JPH06125355A - Packet serial number management system in packet communication system - Google Patents

Abstract

PURPOSE:To add only a terminal equipment without increasing a table memory of all equipments by allowing equipments opposite to each other to independently implement the management of a serial number of a packet. CONSTITUTION:A repeater A has packet serial number management sections aA1-aAn and serial number management tables (A1-An) with respect to each of terminal equipments A1-An under its control. Moreover, a repeater B is provided with packet serial number management sections bB1-bBn and serial number management tables (B1-Bm) similarly to the case with the repeater A. Furthermore, a packet serial number management section AB and a packet serial number management table A or B are provided to manage the serial number of the opposite party between the repeaters A, B. Then an own address A1 as a caller station address and an address of the repeater A opposite to each other as a reception station address are added to a Tn header of the packet from the terminal equipment A1 respectively. Since the packet serial number management is implemented independently between the repeaters A, B, the increase in the tables aAn, bBn attended with the extension is not required for the receiver side.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a packet sequence number management system in a packet communication system.

[0002]

2. Description of the Related Art A conventional packet serial number management system of this kind has a structure as shown in FIG. In the figure, a relay device A has a plurality of terminal devices A1 to An under it, and a relay device B has a plurality of terminal devices B1 to An under it.
Has Bm.

The terminal devices A1 to An are connected to the terminal devices B1 to An, respectively.
It is possible to perform packet communication with each other through Bm and the relay devices A and B, and when performing packet serial number management of each terminal device in such a network configuration,
A serial number management table is provided for each partner terminal device between the source and destination of the packet, and the serial number management is performed in each terminal device.

For example, the terminal device A1 under the control of the relay device A
The serial number management unit a11 is provided, and the serial number management table a1 corresponding to each of the terminal devices B1 to Bm under the control of the relay device B, which is a communication partner, is provided.

Therefore, when the communication partner of the terminal device A1 is the terminal device B1, the terminal device A1 is controlled by the management table a1.
The packet serial number is managed by the table (B1) for the terminal device B1 in the inside. This packet serial number management is performed by the terminal device A.
When sending a packet from 1 to the terminal device B1, the serial number (serial number) to the terminal device B1 is written in the header part of the packet, and the receiving side terminal device B1 stores this serial number for the terminal device A1 in the management table b1. The table (A1) is checked for normality and abnormality. Management such as checking of these serial numbers is performed by each serial number management unit a11, b11.
The other terminal devices have exactly the same configuration and perform the same operation.

In such a conventional serial number management system, as the number of terminal devices communicating on the network increases, it is necessary to provide each terminal device with a serial number management table corresponding to the number. For this reason, there is a drawback in that it is necessary to increase all the table memories in accordance with the expansion of the network.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to add a serial number management table to an extension terminal device and a relay device under the extension number device in accordance with the expansion of a network, which leads to an increase in table memory in all devices. It is to provide a packet serial number management system that does not do.

[0008]

According to the present invention, there is provided a packet serial number management system in a communication system in which a plurality of terminal devices perform packet communication with each other via corresponding relay devices, each of the terminal devices being a corresponding relay device. Between the relay device and the corresponding terminal device, each of the relay devices is provided in correspondence with each of the subordinate terminal devices. Managing means for managing each of the other relay devices connected to the own relay device, and managing means for managing the serial number of the packet to the other relay device with the corresponding other relay device. A packet sequence number management system characterized by having

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a system block diagram showing an embodiment of the present invention, and the same portions as those in FIG. 5 are designated by the same reference numerals. The terminal devices A1 to An subordinate to the relay device A have packet serial number management units a1A to anA for the relay device A, respectively, and a serial number management table (A) for the relay device A as well. The relay device A has packet serial number management units aA1 to aAn for the respective subordinate terminal devices A1 to An, and similarly serial number management tables (A1 to An) for the respective terminal devices A1 to An.

The configuration of the relay device B side is the same as that of the relay device A side, and the description thereof is omitted.

In order to manage the relay packet serial numbers between the relay devices A and B, the relay device A is provided with a packet sequence number management unit AB for the relay device B and a packet sequence number management table (B). Has been. Repeater B
The same is true for.

FIG. 2 is a diagram showing a packet format, showing a packet format between relay devices and a packet format between a terminal device and a relay device, respectively. The packet format from the terminal device to the relay device is such that a Tn header is added to the beginning of the data part. And have.

The packet format between the relay devices has a Tu header at the beginning of the data. This Tu header includes a Tn header from the terminal device with a serial number area between the relay devices, a source station address, and a receiving station address. have.
That is, this inter-relay device packet includes a packet sent from the terminal device, a serial number area, a source station address,
It is formed by adding the receiving station address.

FIG. 3 is a diagram showing a packet flow when packet communication is performed from the terminal device A1 or the terminal device A2 to the terminal device B1 via the relay devices A and B.

To the Tn header of the packet from the terminal device A1, the own address A1 is added as the source station address, and the address A of the opposite relay device A is added as the receiving station address. In the serial number area, the serial number of the packet transmitted from the terminal device A1 to the relay device A (serial number)
Is added. This serial number α is added by the serial number management unit a1A of the terminal device A1 by referring to the management table (A).

That is, since the serial number immediately before the transmission of this packet is stored in the table (A), the content is incremented by +1 and added to the Tn header as the serial number α. This latest serial number α is updated and stored in the table (A).

Upon receiving this packet, the relay device A manages the serial number in the packet serial number management unit aA1 corresponding to the terminal device A1. The sent serial number α of the Tn header is compared with the latest serial number (stored in the serial number management table A1),
If they do not match, this received packet is discarded.

If they match, the current serial number in the serial number management table A1 is updated by incrementing it by +1 to wait for packet reception from the next terminal device A1 and process the received packet. In this processing, a Tu header is formed in the received packet and the packet is sent to the opposite relay device B.

In this case, the source station address is A, the receiving station address is B, and the serial number in the serial number area is α '. This α'is a serial number between the relay devices A and B, and is performed by the serial number management unit AB of the relay device A for the relay device B. The management table (B) shows the serial number between the relay devices A and B. The packet serial number is stored.

Therefore, the serial number management unit AB is in the table (B).
The latest serial number is read from and the serial number area α'of the Tu header
And is sent to the relay device B.

In the relay device B, Tu of this received packet
The serial number management unit BA receives α'in the serial number area of the header and compares it with the latest serial number in the management table (A) (serial number between the relay device A and the relay device B).

If they do not match, this packet is discarded, and if they match, packet processing is performed. In this packet processing, a packet format between the terminal device and the relay device is generated,
The source station address B and the receiving station address B1 are added respectively. The latest serial number α ″ between the relay device B and the terminal device B1 is added to the serial number area by the corresponding serial number management unit bB1.

This packet is received by the terminal device B1 which is the receiving station, and the serial number management at this time is performed by the serial number management unit b1B.
At, the check is made to see if the sent serial number α ″ matches the latest serial number in the table (B).

Here, referring to FIG. 4A, a processing flow of the serial number management unit in the terminal device is shown. For example, when the terminal device B1 receives a packet, the normality of the packet sequence number α ″ (see FIG. 3) with the relay device B is checked. That is, the latest sequence number in the table (B) and α ″ match. It is checked whether or not they match, and if they do not match, the received packet is discarded, and if they match, packet reception processing is performed. At this time, the serial number in the table (B) is incremented by +1 and updated, and the next packet reception from the relay apparatus B is waited for.

FIG. 4B shows a serial number management unit A between the relay devices.
The processing flow of B and BA is shown. When a packet is received from the other relay device, the number (address) of the relay device, which is the transmitting station, is checked by the Tu header to check which relay device the packet is from. In the system of FIG. 1, the number of relay devices A and B is simplified, but
In an actual network, a plurality of relay devices are often provided.

For example, if the originating station relay device is A, the receiving station relay device B checks the packet sequence number with the relay device A at the sequence number management unit BA. If it is normal, packet processing is performed. If they do not match, they are discarded.

FIG. 4C shows the serial number management unit b in the relay device B.
In the management flow of B1 to bBm, if the receiving station terminal number (address) is B1, control is passed to the management unit bB1 corresponding to the terminal device B1, and the normality of the packet serial number with the terminal device B1 is checked. This is as described above, and the operation based on the check result is also as described above.

In the packet communication from the terminal device A2 to the terminal device B1 shown on the lower side of FIG. 3, the serial number management is performed by the same processing procedure.

In the above-mentioned embodiment, the communication from the terminal devices A1 and A2 to the terminal device B1 has been described, but the same serial number management is performed even in the reverse communication.
At this time, each serial number management table needs to be provided with an area for storing each serial number in the relevant direction.
It is assumed that each table stores each serial number in both directions.

[0031]

As described above, according to the present invention, the packet serial number management is not performed between the terminal devices but is performed independently between the devices facing each other. Therefore, the serial number management accompanying the expansion of the network is performed. There is an effect that the number of tables need only be increased on the side of the additional terminal device and is unnecessary on the side of reception.

[Brief description of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a packet format applied to an embodiment of the present invention.

FIG. 3 is a diagram showing changes in packet format during serial number management according to the embodiment of this invention.

FIG. 4A is a flow chart of serial number management processing on the terminal device side when a packet is received from the relay device to the terminal device;
(B) is a sequence number management processing flow diagram of the relay device when the packet is received between the relay devices, and (C) is a sequence number management process flow diagram of the relay device side when the packet is transmitted from the relay device to the terminal device. .

FIG. 5 is a system block diagram illustrating a conventional serial number management system.

[Explanation of symbols]

 A, B Relay device A1 to An Terminal device B1 to Bm Terminal device a1A to anA Serial number management unit b1B to bmB Serial number management unit aA1 to aAn Serial number management unit bB1 to bBm Serial number management unit AB, BA Serial number management unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akinori Yokota 3-5-11 Chomeigaoka, Izumi-ku, Sendai-shi, Miyagi (72) Inventor Masatoshi Suzuki 4-5-4 Kunimi-gaoka, Aoba-ku, Sendai-shi, Miyagi (72) Inventor Motoyuki Suzuki 1-5-5, Kunimi, Aoba-ku, Sendai-shi, Miyagi (72) Inventor Yoshiro Funasaka 3-8-5, Kaigamori, Aoba-ku, Sendai-shi, Miyagi (72) Kiyoshi Nanba Sendai-shi, Miyagi-ken Izumi Ward Nijinooka 1-4-16 (72) Inventor Tadayuki Kato 4-11-16 Masuda, Natori City, Miyagi Prefecture (72) Inventor Kazuo Sakamoto 5-33-1 Shiba, Minato-ku, Tokyo Morinaga Plaza Building 17th floor NEC Electric Power Engineering Co., Ltd.

Claims (1)

[Claims] 1. A packet sequence number management system in a communication system in which a plurality of terminal devices perform packet communication with each other via corresponding relay devices, wherein each of the terminal devices sends its own packet to the corresponding relay device. Has a management unit that manages a serial number for each of the relay devices,
It corresponds to each of the subordinate terminal devices and corresponds to each of the other relay devices connected to the own relay device and the management means for managing the serial number of the packet to the corresponding terminal device with the corresponding terminal device. A packet serial number management system for managing the packet serial number for the corresponding other relay device.