JP3660620B2 - Optical communication network and node, program and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used for optical communication. The present invention relates to an optical burst data transfer technique in a communication network that uses optical wavelengths as communication media for burst data transfer.
[0002]
[Prior art]
In normal IP (Internet Protocol) data transfer in optical communication, a plurality of routers are arranged from a starting point to an end point, and data is transferred through the routers. At this time, each router determines the router to be transferred next while referring to the IP address given to the packet and performs the transfer.
[0003]
In such an optical communication network, when reading the header information of a packet, the optical signal is once converted into an electric signal and then read. The router determines the next router to be transferred in accordance with the IP address read in this way.
[0004]
In addition, when transferring data in bursts, reading the IP address for each packet is not good for transfer efficiency, so a cut-through path is set between the starting point and the ending point in advance. In addition, since it is not necessary to read the IP header in this cut-through path section, the optical signal can be transferred as it is at a high speed.
[0005]
[Problems to be solved by the invention]
In such conventional optical communication, when burst data is transferred using a cut-through path, it is necessary to set the cut-through path in advance. In order to set a cut-through path in advance, a request to set a cut-through path is made to each router that passes from the start point to the end point, and each router responds to this request before the pre-setting of the cut-through path is completed. To do.
[0006]
At this time, looking at the cut-through path setting procedure in each router, first, the header information of the arriving optical IP packet is converted into an electrical signal, which includes information corresponding to the cut-through path setting request. If a setting request is included, the wavelength for setting the cut-through path is selected, and if the wavelength can be selected, the cut-through path setting is actually performed. Then, since it is no longer necessary to read the header information of the IP packet for the wavelength for which the cut-through path is set, the setting is changed so that the IP packet is handled as distinct from other wavelengths in order to transfer the IP packet as an optical signal.
[0007]
However, such a setting procedure takes a considerable amount of time. For example, assume that 2 t seconds are required for setting a cut-through path. If it takes 3 t seconds to transfer burst data using this cut-through path, it takes 5 t seconds to complete the transfer of burst data after setting the cut-through path. In this example, approximately half of the 5 t seconds required for burst data transfer is used for setting the cut-through path. If the time required for such a prior cut-through path can be used for data transfer, further improvement in transfer efficiency can be expected.
[0008]
The present invention has been made in such a background, and provides an optical communication network, a program, and a recording medium capable of efficiently performing burst data transfer without the need to set a cut-through path in advance. Objective.
[0009]
[Means for Solving the Problems]
The present invention detects the leading packet of burst data at the time when burst data arrives at the transmission-side edge node without setting a cut-through path in advance before burst data transfer. Sets a cut-through path. At this time, burst data is temporarily stored in the transmitting edge node until the setting of the cut-through path from the transmitting-side edge node to the receiving-side edge node is completed, and is stored when the setting of the cut-through path is completed. The transferred burst data is transferred to the receiving edge node.
[0010]
That is, the first aspect of the present invention provides a transmission-side edge node that accommodates a data transfer source, a reception-side edge node that accommodates a data transfer destination, and the transmission-side edge node and the reception-side edge node. An optical communication network comprising: a relay node arranged; and means for setting and releasing a cut-through path passing through the relay node between the transmission-side edge node and the reception-side edge node.
[0011]
Here, a feature of the present invention is that means for detecting arrival of a leading packet of burst data to the transmitting edge node is provided, and means for setting and releasing the cut-through path is the arrival of the leading packet. Means for setting a cut-through path from the transmitting edge node to the receiving edge node when the arrival of the first packet of burst data at the transmitting edge node is detected by the detecting means. Means for temporarily storing burst data arriving at the transmitting-side edge node until the setting of the cut-through path is completed, and when the setting of the cut-through path by the setting means is completed, the burst data is stored in the means for temporarily storing the burst data. Using the cut-through path And means for transferring to the receiving edge node, means for storing the temporarily is in place to provide a single burst buffers in common to a plurality of input lines. Further, the means for temporarily accumulating means is characterized in that the means for temporarily accumulating provides a burst buffer for each of a plurality of input lines, or provides a burst buffer for each subsequent router.
[0012]
As a result, the time required for setting can be shortened compared to the case of setting a cut-through path in advance, and efficient burst data transfer can be performed. In addition, by not performing burst data transfer from the sending edge node to the receiving edge node until the cut-through path setting is completed, the control procedure such as retransmission processing when cut-through path setting fails in the middle is simplified. Can be Furthermore, since burst data can be temporarily stored, a route that can save the most optical network resources can be selected and a cut-through path can be set.
[0013]
The transfer rate between the data transfer source and the transmission side edge node is v1, the transfer rate between the data transfer destination and the reception side edge node is v2, and the transmission side edge node and the reception side edge node are When the transfer speed during the period is v3, the means for temporarily storing is:
v1 << v3
And v2 << v3
It is desirable that the transmission-side edge node of the communication path including the transmission-side edge node and the reception-side edge node accommodating the data transfer source and the data transfer destination, which are
[0014]
In other words, if the data transfer rate from the data transfer source to the transmission side edge node is extremely slow compared to the data transfer rate in the optical communication network, the setting of the cut-through path is completed after the arrival of the first packet of burst data. While waiting for burst data transfer, if the data transfer source has finished sending the last packet of burst data, the cut-through path has already been set and burst data transfer has started. As a data transfer source, it does not matter whether burst data has been temporarily waited at the transmitting edge node.
[0015]
If the data transfer rate from the receiving edge node to the data transfer destination is extremely slow compared to the data transfer rate in the optical communication network, the data transfer destination receives the burst data that was transferred to the receiving edge node last time. In the meantime, if the current burst data waiting at the transmitting edge node arrives, it does not matter whether the burst data is temporarily waited at the transmitting edge node as the data transfer destination.
[0016]
In this way, by applying the present invention only to communication paths that satisfy the above conditions, burst data transfer can be realized with little concern about temporary retention of burst data at the data transfer source and data transfer destination. can do.
[0017]
A second aspect of the present invention is a program, and the feature of the present invention is that the information processing apparatus is installed in the information processing apparatus so that the transmission side edge node, relay node, and reception in the optical communication network are installed. As a function of setting and releasing a cut-through path passing through the side edge node, the function of detecting the arrival of the leading packet of burst data to the transmitting side edge node and the function of detecting the arrival of the leading packet provide the transmission side edge. When the arrival of the first packet of burst data to the node is detected, the function of setting a cut-through path from the transmitting-side edge node to the receiving-side edge node, and until the setting of the cut-through path by the setting function is completed Temporarily accumulates burst data arriving at the sending edge node Function and a function of storing the temporarily is common to provide one burst buffer for a plurality of input lines, or, provided a burst buffers for each of the plurality of input lines, a burst buffers for each of the following router function that features a, when the setting of the cut-through path by function of the setting is completed for transferring burst data stored in the function of temporarily storing the burst data to the receiving edge node by using the cut-through path is provided It is in a place to realize.
[0018]
The third aspect of the present invention is the information processing apparatus-readable recording medium on which the program of the present invention is recorded. By recording the program of the present invention on the recording medium of the present invention, the information processing apparatus can install the program of the present invention using this recording medium. Alternatively, the program of the present invention can be directly installed in the information processing apparatus via a network from a server holding the program of the present invention.
[0019]
As a result, an optical communication network capable of efficiently performing burst data transfer without the need to set a cut-through path in advance by an information processing device such as a computer device can be realized.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An optical communication network according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram of an optical communication network according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the burst data detection unit and the cut-through path setting release unit according to the embodiment of the present invention. FIG. 3 is a diagram for explaining the common burst buffer according to the first embodiment of the present invention. FIG. 4 is a diagram for explaining a burst buffer provided for each input port according to the second embodiment of the present invention. FIG. 5 is a diagram for explaining a burst buffer provided for each next router.
[0021]
In the embodiment of the present invention, the transmission-side edge node S and the reception-side edge node R are distinguished from each other for easy understanding, but in actuality, the edge node has functions of the transmission side and the reception side. Both functions are provided, and two-way communication can be performed.
[0022]
As shown in FIG. 1, the present invention includes a transmission-side edge node S that accommodates a data transfer source, a reception-side edge node R that accommodates a data transfer destination, a transmission-side edge node S, and a reception-side edge node R. Optical communication provided with relay nodes L1 to L4 arranged between them, and having a function of setting and releasing a cut-through path passing through the relay nodes L1 to L4 between the transmission side edge node S and the reception side edge node R It is a net. In this embodiment, the function of setting and releasing the cut-through path corresponds to the cut-through path setting / releasing unit 10 shown in FIG. 2, and is provided in each of the transmission-side edge node S, the relay nodes L1 to L4, and the reception-side edge node R. Alternatively, one or a plurality of devices may be distributed in an optical communication network outside the node as a device for collectively managing cut-through paths. In addition, this function is a well-known technique and will not be described in detail.
[0023]
Here, as shown in FIG. 2, a feature of the present invention is that a burst data arrival detection unit 1 for detecting the arrival of the first packet of burst data at the transmission-side edge node S is provided, and the cut-through path setting is released. The unit 10 sets the cut-through path from the transmission side edge node S to the reception side edge node R when the burst data arrival detection unit 1 detects the arrival of the leading packet of the burst data to the transmission side edge node S, and A burst buffer 20 is provided for temporarily accumulating burst data arriving at the transmitting-side edge node S until the setting of the through-path is completed. Used to forward to the receiving edge node R.
[0024]
The transfer rate between the data transfer source and the transmission side edge node S is v1, the transfer rate between the data transfer destination and the reception side edge node R is v2, and the transmission side edge node S and the reception side edge node R When the transfer rate between is set to v3, the burst buffer 20
v1 << v3
And v2 << v3
The transmission-side edge node S of the communication path including the transmission-side edge node S and the reception-side edge node R that accommodate the data transfer source and the data transfer destination as described above is provided.
[0025]
The optical communication network of the present invention is installed in a computer device serving as an information processing device, so that the computer device passes through the transmission-side edge node S, the relay nodes L1 to L4, and the reception-side edge node R in the optical communication network. As a function for setting and releasing a cut-through path, transmission is performed by a function corresponding to the burst data arrival detection unit 1 for detecting the arrival of the leading packet of the burst data to the transmitting edge node S and a function for detecting the arrival of the leading packet. A function corresponding to the cut-through path setting release unit 10 for setting the cut-through path from the transmitting-side edge node S to the receiving-side edge node R when the arrival of the first packet of burst data at the side edge node S is detected, and this setting Setting of the cut-through path by the function to be completed The burst stored in the function corresponding to the burst buffer 20 for temporarily storing the burst data arriving at the transmitting edge node S and the function for temporarily storing the burst data when the setting of the cut-through path by the setting function is completed. It can be realized by using the computer device by installing a program for realizing the function of transferring data to the receiving edge node R using the cut-through path.
[0026]
By recording the program of the present invention on the recording medium of the present invention, the computer apparatus can install the program of the present invention using this recording medium. Alternatively, the program of the present invention can be installed directly on the computer device from a server holding the program of the present invention via a network.
[0027]
Thereby, it is not necessary to set a cut-through path in advance by the computer device, and an optical communication network capable of efficiently performing burst data transfer can be realized.
[0028]
Next, the operation of the transmitting edge node in the optical communication network of the embodiment of the present invention will be described with reference to FIG. When burst data arrives, the header information of the leading packet is read by the header information reading unit 4 and analyzed by the burst data arrival detection unit 1 of the burst data detection unit 3. It is determined whether or not the data is to be cut-through. If the data arrived by the determination is sporadic data that is not burst data, IP transfer is performed. Specifically, information indicating that the packet is the first packet of burst data is written in the header information. Information indicating the head packet includes information on the number of subsequent packets or the subsequent packet length.
[0029]
Here, the cut-through path setting release unit 10 sets a cut-through path from the transmission-side edge node S to the reception-side edge node R in response to the detection result from the burst data arrival detection unit 1. Since this setting procedure is an existing technology, a description thereof will be omitted. During this time, the incoming burst data is stored in the burst buffer 20.
[0030]
When receiving the setting completion notification from the receiving edge node R, the cut-through path setting release unit 10 transfers the burst data stored in the burst buffer 20 using the cut-through path.
[0031]
The above is the overall description of the embodiment of the present invention. Hereinafter, the first to third embodiments of the burst buffer configuration will be described with reference to FIGS.
[0032]
(First Example)
A first embodiment of the present invention will be described with reference to FIG. In the first embodiment, one common burst buffer 50 is provided for the optical cross-connect 40 that accommodates a plurality of input lines. A plurality of burst data coming from a plurality of input lines are stored in one common burst buffer 50. The plurality of burst data can be distinguished from each other by the header information of the head packet, and each burst data is read using this header information. As a result, the scale of the burst buffer can be made relatively small and the configuration can be simplified.
[0033]
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, burst buffers 60-1 to 60-n are provided for each of a plurality of input lines. According to the second embodiment, it is only necessary to wait for an empty output line, and the control procedure can be simplified.
[0034]
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. In the third embodiment, burst buffers 70-1 to 70-n for the next routers are provided in the buffer pool 70, respectively. According to the third embodiment, since the waiting is performed for each wavelength path to the next router, the control procedure can be further simplified as compared with the second embodiment.
[0035]
【The invention's effect】
As described above, according to the present invention, burst data transfer can be performed efficiently without the need to set a cut-through path in advance.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of an optical communication network according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining a burst data detection unit and a cut-through path setting release unit according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining a common burst buffer according to the first embodiment of the present invention.
FIG. 4 is a diagram for explaining a burst buffer provided for each input port according to the second embodiment of the present invention.
FIG. 5 is a diagram for explaining a burst buffer provided for each next router;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Burst data arrival detection part 2 Burst data end detection part 3 Burst data detection part 4 Header information reading part 10 Cut through path setting release part 20, 60-1 to 60-n, 70-1 to 70-n Burst buffer 40 Optical cross Connect 50 Common burst buffer 70 Buffer pools L1 to L4 Relay node R Reception side edge node S Transmission side edge node

Claims (8)

A transmission-side edge node accommodating a data transfer source, a reception-side edge node accommodating a data transfer destination, and a relay node disposed between the transmission-side edge node and the reception-side edge node;
Means for setting and releasing a cut-through path passing through the relay node between the transmitting-side edge node and the receiving-side edge node ;
Means for detecting the arrival of the first packet of burst data by detecting information indicating that the packet is the first packet of burst data from the header information of the packet arriving at the transmitting edge node;
The means for setting and releasing the cut-through path is configured such that when the arrival of the leading packet of burst data to the transmitting-side edge node is detected by the means for detecting the arrival of the leading packet, the cut-through path is set from the transmitting-side edge node. Means for setting up to the receiving edge node;
Means for temporarily storing burst data arriving at the transmitting edge node until the setting of the cut-through path by the setting means is completed;
An optical communication network comprising: means for transferring burst data stored in the means for temporarily storing the burst data to the receiving edge node using the cut-through path when the setting of the cut-through path by the setting means is completed In
The means for temporarily storing the burst data is provided with one burst buffer in common for a plurality of input lines. 2. The optical communication network according to claim 1, wherein the means for temporarily storing the burst data includes a burst buffer for each of a plurality of input lines. 2. The optical communication network according to claim 1, wherein the means for temporarily storing the burst data includes a burst buffer for each next router. 2. A cut-through path that passes through a transmission-side edge node, a relay node, and a reception-side edge node in an optical communication network is set and released by installing the information processing device in the information processing device. Thru 3 programs. The information processing apparatus-readable recording medium on which the program according to claim 4 is recorded. An optical communication network comprising a transmission side node accommodating a data transfer source, a reception side node accommodating a data transfer destination, and a relay node arranged between the transmission side node and the reception side node Provided ,
Means for setting and releasing a cut-through path via the relay node with the receiving node;
Means for detecting the arrival of the first packet of burst data by detecting information indicating that the packet is the first packet of burst data from the header information of the packet arriving from the data transfer source,
The means for setting and releasing the cut-through path sets the cut-through path up to the receiving side node when the arrival of the leading packet of burst data to the transmitting side node is detected by the means for detecting the arrival of the leading packet. Including means,
Means for temporarily accumulating the incoming burst data until the setting of the cut-through path by the means for setting is completed;
Means for transferring the burst data stored in the means for temporarily storing the burst data to the receiving side node using the cut-through path when the setting of the cut-through path by the setting means is completed;
The node for temporarily storing the burst data is provided with one burst buffer in common for a plurality of input lines . 7. The node according to claim 6, wherein the means for temporarily storing the burst data includes a burst buffer for each of a plurality of input lines. 7. The node according to claim 6, wherein the means for temporarily storing the burst data includes a burst buffer for each next router.

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