JP3843062B2 - Node control method and node control apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a node control method and a node control device used for an optical path switching device (for example, an optical router) that performs routing processing of a large-capacity optical path network.
[0002]
[Prior art]
Optical cross-connect technology based on high-reliability optical switches enables the construction of optical network platforms that provide various types of network services. Supporting the construction of such an optical network platform is a multilayer router in which an optical switch and an IP switch or an SDH cross connector are integrated (Non-Patent Document 1). As shown in FIG. 9, the multi-layer router includes an optical switch (wavelength routing unit (LRU)) 51 and a packet switch (MPLS router) 52 that performs optical path setting / switching by MPLS (Multi-Protocol Label Switching). In addition, a node control device 53 that performs such cooperative control is provided, and it is possible to tunnel not only IP traffic but also a plurality of paths such as an Ether-path, an SDH-path, and an optical path.
[0003]
Here, the Ether-path is realized by Ether over MPLS technology and is a connection for tunneling the customer's Ether frame traffic as it is. Typical values for connection bandwidth are 10 Mbit / s and 100 Mbit / s. The SDH-path is a tunneling of VC-3 or VC-4 corresponding to the payload of the SDH frame. VC-3 is 50 Mbit / s, and VC-4 is 150 Mbit / s. On the other hand, the optical path is a service for tunneling all traffic information input from customers including SDH frames.
[0004]
In this multi-layer router, the optical switch 51 and the packet switch 52 cooperate to perform an optical path transfer process in which an IP packet passing through the router is accommodated, and an IP packet terminated at the router is transmitted. By connecting the accommodated optical path to the packet switch 52, the IP packet transfer capability as a whole is improved and the burden on the packet switch is reduced.
[0005]
The challenge for distributed control of such an optical network platform using GMPLS (Generalized MPLS) technology is to establish a connection for a path having various attributes such as an Ether-path, an SDH-path, and an optical path. This is a route search method. At present, the IETF (Internet Engineering Task Force), which is a GMPLS standardization organization, is discussing standardization focusing on the extension of link state routing protocols such as OSPF / IS-IS protocol. In the link state type routing protocol, costs are defined for all links, and the node control device at the end point of the link notifies the other nodes of these link identification numbers and cost information. Each node control device searches for the route of the path to be set in consideration of the link identification number and cost information notified from the other node and the information of the link connected to itself. GMPLS adds link attribute information notified by the above routing protocol, and adds a function of advertising the path type that each link can accommodate and the switch capability at the end node of each link. Here, the switching capability to be advertised is information such as “switching is possible at the SDH VC-3 level”, “switching of the Ether-path is possible”, and the like.
[0006]
[Non-Patent Document 1]
KI. Sato et al., "GMPLS-Based Photonic Multilayer Router (Hikari Router) Architecture: An overview of traffic engineering and signaling technology", IEEE Comm. Mag. Vol.40, pp.96-101, March, 2002
[0007]
[Problems to be solved by the invention]
By the way, when providing various path tunneling services based on GMPLS and optical cross-connect technology to customers, it is necessary to solve the following two problems.
[0008]
The first problem is the interface capability of each switch. FIG. 10 shows the state of the network node interface (Network-Node IF: NNI) of the optical switch 51 shown in FIG. 9 and the internal interface (Internal IF) between the optical switch 51 and the packet switch 52. Case 1 is a case where all ports are used for connection of the optical path in the NNI, and indicates that the optical path cannot be added. However, it is possible to add an electrical path using the existing optical path. Case 2 is a case where the internal IF is used for all ports to connect the optical path, and indicates that the optical path cannot be terminated.
[0009]
As shown in Case 2, even if the switching capability of the optical switch 51 is sufficient, if the interface capability to be input to the packet switch 52 that terminates the optical path is used up, the multi-layer router The terminating optical path cannot be set.
[0010]
The second problem is the problem of handling various routing information. As shown in FIG. 11, when a network 61 using a multi-layer router 50 is connected to a user network 62, in order to increase the security of the network, network information that each node notifies other nodes to the user side. Some or all need to be filtered. At this time, the information that the user A should have is not all the information of the networks 61 and 62, but the IP routers 63, 64, and 65 owned by the user and the optical path 66 and the IP routers 64 and 65 connecting the IP routers 63 and 65. This is an optical path 67 connecting the two. That is, it is not desirable to notify the user A of connection information of routers installed in areas where the service of the user A is not provided.
[0011]
The present invention solves the above problems, transfers part of the authority of network control to the user, and provides node control capable of providing customers with various path tunneling services based on GMPLS and optical cross-connect technology. It is an object to provide a method and a node control apparatus.
[0012]
[Means for Solving the Problems]
The present invention relates to a node control method performed by a routing processing function unit that manages a state of a termination interface in a node having a plurality of types of termination interfaces. The routing processing function unit includes information on switching capability of the own node and termination interface attribute information. At least one of them is advertised to other nodes, the information to be advertised is filtered so as to limit each user, and the information is notified to each user.
[0013]
The present invention relates to a node control apparatus having a routing processing function unit that manages a state of a termination interface in a node having a plurality of types of termination interfaces, and the routing processing function unit includes information on switching capability notified from an adjacent node; A reception function unit that receives at least one of the termination interface attribute information, a flooding processing unit that adds the termination interface attribute information of the own node to the received termination interface attribute information, and information about the switching capability accumulated in the flooding processing unit; A filtering processing unit that filters at least one of the termination interface attribute information for each output route, and at least one of the filtered switching capability information and the termination interface attribute information as an adjacent node Comprising a transmission function unit for transmitting, and a user policy control function unit for controlling the filtering process unit in accordance with the information restricted for each user.
[0014]
Further, the termination interface attribute information may include interface type information and interface number information of an optical path that can be terminated at a node.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(First configuration example of optical communication node)
FIG. 1 shows a first configuration example of an optical communication node including a node control device of the present invention.
[0016]
In the figure, an optical switch unit 10 includes an optical cross connect 11 that realizes a cross connection in units of optical paths, a digital cross connect 12 that realizes a cross connection in units of SDH VC-4, and an Ether switch 13.
[0017]
The optical cross connect 11 has an ability to switch the optical path transparently. In this configuration, four (16 waves per fiber) fiber link on the network side and 16 (4 waves per fiber) fiber link are connected to the 128 × 128 optical switch. The digital cross-connect 12 is equipped with 10 interfaces having a capability of terminating an optical path of 10.7 Gbit / s OTN format and 10 interfaces having a capability of terminating 10 Gbit / s STM-64. The Ether switch 13 is equipped with 10 10 Gbit / s Ether over SONET interfaces.
[0018]
FIG. 2 shows a configuration example of the node control apparatus 20 of the present invention. In the figure, the node control device 20 manages the state of the optical switch unit 10 and the termination interface via the switch control firmware 14, and implements a routing processing function unit (OSPF / IS) that realizes optical path setting / deletion / switching / routing. -IS protocol processing function) 21, path setting management function unit (RSVP-TE / CR-LDR protocol processing function) 22 for performing optical path setting / deleting signaling, fault management function unit for monitoring faults of optical fibers and adjacent nodes ( LMP protocol processing function) 23 and an IP processing unit 24 that accommodates the control channel.
[0019]
The present invention extends the routing processing function unit (OSPF / IS-IS protocol processing function) 21. The routing processing function unit 21 includes a reception function unit 31 that receives information on switching capability and termination IF attribute information from adjacent nodes, a flooding processing unit 32 that adds the termination IF attribute information of the own node to this reception information, and a flooding processing unit 32. Filtering processing unit 33 for filtering information on switching capability and termination IF attribute information stored in each output path, transmission function unit 34 for transmitting filtered switching capability information and termination IF attribute information to adjacent nodes, filtering A user policy control function unit 35 that controls the processing unit 33, a link state database 36, a termination IF management database 37 that manages the switching capability and termination interface capability of each switch, and a channel state database 36 Management database 38 is connected.
[0020]
By the operations of the reception function unit 31 and the flooding processing unit 32, not only the switching capability of each multilayer router but also the termination IF capability becomes clear at each node of the entire network.
[0021]
(Embodiment of Node Control Method of the Present Invention)
FIG. 3 shows an operation example of the reception function unit 31 and the flooding processing unit 32. When the user A dynamically sets a VC-4 (155 Mbit / s) path between the nodes # 1 to # 4, the conventional node control apparatus accommodates the VC-4 path in any OTN optical path. The user A did not have the right to decide. That is, restrictions are imposed on the communication carrier network information released to the user A, and the nodes in which the line of the user A is accommodated, for example, the information of the node # 1 and the node # 4 are not released.
[0022]
On the other hand, in the present embodiment, the operation of the reception function unit 31 and the flooding processing unit 32 causes the switching capability and termination interface capability in the relay nodes such as nodes # 2 and # 3, and information on the optical path set between the nodes. Is clearly open to the user A. The termination interface capability of the relay node is provided from the termination IF management database 37 of the relay node, and is notified via the flooding processing unit 32 of the routing processing function unit 21 of each node. Therefore, under the control of the user A, a new optical path is directly established between the node # 2 and the node # 3, and the already set optical paths of the nodes # 1- # 2 and # 3- # 4 are also used to perform VC-4. The paths can be accommodated in these optical paths and opened between the nodes # 1 to # 4. As a result, a new optical path is provided only between the node # 2 and the node # 3, so that it is not necessary to set an end-to-end broadband OTN optical path, and network resources can be used effectively.
[0023]
Further, network information such as the termination interface capability and switching capability of the relay node is notified to the user A through the filtering process. By this filtering processing unit 33, the network information notified from the flooding processing unit 32 is limited, and the limited information is changed for each user connected to the node. The user policy control function unit 35 has a function of setting in the filtering processing unit 33 what kind of information restriction is given to each user.
[0024]
In the example shown in FIG. 4, in the SDH layer to which the digital cross-connect 12 is connected via an optical path, the route setting of the VC-4 path can be performed for the user A by the designation from the user. , Shows a state in which all of the SDH link information is provided. Here, the user A is the same carrier as the telecommunications carrier that provides the optical platform service, but is another business unit that provides the VC-4 path leased line service. All network information of Hikari Platform Service is disclosed to users in the same business.
[0025]
The example shown in FIG. 5 shows a case where the user B is an Internet service provider in a fiber layer to which the optical cross connect 11 is connected via a fiber link. User B is a business operator who merely requests provision of a large-capacity dedicated line, but maximizes the controllability of the optical platform service between the four sites of nodes # 2, # 3, # 4, and # 5. The network topology can be freely changed while observing the traffic state of its own network. The user B is notified of the interface capabilities of the nodes # 2, # 3, # 4, and # 5 and whether or not the connection between these interfaces is possible. This notification information is the content notified from the node # 2 to the user side, and the cost information included therein is the connection cost calculated from the link information managed by the optical platform service provider.
[0026]
The example shown in FIG. 6 shows a case where the user C is a large-scale enterprise user who is a pure customer as viewed from the communication carrier in the SDH layer to which the digital cross-connect 12 is connected via the SDH link. The user C is a user who only requests the provision of a large-capacity virtual dedicated line, and connects the Ether path between the three bases of the nodes # 2, # 3, and # 4. For such user C, no internal information of the optical network is disclosed.
[0027]
As described above, the optical network information can be provided at various levels according to the request of the customer who intends to provide the service according to the present invention. In addition to providing a fixed dedicated line as in the past, part of the optical network resources can be lent to the customer, and path networking can be realized by the customer's own control.
[0028]
(Second configuration example of optical communication node)
FIG. 7 shows a second configuration example of the optical communication node including the node control device of the present invention.
[0029]
In the figure, an optical switch unit 10 realizes a wavelength band cross connect 15 that realizes a cross connection in units of wavelength band paths, an optical cross connect 16 that realizes a cross connection in units of optical paths, and a cross connection in units of SDH VC-4. It is constituted by a digital cross connect 17.
[0030]
The wavelength band cross connect 15 has a capability of switching the wavelength band path transparently. In this configuration, four (8 bands per fiber) fiber links are connected to the 32 × 32 optical switch on the network side. Also, four wavelength paths are accommodated per wavelength band. The optical cross-connect 16 is provided with 32 interfaces having the capability of terminating an optical path of 10.7 Gbit / s OTN format. The digital cross-connect 17 is equipped with 16 interfaces having a capability of terminating a 10 Gbit / s SONET frame.
[0031]
As shown in FIG. 2, the node control device 20 includes a routing processing function unit (OSPF / IS-IS protocol processing function) 21, a path setting management function unit (RSVP-TE / CR-LDR protocol processing function) 22, and a fault management. A function unit (LMP protocol processing function) 23 and an IP processing unit 24 are included. Here, an example of the termination IF attribute information notified to the other nodes by the flooding processing unit 32 of the routing processing function unit 21 is shown in FIG. Here, the format of information advertised by the OSPF protocol is shown. It includes the optical path interface type (SONET OC-48) that can be terminated at this node, the frame format (SONET ANSI T1.105), the number of interfaces (four), and the connection destination (PSC) of the termination interface.
[0032]
【The invention's effect】
As described above, the node control method and the node control device according to the present invention do not notify the same information (information about the switching ability of the own node and termination interface attribute information) to all adjacent nodes, but advertises it. The information is filtered so as to limit each user, and the information is notified for each user. This makes it possible to transfer the authority of network control to some users, and change the control range to be transferred for each user. That is, the telecommunications carrier can provide not only a leased dedicated line to the customer but also various services.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first configuration example of an optical communication node including a node control device of the present invention.
FIG. 2 is a diagram showing a configuration example of a node control apparatus 20 according to the present invention.
FIG. 3 is a diagram for explaining an operation example of a reception function unit 31 and a flooding processing unit 32;
FIG. 4 is a diagram for explaining link information to be disclosed to a user A.
FIG. 5 is a diagram for explaining link information to be disclosed to user B;
FIG. 6 is a diagram for explaining link information to be disclosed to a user C.
FIG. 7 is a diagram showing a second configuration example of an optical communication node including the node control device of the present invention.
FIG. 8 is a diagram showing an example of termination IF attribute information.
FIG. 9 is a diagram illustrating a configuration example of a multi-layer router.
FIG. 10 is a diagram showing an optical switch IF and a packet switch IF.
FIG. 11 is a diagram for explaining all network information and information that user A should have.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Optical switch part 11 and 16 Optical cross connect 12 and 17 Digital cross connect 13 Ether switch 14 Switch control firmware 15 Wavelength band cross connect 20 Node control apparatus 21 Routing processing function part 22 Path setting management function part 23 Fault management function part 24 IP processing unit 31 reception function unit 32 flooding processing unit 33 filtering processing unit 34 transmission function unit 35 user policy control function unit 36 link state database 37 termination IF management database 38 channel management database 50 multilayer router 51 optical switch 52 packet switch 53 node Control device

Claims (3)

In a node control method performed by a routing processing function unit that manages the state of a termination interface in a node having multiple types of termination interfaces,
The routing processing function unit
Advertise at least one of switching node's switching capability information and terminal interface attribute information to other nodes,
A node control method comprising filtering the information to be advertised so as to limit each user and notifying the user of the information. In a node controller having a routing processing function unit that manages the state of a termination interface in a node having multiple types of termination interfaces,
The routing processing function unit
A reception function unit that receives at least one of information on switching capability and termination interface attribute information notified from an adjacent node;
A flooding processing unit for adding termination interface attribute information of the own node to the received termination interface attribute information;
A filtering processing unit that filters at least one of the information regarding the switching capability accumulated in the flooding processing unit and the termination interface attribute information for each output route;
A transmission function unit that transmits at least one of the filtered switching capability information and termination interface attribute information to an adjacent node;
A node control apparatus comprising: a user policy control function unit that controls the filtering processing unit according to information restriction for each user. The node control device according to claim 2,
The node control device characterized in that the termination interface attribute information includes interface type information and interface number information of an optical path that can be terminated at the node.

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