JPS5925538B2 - Packet transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packet transfer device that can improve the efficiency of packet reception in a partner device and is also economically advantageous.

Conventionally, when this type of device converts transfer information into packets and transfers them to a partner device, the transfer is performed continuously regardless of the length of the packet.

FIG. 1 is an example of a conventional packet transfer device.

In FIG. 1, 1 and 2 are packet transfer devices that transfer data, 3 and 8 are control devices that control packet transfer, 4 and T are circuits that send packets to a partner device,
5 and 6 are circuits that receive packets from the other device; 9
and 10 are communication lines for transferring packets, and 11 and 12 are storage devices possessed by the unit. For example, when sending many packets continuously from the packet transfer device 1 to the packet transfer device 2, the control device 3 continuously sends the packets to the packet receiving circuit 6 of the other device via the packet sending circuit 4, and 6 reports to the control device 8 that the packet has been received.

The control device 8 interprets information related to packet transmission control and stores the transfer information in the storage device 12 in the mobile device. Such processing is executed every time each successively transferred packet is received. Therefore, in a conventional packet transfer device, when consecutive short packets are received, the next packet arrives before the previous packet has been interpreted because the packet length is short, and the next packet cannot be interpreted. There were cases where it was not possible to do so.

Therefore, especially in the case of a device that mostly uses long packets, if the device is configured to tolerate continuous transmission of short packets that occur only occasionally,
As for the processing speed requirements of the device, most long packets require unnecessary high-speed processing, which imposes excessive requirements on the device processing speed and has the disadvantage that an economical design cannot be achieved. In order to eliminate such drawbacks of the prior art, the present invention provides a packet transfer device with a function of detecting the packet length at the time of packet transmission and changing the packet transmission interval depending on the packet length. , the drawings will be explained in detail below.

FIG. 2 shows an embodiment of the packet transfer device of the present invention, in which 21 and 22 are packet transfer devices that transfer data, 23 and 30 are control devices that control packet transfer, and 26 and 31 are packet transfer devices. circuits 27 and 32 having length detection and timing functions are managed by control devices 23 and 30, and storage devices 24 for storing transfer packets;
and 29 is a circuit that sends the packet to the other device, 25
and 28, a circuit for receiving packets from the partner device; 3;
3 and 34 are communication lines for transferring packets. When using this packet transfer device 21 to transfer information to the other device 22, the control device 23 takes out the packet from the storage device 27, adds control information to the beginning, and sends the packet via the circuit 26 that detects the packet length. process to send it.

The circuit 26 for detecting the packet length takes a constant timing longer than the minimum timing if the previous packet was short and the packet currently being sent is short, otherwise it takes the minimum timing and sends the packet. It is sent to the sending circuit 24. The packet sending circuit 24 uses the communication line 33 to send the packet to the other party's packet transfer device 22.
Transfer to. The packet transfer device 22 receives the control information via the packet receiving circuit 28, interprets the control information in the control device 30, and if the packet includes information to be transferred to the storage device 32, performs processing to transfer the packet to the storage device 32, and then transfers the packet to the storage device 32. If there is only control information between devices that are not connected to each other, processing corresponding to the control information is performed. The control device 30 performs a reporting process to report to the packet transfer device 21 that the packet has been received. In the reporting process, if there is a packet that the control device 30 sends to the packet transfer device 21, it is carried on it, and if there is no packet, a new report packet is created, and the same process as the packet sending process performed by the control device 23 is performed. Then, it is sent to the packet transfer device 21 via the packet length detection circuit 31, and information is exchanged. In this way, when short packets are sent consecutively via the packet length detection circuits 26 and 31, the sending side sends them out at a certain timing, and as a result, the receiving side control device 30 An economical equipment design that allows the interpretation of the control information of a packet to be completed within a certain amount of time, so that even if the next packet is transferred, the interpretation of the control information will not be delayed, and the equipment processing speed can be set to an appropriate value. becomes possible. As explained above, in the packet transfer device of the present invention, since short packets are sent at a fixed timing in continuous transmission, the receiving device does not become unable to interpret the packets, and the packets are not retransmitted. The number of times decreases.

Retransmission is controlled at a timing of several seconds, which is the response waiting timing in the transfer device, and is much longer than the minimum time limit of number Ms, which is the packet transmission interval. Therefore, by reducing the number of retransmissions, transfer control can be performed with extremely less time loss compared to conventional devices. Furthermore, eliminating retransmissions has the advantage of increasing the amount of effective information transfer between devices. Another advantage is that an economical device can be designed because the speed can be set to an appropriate value without requiring a device with a high processing speed.

[Brief explanation of drawings]

FIG. 1 is a diagram of a connection between a conventional packet transfer device and a communication line, and FIG. 2 is a diagram of a connection between a packet transfer device and a communication line according to an embodiment of the present invention. 1, 2, 21, 22...Packet transfer device, 3
, 8, 23, 30...Packet control device, 26
, 31... Packet length detection circuit and timing circuit, 4, 7, 24, 29... Packet sending circuit, 5, 6, 25, 28... Packet receiving circuit, 11, 12, 27, 32... Storage device, 9
, 10, 33, 34... Communication line.

Claims (1)

[Claims] 1. A packet transfer device that has a control function and a data storage function and transfers a series of digital data signals in packet format, is equipped with means for detecting the length of a packet and determining the timing of packet transfer, and has a minimum A packet transfer device characterized by setting a time limit and transferring packets at intervals longer than the minimum time when transferring successive short packets.