JP3925468B2 - Path capacity and path route changing method, and node device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a path capacity and path route changing method in a variable capacity path, and more particularly, to a method for changing the capacity and route of a lower layer path according to the traffic amount of an upper layer network and the resource utilization status of a lower layer network.
[Prior art]
In recent years, traffic of data communication including the Internet has increased rapidly. For this reason, the network needs a large capacity network node device and a large capacity link technology in order to process a large amount of traffic and perform large capacity transmission.
[0002]
IP (Internet Protocol) networks such as the Internet and Ethernet (registered trademark), which are representative of the Internet, use SDH (Synchronous Digital Hierarchy), which is a circuit-switched network with a fixed bandwidth, as a lower layer network for transmitting traffic. Often used network. The SDH network is a network having a method of setting a start point and an end point, and setting a path in a fixed manner. Once a path is set, a constant route and capacity are always secured in the network.
[0003]
Recently, a WDM (Wavelength Division Multiplexing) technique and a photonic network using an optical cross-connect technique using an optical switch are coming soon as a next-generation lower layer network technique. In the above network, in the photonic network, the start point node and the end point node are determined and a path called an optical path is set to realize a large-capacity and flexible network. The path capacity is determined using the same method as that for the SDH network, and the optical path capacity and the optical path path are fixed. Therefore, the wavelength resources in the photonic network are reduced for IP traffic with extremely large traffic fluctuations. It cannot be said that it can be used flexibly, and as a result, the use efficiency of the wavelength resource does not increase, and it is difficult to reduce the cost per wavelength in the photonic network.
[0004]
In order to effectively use wavelength resources in a photonic network and reduce the cost per wavelength, a variable capacity link device and a variable capacity link setting method (for example, Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document) 3), a variable capacity link mechanism has been proposed.
[0005]
In this variable capacity link mechanism, traffic such as IP and Ethernet (registered trademark) is observed in the upper layer, the optical path capacity in the photonic network is controlled according to the traffic volume, and wavelength resources in the photonic network are effective. It can be used.
[0006]
[Non-Patent Document 1]
"Tsukushima, Takahashi, Okazaki, Watanabe" Variable capacity optical path virtual concatenation method in photonic network "March 28, 2002, IEICE General Conference, Proceedings p.502"
[0007]
[Non-Patent Document 2]
"Okazaki, Tsukishima, Watanabe, Takahashi" Effects of variable-capacity optical path system in photonic network "August 2, 2002, IEICE Technical Committee, Proceedings pp.49-54"
[0008]
[Non-Patent Document 3]
“Okazaki, Watanabe, Tsukishima, Takahashi, Takikawa,“ VCOP (Virtual Concatenated Optical Path) system evaluation ”March 28, 2002, IEICE General Conference, Proceedings p.503”
[0009]
[Problems to be solved by the invention]
However, in order to share resources in a network with multiple optical paths and increase the resource utilization efficiency of the entire network, it is necessary to set path routes that take into account the resources in the network. No specific method has been proposed for how to allocate between paths.
[0010]
In the conventional SDH network, in order to improve the resource utilization efficiency in the network, in order to optimize the resource usage status of the entire network, the path route is periodically changed to equalize the paths in the network. A network reconfiguration is performed to perform the distribution.
[0011]
However, in the network reconfiguration in the conventional SDH network, since the path route switching operation is performed at the path termination unit that accommodates the traffic in the SDH path, a traffic loss occurs when the path route is switched. Furthermore, in order to prevent traffic loss, a large amount of buffers must be provided in the path termination unit according to the time required for path switching, and path routing without traffic loss is a very expensive method. It has become.
[0012]
In addition, since switching a path route in a conventional SDH network requires a lot of manpower and time from the path route selection until the path route is actually switched, the traffic volume and the traffic route mainly using the latest IP In such a traffic form that dynamically changes in a short time, there is a problem that the speed of network reconstruction cannot keep up with the speed of change of IP traffic flowing into the network.
[0013]
Here, by combining the above-described variable capacity link device and variable capacity link setting method with the network reconfiguration method in the conventional SDH network, the network reconfiguration is periodically performed in the photonic network, so that the traffic volume is increased. In addition to increasing / decreasing the optical path capacity at the same time, when considering the effective use of resources as a whole network, the path route switching method in the SDH network is configured to reconfigure the network with respect to the fluctuation cycle of the IP traffic. The frequency is not sufficient, and a traffic loss occurs when the path route is switched, which adversely affects the throughput of IP traffic.
[0014]
In order to prevent traffic loss, providing a large amount of buffer at the path termination portion of the photonic network is contrary to the purpose of effectively using network resources and reducing costs.
[0015]
The present invention has been made in view of the above points, and according to the traffic amount in the upper layer network and the resource utilization status of the lower layer network, the path and capacity of the lower layer path without losing the upper layer traffic. It aims at providing the technology which changes.
[0016]
[Means for Solving the Problems]
In the layered network having a node device having a function of distributing the upper layer traffic to each member path of the lower layer path, the member path depends on the upper layer traffic amount and the resource usage status of the lower layer network. By changing the route and capacity of the lower layer path without losing the upper layer traffic by adding, removing, changing the route, and distributing the upper layer traffic to the member paths, A step of acquiring a lower layer network resource utilization state, a step of determining a necessary number of member paths from the upper layer traffic volume, and a route search of the necessary number of member paths using the lower layer network resource utilization state. , Route search The steps to determine the member path to be added or deleted according to the setting status of the existing member path, the member path that needs to be added are added, the upper layer traffic is distributed to the added member path, and the member that needs to be deleted And a method of removing and allocating traffic from the path and deleting member paths that need to be deleted.
[0017]
According to the present invention, upper layer traffic is distributed to the member path determined by the route search including the added member path. Therefore, in the case of the conventional SDH path in which the path route switching operation is performed at the path termination unit. In contrast, it is possible to increase or decrease the path capacity and change the path route without losing the traffic of the upper layer network accommodated in the lower layer path. Thereby, path capacity increase / decrease and path route change can be executed at any time according to actual upper layer traffic fluctuation.
[0018]
In addition, according to the upper layer network traffic volume accommodated in the lower layer path and the resource usage status in the lower layer network, it is possible to execute lower layer path capacity increase / decrease and lower layer path route change. It can be used efficiently.
[0019]
In addition, by selecting a route search algorithm as appropriate, the route of all member paths that make up the lower layer path can be simultaneously searched and reset depending on the number of member paths, thus improving the network resource utilization rate. In addition, it is possible to set a lower layer path having high fault tolerance.
[0020]
In the step of determining the member paths to be added or deleted, there are N existing member paths (N is a natural number), and the required number of member paths according to higher layer traffic is N + M (M is an integer, N ≧ − M), the member path route obtained as a result of the route search is compared with the existing member path route, and the number h (h is a natural number) of member paths to be added and the route are deleted. The number of member paths (Mh) and the route are determined.
[0021]
The addition and deletion of the member path is performed using inter-node device signaling, and information for specifying the member path addition, information for specifying the member path deletion, or information for changing the member path route, In addition, information indicating that higher layer traffic is allocated to member paths is included in the signaling message.
[0022]
When a member path is added using the above-mentioned signaling between node devices, if the lower layer management control means receives a signaling message for member path setting at the start or end node of the member path, the necessary information from the message And sends a message requesting movement and distribution of upper layer traffic to the upper layer management control means, and the upper layer control means receives the request message and moves the upper layer traffic to the set member path. And control to perform allocation.
[0023]
When the member path is deleted using the above-mentioned inter-node device signaling, at the start or end node of the member path, a message requesting movement and distribution of upper layer traffic is sent to the upper layer management control means, After the upper layer traffic is removed from the member path that needs to be deleted and distributed to other member paths by the control of the layer management control means, a completion notification is sent from the upper layer management control means to the lower layer management control means, Upon receiving the notification, the lower layer management control means transmits a signaling message for deleting the member path to delete the member path in the network.
[0024]
When changing the path of a member path using the above-mentioned signaling between node devices, at the start or end node of the member path, after receiving the signaling message for setting the member path, the movement of higher layer traffic from the message and Information necessary for distribution is extracted, and a message requesting movement and distribution of upper layer traffic is sent to the upper layer management control means. The upper layer management control means receives the request message and sets the member After completing the removal and redistribution of the upper layer traffic from the member path that needs to be moved and distributed to the path, the lower layer management control unit receives the notification. To delete the member path To remove a member path in the network by sending a grayed message.
[0025]
In the inter-node-device signaling, RSVP-TE (Resource Reservation Protocol for Traffic Engineering), CR-LDP (expanded) is included by including information instructing the change of the lower layer path of the upper layer traffic in the signaling message. Constraint Based-Label Distribution Protocol), PNNI, LDP, or ONNI signaling protocol can be used.
[0026]
In the method of the present invention, an NMS (Network Management System) is installed in the lower layer network, the NMS searches for the route, determines a member path to be added or deleted, and further adds or deletes the member path. Information used for signaling between the NMS and the node device, and information for clearly indicating member path addition, information for clearly indicating member path deletion, or member in a signaling message between the NMS and the node device Information for changing the path route and information for instructing to allocate higher layer traffic to the member paths may be included.
[0027]
The upper layer traffic in the method of the present invention includes, for example, an IP packet, an Ethernet frame, a fiber channel frame, a frame relay frame, an ATM cell, or an X. 25 packets.
[0028]
In addition, the lower layer path is, for example, ITU-TG. 707-compliant VC-3, VC-4 path, G.707. 709-based OCh path, ATM VP (Virtual Path), VC (virtual Channel), or MPLS or GMPLS (Label Switched Path).
Also, the lower layer path is ITU-T G.264. 707, G.M. 709-compliant VC-3xc, VC-4xc, or ODU-xc virtual concatenation path, and a plurality of member paths in the lower layer path can be linked to LCAS (Link Capacity Adjustment Scheme) technology or IEEE802. .3ad Link Aggregation technology may be used to recognize a single large capacity lower layer path.
[0029]
The node device in the method of the present invention has a forwarding table in which information of upper layer traffic and a forwarding destination member path are paired, and members described in the forwarding table in the allocation of the upper layer traffic By changing the path, the transfer destination member path can be changed. By determining the transfer destination member path of the upper layer traffic using such a transfer table and transferring the upper layer traffic, the upper layer traffic can be distributed.
[0030]
The information possessed by the upper layer traffic can be a hash value obtained by substituting the predetermined information owned by the upper layer traffic itself into a hash function. Thereby, traffic can be distributed equally.
[0031]
The predetermined information possessed by the upper layer traffic itself is information including all or part of an IP address, a port number, and a protocol number when the upper layer traffic is an IP packet. Is an Ethernet (registered trademark) frame, it is information including all or part of the Ethernet (registered trademark) address, IP address, port number, protocol number, and when the upper layer traffic is an FC frame, This information includes all or part of a WWNN (World Wide Port Name), protocol number, and SCSI ID.
[0032]
In the route search in the method of the present invention, the link cost in the network used for the route search is dynamically changed with the number of member paths using the link as a variable, and the link usage rate is changed to the node device in the network. By notifying, the node device can perform a route search considering the resource usage status in the network.
[0033]
In the route search, OSPF-TE (Open Shortest Path First for Traffic Engineering), IS-IS (Intermediate System-Intermediate System), OSPF, or IGRP is used as a protocol for notifying the network of link cost information used for route search. (Interior Gateway Routing Protocol) can be used.
[0034]
In the route search, a policy server is installed in the lower layer network, the link cost information in the lower layer network is held in the server, and the node device of the network communicates with the server, so that the route information May be obtained.
[0035]
Further, in the route search, when the starting point node of the lower layer path performs the route search of a plurality of member paths one by one, the link cost information collected in the network is used, and the member path searched first is By increasing the cost of the passing link by a certain amount, the link cost is further changed, the next link path is searched using the changed link cost, and the member paths of a plurality of different paths are searched. You can also search for routes.
[0036]
In the route search for a plurality of member paths, when the lower layer network is recognized as a directed graph and the search is performed from the start node to the end node, the positive direction of the member path is the direction from the start node to the end node. Using the directed graph, the member path route is searched using its network cost, and the cost of the link that the searched member path has passed is set to a fixed value in the direction in which the member path is set. In addition, the link cost in the direction opposite to the direction of the member path is set to a negative value, and the shortest path search of the next member path is performed using the changed link cost. When there is a link that crosses in the opposite direction with the member path searched earlier In the nodes located at both ends of the corresponding link, the path of the member path searched earlier and the path of the member path searched later are exchanged, and a plurality of paths of different path member paths are determined simultaneously. The member path route can be searched simultaneously.
[0037]
In the route search, the Dijkstra shortest route search method, Node Disjoint Algorithm shortest route search method that is an extended algorithm of Dijkstra shortest route search method, or Link Disjoint Algorithm shortest route search method that is an extended algorithm of Dijkstra shortest route search method. A plurality of different path member paths may be searched using.
[0038]
Further, the present invention for solving the above-described problem is a node device that distributes upper layer traffic to each member path of a lower layer path, and includes an upper layer traffic transmission / reception unit that accommodates upper layer traffic, and upper layer traffic distribution And an upper layer traffic switching unit that performs forwarding, an upper layer traffic accommodating unit that accommodates upper layer traffic in a lower layer path, a lower layer path termination unit that terminates a lower layer path including member paths, and a cross that performs cross connection of lower layer paths A connection switch unit, an upper layer traffic management control unit that manages the distribution and transfer of upper layer traffic, and a lower layer path management control unit that sets, deletes, and sets a lower layer path. A communication line is provided between the management control unit and the upper layer traffic management control unit, and the lower layer path management control unit notifies the upper layer traffic management request to the upper layer traffic management control unit via the communication line. The management control unit notifies the lower layer path management control unit of requests for addition and deletion of member paths.
[0039]
Further, the above node device includes an upper layer network node having an upper layer traffic switch unit, an upper layer traffic transmission / reception unit, and an upper layer traffic management control unit, an upper layer traffic accommodating unit, a lower layer path termination unit, a cross-connect switch unit, And the lower layer network node having the lower layer path management control unit, and the control between the main signal line through which the upper layer traffic passes between the upper layer network node and the lower layer network node and the management control unit A control signal line through which signals pass may be provided.
[0040]
The upper layer traffic management control unit in the node device has a transfer table in which information of the upper layer traffic and a transfer destination member path are paired, and the upper layer traffic switch unit refers to the transfer table. The upper layer traffic is distributed. To change the transfer destination member path, the transfer destination member path in the transfer table may be changed.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0042]
First, the concept of the embodiment of the present invention will be described.
[0043]
In current IP-centric networks, most communications are maintained and are rarely recognized as quality degradation unless IP packets are lost. Conventionally, in a path communication network used as a lower layer network such as an IP network, particularly an SDH network, when switching a path route without traffic loss, the purpose is to switch without loss of traffic in bit units. However, there is a communication paradigm shift in which most communication is maintained unless packets are lost as described above.
[0044]
Therefore, even when IP traffic is accommodated in the optical path, if the setting, deletion, and route change of the optical path can be executed so that even the packets constituting the IP traffic are not lost, it is effective for the IP network. In the lower layer network, dynamic network resources can be used while providing a variable capacity optical path without traffic loss.
[0045]
In this specification, a network that performs packet-based traffic transfer such as IP is referred to as an upper layer network, and packet-based traffic is referred to as upper-layer traffic, which accommodates packet-based traffic such as IP packets and is based on circuit switching. A path communication network that sets and deletes a path and transfers traffic is called a lower layer network, and a path in the path communication network is called a lower layer path.
[0046]
Further, the upper layer network in the present embodiment is a network having a function of distributing and transferring traffic according to destination information that the traffic itself has. Furthermore, the lower layer network in the present embodiment has a path communication function that sets a path between any two nodes in the network, accommodates traffic in the path, and transfers traffic transparently between the nodes. If the path in the lower layer can be managed as an aggregate of one or more paths and each path constituting the path is defined as a member path, the number of member paths is the traffic volume. It is a path communication network having a variable capacity link function that can change the path capacity by increasing / decreasing according to.
[0047]
In the upper layer network, traffic is transferred in units of packets as described above, and a packet switch is generally used to execute the transfer. Using the switch, packets can be distributed and transferred to different destinations.
[0048]
Accordingly, in the present invention, a packet switching function in the upper layer network and a path setting / deleting function in the lower layer network are combined to manage and control the packet transmission destination in the upper layer network, and path management control in the lower layer network. Link up and down functions to distribute / forward upper layer traffic and set / delete lower layer path to increase / decrease path capacity and change path path in path communication network without losing upper layer traffic A method is proposed. In other words, using a path capacity increase / decrease as a trigger, set a new path in the lower layer network, move traffic without loss of traffic from the existing path, and then delete the existing path. And reconfigure the network.
[0049]
As described above, in the present embodiment, means and procedures necessary for the upper layer network and the lower layer network to cooperate to increase / decrease the lower layer path and change the route of the lower layer path without traffic loss. In addition, the lower layer path capacity is increased / decreased by increasing / decreasing the number of member paths according to the upper layer traffic volume that can be obtained as a result, and the path of the lower layer path is changed according to the usage status of the lower layer network resources. A method for this will be described.
[0050]
First, a schematic configuration of the embodiment of the present invention will be described.
[0051]
The node in the embodiment of the present invention, as will be described in detail later, is a lower layer path management control unit that manages lower layer network resources in the device, and upper layer traffic that performs processing such as observing an upper layer traffic amount. A management control unit is provided, and a communication line is provided between the two function units so that necessary information can be exchanged between the two networks.
[0052]
FIG. 1 shows an outline of the operation related to node control in the present embodiment.
[0053]
As shown in FIG. 1, an upper layer traffic distribution request message is sent from the lower layer path management control unit to the upper layer traffic management control unit, and an upper layer traffic distribution completion notification is sent from the upper layer traffic management control unit to the lower layer path management control unit. A message is sent out.
[0054]
The upper layer traffic distribution request message includes a notification requesting that upper layer traffic is distributed to the set member path when the member path is set in the lower layer network, and when the member path is deleted. And a notification requesting to allocate higher layer traffic from the member path to be deleted to other member paths constituting the path.
[0055]
The upper layer traffic distribution completion notification message is used to notify the lower layer network from the upper layer network that the upper layer traffic distribution has been completed.
[0056]
Further, the node device according to the present embodiment may have a function of requesting addition and deletion of member paths from the upper layer network to the lower layer network.
[0057]
FIG. 2 shows a basic flow for realizing the present embodiment.
[0058]
First, the upper layer traffic volume and the lower layer resource utilization status are observed (step 1), and the number of member paths that need to be increased or decreased, or the number of member paths that need to be changed, or both are determined from the observation results (step 2) and set. The member path route to be searched is searched (step 3), and the lower layer path route change and capacity increase / decrease are executed without losing the upper layer traffic (step 4).
[0059]
Hereinafter, embodiments of the present invention will be described in more detail.
[0060]
(First embodiment)
First, the network configuration in the first embodiment will be described with reference to FIG.
[0061]
The network in the present embodiment includes upper layer network nodes 21 and 22, edge nodes 23 and 24, and core nodes 25 and 26. Each edge node is a node that is connected to the upper layer network node 21, serves as a boundary between the upper layer network and the lower layer network, and can perform upper layer processing and lower layer processing. Each core node is a node that performs only a lower layer path cross-connection process. The edge node can also be used as a core node that performs only lower layer processing.
[0062]
Among the edge nodes, a node that is a starting point of a lower layer path is particularly referred to as a starting node, and a node that is an end point of a lower layer path is referred to as an end node. A core node through which a path passes is defined as a transit node, and a lower layer path is set from the start node to the end node via the transit node. The lower layer path may be a unidirectional path for transmitting traffic in one direction from the start node to the end node, or may be a bidirectional path for transmitting traffic bi-directionally between the start node and the end node.
[0063]
In the case of a bidirectional path, the start point node and the end point node are distinguished from each other in advance by determining which edge node is set as the start point node and the end point node when setting the path.
[0064]
FIG. 4 shows a network node configuration in the embodiment of the present invention. This network node corresponds to the edge node in FIG.
[0065]
As shown in FIG. 4, the network node according to the present embodiment includes an upper layer signal transmission / reception unit 1 for transmitting / receiving upper layer packet / frame-based traffic, a transfer process of upper layer traffic, and an arbitrary lower layer path. Upper layer traffic switch unit 2 that forwards traffic, upper layer traffic accommodation unit 3 that accommodates upper layer traffic in the lower layer path, lower layer path termination unit 4 that terminates the lower layer path, and lower layer that performs cross connection of the lower layer path Layer path cross-connect switch unit 5, upper layer traffic management control unit 6 that performs management control of upper layer traffic transfer, and lower layer path that manages lower layer paths and performs routing / signaling in the lower layer And a management control unit 7.
[0066]
The user data signal is exchanged with the upper layer network 8 via the link 9 and exchanged with the lower layer network via the link 13.
[0067]
In the node, the upper layer signal transmission / reception unit 1 and the upper layer traffic switch unit 2 are connected via a data transfer channel 10, and the upper layer traffic switch unit 2 and the upper layer traffic accommodation unit 3 are connected via a data transfer channel 11. In addition, the lower layer path termination unit 4 and the cross-connect switch unit 5 are connected via a data transfer channel 12.
[0068]
The upper layer switch traffic management control unit 6, the lower layer path management control unit 7, the upper layer traffic switch unit 2, the lower layer traffic accommodation unit 3, and the lower layer path termination unit 4 are managed via control signal lines 15, 16, and 17. Exchange control signals.
[0069]
Exchange of management control messages with the upper layer network 8 is performed via the control signal line 18, and management control messages with the lower layer network 14 are exchanged via the control signal line 19.
[0070]
In the present embodiment, the lower layer path can be a single large-capacity path by bundling a plurality of lower layer paths. In this case, individual paths constituting the large capacity path are hereinafter defined as member paths.
[0071]
In the present embodiment, the member path may be recognized as one large capacity lower layer path using an LCAS (Link Capacity Adjustment Scheme) technique, or one path using the IEEE 802.3ad Link Aggregation technique. It may be regarded as a large capacity lower layer path.
[0072]
The upper layer traffic in the present embodiment includes, for example, an IP packet, an Ethernet (registered trademark) frame, a fiber channel frame, a frame relay frame, an ATM cell, an X. One of 25 packets. The method in this embodiment can be applied to any traffic.
[0073]
The upper layer network in the present embodiment is, for example, any of an IP / MPLS network, an Ethernet (registered trademark) network, a fiber channel network, an ATM network, and a frame relay network.
[0074]
In addition, the lower layer path or member path in the present embodiment is, for example, ITU-TG. 707-compliant VC-3, VC-4 path, G.707. 709-based OCh path or ATM VP (Virtual Path), VC (Virtual Channel), MPLS, or LSP (Label Switched Path) defined in GMPLS.
Next, the processing of the node for changing the path capacity and path route in the present embodiment will be described with reference to the flowchart of FIG.
[0075]
First, the upper layer traffic volume and the lower layer network resource utilization status are regularly observed (step 10).
[0076]
Then, based on the observation results, the member paths are increased / decreased and the number of member paths to be increased / decreased is determined (step 11). When the number of existing member paths before the increase / decrease of the member paths is N (N is a natural number), the number of member paths to be increased / decreased is determined to be M (M: integer) according to the determination in step 11. After the member paths are increased / decreased, the number of member paths is N + M (M is an integer).
[0077]
Next, all N + M member path routes after the increase / decrease of member paths are searched based on the observed lower layer resource utilization status (step 12).
[0078]
Next, the newly searched N + M member path routes are compared with the existing member path routes that have already been set, and the number h of member paths to be additionally set and the number i of member paths to be deleted are determined. (Step 13).
[0079]
Next, h member paths are set, i member paths are deleted, and upper layer traffic is distributed from the member paths to be deleted to other member paths (step 14).
[0080]
Step 14 includes more detailed steps (Step 15, Step 16, Step 17, Step 18, Step 19, and Step 20).
[0081]
By executing the above five steps, it is possible to perform variable capacity operations while increasing the use efficiency of network resources by changing the member paths in accordance with the network conditions at the same time as increasing or decreasing the member paths.
[0082]
Hereinafter, each step will be described in more detail.
[0083]
First, step 10 will be described.
[0084]
At the start node and the end node, the upper layer traffic volume accommodated in the lower layer path is observed in the node device. This is executed, for example, by the upper layer traffic management control unit 6 in the node. On the other hand, the resource usage status in the lower layer network is collected using a protocol such as a routing protocol in the network. This process is executed by, for example, the lower layer path management control unit 7.
[0085]
In order to collect the resource usage status in the lower layer network, for example, nodes connected to both ends of the link advertise information in the network using OSPF-TE (Open Shortest Path First-Traffic Engineering). This is performed by collecting network link cost information in a distributed manner for each node. Further, a server that collectively manages route information may be provided in the lower layer network, and each node may acquire information from the server.
[0086]
Next, step 11 will be described in detail.
[0087]
Compare the observed traffic volume with the number of member paths. If the lower layer path capacity is insufficient, decide to increase the member path. If the lower layer path capacity is excessive, decide to reduce the member path. Determine the number of member paths to increase or decrease. As a method for determining the member path increase / decrease setting, for example, the methods described in Non-Patent Documents 1 to 3 can be used.
[0088]
Next, step 12 will be described in detail.
[0089]
In step 11, when it is determined that the existing N member paths are set to N + M (M: integer), the present embodiment searches for the path of each member path according to the following procedure.
[0090]
The search for the member path route may be performed in a centralized manner using a policy server existing in the lower layer network, or may be performed in a distributed manner by each edge node in the network. In this embodiment, a case where member path search is performed in a distributed manner will be described. In each edge node, for example, the lower layer path management control unit performs a route search.
[0091]
As a route selection method, Dijkstra's shortest route search method in which the link cost used for route search is dynamically changed is used. According to the shortest path search method, first, a variable cost is defined for the link between nodes in the network, with the amount of used resources as a variable. In this embodiment, if the total amount of prepared resources in a link is A, and the number of member paths that use a link between nodes at a certain time is B, the link cost is given by A / (A−B). I will do it.
[0092]
At the starting point node that is the starting point of the path, the shortest path search is performed based on the collected information, and the path of each member path is determined. The route is searched one by one, and each time one route is searched, the variable B related to the cost of the link is increased along the searched route. The second and subsequent member path routes are searched based on the updated link cost information.
[0093]
Next, step 13 will be described in detail.
[0094]
First, the route of N + M member paths searched in step 12 is compared with the route of N existing member paths that already exist, and whether there is an existing member path of the same route as the route of the new member path. Search for. Then, the number h of new member paths and routes that need to be additionally set and the number i of member paths that need to be deleted that need to be deleted are determined. Here, the relationship between M, h, and i is h−M = i (M: integer, h: natural number, i: natural number).
[0095]
Next, step 14 will be described in detail.
[0096]
In step 14, in the present embodiment, different flows are used in the case of member path addition and reduction. First, a description will be given of the case of member path expansion in the case where M is a positive integer (step 14) shown in FIG.
[0097]
As a result of the route comparison between the existing member path and the new member path, it is assumed that there are h (= M + i) new member paths and i required deletion member paths out of the N existing member paths.
[0098]
First, of the h (= M + i) new member paths, M new member paths are set first. After the member path setting is completed, traffic is distributed among the N existing member paths (step 16).
[0099]
Next, i sets of i deletion-needed member paths and h-M (= i) unset new member paths are created. For each group, a new member path is set, the traffic is moved from the paired deletion-needed member path to the new member path, and the deletion-needed member path is deleted after the traffic is moved. As a result, the member path is changed (step 19). The movement of i pairs of traffic may be executed sequentially or in parallel.
[0100]
By performing the above processing, M member path expansion and path change are completed.
[0101]
Next, a description will be given of the case of member path reduction shown in FIG. 5 when M is a negative integer (step 14).
[0102]
As a result of the route comparison between the existing member path and the new member path, it is assumed that there are h (= M + i) new member paths and i required deletion member paths out of the N existing member paths. First, of the i books, | M | The traffic is redistributed from the required deletion path to other existing member paths. After the traffic redistribution is completed, | M | number of required deletion paths are deleted (step 18).
[0103]
Next, h sets of unset new member paths h (= M + i) new member paths and undeleted i + M (= h) member member paths that need to be deleted are created. For each of these sets, a new member path is set, the traffic is moved from the pair-required member path to be deleted, and the member path required is changed by deleting the member path that needs to be removed after the movement of the traffic (step 19). ). The movement of h pairs of traffic may be executed sequentially or in parallel.
[0104]
In addition, when M = 0, h sets of h (= i) new member paths and i (= h) deletion-needed member paths are created. For each set, a new member path is set, the traffic is moved from the pair-required member path that needs to be deleted, and the member path is changed by deleting the member path that needs to be removed after the traffic is moved (step 17). ). The movement of h pairs of traffic may be executed sequentially or in parallel.
[0105]
By performing the above processing, M member path reduction and route change are completed. Next, traffic distribution and traffic movement will be described in more detail.
[0106]
For allocation of traffic to member paths, a traffic distribution function is used in an upper layer. This will be briefly described below.
[0107]
As shown in FIG. 6, the upper layer traffic management control unit 6 holds two upper layer traffic transfer tables indicating the transfer destination of the upper layer traffic.
[0108]
The upper layer traffic switch unit 2 determines the transfer destination lower layer path using the destination information. Therefore, the destination information attached to the upper layer traffic and the transfer destination lower layer path are paired. This transfer table is referred to as a destination transfer table 41. The upper layer traffic is first distributed to the transfer destination lower layer path using the destination information of the upper layer traffic.
[0109]
The functional unit in the upper layer traffic switch unit 2 corresponding to the destination transfer table 41 is the destination transfer switch unit 43 shown in FIG.
[0110]
Since the lower layer path is composed of a plurality of member paths, it is necessary to determine which member path the upper layer traffic is forwarded to. For this reason, the upper layer management control unit 6 has a distribution transfer table 42 which is another transfer table in which a hash value calculated using partial information of upper layer traffic and a transfer destination member path are paired. is doing. When the member path is increased or decreased and the route is changed, the destination member path of the higher layer traffic is changed by changing the transfer destination member path of the distribution transfer table. A function unit in the upper layer traffic switch unit corresponding to the distribution transfer table is a distribution transfer switch unit 44.
[0111]
When the hash value is obtained, appropriate information may be used among the information of the upper layer traffic. A hash value is obtained by inputting the information as a variable into a hash function. In order to obtain an even distribution, the number of hash values should be larger than the number of member paths. Ideally, it should be a value that is an integral multiple of the least common multiple of the number that the transfer destination member path can take. For example, when the number of member paths can be changed from 1 to 5, a hash function for which 60 hash values that are the least common multiple of 1 to 5 are calculated is selected.
[0112]
In actual operation, for example, packet A, packet B, and packet C are transmitted in this order, and the transfer destination member path is changed from the A member path to the B member path. In that case, after the transmission of the packet A to the A member path, the change of the distribution forwarding table is applied and the switch configuration of the upper layer traffic switch unit is changed, so that the packets B and C become the B member. It will be sent to the path.
[0113]
By using such a packet transfer mechanism, the accommodation member path of the upper layer traffic can be changed. Further, by using the upper layer traffic transfer method, it is possible to switch the member path route without losing the upper layer traffic. That is, the accommodation member member path is changed according to the setting of the distribution transfer table, so that the upper layer traffic is not lost.
[0114]
Next, a signaling sequence example of member path addition / deletion and traffic movement / distribution in step 14 of FIG. 5 is shown.
[0115]
[Signaling sequence for additional member paths]
First, FIG. 7 and FIG. 8 show the detailed signaling sequence in the case of member path extension in step 14.
(1) First, the lower layer path management control unit of the starting node searches for the port of the lower layer path termination unit used by the new member path and the free port of the cross-connect switch unit of the lower layer. A reservation is made at (Step 21).
(2) Next, the new member path sets information that clearly indicates that the member path is set to increase the member path, and a message that contains information for requesting a change in the distribution / forwarding table of traffic in the upper layer. To the transit node scheduled to be executed (step 22).
[0116]
In FIG. 7, there is one transit node, but there may be no transit node between the start node and the end node, or there may be two or more.
(3) When the relay node receives the above message, the lower layer path management control unit searches for a lower layer path resource vacancy, reserves a path on the lower layer path management control unit (step 23), and then passes the next relay node. In response to this, a message similar to the above message is transmitted (step 24).
(4) When the destination node receives the message, it searches for the lower layer termination port used by the new member path and the empty port of the lower layer cross-connect switch unit, and the port on the lower layer path management control unit. Is reserved (step 25), the upper layer traffic management control unit is notified of information for instructing that the port of the upper layer switch can be used (step 26).
(5) Upon receiving the notification, the upper layer traffic management control unit sets the upper layer switch unit switch port so as to be able to transmit and receive upper layer traffic (step 27), and to the lower layer path management control unit, A message containing information indicating that the output port to the lower layer path of the upper layer switch can transmit and receive is notified (step 28).
(6) Upon receiving the notification, the lower layer path management control unit executes the settings of the lower layer path termination unit and the cross-connect switch unit (step 29), and sends a message containing setting completion information at the end point to the relay node. It transmits to (step 30).
(7) Upon receipt of the message, the transit node sets the cross-connect switch unit (step 31), and transmits a message containing information similar to the above message to the next transit node ( Step 32).
(8) When the source node receives the message, the lower layer path management control unit sets the lower layer path termination unit and the cross-connect switch unit (step 33), completes the member path setting, and performs upper layer traffic management. The control unit is notified (step 34).
(9) Upon receiving this notification, the upper layer traffic management control unit sets the upper layer traffic switch unit port to transmit / receive, changes the upper layer traffic distribution / forwarding table of the upper layer traffic switch unit, and changes the existing member path. Then, the traffic is distributed among the new member paths (step 35).
[0117]
Next, information indicating that preparation for transmission / reception of upper layer traffic is completed is sent to the lower layer path management control unit (step 36).
(10) The lower layer path management control unit confirms the notification (step 37), and transmits a message including information indicating that the setting is completed at the start node to the transit node of the new member path. (Step 38).
(11) The relay node confirms the message (step 39) and relays it to the next relay node (step 40).
(12) When the destination node receives and confirms the message (step 41), the lower layer path management control unit confirms the message (step 42), and notifies the upper layer traffic management control unit to perform upper layer traffic management control. The unit changes the upper layer traffic distribution / forwarding table of the upper layer traffic switch unit, and distributes the traffic between the existing member path and the new member path (step 43).
[0118]
If the upper layer traffic switch at the end node receives traffic from the start node to the end node, the upper layer traffic management control unit uses the upper layer traffic transfer table as a trigger triggered by the reception of the upper layer traffic. You may rewrite it.
[0119]
By executing the above procedure, setting of a new member path and distribution of traffic between the new member path and the existing member path are completed.
[0120]
[Member path change signaling sequence]
Next, detailed signaling sequences for member path routing changes (step 19, step 17, and step 20) that are common in step 14 are shown in FIG. 9, FIG. 10, and FIG.
(1) First, in the start node, the lower layer path management control unit searches for the port of the lower layer path termination unit used by the new member path and the empty port of the cross connect switch unit of the lower layer, and the lower layer path management control unit The above reservation is made (step 61).
(2) Next, the new member path sets information that clearly indicates that the member path is set to increase the member path, and a message that contains information for requesting a change in the distribution / forwarding table of traffic in the upper layer. To the transit node scheduled to be sent. (Step 62). In FIG. 9, there is one transit node, but there may be no transit node between the start node and the end node, or there may be two or more transit nodes.
(3) When the relay node receives the message, the lower layer path management control unit searches for a lower layer path resource vacancy and reserves the lower layer path management control unit (step 63). A message similar to the above message is transmitted (step 64).
(4) When the destination node receives the message, it searches the lower layer path termination port used by the new member path and the empty port of the lower layer cross-connect switch unit, and reserves it on the lower layer path management control unit. After (Step 65), the upper layer traffic management control unit is notified of information instructing that the port of the upper layer traffic switch unit can be used (Step 66).
(5) Upon receiving the notification, the upper layer traffic management control unit sets the upper layer traffic switch unit port so that the upper layer traffic can be transmitted and received (step 67), and the upper layer traffic management control unit A message containing information indicating that the output port to the lower layer path of the layer switch can transmit and receive is notified (step 68).
(6) Upon receiving the notification, the lower layer path management control unit executes the settings of the lower layer path termination unit and the cross-connect switch unit (step 69), and sends a message containing information on the completion of setting at the end point to the via node (Step 70).
(7) Upon receipt of the message, the transit node sets the cross-connect switch unit (step 71), and transmits a message containing the same information as the message to the next transit node (step 71). 72).
(8) When the source node receives the message, the lower layer path management control unit sets the lower layer path termination unit and the cross-connect switch unit (step 73), completes the member path setting, and performs upper layer traffic management. The control unit is notified (step 74).
(9) Upon receiving this notification, the upper layer traffic management control unit sets the upper layer traffic switch unit port so that transmission / reception is possible, changes the upper layer traffic distribution / forwarding table of the upper layer traffic switch unit, The traffic is moved between the path and the new member path (step 75).
[0121]
Next, information indicating that preparation for transmission / reception of upper layer traffic has been completed is notified to the lower layer path management control unit (step 76).
(10) The lower layer path management control unit confirms the notification (step 77), and at the start node, transmits a message containing information indicating that the setting is completed to the transit node of the new member path ( Step 78).
(11) The relay node confirms the message (step 79) and relays it to the next relay node (step 80).
(12) When the destination node receives and confirms the message (step 81), the lower layer path management control unit confirms (step 82) and notifies the upper layer traffic management control unit. Then, the upper layer traffic distribution / forwarding table of the upper layer traffic switch unit is changed, and the traffic is moved between the member path requiring deletion and the new member path (step 83).
(13) As shown in FIG. 11, after sending the above message along the new member path route, the start node sends the unused lower layer path termination unit related to the member path to be deleted and the port of the cross-connect switch unit. The release is in progress (step 85), and a message including information for deleting the member path is transmitted along the member path to be deleted (step 86).
(14) When the relay node receives the message, the port of the corresponding cross-connect switch unit is changed to be released on the lower layer path management control unit (step 87), and the message is transferred to the next relay node. (Step 88).
(15) Upon receipt of the message, the end node changes the port of the corresponding cross-connect switch unit while being released on the lower layer path management function unit (step 89), and sends the upper layer traffic management control unit to the upper layer traffic management unit. A message containing information requesting to close the traffic switch unit port is notified (step 90).
[0122]
Upon receiving the notification, the upper layer traffic management control unit confirms that the upper layer traffic has moved to the new member path, closes the port of the upper layer traffic switch unit (step 91), and The lower layer path management control unit is notified of a message including information on closing the port (step 92).
(16) Upon receiving the message, the lower layer path management control unit cancels the setting of the lower layer path termination unit and the setting of the lower layer cross-connect switch unit (step 93). A message containing the information for which the deletion process has been completed is transmitted (step 94).
(17) Upon receipt of the message, the transit node cancels the setting of the port of the cross-connect switch unit (step 95) and transfers the message to the next transit node (step 96).
(18) When the source node receives the message, after confirmation (step 97), it notifies the upper layer traffic management control unit of a message requesting to cancel the setting of the upper layer switch unit (step 98).
(19) Upon receiving the notification, the upper layer traffic management control unit closes the port of the upper layer switch (step 99) and notifies the lower layer path management control unit. (Step 100)
(20) Upon receiving the message, the lower layer path management control unit cancels the setting of the lower layer path termination unit and the setting of the cross-connect switch unit (step 101), and the deletion of the member path requiring deletion is completed.
[0123]
[Signaling sequence for member path reduction]
Finally, the detailed signaling sequence (step 18) for member path reduction in step 14 will be described with reference to FIG.
(1) First, in the upper layer traffic management control unit, the upper layer traffic distribution / forwarding table is changed, and upper layer traffic is distributed from the member path requiring deletion to other member paths (step 111), and the lower layer path management control unit (Step 112).
(2) The start node receives the above notification and determines that the unused lower layer path termination related to the member path that needs to be deleted and the port of the cross-connect switch are being released (step 113). A message containing information for deleting the path is transmitted (step 114).
(3) When the relay node receives the message, the port of the corresponding cross-connect switch unit is changed to be released on the lower layer path management control unit (step 115), and the message is transferred to the next relay node. (Step 116).
(4) Upon reception of the message, the end node changes the port of the corresponding cross-connect switch unit to be released on the lower layer path management control unit (step 117), and changes the upper layer traffic management control unit to the upper layer traffic management control unit. A message containing information requesting to close the traffic switch port is notified (step 118).
(5) Upon receiving the notification, the upper layer traffic management control unit changes the upper layer traffic switch distribution / forwarding table, and distributes the traffic from the end node to the start node from the member path that needs to be deleted to other member paths. After closing the port of the upper layer traffic switch unit (step 119), the lower layer path management control unit is notified of a message including information on closing the port of the upper layer traffic switch unit (step 120).
(6) Upon receiving the message, the lower layer path management control unit cancels the setting of the lower layer path termination unit and the setting of the lower layer cross-connect switch unit (step 121). A message containing the information for which the deletion process has been completed is transmitted (step 122).
(7) When the relay node receives the message, it cancels the setting of the port of the cross-connect switch unit (step 123), and transfers the message to the next relay node (step 124).
(8) When the source node receives the message, after confirming (step 125), it notifies the upper layer traffic management control unit of a message requesting to cancel the setting of the upper layer traffic switch unit (step 126).
(9) Upon receiving the notification, the upper layer traffic management control unit closes the port of the upper layer switch (step 127) and notifies the lower layer management control unit (step 128).
(10) Upon receiving the message, the lower layer path management control unit cancels the setting of the lower layer path termination unit and the setting of the cross-connect switch unit (step 129), and the deletion of the member path requiring deletion is completed.
[0124]
(Second Embodiment)
Next, a second embodiment of the present invention will be described. The second embodiment is the same as the first embodiment except for the route search method. Hereinafter, a route search method according to the second embodiment will be described.
[0125]
In the second embodiment, when searching for a member path, Node Disjoint Algorithm or Link Disjoint Algorithm, which is an extended algorithm of Dijkstra method, is used. In this embodiment, the application of the Link Disjoint Algorithm will be described in detail.
[0126]
Examples of execution when the execution method of the Link Disjoint Algorithm is applied will be described in order from FIGS.
[0127]
FIG. 13 shows the network configuration and initial variable settings. A51, B52, C53, D54, E55, F56, G57, and Z58 indicate network nodes, and links are set between the nodes, for example, a link 59 between DE. The numerical value shown near the link is the link cost at that time. For links that are not specifically indicated, the link cost is the same for both directions. In the above configuration, one member path 61 is set as a result of the shortest route search. The member path 61 is set up from the node A to the node Z.
[0128]
FIG. 14 shows a change in the cost of each link after one member path is set. The link used by the member path is changed so as to be handled as a directed graph, and the cost used for route search differs depending on the direction. In the figure, the costs for searching for member paths in the direction of the arrows are shown. For the direction in which the member path is searched, a constant value is added to the cost (65, 66, 67), and for the opposite direction in which the member path is searched, the cost is changed to a negative cost (62, 63, 64).
[0129]
The route of the second member path is searched using the cost set in FIG. FIG. 15 shows a member path route search result. The second member path 68 is searched, the direction of the path is reversed between the nodes B and C 69, and it can be seen that the path routes overlap.
[0130]
Here, as shown in FIG. 16, the node B and the node C are switched between the member paths, and the paths of the two member paths (70, 71) are determined. By setting in this way, the total cost of the two paths can be reduced in the different path search as compared to the case of additionally searching for the second member path.
[0131]
FIGS. 17 and 18 show how member paths are selected in the case of the third search. Similar to the search for the second member path, the link cost is changed and the route is searched, whereby the routes of the three member paths (73, 74, 75) can be searched simultaneously.
[0132]
(Third embodiment)
Next, a third embodiment will be described.
[0133]
In the third embodiment, an upper layer network is an IP network, and a lower layer network is a G. This embodiment is the same as the first embodiment except that a photonic network conforming to 709 is specified. As the route search method, the route search method of the second embodiment may be used.
[0134]
FIG. 19 shows a node device configuration in the present embodiment.
[0135]
The node in the third embodiment includes an IP signal transmission / reception unit 81 for transmitting / receiving IP packets, an IP packet switch unit 82 for performing IP packet transfer processing and forwarding traffic to an arbitrary optical path, and IP packet optical IP traffic accommodating unit 83 that accommodates the path, optical path terminating unit 84 that terminates the optical path, optical cross-connect switch unit 85 that performs the cross-connection of the lower layer path, and IP network management that performs management control of the upper layer traffic transfer The control unit 86 has a photonic network management control unit 87 that manages optical paths and executes routing / signaling in the photonic network.
[0136]
The user data signal is exchanged with the IP router 88 via the link 89 and connected to another optical cross-connect device in the photonic network via the link 93. The link 89 is, for example, a link such as an Ethernet (registered trademark) link or a POS link. The link 93 is a link such as a WDM link or a fiber bundle link.
[0137]
In the node, the IP signal transmission / reception unit 81 and the IP packet switch unit 82 are connected via the data transfer channel 90, and the IP packet switch unit 82 and the IP traffic accommodating unit 83 are connected via the data transfer channel 91, Further, the optical path termination unit 84 and the optical cross-connect switch unit 85 are connected via a data transfer channel 92.
[0138]
The IP network management control unit 86, the photonic network management control unit 87, the IP packet switch unit 82, the optical path termination unit 84, and the IP traffic storage unit are connected via control signal lines 95, 96, 97, and 98. Exchange management control signals.
[0139]
As the optical path, a plurality of optical paths can be bundled into one large-capacity optical path. In this case, each path constituting the large capacity path is defined as a member optical path. As a technique for realizing a large-capacity optical path, IEEE 802.3ad, Link Aggregation technology, or virtual concatenation technology can be used.
[0140]
As shown in FIG. 20, the IP network management control unit 86 has two IP packet transfer tables. One is a destination transfer table 101 having a configuration in which destination information held by an IP packet and a large-capacity optical path are paired, and the other is a hash calculated using partial information held by the IP packet. The distribution transfer table 102 is a pair of a value and a transfer destination member optical path.
[0141]
When an IP packet is input, the destination transfer switch unit 103 in the IP packet switch unit 82 uses the destination information in the destination transfer table 101 to determine the transfer destination large-capacity optical path of the IP packet. That is, the transfer destination optical path corresponding to the destination IP address of the IP packet is determined, and the destination transfer switch unit 103 distributes the IP packet to the port corresponding to the optical path using the packet switching function.
[0142]
Since the large-capacity optical path is composed of a plurality of member optical paths, it is necessary to determine which member optical path the IP packet is distributed to. Therefore, the distribution transfer switch unit 104 refers to the distribution / distribution table 102 to determine which member optical path to distribute, and performs distribution. When the member optical path is increased or decreased and the route is changed, the destination member optical path of the IP packet is changed by changing the transfer destination member path of the distribution transfer table.
[0143]
As information of an IP packet used for distribution that is a source of a hash value, a value obtained by combining a destination IP address, a source IP address, a port number, a protocol number, and the like can be used.
[0144]
(Fourth embodiment)
Next, a fourth embodiment will be described.
[0145]
In the fourth embodiment, instead of inter-node signaling in the lower layer network, an NMS (Network Management System) communicates with the nodes in the network to make various settings. Except for this, it is the same as the first embodiment and the second embodiment.
[0146]
FIG. 21 shows a network node configuration in the fourth embodiment. Each of the edge nodes 111 and 112 and the core nodes 113 and 114 is connected to the NMS 115 using a dedicated control line. The work performed by the NMS 115 may be only the route determination of the member path, or the NMS may set each edge node and core node instead of inter-node signaling.
[0147]
(Fifth embodiment)
Next, a fifth embodiment will be described.
[0148]
In the fifth embodiment, the node device configuration is separated on the upper layer network side and the lower layer network side. Further, O-UNI or other signaling protocol is used between the device on the upper layer network side and the device on the lower layer network side. Except for these points, the present embodiment is the same as the first embodiment and the second embodiment.
[0149]
A network node configuration in the fifth embodiment is shown in FIG.
[0150]
In the configuration shown in FIG. 22, for example, an IP network, an Ethernet (registered trademark) network, a fiber channel network, or the like can be used as the upper layer network, and as the lower layer network, for example, ITU-TG. 707-compliant SDH network, ITU-TG 709-compliant OTN (Optical Transport Network), ATM network, or the like can be used.
A control signal line 121 is set between the upper layer traffic management control unit and the lower layer path management control unit, and control information is exchanged using the signaling protocol. Also, an Ethernet (registered trademark) line, a fiber channel line, an SDH line or the like is provided between the lower layer network apparatus and the upper layer network apparatus, and the upper layer traffic is transferred to the lower layer network apparatus through the line. .
[0151]
The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.
[0152]
【The invention's effect】
As described above, according to the present invention, it is possible to increase / decrease a path capacity and change a path route without losing traffic of an upper layer network accommodated in a path in a path communication network as a lower layer network. In addition, it is possible to execute network reconfiguration that follows fluctuations in upper layer network traffic such as IP traffic. Furthermore, it becomes possible to change the path route at any time according to the path capacity and the resource utilization status in the lower layer network.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of operation related to node control in an embodiment of the present invention;
FIG. 2 is a basic flow in the embodiment of the present invention.
FIG. 3 is a diagram showing a network configuration in the first embodiment of the present invention.
FIG. 4 is a diagram showing a network node configuration in the first exemplary embodiment of the present invention.
FIG. 5 is a detailed flow in the first embodiment of the present invention.
FIG. 6 is a diagram showing an upper layer traffic forwarding table in the first embodiment of the present invention;
FIG. 7 is a first diagram illustrating a signaling sequence for executing new member path setting and traffic distribution according to the first embodiment of this invention;
FIG. 8 is a second diagram showing a signaling sequence for executing new member path setup and traffic distribution in the first exemplary embodiment of the present invention.
FIG. 9 is a first diagram illustrating a signaling sequence for executing new member path setting, traffic movement, and deletion of a member path requiring deletion according to the first embodiment of this invention.
FIG. 10 is a second diagram illustrating a signaling sequence for executing new member path setting, traffic movement, and deletion of a member path requiring deletion according to the first embodiment of this invention.
FIG. 11 is a third diagram illustrating a signaling sequence for executing new member path setting, traffic movement, and deletion of a member path requiring deletion according to the first embodiment of this invention.
FIG. 12 is a diagram showing a signaling sequence for executing traffic distribution and deletion of a member path required deletion according to the first embodiment of the present invention.
FIG. 13 is a first diagram for explaining a route search method according to the second embodiment of the present invention;
FIG. 14 is a second diagram for explaining a route search method according to the second embodiment of the present invention;
FIG. 15 is a third diagram for explaining the route search method according to the second embodiment of the present invention;
FIG. 16 is a fourth diagram illustrating the route search method according to the second embodiment of the invention.
FIG. 17 is a fifth diagram for illustrating the route search method according to the second embodiment of the invention.
FIG. 18 is a sixth diagram for explaining the route search method according to the second embodiment of the present invention;
FIG. 19 is a diagram showing a node configuration in the third exemplary embodiment of the present invention.
FIG. 20 is a diagram showing an IP packet transfer method according to the third embodiment of the present invention;
FIG. 21 is a diagram showing a network configuration in a fourth embodiment of the present invention.
FIG. 22 is a diagram showing a node configuration in a fifth exemplary embodiment of the present invention.
[Explanation of symbols]
1 Upper layer signal transmitter / receiver
2 Upper layer traffic switch
3 Upper layer traffic accommodating part
4 Lower layer path termination
5 Lower layer path cross-connect switch section
6 Upper layer management controller
7 Lower layer management control unit
8 Upper layer network
9, 13 links
10, 11, 12 Data transfer channel
21, 22 Upper layer network node
23, 24, 111, 112 Edge node
25, 26, 113, 114 core nodes
41, 101 Destination transfer table
42, 102 Distribution transfer table
43, 103 Destination transfer switch
44, 104 Distribution transfer switch
81 IP signal transceiver
82 IP packet switch
83 IP traffic accommodation
84 Optical path termination
85 Optical cross-connect switch
86 IP network management controller
87 Photonic Network Management Control Unit
89, 93 links
88 IP router
90, 91, 92 Data transfer channel
95, 96, 97, 98 Control signal line
115 NMS

Claims (24)

In a hierarchical network that has node devices with a function to distribute upper layer traffic to each member path of the lower layer path, member paths can be increased or decreased according to the upper layer traffic volume and the resource usage status of the lower layer network. A method of changing the route and capacity of the lower layer path without losing the upper layer traffic by performing route change and distribution of the upper layer traffic to the member path,
Obtaining upper layer traffic volume and lower layer network resource usage;
Determining the required number of member paths from the upper layer traffic volume;
Performing route search of the required number of member paths using lower layer network resource usage status, determining a member path to be added or deleted according to the result of route search and the setting status of existing member paths;
A step of adding a member path that needs to be added, allocating upper layer traffic to the added member path, removing and distributing traffic from the member path that needs to be deleted, and deleting a member path that needs to be deleted;
A method characterized by comprising: In the step of determining the member path to be added or deleted,
When the number of existing member paths is N (N is a natural number) and the required number of member paths according to upper layer traffic is N + M (M is an integer, N ≧ −M), the result of the route search is obtained. The route of the obtained member path is compared with the route of the existing member path, and the number h of member paths to be added (h is a natural number) and the route, the number of member paths to be deleted (Mh) and the route are determined. The method according to claim 1. Performing addition and deletion of the member path using inter-node device signaling,
Signaling message includes information for specifying member path addition, information for specifying member path deletion, information for changing member path route, and information for instructing allocation of upper layer traffic to member paths The method according to claim 1, wherein the method is contained in In the case of extension of the member path,
When the lower layer management control means receives the signaling message for setting the member path at the start or end node of the member path, it extracts necessary information from the message,
A message requesting the movement and distribution of upper layer traffic is sent to the upper layer management control means, and the upper layer management control means receives the request message and moves and distributes the upper layer traffic to the set member path. 4. The method of claim 3, wherein the control is performed to do so. When deleting the member path:
At the start or end node of the member path, a message requesting the movement and distribution of upper layer traffic is sent to the upper layer management control means, and the upper layer traffic from the member path that needs to be deleted is controlled by the upper layer management control means. After the completion of the exclusion and distribution to other member paths, the completion notification is sent from the upper layer management control means to the lower layer management control means. Upon receiving the notification, the lower layer management control means sends a signaling message for deleting the member path. The method according to claim 3, wherein the member path in the network is deleted by sending. In the case of route change of the member path,
After receiving the signaling message for setting the member path at the start or end node of the member path, information necessary for movement and distribution of the upper layer traffic is extracted from the message, and the upper layer management control means Send a message requesting movement and distribution of traffic,
The upper layer management control means receives the request message, completes the removal and redistribution of the upper layer traffic from the member path that needs to be moved and distributed, and deleted for the set member path. 4. The method according to claim 3, wherein a notification is sent to the control means, and the lower layer management control means receives the notice and deletes the member path in the network by sending a signaling message for deleting the member path. In the inter-node device signaling,
RSVP-TE (Resource Reservation Protocol for Traffic Engineering), CR-LDP (Constraint Based-Label Distribution Protocol) expanded by including information instructing the change of the lower layer path to which the upper layer traffic is transferred in the signaling message 4. The method of claim 3, using PNNI, LDP, or ONNI signaling protocols. An NMS (Network Management System) is installed in the lower layer network, the NMS searches for the route and determines a member path to be added or deleted, and further, the member path is added or deleted between the NMS and a node device. Using signaling in
Information for specifying member path addition, information for specifying member path deletion, information for changing member path route, and upper layer in signaling message between the NMS and the node device The method of claim 1 including information indicating that traffic is allocated to member paths. The upper layer traffic includes an IP packet, an Ethernet (registered trademark) frame, a fiber channel frame, a frame relay frame, an ATM cell, an X. The method of claim 1, wherein the method is any one of 25 packets. The lower layer path is an ITU-TG. 707-compliant VC-3, VC-4 path, G.707. The method according to claim 1, wherein the method is any one of a 709-based OCh path, ATM VP (Virtual Path), VC (virtual Channel), or MPLS or GMPLS (Label Switched Path). The lower layer path is an ITU-TG. 707, G.M. The method of claim 1, wherein the method is one of a 709 compliant VC-3xc, VC-4xc, or ODU-xc virtual concatenation path. The method according to claim 1, wherein, in the lower layer path, a plurality of member paths are recognized as one large capacity lower layer path by using an LCAS (Link Capacity Adjustment Scheme) technique or an IEEE 802.3ad Link Aggregation technique. The node device has a transfer table in which upper layer traffic information and a transfer destination member path are paired,
The method according to claim 1, wherein, in the distribution of the upper layer traffic, the transfer destination member path is changed by changing the member path described in the transfer table. The predetermined information owned by the upper layer traffic itself is used as a variable, and the hash value is calculated by substituting the variable into a hash function, and the hash value is used as information included in the upper layer traffic. Method. The predetermined information owned by the upper layer traffic itself is
When the upper layer traffic is an IP packet, it is information including all or part of an IP address, a port number, and a protocol number;
When the upper layer traffic is an Ethernet (registered trademark) frame, the information includes all or part of an Ethernet (registered trademark) address, an IP address, a port number, and a protocol number;
The method according to claim 14, wherein when the upper layer traffic is an FC frame, the information includes all or part of a WWNN (World Wide Port Name), a protocol number, and a SCSI ID. In the route search, the link cost in the network used for the route search is dynamically changed with the number of member paths using the link as a variable, and the link usage rate is notified to the node device in the network. The method according to claim 1, wherein the node device performs a route search in consideration of resource usage in the network. In the route search, OSPF-TE (Open Shortest Path First for Traffic Engineering), IS-IS (Intermediate System-Intermediate System), OSPF or IGRP (Interior) is used as a protocol for notifying the network of link cost information used for route search. The method according to claim 1, wherein Gateway Routing Protocol is used. In the route search, a policy server is installed in the lower layer network, the link cost information in the lower layer network is held in the server,
The method according to claim 1, wherein the node device of the network acquires route information by communicating with the server. In the route search, when the starting point node of the lower layer path performs route search for a plurality of member paths one by one,
In addition to using link cost information collected in the network, the link cost through which the previously searched member path passes is increased by a certain amount to further change the link cost and use the changed link cost. The method according to claim 1, further comprising: searching for a route of a next member path and searching for a plurality of member path routes of different paths. In the route search for a plurality of member paths,
When recognizing the lower layer network as a directed graph and searching from the start point node toward the end point node, the positive direction of the member path is defined as the direction from the start point node to the end point node. While searching for a path route using its network cost,
The cost of the link that the searched member path has passed is increased by a certain value in the direction in which the member path is set, and the link cost in the direction opposite to the direction of the member path is set to a negative value. Using the cost, perform the shortest route search for the next member path,
As a result, when there is a link that crosses the member path searched in the opposite direction with the previously searched member path, the member path searched in the nodes located at both ends of the corresponding link The method according to claim 1, wherein a plurality of member path routes are searched simultaneously by exchanging a route and a member path route searched later and simultaneously determining a plurality of different route member path routes. In the route search,
Dijkstra shortest path search method, Node Disjoint Algorithm shortest path search method that is an extension algorithm of Dijkstra shortest path search method, or Link Disjoint Algorithm shortest path search method that is an extension algorithm of Dijkstra shortest path search method The method of claim 1, wherein the member path is searched. A node device that distributes upper layer traffic to each member path of a lower layer path,
An upper layer traffic transceiver for accommodating upper layer traffic;
An upper layer traffic switch unit that distributes and forwards upper layer traffic; and
An upper layer traffic accommodating unit accommodating upper layer traffic in the lower layer path;
A lower layer path termination section that terminates a lower layer path including a member path;
A cross-connect switch that performs a cross-connection of the lower layer path;
An upper layer traffic management control unit for managing the distribution and transfer of upper layer traffic;
A lower layer path management control unit configured to set, delete, and set a lower layer path,
A communication line is provided between the lower layer path management control unit and the upper layer traffic management control unit, and the lower layer path management control unit notifies the upper layer traffic management control unit of the upper layer traffic distribution request via the communication line. A node device characterized in that a layer traffic management control unit notifies a lower layer path management control unit of a request to add or delete a member path. The node device is
An upper layer network node having an upper layer traffic switch unit, an upper layer traffic transmission / reception unit, and an upper layer traffic management control unit, an upper layer traffic accommodating unit, a lower layer path termination unit, a cross-connect switch unit, and a lower layer path management control unit A separate lower layer network node
The node apparatus according to claim 22, further comprising: a main signal line through which upper layer traffic passes and a control signal line through which a control signal between management control units passes between an upper layer network node and a lower layer network node. The upper layer traffic management control unit has a transfer table in which information of the upper layer traffic and a transfer destination member path are paired,
The node device according to claim 22, wherein the upper layer traffic switch unit distributes the upper layer traffic using the forwarding table.

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