JP2550155B2 - Packet communication system and packet communication device used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a digital receiver for transmitting data digitally.
The present invention relates to a packet communication system which is one of data exchange (DDX) and a packet communication device used for the packet communication system.

(Prior Art) Conventionally, when digitally transmitting data, the digital data is divided into predetermined lengths, and a header having an address or the like is added to each of the divided messages to form a packet. A communication method has been proposed in which data is transmitted in units of.

Devices 101, 10 shown in FIG.
The case where the lines 107 and 109 are present between the respective 3,105 will be described as an example. The packet 111 transmitted between the devices 101, 103 and 105 is, as shown in FIG.
13 and a header 115 having a destination address and the like.

Here, when data consisting of packets from the devices 101 and 105 concentrates on the device 103 and becomes a so-called high load state or an overload state, the device 103 performs control for reducing such concentration of packets.

For example, when the device 103 receives a packet from the device 101 when the device 103 is in a high load state, it transmits a control packet to the device 101 to “temporarily suspend the transmission of the current packet and wait”. At this time, the device 103 needs to generate information about the destination of the control packet, that is, the header. Therefore, the device 103 decodes the transmission source information included in the received packet or the information about the channel number (LCN) set corresponding to the line 107 included in the header part, and the transmission source of this packet is the device 101. If it is determined, the header part with the device 101 as the destination is added to the above-mentioned packet for transmission.

(Problems to be Solved by the Invention) However, when transmitting a control packet as described above, it is necessary to decode the received packet and replace the so-called header part.
The process is complicated and time-consuming.

Further, in order to decode the transmission source information or the information about the channel number of the header portion included in the above-mentioned packet, it is necessary to drive an arithmetic processing unit such as a microcomputer, and it is desirable to reduce the load on the arithmetic processing unit. It was rare.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a packet communication device capable of reducing the load on the arithmetic processing unit and rapidly transmitting control packets and the like.

[Configuration of the Invention] (Means for Solving the Problems) In order to achieve the above object, the first invention relates to a packet communication system, and a first information data including a first channel number information. A first packet communication device for transmitting a first packet to which a header part is added via a first communication line, and the first packet communication device transmitted from the first packet communication device via the first communication line. The first channel number information is received, the same channel number information as the first channel number information is set in the second channel number information, and a second header part including the set second channel number information is added. The first information is transmitted to the second information data via the second communication line.
And a second packet communication device for transmitting to the packet communication device.

According to a second aspect of the present invention, a channel number is set in a line from one device to the other device and a line from the other device to the one device, and is formed by a header part including the channel number and a message part. A packet communication device that communicates via these lines with a packet
The one device or the other device transmits a packet with a duplicating unit for duplicating a header portion added to a packet received through the line, and a packet with the header portion duplicated by the duplicating unit. And a transmission means for transmitting the data to the original.

Furthermore, a third aspect of the invention is that the same channel number is set for a line from one device to the other device and a line from the other device to the one device, and a header part and a message part including the channel number are set. A packet communication device that communicates via these lines with a packet formed by, and a duplication unit that duplicates a header portion added to a packet received through the line, and a load state of the packet communication device. A load state monitoring means for monitoring the load state, a generating means for generating a control packet to which the header section duplicated by the duplicating means is added when the load state monitoring state detects a high load state of the packet communication device, and the generating means. Transmission means for transmitting the control packet generated by the means to the source of the received packet.

(Operation) In the packet communication system according to the first aspect of the present invention, the second communication device is provided with so-called channel number setting means, so that the first channel number information and the second channel number information are set to be the same. As a result, it becomes unnecessary to allocate new destination information for performing control for alleviating the concentration of packets performed according to, for example, the line connection state, that is, the congestion state of the packet communication device. That is, when it is estimated that different values are used for the first channel number information and the second channel number information, conventionally, it is necessary to perform a check operation using a table in which the corresponding relationship is described. According to the present invention, the checking operation is unnecessary, and the system can be simplified.

Since the packet communication device according to the second aspect of the present invention is provided with the duplicating means, it duplicates the header portion added to the received packet and sends it as the header portion of the transmission packet to the transmission source. The generation of a so-called control packet for performing control for mitigation can be easily performed without the need for decoding the received packet or replacing the header portion as in the related art.

A packet communication device according to a third aspect of the present invention is provided with a duplication unit and a load state monitoring unit, and when the load state monitoring unit detects a high load state, the header unit of the received packet duplicated by the duplication unit is a control packet Is added to the header part of the packet and transmitted to the transmission source of the received packet, so that the transmission source can know the load state more quickly and easily.

(Example) Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

First, the connection configuration of the present embodiment will be described with reference to FIG. A plurality of communication devices 1, 3 and 5 including exchanges are provided,
It is assumed that the communication devices 1 and 3 and the communication devices 3 and 5 are connected to each other via corresponding transmission lines, and that a channel number is set for each line and communication is performed in units of packets.

More specifically, an uplink for transmitting packets from the communication device 1 to the communication device 3 via the transmission line L ₁₃ , and a communication device 1 for transmitting packets from the communication device 3 via the transmission line L _31.
The same channel number is set for the downlink to be transmitted to. Similarly, the packet from the communication device 3 is transmitted to the transmission line L _35.
And the communication device 5 for transmitting to the communication device 5 via the
The same channel number is set for the downlink which transmits the packet from the communication device 3 to the communication device 3 via the transmission line L ₅₃ . The packet is formed of a header section as destination information including such a channel number and a message section having data information.

Next, of the plurality of communication devices, the communication device 3 will be described as a representative with reference to FIG.

The packet receiving unit 11 is connected to the transmission line L ₁₃ and receives a packet from the communication device 1. When the packet received by the packet reception unit 11 is decoded and the received packet is a packet to be transmitted to the transmission line L ₃₁ , it is output to the packet transmission generation unit 13 via a packet switch unit (not shown). The packet switch unit performs control for delivering a packet from the packet receiving unit 11 to a target line by a contention control method using a bus, for example.

The header copy unit 15 is a packet reception unit via the signal line 21.
It is connected to 11 and receives a packet from this packet receiving unit 11. The header copy unit 15 is a copy means for copying the header part added to the input packet. The header copy unit 15 is connected to the loopback transfer control unit 17 via a plurality of signal lines 23, and performs the above-described copying operation based on a control command from the loopback transfer control unit 17. Further, the header copy unit 15 is connected to the packet transmission generation unit 13 via a plurality of signal lines 25, and outputs information about the duplicated header portion to the packet transmission generation unit 13.

Next, an example of the internal configuration of the header copy unit 15 will be described with reference to FIG.

The header portion is formed by a plurality of bits, and the number of D-type flip-flop circuits 31 corresponding to the number of bits is used.
a, 31b, ... 31n are connected in series. The input terminal D of the first-stage flip-flop circuit 31a is connected to the signal line 21, and receives a packet output as serial data from the packet receiving unit 11.

One input terminal of the AND circuit 33 is connected to the loopback transfer control unit 17 via the signal line 23a, and for example, in a packet formed of a plurality of bit signals, a period corresponding to a bit signal forming a header unit. Only input "H" level signal. The other input terminal of the AND circuit 33 is connected to the loopback transfer control unit 17 via the signal line 23b, and inputs a bit clock synchronized with each bit signal of the header section formed by a plurality of bit signals. AND circuit
The output terminal of 33 is connected to the respective clock input terminals of the flip-flop circuits 31a, 31b, ... 31n, and the logical product output of the AND circuit 33 is used as the clock signal 33a for each of the flip-flop circuits 31a, 31b ,. Apply to the clock input pin.

Therefore, the signal of a plurality of bits formed by the packet as the serial data input via the signal line 21 is sequentially flip-flop circuit 31a to the flip-flop circuit 31b in synchronization with the output timing of the clock signal 33a for each 1-bit signal. , ... Shifted to 31n.

Output terminals Q of the flip-flop circuits 31a, 31b, ... 31n
Are connected to the packet sending / generating unit 13 via the corresponding signal lines 25a, 25b, ... 25n, and convert the signal of the header part as serial data into parallel data for duplication and packet sending / generating. Output to section 13.

Referring back to FIG. 1, the loopback transfer control unit 17 has a monitoring means for monitoring the load state of the communication device 3, and in the high load state, for example, a packet from another communication device 1 is detected. When the data is intensively transmitted to the communication device 3, the loopback transfer control for alleviating the high load state is executed.

The packet transmission generation unit 13 has a generation unit that generates a control message, for example, a message “temporarily suspend transmission of current packet and wait”. The packet transmission generation unit 13 is connected to the loopback transfer control unit 17, and transmits a packet having a control message based on a control command from the loopback transfer control unit 17. That is, after converting the duplicated header part from the header copy part 15 into serial data, this header part is added to the above-mentioned control message to generate a control packet,
This control packet is transmitted via the transmission line L ₃₁ .

That is, the communication device 3 includes the packet reception unit 11, the header copy unit, the loopback transfer control unit 17, and the packet transmission generation unit.
With the configuration of 13, it is possible to set the same channel number information as the channel number information of the received packet in the transmission packet.

At this time, the loopback transfer control unit 17 may perform control so that control packets having the same content are not duplicated and transmitted to the same communication device 1.

The communication devices 1 and 5 similarly have the device configuration shown in FIG. 1, and a detailed description thereof will be omitted. Next, the operation will be described.

When the return transfer control unit 17 determines that the load is high, when the packet from the communication device 1 is received, the header copy unit 15 and the packet transmission generation unit 13 are operated to execute the return transfer control.

That is, the header copy section 15 duplicates the header section added to the packet from the communication device 1 and outputs it to the packet transmission generation section 13. The packet transmission generation unit 13 adds the header portion copied by the header copy unit 15 to the control message to generate a control packet, and transmits this control packet to the communication device 1 via the transmission line L ₃₁ . To transmit.

As described above, in order to perform the loopback transfer of the packet received by the communication device 3 and set the same channel number information as the channel number information of the received packet in the transmission packet, the header part regarding the transmission source of the packet is added. At this time, it is possible to easily transfer without having to refer to a table, a chart, or the like regarding the prepared header section in advance.

Further, it is not necessary to operate an arithmetic processing unit such as a microcomputer, and it is possible to simplify the processing relating to the addition of the header portion for the return transfer of the packet.

Next, an operation in the case of relaying a packet from the communication device 1 and transmitting it to the communication device 5 will be described as an example with reference to FIG.

The communication device 3 relays the packet from the communication device 1 and relays the packet from the communication device 5 and the information about the header portion added when transmitting the packet to the communication device 5.
And a storage unit for storing information regarding a header portion added when transmitting to the. For example, transmission line L ₁₃
When the header part added to the uplink packet transmitted via the header is a1, the header added to the uplink packet transmitted via the transmission line L ₃₅ corresponding to this header part a1. Stores information about part a2. This storage means stores such information about the header portion for each line. For example, when the communication device 3 receives a packet from the communication device 1 destined for the communication device 5, the header part a1 added to this packet is replaced with the header part a2 and transmitted via the transmission line L ₃₅ .

As described above, when the packet from one device is relayed and transmitted to the other device, a new header part corresponding to the header part of the received packet, that is, the header part of the destination is read from the storage means and the header part is read. The packet relay process can be simplified because the replacement is performed. For example, when the storage means is a table or chart configured so that the same header part as the header part of the received packet is selected,
The header part can be duplicated by a simple method such as modification of software. That is, the communication device 3 sets the same channel number information as the channel number information of the received packet when transmitting the control packet to the transmission source (communication device 1) of the received packet by the storage means, and The received packet is transmitted to another communication device 5
When transferring to, the channel number information corresponding to the channel number information of the received packet is read and set, so that the configuration of the communication device 5 is significantly simplified.

Next, another embodiment of the present invention will be described with reference to FIG.

In the example shown in FIG. 4, the packet receiving unit 11 has a discriminating means for deciphering the packet received and discriminating whether or not it is necessary to loop back and transfer the packet to be looped back to the source. If it is determined that the received packet needs to be returned to the transmission source and transferred, the header copy unit 15 is operated to duplicate the header part added to the packet and the packet transmission generation unit 13 is operated. Then, the header part of the received packet is replaced with a new duplicated header part and transferred to the transmission source of the packet via the transmission line L ₃₁ .

With the above configuration, it is possible to quickly and easily measure the delay time associated with packet transfer between both communication devices.

Further, when the device configuration of this embodiment is applied to a so-called echo canceller transmission system for bidirectionally transmitting a digital signal, a function relating to so-called echo back in which character information transmitted from the terminal device is sent back from the center device to the terminal device is facilitated Can be realized.

In the embodiment shown in FIG. 1, the loopback transfer control unit 17
Was configured to monitor the load condition in its own device 3,
If a packet for control relating to such state information is transmitted from the communication device 5 to the communication device 3 when the adjacent communication device, for example, the communication device 5 is in a high load state or a faulty state, communication is performed. By decoding the content of the control packet from the communication device 5, the device 3 can remotely monitor the load state or the fault state of the communication device 5 that is an adjacent device.

As described above, according to the present invention, the first channel number information and the second channel number information can be set to the same by the channel number setting means. It can be easily configured.

Further, according to the present invention, when a packet from one device is received, the header part added to this packet is copied by the copying means, and the packet having this copied header part is transferred to the device. Because I did
The processing relating to the replacement of the header section is unnecessary, the burden on the arithmetic processing section that supervises these processing can be reduced, and a packet communication device capable of transferring packets quickly can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing an internal configuration of the header copy section shown in FIG. 1, and FIG. 3 is applied to the embodiment shown in FIG. FIG. 4 is an explanatory diagram showing an example of a system configuration to be performed, FIG. 4 is a block diagram showing another embodiment of the present invention, and FIG. 5 is an explanatory diagram showing a conventional example.
FIG. 6 is an explanatory diagram of packets. 13 …… Packet transmission generation unit 15 …… Header copy unit 17 …… Foldback transfer control unit

Claims (6)

(57) [Claims] 1. A first packet communication device for transmitting a first packet, in which a first header portion including first channel number information is added to first information data, through a first communication line, The first packet transmitted from the first packet communication device via the first communication line is received by the first packet communication device.
The same channel number information as that of the second channel number information is set in the second channel number information, and the second information data to which the second header part including the set second channel number information is added is set to the second channel number information. A second packet communication device for transmitting to the first packet communication device via a communication line. 2. The second packet communication device is the first packet communication device.
2. The packet communication system according to claim 1, wherein the communication line and the second communication line are set to the same channel number. 3. A channel number is set in a line from one device to the other device and a line from the other device to the one device, and is formed by a header part including the channel number and a message part. A packet communication device for communicating via packets through these lines, wherein the one device or the other device duplicates a duplication unit that duplicates a header part added to a packet received through the line, A packet communication device, comprising: a transmitting unit configured to transmit a packet, to which a header section added by the copying unit is added, toward a source of the packet. 4. The channel number from the one device to the other device and the channel from the other device to the one device are set to the same channel number. Packet communication device. 5. The same channel number is set in the line from one device to the other device and the line from the other device to the one device, and is formed by a header part including this channel number and a message part. A packet communication device that communicates via these lines with a packet that is transmitted, and a duplication unit that duplicates the header part added to the packet received via the line, and monitors the load state of the packet communication device. Load state monitoring means, generating means for generating a control packet to which the header section duplicated by the duplicating means is added when the load state monitoring state detects a high load state of the packet communication device, and the generating means And a transmitting means for transmitting the generated control packet to the source of the received packet. Apparatus. 6. The one device transmits a control packet related to the packet transmitted from the other device that receives the transmission packet from the time when the one device transmits the packet to the other device. 6. The packet communication device according to claim 3, further comprising a measuring unit that obtains a delay time by measuring a time until the device receives the packet.