JPH10145426A - Packet information transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically execute the change/update of a reception managing table at a packet reception terminal during ordinary operation by providing a processing means for abandoning a received packet by judging double reception when that packet is already registered but for performing registering processing when that packet is not registered. SOLUTION: This device is provided with a packet reception part 1 for receiving a packet and a reception managing processing part 2 for performing processing to show whether this packet is already registered in a reception table or not. The respective identification codes of packets 1, 2...N are stored in a reception table 3 at this reception managing processing part 2. In reception managing processing at the reception managing processing part 2, it is judged whether the received packet is already registered or not and when it is registered, processing is finished by abandoning that reception packet by judging double reception. When the packet is not registered, registering processing is performed to the reception managing table by a first-in/first-out(FIFO) system, old data are abandoned and latest data are stored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a packet information transmission device, and more particularly to a packet information transmission device for performing packet transmission and packet reception in a system that requires reliable transmission of information within a fixed time in packet communication.

[0002]

2. Description of the Related Art In packet communication, data information (digital information) to be transmitted is divided into appropriate lengths, and control information such as a destination is attached to each. This is called a packet, and this packet is used as a unit, one by one, according to the destination.
Transfer to the other party. In this way, since packets from one terminal come intermittently, one line can be shared by a plurality of communication packets, and the time that the line is substantially idle is reduced, thereby increasing the use efficiency. When two or more packets arrive, they are stored in a memory and kept waiting until the line is free. By performing error control on a packet-by-packet basis or by appropriately selecting a transmission path, high-quality transmission and highly reliable transmission can be realized. Since data information is stored once and then transferred, communication services such as speed conversion and code conversion can be easily performed. Due to these features, packet communication has recently become widespread as a data communication network.

However, the receiving end may receive a packet having the same packet identification code from each of a plurality of routes. It may be received in duplicate, or some packets may be missed.

In the packet switching method disclosed in Japanese Patent Application Laid-Open No. 2-144644, a reception buffer for temporarily storing a data packet to which a transmission sequence number is transmitted from a transmission device and received by a reception device is provided. The device counts the number of receiving buffers in use and compares this count with the upper and lower thresholds. The receiving device checks the state of the flag that controls the timing of window update, calculates the window update number from the transmission order number based on the check result and the comparison result, and adds the window update number to the reception enable packet. On the other hand, the transmitting device calculates a window upper limit value based on the window update number added to the receivable packet, and compares the window upper limit value with the transmission sequence number to determine the number of data packets to be transmitted. And comparing the number of used receive buffers with the upper and lower thresholds,
Data that limits the number of receive buffers used to an upper threshold or less by performing window control by synchronizing between the receiving side and the transmitting side by checking a flag newly provided on the receiving side Continuous transfer is possible.

However, such a configuration is effective as a means for transmitting information generated in a burst manner, but it is necessary to always transmit and receive a response packet, and if this response packet is lost, another recovery means must be provided. In addition, it is necessary to prepare a window management and reception buffer for the previous location for each transmission location for reception,
There is a problem that the use efficiency of the reception buffer is deteriorated.

The packet switching method disclosed in Japanese Patent Laid-Open No. 4-8041 is a packet transmission network having a trunk line connecting each node of a plurality of nodes. Then, a serial number corresponding to each receiving station, which is incremented each time one packet is transmitted to each receiving station, is written in a header portion for writing a transmitting station address and a receiving station address of a packet to be transmitted,
The packet is transmitted to all trunk lines connected to the own node, and for relaying, for each window of all receiving stations to all transmitting stations except the own station of the network, the serial number of the received packet is next to the serial number of the received packet. A serial number is a reception expected serial number, a reception number in a predetermined range larger than the reception expected serial number is a receivable range, a serial number in a predetermined range less than the reception expected serial number is a delay discard range, the receivable range, the delay discard range other than A transmitting station receiving station sequence number management window having a sequence number as an abnormal range is provided.
In the reception processing means, every time a packet to be relayed is received,
Look at the header part of the received packet, refer to the corresponding window of the transmitting station receiving station serial number management window, and if the serial number of the received packet is the expected receiving serial number or the receivable range, the expected receiving serial number of the corresponding window Is updated to a value obtained by incrementing the serial number of the packet, and transmitted to all trunk lines except the received trunk line. If the serial number of the received packet is in the delayed discard range, the packet is discarded. Is discarded and the expected reception serial number of the corresponding window is updated to a value obtained by incrementing the serial number of the packet. With such a configuration, even if an error occurs in some of the nodes or the trunk line in the network, no trouble is taken, and the packet is transmitted to the destination node by bypassing without much load on the node. Make it possible.

However, in such a configuration, since the packet is transmitted to all the relay nodes to be connected, the utilization efficiency of the line is not good. If the network configuration is a mesh or a loop, the packet multiplies in the network. In addition, there is a possibility that packets that do not arrive forever and continue to wander in the network may occur, and are systematically flawed.

Further, when the number of nodes in the network increases, it is necessary to newly create / add a transmitting station / receiving station serial number management table in each node.
There are disadvantages such as an increase in change / update work.

Further, the window control system disclosed in Japanese Patent Application Laid-Open No. Sho 64-20755 is a window control system for controlling data transfer in packet communication. The transmitting side determines the window size based on the average reception interval on the transmitting side of the confirmation packet and the number of retransmission request packets received on the transmitting side, and changes the window size during communication.

However, in such a configuration, it is assumed that a data file of a fixed size is transferred. If the size of the data file is different, the optimum window size is different.

[Problems to be solved by the invention]

Therefore, an object of the present invention is to make it possible to automatically change / update a reception management table at a packet receiving end in the normal operation in accordance with addition / deletion of a packet at a packet transmitting end during information transmission. An object of the present invention is to provide a packet information transmission device that minimizes the influence on a system.

Another object of the present invention is to provide a packet information transmission apparatus having a simple configuration and high line use efficiency.

[0013]

In order to solve the above-mentioned problems, a packet information transmitting apparatus according to the present invention comprises: means for determining whether or not a received packet has already been registered; And processing means for discarding the packet as duplicate reception and performing registration processing when the registration is not performed.

Here, in the processing means, the FIFO
A storage device of the system is used, and a packet registered for a predetermined time or more among the registered received packets can be deleted.

[0015]

FIG. 1 shows an embodiment of a packet information processing apparatus according to the present invention. The embodiment shown in FIG. 1 includes a packet receiving unit 1 that receives a packet, and a reception management processing unit 2 that performs processing such as whether or not the packet has been registered in a reception table. Here, the reception table 3 of the reception management processing unit 2 includes packets 1, 2, 3,.
N identification codes are stored.

Here, the processing procedure of the reception management processing section (2) will be described with reference to the flowchart of FIG. In FIG. 2, in the reception management process S31 of the reception management processing unit 2, it is determined whether or not the packet received in the process S32 has already been registered.
In S), the received packet is discarded as duplicate reception in the next process S34, and the process ends. If not registered (NO), in the next processing S33, registration processing is performed on the reception management table by FIFO (First In First Out) method. Here, old data is automatically discarded, and the latest data is stored.

As described above, the packet received by the packet receiving unit 1 is checked by the reception management processing unit 2 to see if it has already been registered in the reception table 3 (step S32). The contents to be checked include the transmission source and the identification code. If they are the same (YES), they are discarded as duplicated reception in step S34. If they are different (NO), they are registered in the reception management table (process S33).

This registration process is not prepared for each transmission location, but performs common management. The table management method at the time of registration is F
When the table is full by the IFO method, the oldest registration information is discarded and newly registered, so that the reception of packets from all transmission locations is managed with a fixed amount of reception table.
In process S35, the received packet is validated, and
Notify the data reception processing unit (2).

In the above embodiment, the following processing (1) to
Execute (5). (1) Having a common reception management table that does not directly belong to the transmitting end, the identification of the same packet received from a plurality of routes in the network is determined using this reception management table. (2) This reception management table is managed by the FIFO method, is compared with a registered packet by packet identification, registers a new packet, and performs reception processing. (3) If the packet is already registered, discard it as a duplicate received packet. (4) A predetermined number of reception management tables are prepared in advance, and are prepared for the number of packets that may be received within the maximum arrival delay time of packets received from a plurality of routes. (5) Since a packet is transmitted through a plurality of routes, a design is made so that if a transmission failure occurs in each node, the packet does not remain in the network for a certain period of time.

In order to increase the reliability of data transmission control in packet communication, a packet having the same packet identification code is transmitted through a plurality of routes, and the receiving end controls reception of duplicately received packets, and performs redundant transmission. Effectively discard duplicated packets.

According to the embodiment of the present invention, it is possible to automatically change / update the reception management table at the receiving end due to addition / deletion of a packet at the originating end of the packet during normal operation, and to provide a packet information transmission system. The effect on the reception management table can be minimized and the size of the reception management table can be minimized, and an efficient reception management method can be realized.

[0022]

As described above, according to the packet information transmitting apparatus of the present invention, by automatically registering and deleting the window management table at the packet receiving end,
It is possible to add / delete packets at the packet transmission end without affecting the entire information transmission system, and to delete memory once registered by timer monitoring to enable memory air for the window management table. It can be used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a packet information transmission device according to the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of a reception management table according to the embodiment of the present invention.

[Explanation of symbols]

 1 packet reception unit 2 reception management processing unit 3 reception table

Claims (3)

[Claims] 1. A means for determining whether a received packet has already been registered, and discarding the packet as duplicate reception if the registration has been made, and discarding the packet if the registration has not been made. A packet information transmission device comprising: a processing unit for performing a registration process. 2. The packet information transmitting apparatus according to claim 1, wherein said processing means uses a FIFO type storage device. 3. The packet information transmitting apparatus according to claim 1, wherein packets registered for a predetermined time or more among the registered received packets are deleted.