JP3717866B2 - Photonic nodes and photonic networks and programs - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used for a photonic network for switching and connecting optical signals. In particular, the present invention relates to a photonic network including a photonic node that performs 3R (Reshaping, Retiming, Regenerating) relay.
[0002]
[Prior art]
In a photonic network, it is necessary to perform 3R processing in the middle of an optical transmission line in consideration of fiber loss, loss, and crosstalk. A conventional photonic network configuration is shown in FIG. In order to perform 3R processing, a 3R repeater is inserted into a node in the middle of the optical transmission path. Although transmission is possible up to a certain distance without performing 3R processing, since complicated calculation is required to determine the distance, 3R relay is performed every one or two stages as shown in FIG. So as to compensate for the deterioration of the optical signal regardless of the route set.
[0003]
Alternatively, there is a usage form in which a 3R repeater is inserted into a specific route of a photonic network, a path is set by using a common route for many paths, and the 3R repeater is shared. However, in this usage mode, the route through which data transfer requires 3R processing is limited.
[0004]
[Problems to be solved by the invention]
A 3R repeater is expensive, and if this 3R repeater is not used as much as possible, a photonic network can be realized extremely economically. However, in the conventional path setting, there is no consideration that the node grasps the usage status of the 3R repeater and sets the path, and each node only knows a predetermined location of the 3R repeater. When a large number of paths share a small number of 3R repeaters, there is a possibility that a large number of loads are concentrated on some 3R repeaters. In addition, if a large number of paths share a small number of 3R repeaters, it is necessary for the paths to always pass through the insertion location of the 3R repeater, which reduces the flexibility of path setting.
[0005]
For example, even when there is a request to add a new path to a specific route where the 3R load is concentrated, there is a situation where a path cannot be set for that route even though another route is available.
[0006]
The present invention has been implemented against this background, and realizes a highly flexible photonic network even if a photonic network is configured while effectively using network resources using a small number of 3R repeaters. An object of the present invention is to provide a photonic node and a photonic network that can flexibly cope with the addition of a new path.
[0007]
[Means for Solving the Problems]
In the present invention, each node advertises information indicating its own 3R relay capability to other nodes, and each node receives this notification to grasp the 3R relay capability in the other nodes, and each node It is possible to set a path to a route with a low 3R processing load by setting the path in consideration of the 3R relay capability. As a result, even when a photonic network is configured while effectively using network resources using a small number of 3R repeaters, it is possible to avoid a situation where the 3R processing load is concentrated at a specific location. Therefore, a highly flexible photonic network can be realized, and it is possible to flexibly cope with the addition of a new path by effectively using a free route.
[0008]
That is, the first aspect of the present invention is applied to a photonic network for exchanging and connecting optical signals, and between the means for exchanging and connecting optical signals and the own node and the destination node when the own node is a source node. And a means for setting a path to the photonic node, wherein one or more 3R repeaters are provided or not provided, and the 3R repeater is a photonic node selected to be used or unused. The characteristic feature is that there is provided means for notifying other nodes of the number of 3R repeaters possessed by the own node or all nodes to which the own node can connect without 3R relay.
[0009]
It is desirable that the means for notifying periodically announces the number of unused 3R repeaters among the 3R repeaters of the own node or all nodes that can be connected to the own node without 3R relay.
[0010]
A second aspect of the present invention is a photonic network comprising the photonic node of the present invention.
[0011]
As described above, the source node can receive all the notifications from the other nodes, and can grasp all the nodes that perform 3R relay on the shortest path to the destination node and their capabilities. In addition, a node that performs 3R relay can be selected so that the number of 3R relays is minimized. Further, when there are a plurality of node candidates for performing 3R relay with the same number of 3R relays, it is possible to select a node for performing 3R relay with a margin of 3R relay capability.
[0012]
As a result, even if a photonic network is configured using a small number of 3R repeaters, a highly flexible photonic network can be realized, and the addition of a new path can be flexibly handled.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
(First Example)
A photonic node and a photonic network according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating an example of a photonic network according to the present embodiment. FIG. 2 is a block diagram of the photonic node of this embodiment. FIG. 3 is a diagram showing the announcement packet of the first embodiment. FIG. 4 is a diagram showing a 3R relay information list of the first embodiment. FIG. 5 is a flowchart showing the operation of the path setting unit of the first embodiment.
[0014]
This embodiment is applied to a photonic network that exchanges and connects optical signals as shown in FIG. 1, and an optical cross-connect 1 that exchanges and connects optical signals as shown in FIG. In some cases, the route calculation unit 2 calculates the shortest path that minimizes the number of passing nodes between the own node and the destination node, and between the own node and the destination node based on the calculation result of the route calculation unit 2 And a path setting unit 3 for setting a path to the photonic node, which includes or does not include one or more 3R repeaters 71 to 7n.
[0015]
Here, the feature of the first embodiment is that, as shown in FIG. 2, a node located at the limit where it is possible to transfer an optical signal without requiring 3R relay when it is assumed that the own node is a source node. 3R relay information calculation unit 5 that calculates a relayless reachable node each time the network topology changes, the calculation result of this 3R relay information calculation unit 5, and the number of 3R relays 71 to 7n that the own node has As shown in FIG. 3, the 3R relay information announcement unit 6 that advertises to other nodes by the OSPF signaling packet, and the information of the non-relay reachable node and the number of 3R repeaters announced from other nodes as shown in FIG. 3R relay information collection unit 4 that aggregates corresponding to the addresses of the other nodes, and path setting unit 3 has its own node as the source node as shown in FIG. In some cases, the route calculation unit 2 calculates the show test path to the destination node (step 1), determines whether 3R relay is necessary in the middle of the show test path (step 2), and is necessary. If there is, the node that performs 3R relay is selected based on the counting result of the 3R relay information collection unit 4 so that the number of 3R relays is as small as possible to the destination node (step 3), and the selected 3R relay is performed. When there are a plurality of node candidates (step 4), the node that performs the best 3R relay is selected from the node candidates that perform the 3R relay based on the total result of the 3R relay information collection unit 4 and that has the largest 3R relay capability margin (Step 5), and at this time, the node that performs the 3R relaying recognized based on the counting result of the 3R relay information collecting unit 4 The number of 3R repeaters in the accessory is in place to select a node candidate to perform most 3R repeater large number of 3R relay as a margin of the 3R relay capability.
[0016]
(Second embodiment)
A second embodiment will be described with reference to FIG. 2 and FIGS. FIG. 6 is a diagram showing an announcement packet of the second embodiment. FIG. 7 is a diagram illustrating a 3R relay information list according to the second embodiment.
[0017]
As shown in FIG. 2, the second embodiment is characterized in that it is a node located at the limit where it is possible to transfer an optical signal without requiring 3R relay when the own node is assumed to be a source node. The 3R relay information calculation unit 5 that calculates the relay reachable node every time the network topology changes, the calculation result of the 3R relay information calculation unit 5, the number of 3R relays 71 to 7n included in the own node, and the 3R relay 6R that announces the usage status of the devices 71 to 7n to other nodes using the OSPF signaling packet shown in FIG. 6, and the number of non-relay reachable nodes and 3R repeaters announced from other nodes and the 3R relay As shown in FIG. 7, a 3R relay information collecting unit 4 is provided for collecting information on the usage status of the devices in correspondence with the addresses of the other nodes. As shown in FIG. 5, when the node is the source node, the setting unit 3 causes the route calculation unit 2 to calculate the show test path to the destination node (step 1), and 3R is included in the middle of the show test path. It is determined whether or not relaying is necessary (step 2), and if necessary, 3R relaying is performed so that the number of 3R relays is as small as possible to the destination node based on the aggregation result of the 3R relay information collecting unit 4. A node to be performed is selected (step 3), and when there are a plurality of node candidates for performing the selected 3R relay (step 4), based on the total result of the 3R relay information collection unit 4, the node candidates for performing the 3R relay are selected. A candidate having the largest margin of 3R relay capability is selected as a node for performing the optimal 3R relay (step 5).
[0018]
In the second embodiment, as shown in FIG. 7, since the total number of 3R repeaters and the number of unused 3R repeaters in other nodes are announced, the path setting unit 3 in the node candidates that perform 3R relay The number of unused 3R repeaters in the node candidate for performing the 3R relay recognized based on the total result of the 3R relay information collection unit 4 as the margin of 3R relay capability is the most unused 3R relay as the margin of the 3R relay capability. A node candidate that performs 3R relay with a large number of devices is selected.
[0019]
Alternatively, the path setting unit 3 recognizes the number of unused 3R relays in the node candidate that performs the 3R relay recognized based on the aggregation result of the 3R relay information collection unit 4 as the margin of the 3R relay capability in the node candidate that performs the 3R relay. The value obtained by dividing the value obtained by subtracting 1 from the number of all 3R repeaters in the node candidate for performing the 3R relay is selected as a node candidate for performing the 3R relay with the largest division result as a margin of the 3R relay capability.
[0020]
In this way, whether the 3R relay capability margin is high or low can be expressed by whether the usage rate of the 3R relay in the node is high or low. Here, the reason why the value obtained by subtracting 1 from the number of unused 3R repeaters in the node candidate performing 3R relay is divided by the number of all 3R repeaters in the node candidate performing 3R relay is as described above. is there. When the number of unused 3R repeaters is 0, the arithmetic expression is (0-1) / n = -n (n is the total number of 3R repeaters), and the 3R relay cost takes a negative value. However, in such a case, it may be defined that the 3R relay capability is absent (value “0”).
[0021]
The 3R relay information notification unit 6 periodically updates the usage status information of the 3R repeater, and periodically transmits the notification including the updated usage status information.
[0022]
(Third embodiment)
A third embodiment will be described with reference to FIG. 2 and FIGS. FIG. 8 is a diagram showing an announcement packet of the third embodiment. FIG. 9 is a diagram showing a 3R relay information list of the third embodiment. 10 and 11 are flowcharts showing the operation of the path setting unit of the third embodiment.
[0023]
As shown in FIG. 2, the third embodiment is characterized in that it is a node located at the limit where it is possible to transfer an optical signal without requiring 3R relay when it is assumed that the own node is a source node. As shown in FIG. 8, the 3R relay information calculation unit 5 that calculates the relay reachable node every time the network topology changes, and the number of 3R relays 71 to 7n of the own node and the usage status thereof are shown in FIG. The 3R relay information announcement unit 6 that advertises by signaling packets, and the 3R that aggregates the number of 3R repeaters advertised from other nodes and the usage status information corresponding to the addresses of the other nodes as shown in FIG. And the relay information collection unit 4, and the path setting unit 3, as shown in FIG. 10, when the own node is the source node, The short test path is calculated by the route calculation unit 2 (step 1), and it is determined whether or not 3R relay is necessary in the middle of the show test path (step 2). If necessary, the 3R relay information collection unit A node that performs 3R relay is selected so that the number of 3R relays is as small as possible to the non-relay reachable node that goes to the destination node based on the aggregation result of 4 (step 3), and the node that performs this selected 3R relay When there are a plurality of candidates (step 4), the candidate having the largest margin of 3R relay capability among the node candidates that perform the 3R relay based on the total result of the 3R relay information collection unit 4 is set as the node that performs the optimal 3R relay. Select (Step 5).
[0024]
Further, when the own node is a node selected as a node that performs 3R relay from another node, as shown in FIG. 11, when a 3R relay request is received from an upstream node such as a source node (step 1), further 3R It is determined whether or not relaying is necessary (step 2), and if necessary, the number of 3R relays is as small as possible to the non-relayable reachable node heading to the destination node as much as possible based on the aggregation result of the 3R relay information collecting unit 4 In this way, a node that performs 3R relay is selected (step 3), and when there are a plurality of node candidates that perform the selected 3R relay (step 4), the 3R relay is performed based on the counting result of the 3R relay information collection unit 4 A candidate having the largest margin of 3R relay capability is selected from the node candidates as a node for performing the optimal 3R relay (step 5). In the filtrate.
[0025]
In the third embodiment, as in the second embodiment, as shown in FIG. 9, since the total number of 3R repeaters and the number of unused 3R repeaters in other nodes are announced, the path setting unit 3 The number of unused 3R repeaters in the node candidate performing 3R relay recognized based on the total result of the 3R relay information collection unit 4 as the margin of 3R relay capability in the node candidate performing 3R relay is the margin of the 3R relay capability Node candidates that perform 3R relay with the largest number of unused 3R repeaters are selected.
[0026]
Alternatively, the path setting unit 3 recognizes the number of unused 3R relays in the node candidate that performs the 3R relay recognized based on the aggregation result of the 3R relay information collection unit 4 as the margin of the 3R relay capability in the node candidate that performs the 3R relay. The value obtained by dividing the value obtained by subtracting 1 from the number of all 3R repeaters in the node candidate for performing the 3R relay is selected as a node candidate for performing the 3R relay with the largest division result as a margin of the 3R relay capability.
[0027]
The 3R relay information notification unit 6 periodically updates the usage status information of the 3R repeater, and periodically transmits the notification including the updated usage status information.
[0028]
(Fourth embodiment)
The function of controlling the photonic node of this embodiment can be realized by using a computer device that is an information processing device. That is, by installing in a computer device, the optical device is applied to a photonic network for exchanging and connecting optical signals to the computer device. When the own node is a source node, the own node is used. Route calculation unit 2 that calculates the show test path that minimizes the number of passing nodes between the destination node and the destination node, and sets a path between the own node and the destination node based on the calculation result of the route calculation unit 2 And a path setting unit 3 that implements a function for controlling a photonic node that includes or does not include one or more 3R repeaters 71 to 7n, assuming that the node is a source node. This node is located at the limit where optical signals can be transferred without requiring 3R relay. A function corresponding to the 3R relay information calculation unit 5 for calculating the non-relay reachable node every time the network topology is changed, the calculation result of the 3R relay information calculation unit 5, and the 3R relays 71 to 7n of the own node The function corresponding to the 3R relay information announcement unit 6 that advertises the number to other nodes, and the information on the number of non-relay reachable nodes and 3R repeaters announced from other nodes are totaled in correspondence with the addresses of the other nodes. A function corresponding to the 3R relay information collecting unit 4 is realized, and as a function corresponding to the path setting unit 3, when the own node is a source node, the destination is as much as possible based on the total result of the 3R relay information collecting unit 4 A first selection function for selecting a node that performs 3R relay so that the number of 3R relays is small up to the node, and this first selection function When there are a plurality of selected node candidates for 3R relay, a candidate having the largest margin of 3R relay capability is selected from among the node candidates for 3R relay based on the aggregation result of the 3R relay information collection unit 4 As the second selection function, the number of 3R repeaters in the node candidate that performs the 3R relay recognized based on the total result of the 3R relay information collection unit 4 is the 3R relay capability margin as the maximum 3R. By installing a program for realizing a function for selecting a node candidate for performing 3R relay with a large number of repeaters in a computer device, the computer device can realize a function for controlling the photonic node of the first embodiment. .
[0029]
Alternatively, 3R is calculated every time a non-relayable reachable node, which is a node that can transfer an optical signal without requiring 3R relay when it is assumed that the node is a source node, changes in the network topology. The function corresponding to the relay information calculation unit 5, the calculation result of the 3R relay information calculation unit 5, the number of 3R relays 71 to 7n of its own node, and the usage status of the 3R relays 71 to 7n are announced to other nodes. Corresponding to the function of the 3R relay information announcement unit 6 to be performed, the number of non-relay reachable nodes and the number of 3R repeaters announced from other nodes, and the usage status of the 3R repeater corresponding to the addresses of the other nodes, respectively. A function corresponding to the 3R relay information collecting unit 4 to be aggregated is realized, and as a function corresponding to the path setting unit 3, the own node is the source node. 3R selection function for selecting a node that performs 3R relay based on the total result of the 3R relay information collection unit 4 so that the number of 3R relays is as small as possible to the destination node, and this third selection function When there are a plurality of node candidates that perform 3R relay, a fourth selection that selects a candidate having the largest margin of 3R relay capability from among the node candidates that perform 3R relay based on the aggregation result of 3R relay information collection unit 4 By installing the program for realizing the functions in the computer device, the computer device can realize the function of controlling the photonic node of the second embodiment.
[0030]
Alternatively, 3R is calculated every time a non-relayable reachable node, which is a node that can transfer an optical signal without requiring 3R relay when it is assumed that the node is a source node, changes in the network topology. A function corresponding to the relay information calculation unit 5, a function corresponding to the 3R relay information notification unit 6 for notifying other nodes of the number and usage status of the 3R relays 71 to 7n of the own node, and a notification from another node In addition, a function corresponding to the 3R relay information collecting unit 4 that aggregates the number of 3R repeaters and the usage status information corresponding to the addresses of the other nodes is realized. When the node is a source node, or when the local node is a node selected as a node that performs 3R relay from another node, 3R A fifth selection function for selecting a node that performs 3R relaying so that the number of 3R relays to the non-relayable reachable node heading to the destination node is reduced as much as possible based on the tabulation result of the relay information collection unit 4, and the fifth selection When there are a plurality of node candidates for performing 3R relay selected by the function, the candidate having the largest margin of 3R relay capability is selected from the node candidates for performing 3R relay based on the aggregation result of the 3R relay information collection unit 4 By installing a program for realizing the sixth selection function in the computer device, it is possible to realize the function of controlling the photonic node of the third embodiment in the computer device.
[0031]
Further, in order to realize the function of controlling the photonic nodes of the second and third embodiments in the computer device, as the fourth or sixth selection function, there is a margin of 3R relay capability in the node candidate performing 3R relay. As the degree, the number of unused 3R repeaters in the node candidate performing the 3R relay recognized based on the total result of the 3R relay information collecting unit 4 is the 3R with the largest number of unused 3R repeaters as the margin of the 3R relay capability. A function of selecting a node candidate to perform relay is realized, or, as the fourth or sixth selection function, a 3R relay capability margin in a node candidate to perform 3R relay is added to the aggregation result of the 3R relay information collection unit 4 A value obtained by subtracting 1 from the number of unused 3R repeaters in the node candidate performing the 3R relay recognized based on the node candidate performing the 3R relay is determined. All divided by the 3R repeater number to realize the function of selecting the most relevant division result is greater 3R node candidate relaying as margin of the 3R relay capability that.
[0032]
Furthermore, as a function corresponding to the 3R relay information announcement unit 6, a function for periodically updating the usage status information of the 3R repeater and a notification including the usage status information updated by this updating function are periodically And the function to send to.
[0033]
By recording the program of the present embodiment on the recording medium of the present embodiment, the computer apparatus can install the program of the present embodiment using this recording medium. Alternatively, the program of this embodiment can be directly installed on the computer device from the server holding the program of this embodiment via the network.
[0034]
As a result, a highly flexible photonic network can be realized even if a photonic network is configured using a small number of 3R repeaters while effectively using network resources using a computer device, and it is flexible to add new paths. It is possible to realize a photonic node and a photonic network that can cope with the above.
[0035]
【The invention's effect】
As described above, according to the present invention, a highly flexible photonic network can be realized even if a photonic network is configured using a small number of 3R repeaters while effectively using network resources. It can respond flexibly to the addition.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a photonic network according to an embodiment.
FIG. 2 is a block diagram of a photonic node according to the present embodiment.
FIG. 3 is a diagram showing a notification packet of the first embodiment.
FIG. 4 is a diagram illustrating a 3R relay information list according to the first embodiment.
FIG. 5 is a flowchart showing the operation of the path setting unit of the first embodiment.
FIG. 6 is a diagram showing a notification packet according to the second embodiment.
FIG. 7 is a diagram showing a 3R relay information list according to the second embodiment.
FIG. 8 is a diagram showing a notification packet according to a third embodiment.
FIG. 9 is a diagram illustrating a 3R relay information list according to a third embodiment.
FIG. 10 is a flowchart showing the operation of the path setting unit of the third embodiment.
FIG. 11 is a flowchart showing the operation of the path setting unit of the third embodiment.
FIG. 12 is a diagram showing a conventional photonic network configuration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical cross-connect 2 Route calculation part 3 Path setting part 4 3R relay information collection part 5 3R relay information calculation part 6 3R relay information notification part 71-7n 3R repeater

Claims (5)

Applied to a photonic network for exchanging and connecting optical signals, including means for exchanging and connecting optical signals; and means for setting a path between the own node and the destination node when the own node is a source node;
With or without one or more 3R (Reshaping, Retiming, Regenerating) repeaters , the 3R repeaters can be used in photonic nodes that are either in use or unused.
A photonic node comprising means for notifying other nodes of information on nodes that can be connected to the local node without relay, and the number of 3R relays included in the local node. Wherein the means for publication, of the 3R repeater that chromatic of the node, the photonic node as claimed in claim 1, in which publication the number of unused 3R repeaters periodically.   A photonic network comprising the photonic node according to claim 1. By installing in the information processing device,
Applied to a photonic network that exchanges and connects optical signals, and includes a function that exchanges and connects optical signals, and a function that sets a path between the own node and the destination node when the own node is a source node,
One or more 3R (Reshaping, Retiming, Regenerating) relays may or may not be provided, and the 3R relay may realize a function for controlling a photonic node that is selected to be used or unused. And
Realize a function to advertise to other nodes the information of nodes that can be connected to the local node without 3R relay and the number of 3R repeaters that the local node has
A program characterized by that . The program according to claim 4, wherein the function to advertise periodically advertises the number of unused 3R repeaters among the 3R repeaters of its own node.

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