JP2004248174A - Communication network, node device used therein, and transmission control method used therein - Google Patents

Abstract

A buffer output priority control section controls output of packets stored in a buffer so that the output is always given priority from a high-priority storage area. A service for transmitting a packet according to a priority is enabled.
A switching means for switching a packet input on a plurality of channels and outputting the signal on any one of the plurality of channels, and storing and inputting signals input from the plurality of channels, respectively. Buffer means for outputting separately for each channel and having a high-priority buffer for storing a high-priority signal, a non-priority buffer for storing a non-priority signal, and a signal stored in the high-priority buffer. A node device having buffer output priority control means for outputting from the buffer means prior to a signal stored in a non-priority buffer.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication network and a transmission control method, and more particularly, to a network system including a node device for connecting a plurality of terminal devices and a parallel multiplex transmission line for connecting a plurality of the node devices.
[0002]
[Prior art]
In recent years, with an increase in the amount of information, a network system in which node devices are connected by a parallel multiplex transmission path has been studied in order to cope with an increase in the speed and capacity of a network connecting terminal devices. For example, JP-A-8-172394 and JP-A-8-237306 show examples of the configuration.
[0003]
FIG. 10 is a diagram showing a configuration of a packet used in the network of the reference example. N is a node number, and is composed of 5 bits indicating node numbers 1 to 32 if 32 node devices can be connected. T is a transmission channel number, which is composed of 3 bits indicating 1 to 8 if the number of transmission channels (multiplex number) of the parallel multiplex transmission path is eight. In other cases, a synchronization signal, an error correction code, and the like are inserted as needed.
[0004]
FIG. 5 is a configuration diagram of a node device in the network of the reference example, and shows an example in which terminals 551 to 558 are connected to the node device 500 via sub-transmission paths. Reference numerals 501 to 508 denote terminal signal insertion units which are insertion means, and have a function of inserting packets input from the terminals 551 to 558 into a packet stream input from a parallel multiplex transmission line. .
[0005]
Reference numerals 561 to 568 denote terminal signal separation units serving as separation means, which detect the address of a packet input from the parallel multiplex transmission path, and transmit a packet and a terminal to be transmitted to the terminals 551 to 558 via the sub transmission path. It has a function of separating packets to be input to the buffers 511 to 518 via the insertion units 501 to 508.
[0006]
Reference numerals 511 to 518 denote buffers serving as buffer means, and have a function of temporarily storing packets output from the terminal signal insertion units 501 to 508 in a storage area corresponding to a specific output terminal of the switch 541. I have.
[0007]
Reference numerals 521 to 528 and 531 to 538 denote parallel multiplex transmission lines in which a plurality of channels for connecting nodes are provided in parallel, such as a plurality of spatially separated optical fiber transmission lines. It may be a wavelength division multiplexed transmission line that is wavelength division multiplexed on an optical fiber.
[0008]
A switch 541 is controlled by the switch control unit 542 to connect a packet input to the input terminals IN1 to IN8 to an arbitrary output terminal OUT1 to OUT8. When a plurality of optical fiber transmissions are used for the parallel multiplex transmission line, the switch 541 performs switching using a space switch or the like. In the case of using a wavelength division multiplex transmission line, although the configuration is slightly different from that shown in the figure, a transmission unit including a plurality of tunable wavelength laser diodes and a multiplexer is connected to the wavelength division multiplex transmission line to receive the wavelength division multiplex transmission line. A switch is formed between nodes by separating each wavelength by a demultiplexer in the unit, and switching is performed by setting the transmission wavelength of the variable wavelength laser diode to an arbitrary wavelength of wavelengths λ1 to λ8.
[0009]
Reference numeral 542 denotes a switch control unit that controls a switch according to, for example, the control pattern of FIG. Reference numeral 543 denotes a buffer control unit, which controls to read out the stored packet from the buffer when the input terminal of the switch connected to each buffer is connected to a desired output terminal.
[0010]
FIG. 8 is a diagram showing the internal configuration of the terminal signal separation units 561 to 568, where 801 is a header detection unit that detects a destination address from a packet header, and 802 and 803 are gates for outputting or blocking an input signal. . In the terminal signal separating units 561 to 568, the header of the packet input from the parallel multiplex transmission path is detected by the header detecting unit 801 and the gates 802 and 803 are opened and closed according to the contents of the header. The number of the own node (referred to as own node number) is stored in the header detecting unit 801 in advance.
[0011]
The header detection unit 801 includes:
1. When the detected node number matches the stored own node number, the gate 803 is opened and the gate 802 is closed, and the packet is output only in the terminal direction.
[0012]
2. If the detected node number does not match the stored own node number, the gate 802 is opened and the gate 803 is closed, and the packet is output only to the terminal signal insertion unit.
[0013]
Control the route of the packet. The packet output to the terminal signal insertion unit is sent to the buffer via the terminal signal insertion unit.
[0014]
FIG. 9 is a diagram showing the internal configuration of the terminal signal insertion units 501 to 508, in which reference numeral 901 denotes a header detection unit for detecting a destination address from the header of a packet; 904, a selector for outputting one of two input signals; Is a FIFO (First In First Out) for temporarily storing a packet. The terminal signal insertion unit temporarily stores the packet transmitted from the terminal in the FIFO 905. At the same time, the header of the packet stream input from the terminal signal separation unit to the selector 904 is detected by the header detection unit 901, and when there is a gap in the packet stream, the packet stream is read from the FIFO 905 and sent to the buffer through the selector 904. . The header detection unit 901 of the terminal signal insertion unit and the header detection unit 801 of the terminal signal separation unit can be shared.
[0015]
FIG. 3 shows the internal configuration of the buffers 511 to 518, where 301 is a buffer memory composed of storage areas 1 to 8 corresponding to the eight output terminals of the switch 541, and 302 is a header for detecting a destination address from a packet header. A detection unit 303 is an address counter for supplying a write address to the buffer memory 301. In the buffers 511 to 518, the header of the packet input from the terminal signal insertion unit is detected by the header detection unit 302, and the storage area for storing the packet is determined based on the content of the header.
[0016]
The node number (referred to as a downstream node number) of an adjacent downstream node is stored in the header detection unit 302 in advance.
[0017]
The header detection unit 302
1. If the detected node number matches the stored downstream node number, the address counter 303 writes a write address to the storage area (one of the storage areas 1 to 8) having the same number as the detected transmission channel number. Is generated, and the packet is stored in the above-mentioned addressing area of the storage area of the buffer memory 301 (the storage area having the same number as the detected transmission channel number).
[0018]
2. If the detected node number does not match the stored downstream node number, a write address is generated by the address counter 303 for any one of the storage areas 1 to 8, and the buffer memory The path of the packet is controlled so that the packet is stored in the addressing area generated above in the storage area selected above in 301.
[0019]
FIG. 4 is a control pattern showing the input / output connection relationship of the switch 541. The input / output connection relationship of the switch is changed according to the control addresses Al to A8. Input terminals IN1 to IN8 correspond to buffers 511 to 518 (input channels 521 to 528), and output terminals OUT1 to OUT8 (or transmission wavelengths λ1 to λ8) correspond to channels 531 to 538. The switch 541 and the buffers 511 to 518 are controlled synchronously by the switch control unit 542 and the buffer control unit 543. For example, when the output of the buffer 511 is connected to the channel 531 by the switch 541, the buffer 511 outputs the channel 531. Is read out from the storage area 1 corresponding to. When the buffer 511 is connected to the channel 532, the packet stored in the storage area 2 corresponding to the channel 532 is read from the buffer 511.
[0020]
FIG. 6 is a configuration example of a network system using the node devices shown in FIG. 5, in which four node devices 601 to 604 are connected in a ring form by parallel multiplex transmission lines 605 to 608, and each node device has Eight terminals are connected via eight sub-transmission paths. Terminals 611 to 618 correspond to terminals 551 to 558, and similarly, 621 to 628, 631 to 638, and 641 to 648 also correspond to terminals 551 to 558.
[0021]
FIG. 7 is a diagram for explaining the communication principle of this network, in which 701 to 704 are node devices, 705 to 708 are exchange switches corresponding to the switch 541I, 709 to 712 are buffers corresponding to the buffers 511 to 518, and 721. 736 are terminals, and A, B, C, and D are parallel transmission lines forming a ring.
[0022]
First, the communication principle of this network will be described with reference to FIG. This network has a plurality of rings A, B, C, and D, and the rings are interconnected by exchange switches 705-709. Each terminal is connected to one ring transmission line among the parallel transmission lines A, B, C, and D. When communicating with a terminal connected to another ring, at least once, an arbitrary switching switch The communication is performed by exchanging with another ring. Although the position where the exchange is performed is not specified, communication control is facilitated by switching to a destination transmission line at a node immediately before the destination node and switching to an arbitrary transmission line at another node. In order to simplify the node device in this network, the exchange switches 705 to 708 change the input / output connection relationship in accordance with a predetermined pattern and repeat the pattern independently of the input signal. The signal is temporarily stored, and the exchange is performed such that the packet is read from the buffer when the input / output connection relationship of the exchange switch becomes a desired relationship.
[0023]
For example, when communication is performed from the terminal 722 to the terminal 732, packets output from the terminal 722 are accumulated in the buffer 709 of the node 701, and are read from the buffer when the input terminal IN2 of the switch 705 is connected to the output terminal OUT2, for example. The packet is output to the transmission path B, output to the buffer 710 of the node 702, and read from the buffer when the IN2 and OUT4 of the switch 706 are connected, whereby the packet is output to the transmission path D and transmitted to the terminal 732. Sent.
[0024]
As described above, communication is performed by switching to the transmission path of the destination at the node immediately before the destination node and switching to the arbitrary transmission path at the other nodes.
[0025]
Next, details will be described with reference to FIGS. In the description, the parallel multiplex transmission line will be described as a spatially separated double-sensitive optical fiber transmission line, and the switch will be described as a space switch.However, even when a wavelength multiplex transmission line is used, the above principle is used, and almost the same operation is performed. Done. An operation example in the case where communication is performed from the terminal 612 to the terminal 635 will be described.
[0026]
1. Transmission data from the terminal 612 is divided into fixed-length packets, and the header of each packet describes the node number (N = 3) and the transmission channel number (T = 5) of the destination terminal of the transmission terminal, and is output. . The output packet is input to the node device 601 through the sub transmission path, and is temporarily stored in the FIFO 905 of the terminal signal insertion unit 502. The stored packet is read from the FIFO 905 when there is a gap in the packet stream input to the selector 904 from the terminal signal separation unit 562, and is sent to the buffer 512 through the selector 904.
[0027]
2. Since the node number (N = 3) detected from the header of the input packet does not match the stored downstream node number (2), the header detection unit 302 of the buffer 512 is a packet for which a specific channel is not specified. Then, an arbitrary storage area is selected. The write address counter 303 receives the information, generates a write address for the storage area selected above, and writes the packet to the storage area selected in the buffer memory 301. Here, it is assumed that the data is stored in the storage area 1.
[0028]
3. The buffer control unit 543 waits for reading of the packet until the input terminal IN2 of the switch 541 is connected to the output terminal OUT1, and reads the packet when connected.
[0029]
4. The switch control unit 542 sequentially supplies the control addresses A1, A2, A3, A4, A5, A6, A7, and A8 as shown in the table shown in FIG. For example, by supplying the data in one packet length cycle, the same pattern is controlled so as to be repeated in eight packet cycles. By notifying the information to the buffer control unit 543, the timing of reading from the buffer is controlled. Here, when the input terminal IN2 of the switch 541 is connected to the output terminal OUT1, a packet is read from the storage area 1 of the buffer 512, and the packet is output to the transmission line 531 through the switch 541.
[0030]
5. The header of the packet input to the terminal signal separation unit 561 of the node device 602 via the transmission path 531 is detected by the header detection unit 801. Since the detected node number (N = 3) does not match the stored node number (2), the gate 802 is opened, the gate 803 is closed, and the packet is output to the terminal signal insertion unit 501. The packet output to the selector 904 of the terminal signal insertion unit 501 passes through the selector 904 and is input to the buffer 511.
[0031]
6. Since the node number (N = 3) detected from the header of the input packet matches the stored downstream node number (3), the header detection unit 302 of the buffer 51I detects the transmission channel number (T = 5). Select the storage area with the same number as in ()). The write address counter 303 receives the information, generates a write address for the storage area (storage area 5) selected above, and causes the packet to be written to the storage area 5 of the buffer memory 301. Here, since the transmission channel number is 5, the packet is stored in the storage area 5.
[0032]
7. The buffer control unit 543 reads the packet from the storage area 5 of the buffer 511 when IN1 of the switch 541 is connected to OUT5, and the packet is output to the transmission path 535 through the switch 541.
[0033]
8. The header of the packet input to the terminal signal separation unit 565 of the node device 603 via the transmission path is detected by the header detection unit 801. Since the detected node number (N = 3) matches the stored own node number (3), the gate 803 is opened and the gate 802 is closed to output the packet only in the terminal direction.
[0034]
9. The packet output from terminal signal separation section 565 in the terminal direction is sent to terminal 635 via the sub-transmission path and received.
[0035]
Communication is performed in this manner.
[0036]
[Problems to be solved by the invention]
In the reference example network described above, a priority is assigned to each communication connection, and a service for transmitting a packet in accordance with the priority is not considered.
[0037]
Therefore, a communication connection for communicating urgent communication contents (for example, a network abnormality notification, etc.) is given a higher priority than a communication connection for communicating normal communication contents, and a communication connection with a higher priority is performed. Cannot provide such a service that the communication delay is smaller than that of the packet of the communication connection having a lower priority.
[0038]
In connection with that, in the case of communication where the information cannot be reproduced on the receiving side unless the information is sent at a certain period, such as when communicating video information, the information is transmitted at that period. Could not guarantee to send. In other words, when the network is congested due to the influence of other communications, the communication delay may increase, which may hinder the reproduction of information.
[0039]
Furthermore, as a problem when the network becomes congested, there is a possibility that packets may be discarded in the network buffer or the like in the above-described reference example, and even in such a case, priority is given to communication connections according to the importance of communication contents. The service of setting and discarding packets of a communication connection having a low priority cannot be performed.
[0040]
Specific examples are shown below to make the problem easier to understand.
[0041]
An operation example in the case where communication is performed from the terminal 612 to the terminal 625 in the network of the reference example illustrated in FIGS. 5 and 6 will be described.
[0042]
1. The transmission data from the terminal 612 is divided into fixed-length packets, and the header of each packet describes the node number (N = 2) and the transmission channel number (T = 5) of the destination terminal of the transmission terminal, and is output. . The output packet is input to the node device 601 through the sub transmission path, and is temporarily stored in the FIFO 905 of the terminal signal insertion unit 502. The stored packet is read from the FIFO 905 when there is a gap in the packet stream input to the selector 904 from the terminal signal separation unit 562, and is sent to the buffer 512 through the selector 904.
[0043]
2. Since the node number (N = 2) detected from the header of the input packet matches the stored downstream node number (2), the header detection unit 302 of the buffer 512 detects the transmission channel number (T = 5). Select the storage area with the same number as in (). The write address counter 303 receives the information, generates a write address for the storage area (storage area 5) selected above, and causes the packet to be written to the storage area 5 of the buffer memory 301. Here, since the transmission channel number is 5, the packet is stored in the storage area 5.
[0044]
3. The buffer control unit 543 reads the packet from the storage area 5 of the buffer 512 when IN2 of the switch 541 is connected to OUT5, and the packet is output to the transmission path 535 through the switch 541.
[0045]
4. The header of the packet input to the terminal signal separation unit 565 of the node device 602 via the transmission path is detected by the header detection unit 801. Since the detected node number (N = 2) matches the stored node number (2), the gate 803 is opened and the gate 802 is closed to output the packet only in the terminal direction.
[0046]
5. The packet output from terminal signal separation section 565 in the terminal direction is sent to terminal 625 via the sub-transmission path and received.
[0047]
Communication is performed in this manner.
[0048]
Now, it is assumed that the video is transmitted from the terminal 612 to the terminal 625 according to the above procedure, for example. The video information needs to be received at a constant cycle by the terminal 625 that reproduces the video. At the same time, it is assumed that the file is transferred from the terminal 612 to the terminal 625 using another connection. File transfer is communication that does not require real-time properties. The two types of connections can be distinguished from each other by using an area indicated by “other” in the header in the packet having the configuration shown in FIG.
[0049]
In such a case, the following may occur.
[0050]
Both the packet of the video connection and the packet of the file transfer connection are temporarily stored in the storage area 5 of the buffer 512 of the node device 601. When only the packet of the video connection is being communicated, even if the terminal 625 receives the packet at a fixed period, if the packet of the file transfer connection is simultaneously communicated, depending on the burstiness of the file transfer data, Since there is a possibility that a considerable amount of file transfer connection packets may be stored in the storage area 5 instantaneously, immediately after that, the video connection packet stored in the storage area 5 is replaced with the file transfer connection packet stored before that. Is not output until all the packets of the video connection are output, and there is a possibility that the video connection packet does not reach the terminal 625 at a constant period. That is, when the network is congested due to the influence of other communication, the communication delay increases, and there is a possibility that the reproduction of the video information may be hindered.
[0051]
The conventional reference example has the above problems.
[0052]
[Means for Solving the Problems]
The communication network of the present invention is as follows.
[0053]
A plurality of parallel channels, a switch connected to the plurality of channels, and a switch for outputting a signal input from each channel on any one of the plurality of channels; and a switch connected to the plurality of channels. The switch means has a function of, when a specific signal is input, outputting the signal to one of the plurality of channels prior to other signals. A communication network, wherein the plurality of channels are connected in a ring form via the switch means to form a parallel ring transmission path.
[0054]
In the present invention, the switch means has a function of outputting a specific signal first, regardless of the order of input signals, so that each communication connection described in "Problems to be Solved by the Invention" It is possible to implement a service in which a priority is assigned and a packet is transmitted according to the priority. In other words, a signal with a higher priority is output from the switch means before other signals, thereby reducing the communication delay of the signal or reducing the possibility that the signal is discarded in the switch means. Or you can.
[0055]
In the communication network, information (referred to as priority order designation information) that can determine whether or not the signal should be output first to any one of the plurality of channels by the switch means with priority is added to the signal. Means for giving may be provided.
[0056]
Further, the switch means has means for detecting the priority designation information, and the switch means, when a signal to which the priority designation information is added (referred to as high priority information) is inputted, An operation is performed such that a signal to which priority order designation information is not added (referred to as non-priority information) is output to any one of the plurality of channels first.
[0057]
The switch means further includes buffer means for respectively accumulating signals input from the plurality of channels and outputting the signals separately for each input channel; and outputting the signals for each channel from the buffer means and signals from the switch means. Switching means for switching connection with the plurality of output channels, and when the high-priority signal is stored in the buffer means, the priority is given first to the non-priority information stored in the buffer means. A buffer output priority control means for controlling the output from the buffer means so as to output the high priority signal from the buffer means may be provided.
[0058]
Further, the buffer means includes, for each of the plurality of channels, a buffer for storing the high-priority signal (referred to as a high-priority buffer) and a buffer for storing the non-priority signal (referred to as a non-priority buffer). Wherein the buffer output priority control means gives priority to signals stored in the high priority buffer over signals stored in the non-priority buffer, regardless of the order of signals input to the buffer means. Then, the data may be output from the buffer means first.
[0059]
Further, the buffer means includes a first storage means for storing the high priority signal and the non-priority signal for each of the plurality of channels, and a second storage means for storing an address of an unused area of the first storage means. And third storage means for storing the address of the high-priority signal stored in the first storage means, and fourth storage means for storing the address of the non-priority signal stored in the first storage means Wherein the buffer output priority control means controls the reading of the signal stored in the first storage means according to the information stored in the third and fourth storage means. Is also good. .
[0060]
A crossbar switch or the like can be used as the switching means. Also, for example, when a plurality of channels can be identified by wavelength, a wavelength tunable transmission unit is provided corresponding to each output of each input channel, and by switching the output wavelength of the wavelength tunable transmission unit, Output and connection of the output channel can be switched. Further, the switching means is not limited to the wavelength as a channel, has an output channel variable means provided corresponding to each output from the buffer for each channel, controlling the output channel variable means, The connection between the output for each channel input to the switching means and the output channel may be switched by switching the output channel.
[0061]
In the switching means, the output for each channel from the buffer input to the switch and the switching of the output channel are performed according to a predetermined pattern, and a plurality of the outputs from the buffer for each input channel are simultaneously the same output. By not connecting to a channel, arbitration between input and output is not required in the switch, and the control load is greatly reduced.
[0062]
Further, the terminal is connected to the channel via a separating unit, and the separating unit outputs, from the channel, a signal to be output to the terminal among signals transmitted on the channel to which the own separating unit is connected. It may be one that separates and outputs to the terminal.
[0063]
In addition, when a signal is input from the terminal to the network, an insertion unit for inserting a signal into the channel may be provided, and the signal may be inserted into the channel from the insertion unit.
[0064]
A node device having the switch means and the separating means provided therein, or a node device having the switch means, the separating means and the inserting means provided therein may be used.
[0065]
The communication network of the present invention can also be described as follows.
[0066]
A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, wherein the network has a transmission packet that switches transmission channels between the parallel channels. Switch means for performing the transfer, and when a certain packet is input, the switch means has a function of changing over the transmission channel prior to another packet. And a communication network.
[0067]
The communication network of the present invention can also be described as follows.
[0068]
A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, wherein the node device switches packets input on the plurality of channels. It has a function of outputting on any of the plurality of channels, and when a specific packet is input, outputs the packet to any one of the plurality of channels prior to other packets. Switch means having a function of enabling the switch and, in the switch means, means for adding to the packet information for determining whether the input packet is a packet to be output with priority. A communication network, characterized in that:
[0069]
The communication network of the present invention can also be described as follows.
[0070]
A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, wherein the node device switches packets input on the plurality of channels. A switch having a function of outputting the signal on one of the plurality of channels, wherein the switch stores a packet input from each of the plurality of channels and outputs the packet separately for each input channel; Means, switching means for switching the connection between the output of each channel from the buffer means and the plurality of channels from which packets are output from the switch means, irrespective of the order of the packets stored in the buffer means. A buffer output priority for controlling a specific packet to be output first from the buffer means. Communication network, characterized in that a control means.
[0071]
In this application, a node device used in the above-described communication network is also shown.
[0072]
The transmission control method according to the present application is as follows.
[0073]
A plurality of parallel channels, switch means connected to the plurality of channels, and capable of outputting a signal input in each channel on any one of the plurality of channels, and a terminal connected to the plurality of channels A transmission control method for a signal in a communication network configured in a ring type via the switch means, wherein the plurality of channels are input to the communication network and transmitted through the channel. For a specific signal among the signals arriving at the destination terminal, when the specific signal is input to the switch means, even if there is a signal staying in the switch means, Transmission control wherein the specific signal is controlled to be output from the switch means prior to the staying signal. Law.
[0074]
The transmission control method according to the present application is as follows.
[0075]
A plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, and switch means is provided for enabling transmission packets to switch transmission channels between the parallel channels. Transmission control method for a packet in a communication network, wherein the switch means controls, when a specific packet is input, to change over the transmission channel prior to other packets. Transmission control method.
[0076]
The transmission control method according to the present application is as follows.
[0077]
A plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, and switch means is provided for enabling transmission packets to switch transmission channels between the parallel channels. Transmission control method for a packet in a communication network, wherein information that can determine whether or not a packet to be transferred to a transmission channel with priority in the switch means is added to a packet that reaches the destination terminal after transmitting the channel. A transmission control method, wherein the switching means performs control so that a packet in which the information is detected is prioritized over another packet to change the transmission channel.
[0078]
The node device of the present invention is as follows.
[0079]
In a node device used in a communication network in which a plurality of node devices for connecting a plurality of terminal devices are connected in a ring by using a plurality of parallel channels, a packet transmitted through the plurality of channels; Receiving means for receiving a packet transmitted from the terminal device, and switching a packet input on the plurality of channels, outputting the packet on any of the plurality of channels, and A switch unit having a function of enabling output from the switch unit in preference to other packets; and a packet to be output from the switch unit preferentially by the receiving unit. A node device, comprising: a determination unit configured to determine whether the node device is a node device.
[0080]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
A first embodiment of the present invention will be described.
[0081]
FIG. 1 is a diagram showing a configuration of a packet used in the network of the present invention. P indicates priority designation information. The priority designation information is one bit, and when performing communication with high urgency, performing communication in which delay is to be reduced, or performing communication in which it is desired to avoid discarding a packet more than usual, the priority of the packet is designated. The order designation information is set to 1 (a packet with the priority designation information of 1 is called a high priority packet), and is set to 0 in normal communication (a packet with the priority designation information of 0 is a non-priority packet). ). Further, N is a node number, and is composed of 5 bits indicating node numbers 1 to 32 if 32 node devices can be connected. T is a transmission channel number, and is composed of 2 bits indicating 1 to 4 if the number of transmission channels (multiplex number) of the parallel multiplex transmission path is four. In other cases, a synchronization signal, an error correction code, and the like are inserted as needed. Each terminal in the network is individually identified by a node number and a transmission channel number.
[0082]
FIG. 11 is a configuration diagram of a node device used in the network of the present invention. The input / output ports PORT1 to PORT4 for connecting to four terminals via a transmission path such as a twisted pair cable, and the node devices of the present invention are many. The configuration of a node device having four node input terminals IN1 to IN4 and four node output terminals OUT1 to OUT4 for connection via a parallel transmission line such as a core optical fiber cable is shown.
[0083]
In FIG. 11, reference numerals 1101 to 1104 denote node input terminals IN1 to IN4 for inputting signals from a parallel transmission line, and include an optical receiver for converting an optical signal into an electric signal. The optical receiver performs not only photoelectric conversion, but also clock extraction, decoding of a transmission path encoded signal, and the like.
[0084]
Reference numerals 1171 to 1174 denote node output terminals OUT1 to OUT4 for outputting signals to the parallel transmission lines, and include an optical transmitter for converting an electric signal to an optical signal. The optical transmitter performs transmission path coding and the like in addition to electro-optical conversion.
[0085]
Reference numerals 1181 to 1184 denote terminal signal input / output ports for connecting terminals via a twisted pair cable or the like. Each port is composed of a circuit for transmission and a circuit for reception.
[0086]
In FIG. 11, 1121 to 1124 detect the header of the packet input from the input terminals 1101 to 1104, and transmit the packet to be transmitted to the terminal side via the terminal signal input / output ports 1181 to 1184 and the terminal signal insertion units 1131 to 1134. This is a terminal signal separation unit that separates the data into packets to be input to the buffers 1141 to 1144 through the buffer.
[0087]
FIG. 2 shows the internal configuration of terminal signal separation sections 1121 to 1124. 201 is a header detector for detecting N from the header of the packet, and 202 and 203 are gates for outputting or blocking an input signal. The headers of the packets input from the node input terminals 1171 to 1174 are detected by the header detection unit 201, and the gates 202 and 203 are opened and closed according to the contents of the header.
[0088]
The header detection unit 201 stores the node number of its own node (referred to as its own node number) in advance.
[0089]
The header detection unit 201
1. When the node number (N) detected from the header of the input packet matches the stored own node number, the gate 203 is opened and the gate 202 is closed to output the packet to the terminal signal input / output ports 1181 to 1184. .
[0090]
2. If the node number (N) detected from the header of the input packet does not match the stored own node number, the gate 202 is opened and the gate 203 is closed to output the packet only to the terminal signal insertion units 1131 to 1134.
[0091]
Thus, the route of the packet is controlled (see FIG. 12). This control is basically the same as that of the terminal signal separation unit of the reference example.
[0092]
11 have a function of inserting a packet input from a terminal via the terminal signal input / output ports 1181 to 1184 into a packet stream transmitted from the terminal signal separation units 1121 to 1124. This is a terminal signal insertion unit. Since the terminal signal insertion unit is the same as that shown in FIG. 9 in the reference example, detailed description of its operation is omitted here.
[0093]
The header detection section 901 of the terminal signal insertion section and the header detection section 201 of the terminal signal separation section can also be used in common.
[0094]
Reference numerals 1141 to 1144 in FIG. 11 are buffers for temporarily storing packets input from the terminal signal insertion unit and outputting the packets to the switch 1151.
[0095]
FIG. 14 shows the internal configuration of the buffers 1141 to 1144. A buffer memory 1401 includes a high-priority buffer 1404 for temporarily storing high-priority packets, and a non-priority buffer 1405 for temporarily storing non-priority packets. The high-priority buffer 1404 includes high-priority storage areas 1 to 4 corresponding to four output terminals (OUT1 to OUT4) of the switch 1151, respectively. Similarly, the non-priority buffer 1405 includes four switches of the switch 1151. It comprises non-priority storage areas 1 to 4 corresponding to the output terminals (OUT1 to OUT4), respectively. Reference numeral 1402 denotes a header detection unit that detects P, N, and T from the header of the packet. Reference numeral 1403 denotes an address counter for supplying a write address to the buffer memory 1401.
[0096]
In the buffers 1141 to 1144, the header of the packet input from the terminal signal insertion unit is detected by the header detection unit 1402, and the storage area for storing the packet is determined based on the content of the header.
[0097]
The header detection unit 1402 stores in advance the node numbers of adjacent downstream nodes (referred to as downstream node numbers).
[0098]
The header detection unit 1402
1. If the input packet is a high-priority packet (P = 1) and the detected node number (N) matches the stored downstream node number, the same as the detected transmission channel number (T) The write address is generated by the address counter 1403 for the storage area (one of the high-priority storage area 1 to the high-priority storage area 4) in the high-priority buffer 1404 of the number, and the storage area ( The packet is stored in the addressing area generated above in the high-priority storage area having the same number as the detected transmission channel number.
[0099]
2. If the input packet is a high-priority packet (P = 1) and the detected node number (N) does not match the stored downstream node number, the high-priority storage in the high-priority buffer 1404 A write address is generated from the address counter 1403 for any one of the areas 1 to the high-priority storage area 4, and the above-mentioned address designation of the storage area selected in the high-priority buffer 1404 is performed. The packet is stored in the area.
[0100]
3. If the input packet is a non-priority packet (P = 0) and the detected node number (N) matches the stored downstream node number, the same as the detected transmission channel number (T) A write address is generated by the address counter 1403 for the storage area (one of the non-priority storage areas 1 to 4) in the non-priority buffer 1405 of the number, and the storage area ( The packet is stored in the addressing area generated above in the non-priority storage area having the same number as the detected transmission channel number.
[0101]
4. If the input packet is a non-priority packet (P = 0) and if the detected node number (N) does not match the stored downstream node number, the non-priority storage in the non-priority buffer 1405 A write address is generated by the address counter 1403 for any one of the areas 1 to the non-priority storage area 4, and the above-mentioned address designation of the storage area selected above in the non-priority buffer 1405 is performed. The packet is stored in the area.
[0102]
Thus, the packet is controlled (see FIG. 13).
[0103]
That is, if the packet is to be output to the channel connected to OUT1 via the switch 1151, the packet is stored in the high-priority storage area 1 (in the case of a high-priority packet) or the non-priority storage area 1 (in the case of a non-priority packet). If the packet is to be output to the channel connected to OUT2 via the switch 1151, the high-priority storage area 2 (for high-priority packets) or the non-priority storage area 2 (for non-priority packets) If the packet is to be output to the channel connected to OUT3 via the switch 1151, the high-priority storage area 3 (in the case of the high-priority packet) or the non-priority storage area 3 (for the non-priority packet) ) And output to the channel connected to OUT4 via the switch 1151 If you want a packet (in the case of high-priority packets) high-priority memory area 4 or to control so as to be stored in the non-priority memory area 4 (in the case of non-priority packets).
[0104]
Reference numeral 1151 in FIG. 11 denotes a switch, which is controlled by the switch control unit 1152 and connects a packet input to the switch input terminals IN1 to IN4 to an arbitrary switch output terminal OUT1 to OUT4. Reference numeral 1152 denotes a switch control unit, which controls a switch according to, for example, the control pattern of FIG. Operations of 1151 and 1152 are essentially the same as those described as 541 and 542 in FIG. 5 of the conventional example (however, this embodiment shows a case where there are four parallel channels, so only the portions are different). .
[0105]
Reference numeral 1153 denotes a buffer output priority control unit, which controls so that a stored packet is read from the buffer when an input terminal of a switch connected to an output of each buffer is connected to a desired output terminal. The storage areas in which packets to be read when a certain input terminal and a certain output terminal of the switch 1151 are connected are stored in the high-priority buffer 1404 and the non-priority buffer 1405 as described above (for example, the switch 1151). When the input terminal IN1 and the output terminal OUT1 are connected, the storage area in which the packet to be read is stored is the high-priority storage area 1 in the high-priority buffer 1404 and the non-priority storage area 1 in the non-priority buffer 1405. ).
[0106]
The buffer output priority control unit 1153 sets the connection relationship of the switch 1151
1. If a packet to be output exists in the corresponding high-priority storage area in the high-priority buffer, the packet is output from the high-priority storage area (for example, the input terminal IN1 and the output terminal OUT1 of the switch 1151). If a packet exists in the high-priority storage area 1 in the high-priority buffer 1404 when is connected, the packet is output from the high-priority storage area 1).
[0107]
2. If the packet to be output does not exist in the corresponding high-priority storage area in the high-priority buffer but exists in the corresponding non-priority storage area in the non-priority buffer, the packet is output from the non-priority storage area. (For example, when the input terminal IN1 of the switch 1151 is connected to the output terminal OUT1, there is no packet in the high-priority storage area 1 in the high-priority buffer 1404, and If there is a packet, the packet is output from the non-priority storage area 1).
[0108]
3. For the above connection relationship, if a packet to be output exists in both the corresponding high-priority storage area in the high-priority buffer and the corresponding non-priority storage area in the non-priority buffer, priority is given to the high-priority storage area. A packet is output (for example, when the input terminal IN1 and the output terminal OUT1 of the switch 1151 are connected, the packet is output to both the high-priority storage area 1 in the high-priority buffer 1404 and the non-priority storage area 1 in the non-priority buffer 1405). If there is a packet, the packet is output from the high priority storage area 1).
[0109]
The reading of the packet from the buffer is controlled as described above (see FIG. 19).
[0110]
FIG. 15 is a control pattern showing the input / output connection relation of the switch 1151, and the input / output connection relation of the switch is changed by the control addresses A1 to A4. The switch input terminals IN1 to IN4 correspond to the buffers 1141 to 1144 (node input terminals 1101 to 1104 as channels of the node device), and the switch output terminals OUT1 to OUT4 correspond to the node output terminals 1171 to 1174. I have. The switch 1151 and the buffers 1141 to 1144 are synchronously controlled by the switch control unit 1152 and the buffer output priority control unit 1153. For example, when the output of the buffer 1141 is connected to the node output terminal 1171 by the switch 1151 (control address A1 ), The packet stored in the high-priority storage area 1 or the non-priority storage area 1 corresponding to the node output terminal 1171 is read from the buffer 1141. The packet output control at this time is performed by the buffer output priority control unit 1153 as described above. When the output of the buffer 1141 is connected to the node output terminal 1172 (at the control address A2), the buffer 1141 stores the data in the high priority storage area 2 or the non-priority storage area 2 corresponding to the node output terminal 1172. The packet is read. The packet output control at this time is also performed by the buffer output priority control unit 1153. Similar control is performed for the control addresses A3 and A4, and similar control is performed for the other buffers 1142, 1143, and 1144.
[0111]
As described above, the buffer output priority control unit 1153 controls the reading from the buffer, so that the communication of high urgency, the communication of which the delay is to be reduced, and the communication of the communication in which the discarding of the packet is to be avoided than usual are given high priority. As a packet, it is possible to perform control such that it can be controlled separately from normal communication packets, so that a priority can be assigned to each communication connection and a packet can be transmitted according to the priority. become.
[0112]
For example, as described in the section "Problems to be Solved by the Invention", even if communication is performed such that file transfer is performed while video is transmitted from one terminal to another terminal, the communication connection for video transmission is By distinguishing the communication connection of the file transfer by the priority designation information, it is possible to avoid a problem that the packet of the video connection does not reach the receiving terminal at a constant period.
[0113]
Hereinafter, in order to more clearly show the present invention, it is shown that the above-mentioned problem has been solved by the present invention under the same conditions as in the example described in the section of "Problems to be Solved by the Invention".
[0114]
FIG. 16 is a configuration example of a network system using the node devices shown in FIG. 11, in which four node devices 1601 to 1604 are connected in a ring form by parallel multiplex transmission lines 1605 to 1608, and each node device has Four terminals are connected via four sub-transmission paths. The terminals 1611 to 1614 correspond to the terminals connected to the terminal signal input / output ports 1181 to 1184 in FIG. 11, and similarly, 1621 to 1624, 1631 to 1634, and 1641 to 1644 also correspond to the terminal signal input / output ports 1181 to 1184 in FIG. It corresponds to the terminal connected to.
[0115]
In the network of the present invention shown in FIGS. 11 and 16, an example of the operation in the case where video is communicated from the terminal 1612 to the terminal 1623 will be described. As described above, the video information needs to be received at a constant period by the terminal 1623 that reproduces the video. Therefore, in the present embodiment, the packet used in the video connection is a high-priority packet, and the priority designation information of the header of the packet is 1.
[0116]
1. The transmission data from the terminal 1612 is divided into fixed-length packets, and the header of each packet describes the node number (N = 2) and the transmission channel number (T = 3) of the destination terminal of the transmission terminal. For the reason, the priority designation information is output as 1 (P = 1). The output packet is input to the node device 1601 through the sub transmission path, and is temporarily stored in the FIFO 905 of the terminal signal insertion unit 1132. The stored packet is read from the FIFO 905 when there is a gap (which can be determined by the header detector 901) in the packet stream input to the selector 904 from the terminal signal separator 1122, and is sent to the buffer 1142 through the selector 904. .
[0117]
2. Upon detecting the header of the input packet, the header detection unit 1402 of the buffer 1142 determines that the input packet is a high-priority packet (P = 1) and stores the downstream node number stored in the detected node number (N = 2). Since the address matches (2), a write address is generated by the address counter 1403 for the high priority storage area 3 in the high priority buffer 1404 having the same number as the detected transmission channel number (T = 3). The packet is stored in the addressing area generated above in the high priority storage area 3 of the buffer 1404.
[0118]
3. At this time, the switch control unit 1152 controls the input / output connection relation of the switch 1151 in such a manner that the control addresses A1 to A4 are circulated in a fixed cycle according to FIG. 15, and notifies the priority buffer output control unit 1153 of the control address.
[0119]
4. The priority buffer output control unit 1153 determines whether there is a packet stored in the high priority storage area 3 and the non-priority storage area 3 of the buffer 1142 when IN2 of the switch 1151 is connected to OUT3 (at the control address A2). When a packet is stored in the high-priority storage area 3, the packet is read from the high-priority storage area 3 regardless of the presence or absence of the packet in the non-priority storage area 3. With this control, the read packet is output from IN2 to OUT3 of the switch 1151 to the node output terminal 1173, and further output to the transmission path.
[0120]
5. The header of the packet input to the terminal signal separation unit 1123 of the node device 1602 via the transmission path is detected by the header detection unit 201. Since the detected node number (N = 2) matches the stored own node number (2), the gate 203 is opened and the gate 202 is closed to output the packet only in the terminal direction.
[0121]
6. The packet output from the terminal signal separation unit 1123 to the terminal is sent to the terminal 1623 through the terminal signal input / output port 1183.
[0122]
Communication of the video connection is performed in this manner.
[0123]
Subsequently, an operation example in the case of file transfer in which the terminal 1612 communicates with the terminal 1623 at the same time as the video connection will be described. As described above, file transfer is communication that does not require real-time properties. Therefore, in the present embodiment, a packet used for a file transfer connection is set as a non-priority packet, and the priority designation information of the header of the packet is set to 0.
[0124]
1. The transmission data from the terminal 1612 is divided into fixed-length packets, and the header of each packet describes the node number (N = 2) and the transmission channel number (T = 3) of the destination terminal of the transmission terminal. For this reason, the priority order designation information is output as 0 (P = 0). The output packet is input to the node device 1601 through the sub transmission path, and is temporarily stored in the FIFO 905 of the terminal signal insertion unit 1132. The stored packet is read from the FIFO 905 when there is a gap (which can be determined by the header detector 901) in the packet stream input to the selector 904 from the terminal signal separator 1122, and is sent to the buffer 1142 through the selector 904. .
[0125]
2. Upon detecting the header of the input packet, the header detection unit 1402 of the buffer 1142 determines that the input packet is a non-priority packet (P = 0) and stores the downstream node number stored in the detected node number (N = 2). (2), the address counter 1403 generates a write address for the non-priority storage area 3 in the non-priority buffer 1405 having the same number as the detected transmission channel number (T = 3). The packet is stored in the address designation area generated above in the non-priority storage area 3 of the buffer 1405.
[0126]
3. At this time, the switch control unit 1152 controls the input / output connection relationship of the switch 1151 so that the control addresses A1 to A4 are circulated in a fixed cycle according to FIG. 15, and notifies the priority buffer output control unit 1153 of the control address.
[0127]
4. The priority buffer output control unit 1153 determines whether there is a packet stored in the high priority storage area 3 and the non-priority storage area 3 of the buffer 1142 when IN2 of the switch 1151 is connected to OUT3 (at the control address A2). Is checked, and when no packet is stored in the high-priority storage area 3, the packet is read from the non-priority storage area 3. With this control, the read packet is output from IN2 to OUT3 of the switch 1151 to the node output terminal 1173, and further output to the transmission path.
[0128]
5. The header of the packet input to the terminal signal separation unit 1123 of the node device 1602 via the transmission path is detected by the header detection unit 201. Since the detected node number (N = 2) matches the stored own node number (2), the gate 203 is opened and the gate 202 is closed to output the packet only in the terminal direction.
[0129]
6. The packet output from the terminal signal separation unit 1123 to the terminal is sent to the terminal 1623 through the terminal signal input / output port 1183.
[0130]
The communication of the connection for file transfer is performed in this manner.
[0131]
By controlling the video connection packet and the file transfer connection packet by the buffer output priority control unit in this way, it is possible to avoid the problem that the video connection packet does not reach the receiving terminal at regular intervals as described in the conventional problem. it can. In other words, the packet of the file transfer connection is transmitted at the same time as the communication packet of the video connection, and even if a considerable amount of the packet of the file transfer connection is stored in the non-priority storage area 3 due to the burstiness of the file transfer data, Since the packet is output from the high priority storage area 3 with higher priority than the packet of the file transfer connection, the packet of the video connection can be delivered to the terminal 1623 at a constant period. That is, even when the network is congested due to the influence of other communication, it is possible to prevent the communication delay from becoming large, and it is possible to prevent the reproduction of the video information from being hindered.
[0132]
Also, when the network is congested and packets are input in bursts exceeding the capacity of the storage area of the buffer, packet discarding may occur in the buffer. By setting priorities for communication connections according to importance and setting packets of communication connections with high-priority communication contents as high-priority packets, high-priority packets always have priority over non-priority packets. Therefore, it is possible to reduce the possibility that packets of a communication connection with a higher priority are discarded.
[0133]
As described above, according to the present invention, when performing communication with high urgency, when performing communication that wants to reduce delay, or when performing communication that wants to avoid discarding a packet more than usual, the priority of the packet is designated. The information is set to 1 and is set to 0 for normal communication, and the buffer output priority control section always outputs the packet stored in the buffer with priority from the high priority storage area. In this manner, a service can be provided in which priority is assigned to each communication connection and packets are transmitted according to the priority.
[0134]
Further, in the present embodiment, the case where the number of the parallel transmission channels is four is described, but the number of the parallel transmission channels may be any number. For example, as shown in the conventional example, it is clear that even eight are included in the present invention.
[0135]
Further, in the present embodiment, the priority is provided in two stages of the high-priority buffer and the non-priority buffer. However, providing the priority in an arbitrary stage is also included in the present invention. For example, when priorities are provided at three levels of high / medium / low, two bits are required for the priority specification information of the header. The buffer memory 1401 is composed of three areas, a high-priority buffer, a medium-priority buffer, and a low-priority buffer, and each has a storage area corresponding to the output channel from the switch 1151. Further, the buffer output priority control unit 1153 controls the connection relationship of the switch 1151 in the following order.
[0136]
1. If a packet to be output exists in the corresponding high-priority storage area in the high-priority buffer, the packet is output from the high-priority storage area (for example, the input terminal IN1 and the output terminal OUT1 of the switch 1151). If a packet exists in the high-priority storage area 1 in the high-priority buffer when the connection is made, the packet is output from the high-priority storage area 1).
[0137]
2. If the packet to be output does not exist in the corresponding high-priority storage area in the high-priority buffer but exists in the corresponding medium-priority storage area in the medium-priority buffer, the packet is output from the medium-priority storage area. (For example, when the input terminal IN1 of the switch 1151 is connected to the output terminal OUT1, there is no packet in the high-priority storage area 1 in the high-priority buffer, and If there is, the packet is output from the medium priority storage area 1).
[0138]
3. For the above connection relationship, the packet to be output does not exist in both the corresponding high-priority storage area in the high-priority buffer and the corresponding medium-priority storage area in the medium-priority buffer, and the corresponding If the packet exists in the priority storage area, the packet is output from the low priority storage area (for example, when the input terminal IN1 and the output terminal OUT1 of the switch 1151 are connected, the high priority storage area 1 in the high priority buffer and the medium priority buffer If there is no packet in both the middle priority storage area 1 and the low priority storage area 1 in the low priority buffer, the packet is output from the low priority storage area 1).
[0139]
(Embodiment 2)
A second embodiment of the present invention will be described. The configuration of the packet and the configuration of the node device according to the present embodiment are the same as those of the first embodiment (shown in FIGS. 1 and 11, respectively), but the internal configurations of the buffers 1141 to 1144 in the node device are different. . Accordingly, the control method of the output priority control unit 1153 is also different.
[0140]
In the buffers 1141 to 1144 of the first embodiment, as shown in FIG. 14, each output terminal of the switch 1151 has a high-priority storage area and a non-priority storage area. In the case of such a configuration, for example, when a high-priority packet to be output to the output terminal OUT1 of the switch 1151 is input in a burst manner and the capacity of the high-priority storage area 1 becomes full, the capacity is compared with the capacity. Control such as storing in the non-priority storage area 1 with sufficient room cannot be performed. In the present embodiment, such a point of the first embodiment is improved.
[0141]
In this embodiment, the internal configuration of the buffers 1141 to 1144 in the node device is changed to improve the above points. Accordingly, the control method of the output priority control unit 1153 is also changed. Although the details will be described later, the difference between the present embodiment and the first embodiment will be briefly described as follows.
[0142]
In the present embodiment, the configuration in which each output terminal of the switch 1151 has a high-priority storage area and a non-priority storage area for each output terminal as in the first embodiment is modified. Storage areas. The input packet is stored in the single storage area whether the packet is a high-priority packet or a non-priority packet. Then, when outputting, if a high-priority packet is stored in the single storage area, a high-priority packet is input, and if no high-priority packet is stored, a non-priority packet is input. The data is read out in the order specified.
[0143]
Subsequently, an internal configuration of the buffers 1141 to 1145 and a control method of the output priority control unit 1153 according to the present embodiment will be described in detail.
[0144]
FIG. 20 shows the internal configuration of the buffers 1141 to 1144 in the present embodiment. Reference numeral 2001 denotes a buffer memory, which includes storage areas 1 to 4 respectively corresponding to four output terminals (OUT1 to OUT4) of the switch 1151. Reference numeral 2002 denotes a header detection unit that detects P, N, and T (see FIG. 1) from the header of the packet.
[0145]
Reference numerals 2011 to 2014 denote unused area address FIFOs storing addresses for writing packets in the storage area. In the unused area address FIFO, an address at which a packet can be written is stored in the address of the storage area. For example, it is assumed that the storage area 1 originally has a capacity for packets, and the write / read addresses for the four packets are AD1 to AD4. Assuming that a packet is stored in the area of AD1 and AD2 at a certain point in time, AD3 and AD4 are stored in the unused area address FIFO1. In the initial state, the unused area address FIFO stores all writable addresses in the storage area. In the above example, AD1, AD2, AD3, and AD4 are stored in the unused area address FIFO in the initial state.
[0146]
The addresses output from the unused area address FIFOs 2011 to 2014 are used as packet write addresses for the respective storage areas, and at the same time, the high priority use area addresses FIFO 2041 to 2044 and the non-priority use area addresses FIFO 2031 to 2034 are used. The data is input to one of them, and is stored in one of the non-priority / high-priority FIFOs according to the instruction of the header detection unit 2002.
[0147]
2031 to 2034 are non-priority use area address FIFOs for non-priority packets, and 2041 to 2044 are high priority use area address FIFOs for high priority packets. The non-priority use area address FIFO stores an address at which a non-priority packet is written in the address of the storage area. Similarly, in the high-priority use area address FIFO, an address at which a high-priority packet is written is stored in the address of the storage area. For example, in the above example, if a high-priority packet is stored in AD1 and a non-priority packet is stored in the area of AD2, AD1 is stored in the high-priority use area address FIFO and the non-priority use area address FIFO is used. Stores AD2. In the initial state, no address is stored in either the high priority use area address FIFO or the non-priority use area address FIFO. That is, both FIFOs are empty.
[0148]
Addresses output from the high-priority use area address FIFOs 2041 to 2044 or the non-priority use area address FIFOs 2031 to 2034 (output from any of the non-priority / high-priority FIFOs according to the instruction of the buffer output priority control unit 1153) At the same time as being used as a packet read address for each storage area, it is input and stored in an unused area address FIFO 2011-2014.
[0149]
In the buffers 1141 to 1144, the header of the packet input from the terminal signal insertion unit is detected by the header detection unit 2002, and the storage area for storing the packet is determined based on the content of the header.
[0150]
The header detection unit 2002 stores in advance the node numbers of adjacent downstream nodes (referred to as downstream node numbers).
[0151]
The header detection unit 2002
1. If the detected node number (N) matches the stored downstream node number, an unused area address FIFO (any of 2011 to 2014) corresponding to the storage area having the same number as the detected transmission channel number (T) ), The write address for the storage area is output, and the packet is stored in the address designation area output above in the storage area (the storage area having the same number as the detected transmission channel number).
[0152]
2. If the detected node number (N) does not match the stored downstream node number, any one of the storage areas 1 to 4 is selected, and the corresponding storage area is selected. The write address for the selected storage area is output from the unused area address FIFO (any one of 2011 to 2014), and the packet is stored in the address designation area output above in the storage area selected above.
[0153]
As described above, the packet is controlled (see FIG. 21), and at the same time, the address output from the unused area address FIFO is controlled as follows.
[0154]
The header detection unit 2002
1. When the input packet is a high-priority packet (P = 1), the address output from the unused area address FIFO is replaced with a high-priority destination area address corresponding to the storage area having the same number as the detected transmission channel number (T). The data is stored in the FIFO (any of 2041 to 2044).
[0155]
2. When the input packet is a non-priority packet (P = 0), the address output from the unused area address FIFO is replaced with a non-priority used area address FIFO (2041 to 2044) corresponding to the storage area selected above. To be stored.
[0156]
(See FIG. 21).
[0157]
Reference numeral 1153 denotes a buffer output priority control unit, which controls so that a stored packet is read from the buffer when an input terminal of a switch connected to an output of each buffer is connected to a desired output terminal.
[0158]
The operation of the buffer output priority control unit 1153 according to this embodiment is different from that of the first embodiment and operates as follows. The buffer output priority control unit 1153 sets the connection relationship of the switch 1151
1. If the high-priority use area address FIFO corresponding to the connection relationship is not empty (if an address is stored in the FIFO), the read address of the storage area corresponding to the connection relation is read from the high-priority use area address FIFO. Is read out, and the packet is read from the above-mentioned address designation area of the storage area. Further, the address output from the high priority use area address FIFO is stored in an unused area address FIFO corresponding to the storage area (for example, when the input terminal IN1 and the output terminal OUT1 of the switch 1151 are connected, the high priority use area address FIFO is used). If the used area address FIFO 2041 is not empty, an address is output from the high-priority destination area address FIFO 2041 and a packet is read from the area specified by the address in the storage area 1. Further, the address is stored in the unused area address FIFO 2011. ).
[0159]
2. When the high-priority use area address FIFO corresponding to the connection relation is empty (when no address is stored in the FIFO), and when the non-priority use area address FIFO corresponding to the connection relation is not empty (in the FIFO) When the address is stored in the storage area, the read address of the storage area corresponding to the connection relationship is output from the non-priority use amount area address FIFO, and the address designation area of the storage area output as described above is output. Reads a packet from Further, the address output from the non-priority use area address FIFO is stored in an unused area address FIFO corresponding to the storage area (for example, when the input terminal IN1 and the output terminal OUT1 of the switch 1151 are connected, the high priority is used). If the use area address FIFO 2041 is empty and the non-priority use area address FIFO 2031 is not empty, an address is output from the non-priority use area address FIFO 2031 and a packet is read from the area of the storage area 1 designated by the address. Is stored in the unused area address FIFO 2011).
[0160]
3. When the high-priority use area address FIFO corresponding to the connection relation is not empty (when an address is stored in the FIFO) and the non-priority use area address FIFO corresponding to the connection relation is not empty (in the FIFO) If the address is stored), the read address of the storage area corresponding to the connection relationship is preferentially output from the high priority use area address FIFO, and the address designation of the storage area output as described above is performed. Read the packet from the area. Further, the address output from the high priority use area address FIFO is stored in an unused area address FIFO corresponding to the storage area (for example, when the input terminal IN1 and the output terminal OUT1 of the switch 1151 are connected, the high priority use area address FIFO is used). If the use area address FIFO 2041 is not empty and the non-priority use area address FIFO 2031 is not empty, the address is output with priority from the high priority use area address FIFO 2041, and packets are output from the area specified by the address in the storage area 1. The address is stored in an unused area address FIFO02011).
[0161]
Reading of the packet from the buffer is controlled as described above (see FIG. 22).
[0162]
As described above, by configuring and controlling the buffers 1141 to 1145 (see FIG. 20) and controlling (see FIG. 21), and further controlling the output priority control unit 1153 (see FIG. 22), it is difficult to realize the first embodiment. In addition, a storage area that can be used for a high-priority packet and a storage area that can be used for a non-priority packet are not distinguished, and a single storage area is used by both high-priority / non-priority packets according to the flow rate. It is possible to use efficiently.
[0163]
Therefore, "whether the input packet is a high-priority packet or a non-priority packet, the packet is stored in the single storage area. When the packet is output, the packet is stored in the single storage area. If the high-priority packet is stored, the high-priority packet is read, and if the high-priority packet is not stored, the non-priority packets are read out in the order of input.
[0164]
(Embodiment 3)
A third embodiment of the present invention will be described. FIG. 17 is a configuration diagram of a node device according to the present embodiment. In the first embodiment, a space division type switch is used as the switch 1151 and a space division parallel multiplex transmission line such as a ribbon fiber is used as a transmission line. On the other hand, the present embodiment shows an example in which a signal is multiplexed on one optical fiber using wavelength multiplexing and exchange is performed between two opposing node devices.
[0165]
In FIG. 17, reference numerals 1701 to 1704 denote variable wavelength transmitters, which are optical transmitters that convert an input signal into an optical signal of an arbitrary wavelength by controlling an injection current of a laser diode and output the converted signal. Reference numeral 1709 denotes a wavelength controller, which sets the wavelength variable transmitters 1701 to 1704 to an arbitrary wavelength according to the wavelength control pattern shown in FIG. For example, by sequentially and periodically changing the control addresses A1 to A4, the signal input to the input terminal IN1 of the variable wavelength transmission unit 1701 is converted into an optical signal of the wavelength λ1 in the first cycle, and the wavelength λ1 is changed in the next cycle. , And sequentially changed to wavelengths λ and λ4. Similarly, the wavelength variable transmission unit 1702 repeatedly converts a signal input to the input terminal IN2 into an optical signal having the above wavelength in the order of wavelengths λ2, λ3, λ4, and λ1. The same applies to the other wavelength variable transmission units 1703 and 1704.
[0166]
The wavelength change cycle is set to, for example, an integral multiple of the packet length. That is, the transmission wavelength is repeatedly changed every several packets. Although the wavelength control pattern to be used is not limited to the one shown in FIG. 15, a wavelength control pattern in which a plurality of wavelength tunable transmission units do not transmit at the same wavelength at the same time is used. Reference numeral 1721 denotes a multiplexer, which condenses the optical signal output from each variable wavelength transmission unit onto one optical fiber and outputs the optical signal to an external optical fiber transmission line. Reference numeral 1722 denotes a branching filter, which separates optical signals of wavelengths λ1 to λ4 sent from the external optical fiber transmission line into respective wavelengths. Reference numerals 1711 to 1714 denote optical receiving units, which convert optical signals of wavelengths λ1 to λ4 separated by the demultiplexer 1722 into electric signals. Other parts of the node device are the same as in the first embodiment, and the same parts are denoted by the same reference numerals.
[0167]
Next, the operation of the node device of the present embodiment during communication will be described with reference to FIG.
[0168]
First, the operation in the case of communication of high-priority information (P = 1) will be described. A case where a signal is temporarily transmitted from terminal 1612 (own node number: 1, transmission channel number: 2) to terminal 1633 (own node number: 3, transmission channel number: 3) will be described.
[0169]
1. First, the terminal 1612 writes the terminal number (for example, N = 3, T = 3) of the receiving terminal 1633 in the header of the packet and 1 in the P bit (priority designation information) and sends it out. The packet is input to the terminal signal input / output port 1182 of the node device 1601 through the sub transmission path, and then input to the FIFO 905 of the terminal signal insertion unit 1132.
[0170]
2. The selector 904 of the terminal signal insertion unit 1132 inserts the bucket temporarily stored in the FIFO 905 into the gap of the packet flow from the terminal signal separation unit (which can be determined by the header detection unit 901), and transfers the packet flow to the buffer 1142. Send out.
[0171]
3. When the header detection unit 1402 of the buffer 1142 detects the header of the input packet, the input packet is a non-priority packet (P = 1), and the detected node number (N = 3) is stored in the stored adjacent node. Since it does not match the number (2), an arbitrary high-priority storage area of the high-priority buffer 1404 is designated and a packet is stored. Here, for example, the high priority storage area 1 is specified. The address counter 1403 receives the information, generates a write address for the high-priority storage area 1, and stores the packet in the address designation area generated above in the high-priority storage area 1 of the high-priority buffer 1405. Remember.
[0172]
4. At this time, the wavelength control unit 1709 controls the control addresses A1 to A4 so as to circulate in a fixed cycle according to the wavelength control pattern of FIG. 15, and notifies the priority buffer output control unit 1153 of the control addresses.
[0173]
5. The priority buffer output control unit 1153 is stored in the high-priority storage area 1 and the non-priority storage area 1 of the buffer 1142 when the wavelength variable transmission unit 1702 is about to transmit at the wavelength 11 (at the control address A4). The presence / absence of a packet is checked, and when a packet is stored in the high-priority storage area 1, the packet is read from the high-priority storage area 1 regardless of the presence / absence of a packet in the non-priority storage area 1. With this control, the read packet is input to the wavelength variable transmission unit 1702, converted into an optical signal of the wavelength λ1, and output to the optical fiber transmission line 1605 through the multiplexer 1721.
[0174]
6. The packet transmitted through the transmission path is output from the output terminal of the wavelength λ1 by the demultiplexer 1722 of the node device 1602, converted into an electric signal by the optical receiving unit 1711, and input to the terminal signal separating unit 1121.
[0175]
7. The header of the packet input to terminal signal separation section 1121 is detected by header detection section 201. Since the detected node number (N = 3) does not match the stored own node number (2), the gate 202 is opened, the gate 203 is closed, and the packet is output to the terminal signal insertion unit 1131.
[0176]
8. The packet output to the selector 904 of the terminal signal insertion unit 1131 passes through the selector 904 and is input to the buffer 1141.
[0177]
9. Upon detecting the header of the input packet, the header detection unit 1402 of the buffer 1141 determines that the input packet is a high-priority packet (P = 1) and stores the detected node number (N = 3) in the downstream node. Since the number matches the number (3), the address counter 1403 generates a write address for the high priority storage area 3 in the high priority buffer 1404 having the same number as the detected transmission channel number (T = 3). The packet is stored in the address designation area generated above in the high priority storage area 3 of the priority buffer 1404.
[0178]
10. The priority buffer output control unit 1153 is stored in the high-priority storage area 3 and the non-priority storage area 3 of the buffer 1141 when the wavelength variable transmission unit 1701 is trying to transmit at the wavelength λ3 (at the control address A3). The presence / absence of a packet is checked, and when a packet is stored in the high-priority storage area 3, the packet is read from the high-priority storage area 3 regardless of the presence / absence of a packet in the non-priority storage area 3. With this control, the read packet is input to the wavelength variable transmission unit 1701, converted into an optical signal of wavelength λ3, and output to the optical fiber transmission line 1606 through the multiplexer 1721.
[0179]
11. The optical signal input to the node device 1603 via the transmission path is output from the output terminal of the wavelength λ3 of the demultiplexer 1722, converted into an electric signal by the optical receiving unit 1713, and input to the terminal signal separating unit 1113.
[0180]
12. The header of the packet input to terminal signal separation section 1123 is detected by header detection section 201. Since the detected node number (N = 3) matches the stored own node number (3), the gate 203 is opened, the gate 202 is closed, and the packet is output only in the terminal direction.
[0181]
13. The packet output from terminal signal separation section 1123 in the terminal direction is sent to terminal 1633 through terminal signal input / output port 1183.
[0182]
The changes from the first embodiment by using the node device of FIG. 17 are described in detail in the case of the communication of the high-priority information, and the operation in the case of the communication of the non-priority information (P = 0) will be described here. Will be omitted.
[0183]
In this way, even when the node device of FIG. 17 is used, the buffer output priority control unit controls the output of the packet stored in the buffer so that the output is always given priority from the high priority storage area. A priority is assigned to each communication connection, and a service that allows packets to be transmitted according to the priority is enabled.
[0184]
(Embodiment 4)
Next, a fourth embodiment of the present invention will be described. In the first and third embodiments described above, each terminal performing communication outputs a cell having the header shown in FIG. 1 to perform communication while solving the “problem to be solved by the invention”. That made it possible.
[0185]
However, the fact that a cell having a header as shown in FIG. 1 must be output from the terminal also imposes a limit on the NIC (Network Interface Card) equipped in the terminal. That is, a commercially available general NIC (for example, an NIC for ATM) may not be used in the present invention. An embodiment for avoiding this is shown in a fourth embodiment.
[0186]
The configuration of the node device of the present embodiment is the same as the configuration of the node device of FIGS. However, the functions of the terminal signal input / output ports 1181 to 1184 shown in FIGS. 11 and 17 are expanded. The terminal signal input / output ports 1181 to 1184 exist between the terminal signal separation unit and the terminal signal separation unit and a terminal connected thereto (equipped with a commercially available NIC). The terminal signal input / output ports 1181 to 1184 in the present embodiment have a function of performing conversion from a header format that can be output from a commercially available NIC to the header format of FIG. 1 and vice versa. (Referred to as a header conversion table). Therefore, in the present embodiment, the terminal signal input / output ports 1181 to 1184 will be referred to as header conversion means in order to clarify the role of the terminal signal input / output ports 1181 to 1184.
[0187]
FIG. 18 shows a network configuration according to the present embodiment. In FIG. 18, at least one connection acceptance and header conversion means control module 1800 is provided in the network. The other numbers shown in FIG. 18 indicate the same as those in FIG.
[0188]
The location where the connection receiving and header conversion means control module is provided is not particularly specified in the network, but as described below, preliminary communication with the terminal is performed according to a certain protocol, so that any place where the preliminary communication can be performed is sufficient. . Also, the following control is performed on the header conversion means (terminal signal input / output port) in each node. For example, a connection reception and header conversion means control module may be provided on a certain terminal, or may be provided on a node device.
[0189]
In the present embodiment, the connection acceptance and header conversion means control module can exchange information with each terminal according to a predetermined procedure (preliminary communication protocol). Specifically, information is exchanged according to the following procedure.
[0190]
1. Before performing communication (actual communication), the terminal instructs the connection acceptance and header conversion means control module to transmit (transmit) the terminal (own terminal) information (address), destination terminal information (address) of the actual communication, and the high priority information to the communication. Whether to treat as non-priority information (priority identification information) is communicated by a preliminary communication protocol.
[0191]
2. The connection acceptance and header conversion means control module calculates a header (referred to as a terminal node header) to be used for the actual communication from the obtained transmission terminal information, destination terminal information and priority identification information, and transmits the header to the terminal. The header between terminal nodes at this time is a header that can be set by a commercially available NIC.
[0192]
3. The terminal performs actual communication by adding a header between terminal nodes obtained from the connection receiving and header conversion means control module to the packet.
[0193]
At the same time, the connection acceptance and header conversion means control module performs the following based on the above-mentioned transmission terminal information, destination terminal information, and priority identification information.
[0194]
1. The header conversion table of the header conversion means (terminal signal input / output port) connected to the transmitting terminal is converted from the terminal node header transmitted to the terminal by the above-mentioned preliminary communication protocol to the header of FIG. Set the header conversion table in.
[0195]
2. The header conversion table of the header conversion means (terminal signal input / output port) connected to the destination terminal is converted from the header of FIG. 1 to a header between terminal nodes which can be received by a commercially available NIC. Set the conversion table.
[0196]
By performing such processing before the actual communication, it is possible to perform communication according to the present invention even with a terminal equipped with a commercially available NIC. The procedure of the actual communication after this processing is the same as the procedure described in the first embodiment, except that the packet transmitted from the transmitting terminal to the node device (the header is the header between terminal nodes specified in the preliminary communication) is connected to the transmitting terminal. The header conversion means (terminal signal input / output port) converts the header into the header in the format of FIG. 1 and the packet sent from the node device to the destination terminal (the header is in the format of FIG. 1). The point that the connected header conversion means converts the header into a header between terminal nodes that can be received by a commercially available NIC is only applied, and the rest is the same.
[0197]
【The invention's effect】
As described above, according to the present invention, when performing communication with high urgency, when performing communication that wants to reduce delay, or when performing communication that wants to avoid discarding a packet more than usual, the priority of the packet is designated. The information is set to 1 and is set to 0 for normal communication, and the buffer output priority control section always outputs the packet stored in the buffer with priority from the high priority storage area. In this manner, a service can be provided in which priority is assigned to each communication connection and packets are transmitted according to the priority.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a packet used in a network according to the present invention.
FIG. 2 is a diagram showing an internal configuration of a terminal signal separation unit of the node device according to the present invention.
FIG. 3 is a diagram showing an internal configuration of a buffer of a conventional node device.
FIG. 4 is a diagram illustrating a control law of a buffer and a switch.
FIG. 5 is a diagram illustrating a configuration of a conventional node device.
FIG. 6 is a diagram showing a configuration of a network.
FIG. 7 is a diagram illustrating a communication principle of a network.
FIG. 8 is a diagram showing an internal configuration of a terminal signal separation unit of a conventional node device.
FIG. 9 is a diagram showing an internal configuration of a terminal signal insertion unit of the node device.
FIG. 10 is a diagram showing a configuration of a packet used in a conventional network.
FIG. 11 is a diagram showing a configuration of a node device according to the present invention.
FIG. 12 is a flowchart illustrating an operation of a terminal signal separation unit.
FIG. 13 is a flowchart showing the operation of the buffer.
FIG. 14 is a diagram showing an internal configuration of a buffer of the node device according to the present invention.
FIG. 15 is a diagram illustrating a control law of a buffer and a switch.
FIG. 16 is a diagram showing a configuration of a network.
FIG. 17 is a diagram showing a configuration of a node device according to the present invention.
FIG. 18 is a diagram showing a configuration of a network.
FIG. 19 is a flowchart illustrating an operation of a buffer output priority control unit.
FIG. 20 is a diagram showing an internal configuration of a buffer of the node device according to the present invention.
FIG. 21 is a flowchart showing the operation of the buffer.
FIG. 22 is a flowchart illustrating an operation of a buffer output priority control unit.
[Explanation of symbols]
201, 302, 801, 901, 1402, 2002 Header detector
202, 203, 802, 803 gate
301, 1401, 2001 Buffer memory
303, 1403 Address counter
500, 601 to 604, 701 to 704, 1100, 1601 to 1604, 1700 Node device
501-508, 1131-1134 Terminal signal insertion unit
561-568, 1121-1124 Terminal signal separation unit
511-518, 709-712, 1141-1144 buffers
521 to 528, 531 to 538, 605 to 608, 1605 to 1608
541,705-708,1151 switch
542, 1152 switch control unit
543 buffer control unit
551 to 558, 611 to 618, 621 to 628, 631 to 638, 641 to 648, 721 to 736, 1611 to 1614, 1621 to 1624, 1631 to 1634, 1641 to 1644 Terminal
904 selector
905 FIFO
1101-1104 Node input terminal
1153 Buffer output priority control unit
1171 to 1174 Node output terminal
1181 to 1184 Terminal signal input / output port
1404 High priority buffer
1405 Non-priority buffer
1721 multiplexer
1722 duplexer
1711-1714 Optical receiver
1701 to 1704 tunable transmitter
1709 Wavelength control unit
1800 Connection acceptance and header conversion means control module
2011-2014 Unused area address FIFO
2031-2034 Non-priority use area address FIFO
2041 to 2044 High priority use area address FIFO

Claims (32)

Multiple channels in parallel,
Switch means connected to the plurality of channels, for outputting a signal input from each channel in any one of the plurality of channels,
A terminal connected to the plurality of channels,
The switch means, when a certain signal is input, characterized in that it has a function of outputting to any one of the plurality of channels prior to other signals,
A borrowing network, wherein the plurality of channels are connected in a ring type via the switch means to form a parallel ring transmission line. A means for giving, to the signal, information (referred to as priority order designation information) which can determine whether or not the signal should be output first to any one of the plurality of channels by the switch means. 2. The communication network according to 1. The switch means includes means for detecting the priority designation information,
The switch means,
When a signal to which the priority designation information is added (referred to as high priority information) is input, the signals to which the priority designation information is not added (referred to as non-priority information) take precedence over the plurality of signals. The communication network according to claim 2, wherein the output is performed to any one of the channels. The switch means,
Buffer means for accumulating signals input from the plurality of channels and outputting separately for each input channel,
Switching means for switching the connection between the output of each channel from the buffer means and the plurality of channels from which signals are output from the switch means,
When the high-priority signal is stored in the buffer means, the buffer means outputs the high-priority signal from the buffer means prior to the non-priority information stored in the buffer means. 4. The communication network according to claim 2, further comprising: buffer output priority control means for controlling the output of the communication network. The buffer means is provided for each of the plurality of channels.
A buffer for storing the high-priority signal (referred to as a high-priority buffer);
A buffer (called a non-priority buffer) for storing the non-priority signal,
By the buffer output priority control unit, the signal stored in the high priority buffer is given priority over the signal stored in the non-priority buffer, regardless of the order of the signals input to the buffer unit. The communication network according to claim 4, wherein the data is output from the buffer means. The buffer means is provided for each of the plurality of channels.
First storage means for storing the high-priority signal and the non-priority signal,
Second storage means for storing an address of an unused area of the first storage means,
Third storage means for storing the address of the high-priority signal stored in the first storage means,
And fourth storage means for storing the address of the non-priority signal stored in the first storage means,
5. The buffer output priority control unit according to claim 4, wherein the buffer output priority control unit controls reading of a signal stored in the first storage unit according to information stored in the third and fourth storage units. Communication network. The switching means has output channel variable means provided in correspondence with each output from the buffer means for each channel, and switches the output channel of the output channel variable means, thereby providing the output from the buffer means. The communication network according to any one of claims 4 to 6, wherein output of each channel and connection of the output channel are switched. The switching between the output for each channel from the buffer means and the output channel is performed in accordance with a predetermined pattern so that a plurality of outputs for each channel from the buffer means are not simultaneously connected to the same output channel. A communication network according to any one of claims 1 to 7. The terminal is connected to any one of the plurality of channels via a separating unit,
9. The signal processing apparatus according to claim 1, wherein the separating unit separates a signal to be output to a terminal from signals transmitted through the channel to which the own separating unit is connected, from the channel, and outputs the signal to the terminal. A communication network according to. 10. The communication network according to claim 1, further comprising an insertion unit for inserting a signal into the channel. The communication network according to claim 9, further comprising a node device provided with the switch unit and the separation unit. The communication network according to claim 11, further comprising an insertion unit that inserts a signal into the channel in the node device. The communication network according to claim 2, wherein the priority designation information is given to the signal by the terminal. The communication network according to claim 2, wherein the priority order designation information is provided by converting a signal output from the terminal into a predetermined format. A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring by a plurality of parallel channels,
The network is provided with switch means for enabling a transmission packet to switch transmission channels between the parallel channels,
The communication network according to claim 1, wherein said switch means has a function of, when a specific packet is input, prioritizing another packet and switching a transmission channel first. A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring by a plurality of parallel channels,
The node device includes:
It has a function of switching a packet input on the plurality of channels and outputting it on any of the plurality of channels, and when a specific packet is input, takes precedence over other packets before A switch means having a function of enabling output to any one of the plurality of channels, and the switch means for determining whether an input packet is a packet to be output with priority. And a means for adding the information to the packet. A communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring by a plurality of parallel channels,
The node device includes:
Switching means for switching a packet input on the plurality of channels, and having a function of outputting on any of the plurality of channels,
The switch means,
Buffer means for accumulating packets input from the plurality of channels and outputting separately for each input channel,
Switching means for switching the connection between the output for each channel from the buffer means and the plurality of channels from which packets are output from the switch means,
A communication network comprising: buffer output priority control means for controlling a specific packet to be output first from said buffer means regardless of the order of packets stored in said buffer means. 13. A node device used in the communication network according to claim 11, wherein said switch means and said separating means, or said switch means, said separating means and said inserting means are provided therein. apparatus. Multiple channels in parallel,
A switch connected to the plurality of channels and capable of outputting a signal input in each channel on any one of the plurality of channels;
A terminal connected to the plurality of channels,
The plurality of channels is a signal transmission control method in a communication network configured in a ring shape via the switch means,
For a specific signal that is input to the communication network and is transmitted through the channel and reaches the destination terminal,
When the specific signal is input to the switch means, even if there is a signal staying in the switch means, the specific signal is given priority over the staying signal. A transmission control method, wherein control is performed so as to be output from the switch means. Information (priority designation information) that can be used to determine whether the signal transmitted to the destination terminal by transmitting the channel is a signal to be output first to any one of the plurality of channels by the switch means. 20. The transmission control method according to claim 19, further comprising the step of: The switch means determines the priority designation information, and when a signal to which the priority designation information is added (referred to as high priority information) is input, a signal to which the priority designation information is not added ( 21. The transmission control method according to claim 20, wherein the signal is output to any one of the plurality of channels first prior to the non-priority information. The switch means,
Buffer means for accumulating signals input from the plurality of channels and outputting separately for each input channel,
Switching means for switching the connection between the output of each channel from the buffer means and the plurality of channels from which signals are output from the switch means,
22. The transmission control method according to claim 20, wherein when the high-priority signal is input, the signal is output from the buffer unit prior to the non-priority information. The buffer means is provided for each of the plurality of channels.
A buffer for storing the high-priority signal (referred to as a high-priority buffer);
A buffer (called a non-priority buffer) for storing the non-priority signal,
Irrespective of the order of the signals stored in the buffer means, the signal stored in the high priority buffer is output from the buffer means prior to the signal stored in the non-priority buffer. 23. The communication control method according to claim 22, wherein: The buffer means is provided for each of the plurality of channels.
First storage means for storing the high-priority signal and the non-priority signal,
Second storage means for storing an address of an unused area of the first storage means,
Third storage means for storing the address of the high-priority signal stored in the first storage means,
And fourth storage means for storing the address of the non-priority signal stored in the first storage means,
23. The buffer output priority control unit according to claim 22, wherein the buffer output priority control unit controls reading of a signal stored in the first storage unit according to information stored in the third and fourth storage units. Communication control method. 23. The switching between the output for each channel from the buffer means and the output channel is performed according to a predetermined pattern, and is performed so that a plurality of outputs for each channel from the buffer means are not simultaneously connected to the same output channel. 25. The transmission control method according to 24. The terminal is connected to any one of the plurality of channels via a separating unit,
26. The signal processing apparatus according to claim 19, wherein the separating unit separates a signal to be output to a terminal from signals transmitted through the channel to which the own separating unit is connected from the channel and outputs the signal to the terminal. 3. The transmission control method according to 1. 27. The communication network according to claim 19, wherein the input of the signal to the communication network is performed by inserting a signal into the channel by an insertion unit provided in the channel. 21. The transmission control method according to claim 20, wherein the priority designation information is given to the signal from the terminal. 21. The transmission control method according to claim 20, wherein the priority order designation information is given by converting a signal output from the terminal into a predetermined format. A plurality of node devices for connecting a plurality of terminals are connected in a ring shape with a plurality of parallel channels, and switch means is provided for enabling transmission packets to switch transmission channels between the parallel channels. Transmission control method in a communication network, comprising:
The transmission control method according to claim 1, wherein, when a specific packet is input, the switching means performs control so as to prioritize another packet and change the transmission channel first. A communication device in which a node device for connecting a plurality of terminals is connected in a ring shape with a plurality of parallel channels, and a switch means is provided for enabling a transmission packet to switch transmission channels between the parallel channels. A method for controlling transmission of packets in a network, comprising:
A step of giving information to a packet that reaches the destination terminal by transmitting the channel, which can determine whether or not the packet should be switched to a transmission channel with priority in the switch means,
The transmission control method according to claim 1, wherein the switching means controls to switch a transmission channel by giving priority to a packet in which the information is detected over another packet. In a node device used in a communication network in which a plurality of node devices for connecting a plurality of terminals are connected in a ring by a plurality of parallel channels,
Packets transmitted through the plurality of channels, and receiving means for receiving packets transmitted from the plurality of terminal devices,
Switching a packet input by the plurality of channels and outputting the packet to one of the plurality of channels, and outputting a specific packet from the switch unit in preference to another packet. Switch means having a function of enabling
A node device comprising: a determination unit configured to determine whether a packet received by the reception unit is a packet to be output from the switch unit with priority.

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