according to the present embodiment, for example, when it is known in advance that a specific traffic amount is large in various traffics illustrated in FIG. 3, it is easy to allocate wavelengths in advance.

In the present embodiment, the wavelengths to be added / dropped by the general router 22c are two types of the All-By-One wavelength λ ₀ and any of the corresponding hubred wavelengths λ _{1 to} λ _n. Instead of setting the wavelength λ ₀ , two types of unique hubped wavelengths λ _{1 to} λ _n may be set for each general router 22 c. Moreover, it is not necessarily limited to two wavelengths, and three or more wavelengths may be inserted / removed by the general router 22c.

A method for determining static routing for a plurality of wavelengths of two or more will be described according to the flow shown in FIG. First, a hubd wavelength is entered as a wavelength type in the ring, and an All-to-All wavelength is represented as λ _ata and an All-to-All wavelength is represented as λ _abo . Further, a wavelength that directly links to a specific node in λ _ata or λ _abo is expressed as λ _p . According to the flow of FIG. 20, explicit static routing is described as follows for all users to be set by the administrator. First, when describing the forwarding destination to a user connected to a specific router with traffic in the upper ring, if there is λ _p that directly links to this router, the port to which the OTR of wavelength λ _p is connected Next hop (in this case, a layer 3 switch of a specific router) in the routing table, IP address and MAC address (in this case, the IP address and MAC address of the next hop in this case), and MAC address table in the routing table Describes the port (in this case, the port to which the OTR of wavelength λ _p is connected). If λ _p does not exist, it is described to forward to either λ _ata or λ _abo wavelength port. In this case, since it goes through another router, the one with the smaller number of routers going through is selected.

If neither λ _ata nor λ _abo exists, λ _h should exist and forward to this port. Similarly, the traffic in the lower ring is also determined according to the flow of FIG. 20 if the subscript 1 is added to the wavelength type. If λ _p1 exists also in the lower ring, first describe that forwarding is performed here. If λ _p1 does not exist, λ _ata1 or λ _abo1 exists, so the one with fewer routers to be selected is selected. Next, it is a case where the next hop is clear in the traffic outside the ring. This is a packet that is transferred out of the ring via the upper router. In this case, if λ _h to the upper router exists, it is selected as the fastest transfer destination. If there is not, select the router with the smaller number of routers via either λ _ata or λ _abo . What remains is something other than the address that the administrator knows. Since this is traffic to the outside, all traffic is transferred to the upper main router. In the table, it can be described as a known default router.

  Thus, if an appropriate wavelength is selected from a plurality of wavelengths according to the flow, the contents shown in FIG. 17 are generally completed.

  On the other hand, when the number of users increases significantly, the setting of static routing increases the burden on the administrator. For this, dynamic routing is known as a known technique. As a representative one, for example, OSPF (Open Shortest Path First) can be used.

  However, in order to operate OSPF, it is necessary to satisfy predetermined requirements. That is, it is necessary to define a special area called a backbone area so that all routing target routers belong to the backbone area. In a conventional optical network using WDM, a configuration method that meets this condition has not been found. According to the configuration of this embodiment shown in FIG. 14, if the main router 20c is a designated router, and an area composed of links that are defined by hub wavelengths and directly communicate with each general router 22c is a backbone area, OSPF is applied. Can do. The OSPF can be applied not only to the access ring A but also to a form in which a plurality of access rings A are connected to the distribution ring D with reference to FIG. A specific application method is shown in FIG.

(Fourth embodiment: WDS3 network)
FIG. 23 is a partial configuration diagram showing an optical network (WDS3 network) according to the fourth embodiment of the present invention. Similar to the first embodiment, FIG. 23 shows a main router 20d and a plurality of general routers 22d, 22d, .., 22d are connected to the optical ring 24. The main router 20d is connected to the upper optical ring via the upper optical interface 204, and each general router 22d is connected to the lower optical ring via the lower optical interface 205, respectively. Different wavelengths λ _{1 to} λ _n are assigned to the respective general routers 22d in the present embodiment, as in the second embodiment.

The general router 22d includes a signal conversion device 220d, which is an optical IF, and a layer 3 switch 202d. The signal conversion device 220d includes a plurality of wavelength designation OTRs 221d corresponding to the assigned hubded wavelengths λ _{1 to} λ _n , a coupler 222d for multiplexing optical signals of a plurality of different wavelengths, and a splitter for demultiplexing wavelength multiplexed optical signals. 223d.

  The main router 20d includes a signal conversion device 220d and a layer 3 switch 202d, like the general router 22d. The configuration of the main router 20d is the same as that in the third embodiment described above.

According to the optical network configured in this manner, the demultiplexing and multiplexing of the designated wavelengths λ _{1 to} λ _n performed in the main router 20c in the third embodiment are also performed in each general router 22d. Many wavelengths can be allocated for communication between routers in the router 20c and each general router 22d, which is suitable for all-to-all transmission (see FIG. 3).

  Also in the present embodiment, routing can be performed statically as in the third embodiment. In addition, the modification shown in the third embodiment can be applied.

(Fifth embodiment: double optical network)
In the first to fourth embodiments, the connection state of one 0-system optical ring 24 of the double optical rings 24 and 26 shown in FIG. 2 has been described, but the other 1-system optical ring is described. 26 can be configured in the same manner as in the above embodiments. In this case, the double optical rings 24 and 26 may have the same configuration or different configurations.

  For example, as shown in FIG. 24, each of the double optical rings 24 and 26 is configured in the same manner as the optical network (WDS1 network) according to the first embodiment shown in FIG. The other can be used as a control ring. In FIG. 24, the same reference numerals are given to the same parts as those shown in FIG.

  25, the 0-system optical ring 24 is configured in the same manner as the optical network (WDS2 network) according to the third embodiment shown in FIG. 14, and the 1-system optical ring 26 is shown in FIG. By configuring in the same manner as the optical network (WDS1 network) according to the first embodiment, the 1-system optical ring 26 can be used for backup. In FIG. 25, the same components as those shown in FIG. 4 and FIG.

  Similarly, the optical network (WDS3 network) according to the fourth embodiment is backed up by the optical network (WDS1 network) according to the first embodiment (FIG. 34), and the optical network according to the fourth embodiment ( WDS3 network) is backed up by the optical network according to the third embodiment (WDS2 network) (FIG. 35), the optical network according to the fourth embodiment (WDS3 network) is the optical network according to the fourth embodiment. A configuration (FIG. 36) for backup with a network (WDS3 network) is also possible.

(Sixth embodiment: prevention of optical network communication quality degradation by control device)
An IP network is connectionless communication, and communication quality may deteriorate. This inherently has the risk that if traffic concentrates on a specific router, transmission delay will occur, or in the worst case, packets will be discarded and communication will become impossible. For this reason, some measures are required, but as before, dynamic routing is used, such as distributing traffic by specifying multiple paths using OSPF, or detouring to the system 1 route when a system 0 route failure occurs However, the effect is limited.

  In the optical network of the present invention shown in each of the above-described embodiments, various configurations can be achieved by optimization such as static routing giving priority to economy and mixing of dynamic / static routing, especially when the number of users is small. Become. In the present embodiment, a configuration of a control device assigned to one optical ring will be described in order to find an appropriate solution applicable to such various configurations. According to this control device, it is possible to grasp the state of the network and prevent communication quality deterioration, and it has a great effect of providing a solution with excellent quality despite being a large capacity optical IP network.

  The control device according to an embodiment of the present invention is a controller 30 connected to the main router 20 of the optical network shown in FIG. This control device can also be connected to the general router 22.

  In the optical network shown in FIG. 25, a main router 20c assigned number 0 and a general router 22c assigned numbers 1 to n are connected by a 0-system ring 24 to form a WDS2 network. . Further, the main router 20a and the general router 22a are connected by a 1-system ring 26 to form a WDS1 network.

In the 0-system ring 24, the All-By-One wavelength λ ₀ and the two wavelengths of the hubred wavelengths λ _{1 to} λ _n allocated to each general router 22c are transmitted to the general router 22c. On the other hand, in the 1-system ring 26, a common All-By-One wavelength λ ₀ is transmitted. The 0-system and 1-system layer 3 switches 202a and 202c of the routers 20 and 22 are electrically connected to each other. The control apparatus of this embodiment includes a WDM table and a PB-LLM (Port-Based Logical Link Matrix) storage unit in order to express such a network state and a link state. ing.

  The WDM table represents the correspondence between the wavelengths of light propagating in the optical rings 24 and 26 and the ports of the layer 3 switches 202c and 202a. The PB-LLM is a link between the ports of the layer 3 switches 202c and 202a. It specifies the wavelength of the light used for it.

An example of the WDM table in the optical network shown in FIG. 25 is shown in FIG. In order of connection from the main router, the general routers 1, 2,..., N continue, and finally, each of the wavelengths λ _{0 to} λ _n is assigned to the layer 3 switches 202 c, 202 a. If it is connected to a port, that number is specified. On the other hand, 0 is designated if not connected. In the example shown in FIG. 26, the All-By-One wavelength λ ₀ is connected to the first port of the 0-system layer 3 switch 202c in all the routers 20c and 22c. The wavelength λ ₁ is output from the port 2 of the main router 20c and connected to the port 2 of the first general router 22c, and passes through the second to n-th general routers 22c to pass through the port of the main router 20c. Return to. That is, the wavelength λ ₁ designates a hubd wavelength between the main router 20c and the first general router 22c. Similarly, λ ₂ ,..., Λ _n designates a hubd wavelength with the corresponding second to n-th general routers 22c. The wavelengths λ _{1 to} λ _n of the 0-system optical ring 24 are used for links dynamically routed by OSPF, and λ ₀ is used for links that are statically routed. In the 1-system optical ring, the wavelength λ ₀ is designated as an all-by-One wavelength.
FIG. 27 shows an example of the above-described PB-LLM. As shown in FIG. 27, if the number of routers is M (= n + 1), the PB-LLM can be represented by an M × M square matrix whose elements are two types of sub-matrices Lii and Lij (i ≠ j). The diagonal element Lii is referred to as a switch submatrix (SW-SM), and the non-diagonal element Lij is referred to as a half next-hop submatrix (HNH-SM). Lii represents a transfer state between the ports of the layer 3 switch itself in the router i, and Lij represents a transfer state from the layer 3 switch of the router i to the layer 3 switch of the router j. In the following description, it is assumed that the layer 3 switch of each router has the same number of ports p, and SW-SM and HNH-SM are represented by a p × p square matrix. If the number of ports is different and the maximum number of ports is p, the following description is valid.
FIG. 28 shows an example of SW-SM for the main router 20 of the optical network shown in FIG. In FIG. 28, diagonal elements mean the same port, but there is no transfer to the same port, so the diagonal element of SW-SM is always zero. In this network, there are two layer 3 switches 202c and 202a of system 0 and system 1, and serial numbers are assigned to these ports.
The 0-system layer 3 switch 202c has n + 2 ports, and is connected to the n + 1 ports connecting the OTRs of λ ₀ , λ ₁ ,..., Λ _n and the 1-system layer 3 switch 202a. Has one port. In FIG. 28, this portion is indicated by a broken line. The 1-system layer 3 switch 202a has a 1st port connected to the 0-system layer 3 switch 202c and a second port connecting the OTR of λ ₀ . That is, the total number of ports is n + 4. The value of each element is 1 when there is transfer, and 0 when there is no transfer. In the configuration shown in FIG. 25, the inter-port connection between the 0-system layer 3 switch 202c and the 1-system layer 3 switch 202a is the n + 2 port of the 0-system layer 3 switch 202c and the 1-system layer 3 switch 202a. No. 1 (total n + 3) port is connected, so two elements corresponding to transmission / reception are 1 and all others are 0.

FIG. 29 shows an example of HNH-SM for the same network. In this example, L ₀₁ represents transfer from the main router 20 (0th router) to the first general router 22, and L represents transfer from the main router 20 (0th router) to the second general router 22 as well. ₀₂ , and L ₁₂ and L ₂₃ respectively representing transfers from the first general router 22 to the second general router 22 and from the second general router 22 to the third general router 22. HNH-SM indicates the presence or absence of an optical link. When there is a link, a number indicating the wavelength of the light is input, and when there is no link, 0 is input. For example, the (11) element of L ₀₁ is 131, which is the 1st port of the first general router 22 from the 1st port of the main router 20 (0th router) according to the WDM table of FIG. to have a link with a wavelength of lambda _0, it indicates that this wavelength lambda ₀ is 1310 nm. As described above, the number of each element is displayed by 1/10 of the actual wavelength. For example, λ ₀ : 1310 nm → 131, λ ₁ : 1470 nm → 147, λ ₂ : 1490 nm → 149,. It is expressed as follows. Similarly, the (22) element of L ₀₁ is 147. This is because the 2nd port of the main router 20 (0th router) and the 2nd port of the first general router 22 are connected at a wavelength of 1470 nm. It represents that. The (n + 4, n + 4) element of L ₀₁ is 131. This is because the second port of each 1-system layer 3 switch in the main router 20 (0th router) and the first general router 22 has a wavelength of 1310 nm. Indicates that it is connected. This element is used for control.

The same applies to L ₀₂ representing the link from the main router 20 (0th router) to the 2nd general router 22, and the 2nd of the 2nd general router 22 from the 3rd port of the main router 20 (0th router). It shows that the system is connected to the port at a wavelength of 1490 nm and the system 1 layer 3 switch is linked at a wavelength of 1310 nm.
The link from the first router 22 to the second general router 22 is represented by L ₁₂ , indicating that there is a link with a wavelength of 1310 nm between each first port and between the control ports. The same applies to the link from the second router 22 to the third general router 22. This HNH-SM represents a link from i to j by Lij (i ≠ j) and a link from j to i by Lji, but the signal is transferred in one direction in the optical ring. Therefore, generally Lij ≠ Lji.

  The control apparatus of this embodiment can improve the communication quality in an optical network by providing the WDM table and the PB-LLM storage unit described above. This control device can be connected to the layer 3 switches 202a and 202c of the main router 20 as the controller 30 shown in FIG. 25, for example, and can control the entire network by having the control program shown below. . A control signal output from the controller 30 passes through the optical ring 24 or 26 and controls all the layer 3 switches 202c and 202a on the optical ring. Hereinafter, description will be made based on the configuration of the optical network shown in FIG.

First, FIG. 30 shows a general flow for executing the functions of the control device. When constructing the network of FIG. 25, wavelengths λ _{1 to} λ _n for transmitting the 0-system ring
Is set by dynamic routing by OSPF (see FIG. 21), and a link having the wavelength λ _{0 is} set by static routing (see FIGS. 6 to 8). Similarly, the wavelength λ ₀ on the 1-system ring is set by static routing. A WDM table is added to this and input to the control device as an initial setting. After inputting the set value, the control device automatically generates information to be written in each layer 3 switch based on this value. The control device writes the automatically generated value to the file of each layer 3 switch, and sets necessary information such as a routing table. Next, the control device collects routing information of each layer 3 switch, and automatically generates a PB-LLM based on the collected routing information. The PB-LLM needs information on the presence / absence of a link and the value of the wavelength when there is a link. The former is the routing table information itself, and the latter is possible by assigning an integer corresponding to the above-mentioned wavelength as the port ID. When this is generated, the control apparatus grasps all the network information together with the input WDM table. As described above, the control device according to the present embodiment includes a logical link information generation unit that automatically generates port-based logical link matrix information representing a link state based on a specified wavelength between ports of each layer 3 switch based on the control program. I have.

In order to make the control device according to the present embodiment function effectively, it is preferable to apply the wavelength variable ADM shown in FIG. 31 as the ADM 210c included in the general router 22 in the configuration of the optical network shown in FIG. The wavelength tunable ADM includes a plurality of single wavelength ADMs 51 that add / drop only a specific wavelength λx (x = 1, 2,..., N), and an IN / OUT unit 52 that performs wavelength input / output. A slide ferrule 53 is slidably inserted therebetween. The slide ferrule 53 includes therein a light transmission part 531 in which optical waveguide parts are arranged at the same interval as the input / output width of each single wavelength ADM 51, and a light reflection part 532 including a total reflection filter. As a typical example, when the wavelength to be added / dropped is n waves and n corresponding single-wavelength ADMs 51 are arranged, the slide ferrule 53 includes n light transmitting portions 531 and n light reflecting portions 532. In the state shown in FIG. 31, since only one light transmission part 531 is off, the wavelengths to be added / dropped are λ ₁ , λ ₂ ,..., Λ _n−1 and reflected by λ _n. . Therefore, as a result, λ _n passes through the wavelength tunable ADM.

By sliding the slide ferrule 53 in this manner, the wavelength to be added / dropped and the wavelength to pass through in the wavelength tunable ADM can be made variable. Further, if all the light transmission parts 531 are inserted, all wavelengths can be added / dropped, which is equivalent to a coupler or a splitter. That is, it can be an optical component of the WDS3 network (see FIG. 23). On the other hand, when all the light reflecting portions 532 are inserted, all wavelengths pass and the add / drop wavelength disappears. In this case, when a new user is generated later in a state where no user exists, λ ₁ can be added / dropped by sliding the light transmitting part to change by one.

This tunable ADM can also be slid manually. In addition, although not shown in the figure, the wavelength can be automatically increased / decreased or newly added even from a remote place by sliding it by a fixed length according to the signal given by the actuator. In FIG. 31, the order of the wavelengths is λ ₁ , λ ₂ ,..., Λ _n from the bottom, but this is a cyclic one (that is, λ ₂ , λ ₃ ,..., Λ _n , λ ₁ or λ ₃ , λ ₄ ,..., Λ _n , λ ₁ , λ _2, etc.) are prepared and arranged in different routers, the wavelength to be increased or decreased can be changed.

  In the present invention, in the flow shown in FIG. 30, after the automatic generation of the PB-LLM, a signal is sent to the layer 3 switch via the ring of system 1 and the actuator connected thereto is operated, so that the ADM 210c Automatically set the insertion / extraction wavelength. Thereafter, the control device automatically and periodically monitors the traffic amount of each port of the layer 3 switch, and determines whether or not the total traffic amount exceeds the reference amount. If the excess traffic does not exceed the traffic that can be accommodated in the system 1 ring (control ring) 26, the system is diverted to the system 1 ring (control ring) 26. If it exceeds, the WDM table is rewritten so as to add a new wavelength to the ADM, and the process again enters the flow for automatically setting the layer 3 switches 202c and 202a and the insertion / extraction wavelength of the ADM 210c.

  As described above, it is possible to cope with traffic concentration and prevent deterioration of communication quality. Here, for monitoring the traffic, a known technique provided in the layer 3 switch can be used. Further, when a user is added, as described above, a band can be added by adding a wavelength. If information on the wavelength to be added is added, the process can be executed in the same flow as that shown in FIG.

(Seventh embodiment: optical network failure recovery by control device)
The control device shown in the sixth embodiment may have a recovery function that automatically avoids a failure in the network. In an IP network, a technique for recovery using a dynamic routing protocol such as OSPF is generally known. However, in the optical network in each of the above embodiments, static routing may be used, and thus the above-described known technique cannot be used. In the present invention, since the control device grasps the state of the network by the WDM table and the PB-LLM, automatic recovery is possible. The control device of the present embodiment is the controller 30 arranged in the optical network shown in FIG. 25, and the case where the 0-system optical ring 24 is restored will be described below.

  As described in the sixth embodiment, the static routing information is written to each layer 3 switch according to the flow shown in FIG. 30, and routing is performed. When switching to another route due to the occurrence of a failure, the control device rewrites the routing table of the layer 3 switch. An overview of the recovery method is shown in FIG.

  The failure detection uses information of MIB (Management Information Base) operating in each layer 3 switch. MIB information can be acquired by SNMP (Simple Network Management Protocol). The control device has a recovery program and implements the SNMP manager function. The SNMP agent of each layer 3 switch returns MIB data to the control device in response to a command from the manager. In addition, the rewriting of the layer 3 switch directly rewrites the routing table from the control device by telnet.

FIG. 33 shows a recovery flow performed by the control device. As shown in FIG. 33, since the PB-LLM is automatically generated first, the control device holds this as an initial value (= LM ₀ ). Next, the control device collects the port status of each layer 3 switch via the SNMP agent based on the information of the PB-LLM. In order to do this, the value of the known MIB ifOpenStatus is used, and status values can be obtained for link up and down. After obtaining the state values for all the ports, the wavelength ID value of the light is made to correspond to the ports in the up state, and down is set to 0 to update the PB-LLM. The updated PB-LLM and LM _1, obtaining the judgment matrix Judge by performing subtraction between the LM ₀ initial value. If the ports corresponding to the initially set links are all up, the two matrices are identical and Judge is a zero matrix. This is a case where no failure has occurred, and the port monitoring is continued at regular intervals thereafter. When a port that is down due to a failure occurs, a negative value is entered in the element corresponding to the Judge port. The fault location can be extracted by the number of this element. A rerouting route is secured by rewriting the routing table of the corresponding layer 3 switch so that the 0-system link at the failure location is switched to the 1-system link.

  In addition, the control device has the great effect of improving the transmission quality by adding the following functions by changing the monitor information and the control target. In other words, the control device monitors the packets transmitted through the 0-system ring, bypasses packets using UDP (User Datagram Protocol) as the protocol of the OSI layer 4 to the 1-system, and provides quality corresponding to the service type. Has a control function.

  The control device monitors the packets transmitted on the 0-system ring, extracts the port number, selects packets using a specific application, bypasses them to the 1-system, and provides a quality control function corresponding to the application type. Have.

  The control device monitors the packet transmitted through the 0-system ring, and when the packet to a specific destination address exceeds the reference amount, it intercepts the packet and stops the transfer to the 0-system network. To prevent.

Schematic for demonstrating the basic composition of the optical network which concerns on this invention. FIG. 2 is a partial configuration diagram of the optical network shown in FIG. 1. The figure for demonstrating traffic classification. 1 is a partial configuration diagram showing an optical network (WDS1 network) according to a first embodiment of the present invention. The block diagram of the layer 3 switch in a main router or a general router. The figure which shows an example of a routing table. The figure which shows an example of an ARP table. The figure which shows an example of a MAC address table. The partial block diagram which shows the optical network (WCS network) which concerns on the 2nd Embodiment of this invention. The block diagram of the layer 3 switch with which a main router is provided. The figure which shows an example of a routing table. The figure which shows an example of an ARP table. The figure which shows an example of a MAC address table. The partial block diagram which shows the optical network (WDS2 network) which concerns on the 3rd Embodiment of this invention. The block diagram of the layer 3 switch provided in user IF. The block diagram of the layer 3 switch provided in the edge router. The figure which shows an example of a routing table. The figure which shows an example of an ARP table. The figure which shows an example of a MAC address table. The flowchart for demonstrating the process in a routing table. The flowchart for demonstrating dynamic routing. The block diagram which shows the modification of the optical network shown in FIG. The partial block diagram which shows the optical network (WDS3 network) which concerns on the 4th Embodiment of this invention. The partial block diagram which shows the optical network (backup network) which concerns on the 5th Embodiment of this invention. The block diagram which shows the modification of the optical network shown in FIG. The figure which shows an example of the WDM table in the optical network shown in FIG. The figure which shows an example of PB-LLM in the optical network shown in FIG. The figure which shows an example of SW-SM in the optical network shown in FIG. The figure which shows an example of HNH-SM in the optical network shown in FIG. The flowchart for demonstrating the function of the control apparatus in the optical network which concerns on the 6th Embodiment of this invention. The schematic block diagram of wavelength variable ADM. The flowchart for demonstrating the outline | summary of a failure recovery method. The restoration flow figure which a control device performs. The block diagram which shows the modification of the optical network shown in FIG. The block diagram which shows the modification of the optical network shown in FIG. The block diagram which shows the modification of the optical network shown in FIG. The schematic block diagram of the conventional optical network.

Explanation of symbols

10 Node router 12 Edge router 14 User IF
20 Main router 22 General router 24, 26 Optical ring 201 OTR
202 Layer 3 switch 204 Upper optical interface 205 Lower optical interface

Claims (18)

A main router and a plurality of general routers are coupled in a ring shape with an optical fiber to form a main network, and the main network is an optical IP network coupled to an upper network through the main router,
The main router is connected to the higher-level network and the main network, respectively, and controls transmission / reception of an electrical signal between the higher-order optical interface and the main optical interface, and a higher-order optical interface and a main optical interface that mutually convert an optical signal and an electrical signal. Main layer 3 switch to
The general router includes a general optical interface that is connected to the main network and mutually converts an optical signal and an electrical signal;
The main layer 3 switch is an optical network that performs packet routing based on static routing information. The main optical interface and the general optical interface include an optical transceiver having an input / output port,
The optical network according to claim 1, wherein the static routing information is information explicitly described in a routing table, an ARP table, and a MAC address table. The optical network according to claim 2, wherein the optical transceiver included in the main optical interface and the general optical interface outputs a light wave having a single All-by-One wavelength. The optical transceiver included in the main optical interface outputs light waves of a plurality of wavelengths,
The optical network according to claim 2, wherein the main optical interface includes a coupler that multiplexes optical waves of different wavelengths to generate a wavelength multiplexed optical signal, and a splitter that splits the wavelength multiplexed optical signal into optical waves of different wavelengths. . The optical transceiver included in the plurality of general optical interfaces outputs light waves of one or a plurality of designated wavelengths,
The optical network according to claim 4, wherein the general optical interface includes an add / drop module that adds / drops only a light wave having the designated wavelength. The optical network according to claim 5, wherein at least one of the designated wavelengths is a hubd wavelength unique to each general router. The optical network according to claim 6, wherein OSPF (Open Shortest Path First) is adopted as a routing protocol of a link formed by the hubd wavelength between the main router and a general router. 6. The optical network according to claim 5, wherein at least one of the designated wavelengths is the hubd wavelength, and at least one other is an All-by-One wavelength common among the general routers. The optical network according to claim 8, wherein the light wave having the All-by-One wavelength among the light waves demultiplexed by the splitter is directly input to the coupler. OSPF is adopted as a routing protocol for the link formed by the hubd wavelength between the main router and the general router,
The optical network according to claim 8 or 9, wherein a static routing protocol is adopted as a routing protocol of a link formed by the All-by-One wavelength between the main router and the general router. A main router and a plurality of general routers are connected in a ring shape by at least double optical fibers including a service ring and a control ring to form a main network, and the main network is connected to an upper network via the main router. An optical IP network,
The main router and the general router each include a layer 3 switch and a wavelength-designated optical transceiver connected to a port of the layer 3 switch.
An optical network in which wavelength multiplexed optical signals are carried on the service ring, and wavelength control signals are carried on the control ring. The general router further includes an add / drop module for adding / dropping only a light wave of the designated wavelength corresponding to the designated wavelength of the optical transceiver,
The optical network according to claim 11, wherein the add / drop module is configured to change a wavelength to be added / dropped. The add / drop module includes a plurality of single wavelength add / drop modules for adding / dropping only a specific wavelength, an input / output unit for inputting / outputting wavelengths, and the single wavelength add / drop module and the input / output unit. With a slide ferrule inserted slidably,
13. The slide ferrule includes a light transmission part in which optical waveguide parts are provided at the same interval as the input / output part of the single wavelength add / drop module, and a light reflection part including a total reflection filter. The optical network described. The optical network according to claim 11, wherein the control device is connected to the main router or a general router,
A WDM table indicating a correspondence relationship between a wavelength included in a wavelength multiplexed optical signal carried on the service ring and a port of the main router or a general router in which communication by the wavelength is performed;
A logical link that generates port-based logical link matrix information representing a link state by a specified wavelength between ports of each layer 3 switch based on routing information collected from a routing table provided in the layer 3 switch and information in the WDM table A control device comprising an information generation unit. The optical network according to claim 12, wherein the control device is connected to the main router or a general router,
A WDM table indicating a correspondence relationship between a wavelength included in a wavelength multiplexed optical signal carried on the service ring and a port of the main router or a general router in which communication by the wavelength is performed;
A logical link that generates port-based logical link matrix information representing a link state by a specified wavelength between ports of each layer 3 switch based on routing information collected from a routing table provided in the layer 3 switch and information in the WDM table An information generation unit,
A control device that changes a wavelength to be added / dropped by the add / drop module based on the port-based logical link matrix information. The traffic amount of each port of the layer 3 switch is periodically monitored, and when the total traffic amount exceeds a reference amount, the add / drop wavelength of the add / drop module is changed to update the WDM table. Item 16. The control device according to Item 15. 15. The failure occurrence location in the service ring is extracted by acquiring a state value of a port of the layer 3 switch based on the port-based logical link matrix information and comparing the state value with an initial value. 15. The control device according to 15. The control device according to claim 17, wherein the control ring is bypassed from the service ring by rewriting a routing table of the layer 3 switch based on the extraction of the failure occurrence location.

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