JP3955537B2 - Wavelength path switching traffic pattern changing apparatus and wavelength path switching traffic pattern changing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wavelength path switching traffic pattern changing apparatus and a wavelength path switching traffic pattern changing method in an optical communication network (WDM network) adopting a wavelength division multiplexing transmission system (WDM: Wavelength Division Multiplexing).
[0002]
[Prior art]
A conventional wavelength path switching node device monitors traffic to be output to a WDM network from a plurality of own node accommodating devices (for example, IP routers), and autonomously controls wavelength path allocation based on the monitoring result. (For example, refer to Patent Document 1). In a WDM network, a pair of wavelength path switching node devices dynamically add and delete wavelength paths in the facing section without performing signaling. Thereby, the configuration required for signaling can be simplified, and the wavelength use efficiency is improved by the statistical multiplexing effect. Further, wavelength paths set over a plurality of sections are dealt with by connecting a pair of wavelength path switching node devices in tandem.
[0003]
[Patent Document 1]
JP 2001-333045 A (page 2-4, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, as described above, in the conventional wavelength path switching node apparatus, the transmission side and reception side nodes are asynchronously set and released dynamically without performing signaling based on the increase or decrease in traffic volume. Therefore, the trigger of the wavelength path switching operation at the transmission / reception side node is the amount of traffic observed within a certain time, the presence / absence of a packet to be transferred, and the like. In addition, these triggers use the patterns when traffic passes through various communication devices as they are.
[0005]
However, in the above system, no signaling is performed between the transmitting and receiving nodes, and since they operate asynchronously, the two nodes behave differently when detecting a trigger for wavelength path switching operation. there is a possibility. In other words, when it is detected that the amount of traffic within a certain time exceeds (or falls below) a specified threshold, and it is used as a trigger for adding (or deleting) a wavelength path, the transmission and reception side Even if the same traffic is observed on both the sending and receiving sides due to the difference in transmission delay between paths whose observation cycles cannot be synchronized at the node or transmission delay fluctuations within the path, the wavelength path on the other hand A situation may occur in which the trigger of adding or deleting is detected, and on the other hand, these are not detected.
[0006]
Therefore, the present invention has been made in view of the above-described problems, and is a wavelength path switching traffic pattern changing device that transmits a change in traffic that triggers switching of a wavelength path with a specific pattern, and a wavelength. It is an object of the present invention to provide a path exchange traffic pattern changing method.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention proposes the following means.
The invention according to claim 1 is a wavelength path switching traffic pattern changing apparatus used in an optical communication network for multiplex transmission by allocating a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplex transmission system, and for traffic of input traffic A traffic amount detecting means for detecting a volume, a threshold value storing means for storing a threshold value for the input traffic volume, and a traffic pattern for comparing the threshold value with the input traffic volume and changing the input traffic pattern to a predetermined traffic pattern Changing means; traffic pattern extracting means for extracting the predetermined traffic pattern from traffic data; path allocation control means for controlling allocation of an additional path when the predetermined traffic pattern is extracted; and path allocation control means Wavelength path for exchanging wavelength paths according to It proposes a wavelength path replacement traffic pattern change device and a replacement unit.
[0008]
The invention according to claim 5 is a wavelength path switching traffic pattern changing method used in an optical communication network for multiplex transmission by assigning a plurality of traffic to a plurality of wavelength paths by a wavelength division multiplex transmission method, and comprising: A first step of changing the input traffic pattern into a predetermined traffic pattern by extracting the predetermined traffic pattern from the traffic data, comparing the input traffic amount with a threshold stored in advance, and extracting the predetermined traffic pattern from the traffic data; , A wavelength path switching traffic pattern having a second step of controlling allocation of an additional path when the predetermined traffic pattern is extracted, and a third step of exchanging wavelength paths according to the additional path allocation control A change method is proposed.
[0009]
According to these inventions, the input traffic amount is compared with a preset threshold, and the input traffic pattern is changed to a predetermined traffic pattern based on the result, and the predetermined traffic pattern is extracted from the traffic. Therefore, even when the additional path allocation and the wavelength path replacement are performed, especially when the traffic pattern changing means, the path allocation control means, and the wavelength path switching means are mounted in separate devices, Inconsistency of trigger detection in wavelength path switching can be prevented.
[0010]
The invention according to claim 2 is a wavelength path switching traffic pattern changing apparatus used in an optical communication network for multiplex transmission by assigning a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplex transmission method, A traffic pattern extracting unit for extracting a predetermined traffic pattern, a path allocation control unit for controlling allocation of an additional path when the predetermined traffic pattern is extracted, and exchanging wavelength paths according to the control of the path allocation control unit A wavelength path switching traffic pattern changing device having a wavelength path switching means for performing is proposed.
[0011]
According to the present invention, the receiving-side wavelength path switching node device can recognize the increase or decrease in the traffic volume by detecting the pattern in the transmitted traffic, so that it relates to the switching of the wavelength path between the transmitting side and the receiving side. There is no inconsistency in trigger detection.
[0012]
The invention according to claim 3 is the wavelength path switching traffic pattern change device according to claim 1, further comprising a buffer for holding a packet in the traffic data input by the traffic pattern change means, Has been proposed to change the traffic pattern by outputting at intervals of the wavelength path.
[0013]
Further, the invention according to claim 6 is the wavelength path switching traffic pattern changing method according to claim 5, wherein the predetermined traffic pattern temporarily holds the packet in the input traffic data, and then stores the packet. A method for changing a traffic pattern for exchanging wavelength paths formed by outputting at predetermined intervals is proposed.
[0014]
According to these inventions, the traffic pattern changing means includes a buffer and outputs the traffic data input to the buffer at a predetermined interval. For example, the receiving side uses a timer or the like to set the packet data transmission interval. By measuring, specific pattern data can be easily detected.
[0015]
The invention according to claim 4 is the wavelength path switching traffic pattern change device according to claim 1, wherein the traffic pattern change means includes special packet storage means for storing a packet having a predetermined special configuration, There has been proposed a wavelength path switching traffic pattern changing device for adding a packet having a special form stored in the special packet storage means to the input traffic and outputting it.
[0016]
According to a seventh aspect of the present invention, in the wavelength path switching traffic pattern changing method according to the fifth aspect, the predetermined traffic pattern includes a packet having a predetermined special configuration stored in advance as input traffic. A method of changing the traffic pattern for exchanging wavelength paths formed by adding a wavelength path is proposed.
[0017]
According to these inventions, the traffic pattern changing means stores the predetermined traffic pattern and outputs the traffic pattern stored in the input traffic, so that the receiving side stores it in the data table, for example. The specific pattern data can be easily detected by comparing the predetermined traffic pattern and the input traffic data.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a wavelength path exchange traffic pattern changing apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, a wavelength path switching traffic pattern changing apparatus according to an embodiment of the present invention is configured by a WDM network including wavelength path switching node apparatuses 2a and 2b. This WDM network takes the form of point-to-point connection. In the WDM network shown in FIG. 1, traffic flows in a direction from a wavelength path switching node device (hereinafter simply referred to as a node device) 2a on the wavelength path start point side to a node device 2b on the wavelength path end point side. It is assumed that it is.
[0019]
As shown in FIG. 1, the WDM network according to this embodiment includes a plurality of IP routers 1, node devices 2a and 2b, and optical cross-connect devices (OXC) 3a and 3b. Here, the node devices 2a and 2b are respectively connected to the plurality of IP routers 1 by optical fiber cables. The node device 2a is connected to the OXC 3a that sets a semi-fixed wavelength path by an optical fiber cable. Further, the OXC 3a is connected to the opposing OXC 3b by an optical fiber cable. Similarly, the node device 2b is connected to the OXC 3b via an optical fiber cable and is also connected to a plurality of routers 1 via optical fiber cables.
[0020]
The node device 2a assigns the input traffic from each router 1 to a plurality of wavelength paths and outputs it to the OXC 3a, and the OXC 3a multiplexes the inputted traffic of each wavelength path and transmits it to the OXC 3b. The OXC 3b separates and outputs the traffic of each wavelength path received from the OXC 3a to the node device 2b, and the node device 2b outputs the input traffic of the plurality of wavelength paths to the corresponding routers 1 respectively.
[0021]
The node device 2a includes a packet distribution unit 11, an optical switch 12 (wavelength path switching means), and a control unit 13. The packet distribution unit 11 is provided corresponding to each of the routers 1, and the input traffic packets from the corresponding routers 1 are an initial path which is a semi-fixed wavelength path and a wavelength path for dynamic allocation. Categorize as additional path. The packet distributed to the initial path is output to the initial path input port of the optical switch 12. On the other hand, the packet distributed to the additional path is output to the additional path input port of the optical switch 12.
[0022]
The optical switch 12 performs wavelength path exchange according to the wavelength path exchange setting from the control unit 13. The input packet of the initial path input port is output to the initially set initial path output port. The connection relationship between the initial path input port and the initial path output port is set semi-fixed. Further, the input packet of the additional path input port is output to the additional path output port set as appropriate. The connection relationship between the additional path input port and the additional path output port is dynamically set. Further, in each output port, conversion to a predetermined wavelength is performed and the result is output to the connected OXC 3a.
[0023]
The control unit 13 performs wavelength path allocation and wavelength path exchange control according to a specific pattern detection signal from the packet control unit 33 described later. In addition, an additional path control signal is output to the packet control unit 33 to notify that the path cannot be added.
[0024]
As shown in FIG. 2, the router 1 according to the embodiment of the present invention includes a packet switch 14, an O / E (O / E: opto-electric converter) 15, a traffic amount detection unit 16, and a comparator 17. And a storage means 18, a traffic pattern changing device 19, and a traffic pattern storage device 20. The packet switch 14 is an element that transmits packet data at high speed without changing light, assigns the most efficient route to the packet, and enables communication channels to be shared by various connections. The O / E 15 is an element for converting packet data transmitted as an optical signal over the network into an electric signal.
[0025]
The traffic amount detection device 16 detects the transmission amount per predetermined time of traffic transmitted through the packet switch 14 and the O / E. The comparison unit 17 compares the traffic amount detected by the traffic amount detection device 16 with a threshold value related to the traffic amount stored in the storage device 18 and outputs the result to the traffic pattern change device 19.
[0026]
The traffic pattern changing device 19 is a device that changes a traffic pattern based on an output signal of a comparator. As a changing method, for example, a method of controlling a packet transmission interval using a buffer or a special packet within a traffic is used. A method of inserting into the device is conceivable. As a method of using a buffer, packets are temporarily stored in the buffer, for example, traffic is transmitted so that the interval between packets is constant, or some packets are transmitted in an automatic manner. A method of converting to a pattern different from the transmission pattern generated in the above is conceivable. In such a method, information can be encoded and transmitted by variously changing the interval between packets.
[0027]
On the other hand, as a method for inserting special packets into traffic, a dummy packet is inserted between original packets to generate a specific pattern, or a packet having a size different from that of a normal packet or data in the packet. There is a method of generating a specific pattern by inserting a packet composed of full bits. Moreover, the method which combined said each method may be sufficient. Note that the dummy packet, the packet having a different size, the packet in which data in the packet is composed of full bits, and the like are stored in the traffic pattern storage device 20, and are appropriately selected according to the output signal of the comparator 17. The appropriate packet is selected and inserted into the traffic.
[0028]
The traffic pattern changing device 19 is arranged at a point closer to the track source than the traffic pattern extracting means of the transmitting side node. Therefore, when the traffic pattern is extracted by the transmission side wavelength path switch as in this embodiment, the traffic pattern is extracted in the transmission side router or between the input port of the wavelength path switch and the traffic pattern extraction means. When the extraction is performed by the transmission side router, it is arranged between the input port in the transmission side router and the traffic pattern extraction means.
[0029]
Next, the packet distribution unit 11 will be described in detail with reference to FIG. As shown in FIG. 3, the packet distribution unit 11 includes a traffic pattern extraction unit 31, a buffer 32, a packet transmission control unit 33, and an E / O (E / O: electro-optical converter) 34. ing. The E / O 34 is provided corresponding to each of the initial path and the additional path, and the optical output of the initial path E / O 34 is connected to the initial path input port of the optical switch 12. The optical output of each additional path E / O 34 is connected to an additional path input port corresponding to the optical switch 12.
[0030]
The traffic pattern extraction unit 31 extracts a specific traffic pattern from the traffic transmitted from the router 1 and outputs a signal to the packet transmission control unit 33 when the specific traffic pattern is extracted. The packet transmission control unit 33 receiving the signal transmits a specific pattern detection signal to the control unit 13. The packet transmission control unit 33 takes out the packet from the buffer 32 and outputs it to the initial path E / O 34 or the additional path E / O 34. Each E / O 34 converts the input packet from an electrical signal to an optical signal and outputs the packet to an input port connected to each of the optical switches 12.
[0031]
Next, the configuration and operation of the node device 2b will be described in detail.
As illustrated in FIG. 1, the node device 2 b includes a monitoring unit 21, an optical switch 22, and a control unit 23. The optical switch 22 performs wavelength path exchange according to the wavelength path exchange setting from the control unit 23. The optical switch 22 receives the traffic of each wavelength path separated from the OXC 3b. Here, the initial path packet is input to a predetermined initial path input port, and the additional path packet is input to a predetermined additional path input port.
[0032]
The input packet of the initial path input port is output to the initial path output port that is initially set for the destination router 1. The connection relationship between the initial path input port and the initial path output port is set semi-fixed. The input packet of the additional path input port is output to the additional port output port appropriately set for the destination router 1. The connection relationship between the additional path input port and the additional path output port is actively set. Each output port performs conversion to a predetermined wavelength, and the output of each port is connected to the corresponding monitoring unit 21.
[0033]
A traffic packet to be delivered to the corresponding router 1 is input to the monitoring unit 21. As illustrated in FIG. 4, the monitoring unit 21 includes a packet detection unit 41, a specific pattern detection unit 42, and a multiplexing unit 43. The packet detector 41 is provided corresponding to each of the initial path and the additional path. The optical input of the initial path packet detector 41 is connected to the initial path output port of the optical switch 12, and the optical input of each additional path packet detector 41 is connected to the corresponding additional path output port of the optical switch 12. Each is connected.
[0034]
The packet detection unit 41 includes an O / E unit (not shown), and converts a packet input from the optical switch 22 from an optical signal to an electrical signal. The signal converted into the electrical signal is detected by the specific pattern detection unit 42 whether or not the specific pattern exists in the traffic. When the specific pattern is detected, the specific pattern detection signal is sent to the control unit 23. Is output. When the specific pattern detection signal is input from the specific pattern detection unit, the control unit 23 performs wavelength path allocation and wavelength path exchange control. Each wavelength path packet is input to the multiplexing unit 43 via the packet detection unit 41, and the input packet is converted into an optical signal by an E / O unit (not shown). At 43, the signals are combined and output to the router 1.
[0035]
As described above, according to the present embodiment, the increase / decrease in the traffic volume is transmitted not by a special packet but by a specific pattern, so there is no problem due to the loss of the packet, and the traffic is accurately transmitted from the transmission side to the reception side. You can be notified of changes in volume.
[0036]
As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and includes design changes and the like within a scope not departing from the gist of the present invention. It is. For example, in the present embodiment, the processing of the specific pattern on the receiving side is not mentioned. For example, when the traffic is accumulated in the buffer and the specific pattern is detected by the pattern detecting means on the receiving side, the specific pattern is detected. You may make it perform the process which extracts a special packet from a pattern.
[0037]
In addition, the generation of the specific pattern has been described with respect to an example in which packets are transmitted at a predetermined interval. However, a specific pattern in which a packet transmission interval is determined in advance is transmitted and the interval between packets detected on the receiving side is determined. A configuration may be adopted in which the characteristics of the transmission path are estimated based on the difference in the interval and the input traffic on the receiving side is corrected.
[0038]
In the present embodiment, the traffic amount detecting means and the traffic pattern changing device are arranged on the router side. However, they may be configured on the wavelength path switching node device side. In this case, since the output signal to the control unit only needs to share the output of the comparator, the traffic pattern extraction means in the packet distribution unit can be deleted.
[0039]
Further, in the above-described embodiment, the packet distribution unit converts the input optical signal into an electrical signal to perform buffering and distribution of the packet. However, the packet distribution unit processes the optical signal as it is. Also good. FIG. 5 shows a block configuration of the packet distribution unit 11 that buffers and distributes an optical input packet as it is. As shown in FIG. 5, the buffer 32a is an optical buffer that stores optical input packets as optical signals. The packet transmission control unit 33a takes out the packet from the buffer 32a and distributes it to the initial path and the additional path. As a result, the optical input packet from the router 1 is output as an optical signal to the input port of the optical switch 12 corresponding to the wavelength path of the distribution destination. Therefore, according to the embodiment shown in FIG. 5, conversion loss due to optical-electrical conversion and electrical-optical conversion can be reduced, and the efficiency of optical exchange can be improved.
[0040]
【The invention's effect】
As described above, according to the present invention, since trigger detection related to wavelength path switching on the transmission side and reception side is performed by a specific pattern, inconsistency of trigger detection and transmission error in the nodes on the transmission side and reception side. This has the effect of reducing the probability of occurrence.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a WDM network according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a router according to the embodiment of the present invention.
FIG. 3 is a configuration diagram of a packet distribution unit according to the embodiment of the present invention.
FIG. 4 is a configuration diagram of a monitoring unit according to the embodiment of the present invention.
FIG. 5 is a configuration diagram of a packet distribution unit when buffering an optical input packet as it is.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... IP router 1, 2a, 2b ... Node apparatus, 3a, 3b ... Optical cross-connect apparatus, 11, 21 ... Packet distribution part, 12, 22 ... Optical switch, 13, 23 ... Control unit, 14 ... Packet switch, 15 ... O / E, 16 ... Traffic amount detection means, 17 ... Comparator, 18 ... Storage means, 19 ... Traffic pattern Change device, 20 ... traffic pattern storage device, 31, 31a ... traffic pattern extraction means, 32, 32a ... buffer, 33, 33a ... packet transmission control unit, 34 ... E / O, 41 ... Packet detector, 42 ... Specific pattern detector, 43 ... Multiplexer,

Claims (4)

A wavelength path switching traffic pattern changing device used in an optical communication network for multiplex transmission by assigning a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplexing transmission system,
Traffic volume detection means for detecting the traffic volume of input traffic;
Threshold storage means for storing a threshold for the amount of input traffic;
Traffic pattern changing means for comparing the threshold value with the input traffic volume and changing the input traffic pattern to a predetermined traffic pattern;
Traffic pattern extraction means for extracting the predetermined traffic pattern from the traffic;
Path extraction control means for controlling the assignment of additional paths when the predetermined traffic pattern is extracted, and wavelength path exchange means for exchanging wavelength paths according to the control of the path assignment control means,
The traffic pattern changing unit includes a buffer for holding a packet, and outputs the packet at a predetermined interval to change the input traffic pattern to the predetermined traffic pattern. A wavelength path switching traffic pattern changing device used in an optical communication network for multiplex transmission by assigning a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplexing transmission system,
Traffic volume detection means for detecting the traffic volume of input traffic;
Threshold storage means for storing a threshold for the amount of input traffic;
Traffic pattern changing means for comparing the threshold value with the input traffic volume and changing the input traffic pattern to a predetermined traffic pattern;
Traffic pattern extraction means for extracting the predetermined traffic pattern from the traffic;
Path extraction control means for controlling the assignment of additional paths when the predetermined traffic pattern is extracted, and wavelength path exchange means for exchanging wavelength paths according to the control of the path assignment control means,
The traffic pattern changing means includes special packet storage means for storing a predetermined special packet, and adds the special packet stored in the special packet storage means to the input traffic for output. Traffic pattern change device. A wavelength path switching traffic pattern changing method used in an optical communication network for multiplex transmission by assigning a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplex transmission method,
A first step of detecting the traffic volume of the input traffic, comparing the input traffic volume with a pre-stored threshold, and changing the input traffic pattern to a predetermined traffic pattern;
A second step of extracting a predetermined traffic pattern from the traffic and controlling allocation of an additional path when the predetermined traffic pattern is extracted;
A third step of exchanging wavelength paths according to the additional path allocation control,
A method of changing a traffic pattern for wavelength path switching, wherein the predetermined traffic pattern is formed by temporarily holding packets in the traffic and then outputting the packets at predetermined intervals. A wavelength path switching traffic pattern changing method used in an optical communication network for multiplex transmission by assigning a plurality of traffics to a plurality of wavelength paths by a wavelength division multiplex transmission method,
A first step of detecting the traffic volume of the input traffic, comparing the input traffic volume with a pre-stored threshold, and changing the input traffic pattern to a predetermined traffic pattern;
A second step of extracting a predetermined traffic pattern from the traffic and controlling allocation of an additional path when the predetermined traffic pattern is extracted;
A third step of exchanging wavelength paths according to the additional path allocation control,
The traffic pattern changing method for wavelength path exchange, wherein the predetermined traffic pattern is formed by adding a predetermined special packet stored in advance to the traffic.

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