JPH10322394A - Message traffic congestion control method and its system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a transmission station of a message being a cause to occurrence of message traffic congestion to stop transmission of a message by deciding a restriction level denoting a traffic congestion state for a message of an exchange object. SOLUTION: A monitor section 12 of a relay exchange station A1 counts number of messages from each transmission station for each data channel and received by an input output section 11 to obtain the accumulation, compares the accumulated value of messages for each transmission station with a threshold value in the relay exchange station A1 to recognize a congestion state of a message traffic in the relay exchange station A1. In this case, a congestion control management section 14 discriminates which threshold level is exceeded among threshold levels to decide the restriction level. Then the congestion control management section 14 informs the decided restriction level to a congestion control execution section 15, which instructs restriction processing in response to a restriction level to transmission stations with highest exchange object messages to an incoming station through the input output section 11 and a data channel L and the transmission station immediately stops the transmission of the message in response to the restriction level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a message traffic congestion control method and apparatus, and more particularly to a message traffic congestion control method and apparatus for preventing a data communication process from becoming congested due to an increase in message transmission requests.

[0002]

2. Description of the Related Art Conventionally, in a message traffic congestion control system in this type of data communication system, when message traffic congestion occurs, the message is discarded according to the priority assigned to a message to be exchanged. This eliminates the congestion state of the message traffic.

As a conventional example of this kind of technology, Japanese Patent Laid-Open No.
JP-A-252160 discloses a "fault recovery method in the event of multiple failures". In this failure recovery method, when a plurality of types of failures occur in a network, priority is given to a failure recovery message, Failure recovery messages other than the priority failure are discarded.

Another conventional example is disclosed in Japanese Patent Application Laid-Open No. 8-89.
No. 26, "Buffer priority control method" is mentioned. In this buffer priority control method, in a packet switching method, when a buffer is congested at the time of temporary overload, when a buffer is congested, Some cells are discarded, and cells subsequent to the cell are aggressively discarded.

[0005]

In this conventional message traffic congestion control method in a data communication system, when congestion occurs due to a relay message, a priority assigned to a message to be exchanged only at a station where the congestion occurs is given. Since the message discarding process is performed depending on the degree, the originating station of the discarded message retransmits the discarded message, and when the same message is continuously transmitted, the message discarding process is performed. And the performance of the message exchange processing is degraded.

SUMMARY OF THE INVENTION It is an object of the present invention to determine a regulation level indicating a traffic congestion state of a message to be exchanged when message traffic congestion occurs, and to a message transmitting station which has caused the message traffic congestion. It is an object of the present invention to provide a message traffic congestion control method for stopping transmission of a message and an apparatus therefor.

[0007]

According to the first aspect of the present invention, the relay exchange for data communication constantly monitors the load status of the message transmission process of each originating station, and based on the result, the traffic congestion of the message to be exchanged. A restriction level indicating a state is determined, and when the load of the message exceeds the restriction level for each type of the message, the transmission stop of the message is notified to the transmission station and the message is discarded. The characteristic message traffic congestion control method is obtained.

[0008] Further, a message traffic congestion control method is provided, wherein the transmitting station, which has been notified of the transmission stoppage of the message from the transit exchange, performs processing for stopping transmission of the message.

Further, when the load of the message falls below the regulation level for each type of the message, the transmitting station which has stopped transmitting the message is notified of the resumption of transmission of the message, and receiving the notification. A message traffic congestion control method is characterized in that the source station performs the message transmission resuming process.

[0010] According to the second invention, each relay exchange of data communication monitors the load status of the message transmission process of each originating station, and the load at the time of message transmission detected from the monitor information. A restriction level determining means for determining a restriction level for each message by comparing with a preset load reference value, and an exchange target according to the restriction level determined for each message when congestion of the message traffic occurs. And a discarding means for discarding the message.

[0011] Further, each of the relay exchanges is provided with a notifying means for notifying the originating station that transmission of the message to be exchanged is stopped when the congestion of the message traffic occurs and exceeds the regulation level. Is obtained.

Further, when the congestion of the message traffic is resolved and the traffic level falls below the regulation level, the notifying means notifies the transmitting station of the message of restarting transmission of the message. A control device is obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the operation of the present invention will be described.

The present invention regulates the transmission of a message by notifying the originating station that has caused the message traffic congestion that the transmission of the message has stopped. For this reason, the message transmitting station does not need to retransmit the message caused by discarding the message or continuously transmit the equivalent message, and the congestion is eliminated in the station where the message traffic congestion has occurred.

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of a message traffic congestion control method and apparatus according to the present invention. FIG. 2 is a block diagram of a network showing a data communication network to which the present invention is applied and a data flow. FIG. 3 is a flowchart showing the flow of processing when message traffic congestion occurs and when it is resolved in the network shown in FIG.

Referring first to FIG. 2, in the data communication network of this application example, a transmitting station B2, a transmitting station C3 and a receiving station D
4 are connected to the switching center A1 by data lines L1, L2 and L3, respectively, and data communication is performed via the switching center A1.

Then, the switching center A1 detects occurrence of message traffic congestion on the data line L1 or L2.

Next, referring to FIG. 1, the switching center A1 according to the present embodiment includes an input / output unit 11 for inputting a message from an originating station through a data line L and outputting a congestion control signal to the originating station. A monitor unit 12 for constantly monitoring the load status of the message transmission process of each transmitting station, and a threshold value storage for storing a preset threshold value for comparing the load at the time of message transmission detected from the monitor information. The load at the time of message transmission detected from the monitor information by the monitor unit 12 and the monitor unit 12 is stored in a threshold value in the threshold value storage unit 13 (for level 1 control, level 2 control, level 3 control and control release). A congestion control management unit 14 for determining a restriction level (level 1 restriction, level 2 restriction, level 3 restriction and restriction release) for each message, A discarding process for discarding messages to be exchanged according to the above-mentioned regulation level when congestion of traffic occurs, and notifying the originating station that transmission of the messages to be exchanged is stopped to the originating station when the above-mentioned regulation level is exceeded, and congestion of message traffic. And the congestion control execution unit 15 performs a notification process of notifying the message transmitting station of the resumption of transmission of the message when the transmission level falls below the regulation level.

In the present embodiment, the regulation level is determined as follows, but the regulation level is not limited to this. Level 1 regulation: Stop sending output of only low priority messages Level 2 regulation: Stop sending output of only low and medium priority levels Level 3 regulation: All except high priority messages Discard message and stop transmission output. Release regulation: Release all restrictions. Next, the operation of this embodiment will be described with reference to FIG.

When a message to be exchanged from the originating station B2 and the originating station C3 to the terminating station D4 is inputted to the transit exchange 1 via the data line L, the monitor unit 12 is inputted to the input / output unit 11 in the transit exchange A1. The number of messages from each transmission station is counted for each data line L to obtain a total (step S31), and the total value of the messages for each transmission station is compared with the threshold value registered in the threshold value storage unit 13. Then, the congestion state of the message traffic in the relay exchange A1 is recognized (step S32).

At this time, the congestion control management unit 14 sets a threshold value (for level 1 regulation, level 2 regulation, and level 3 regulation).
Of the thresholds is exceeded, and based on the determination result, the restriction level of each message (level 1 restriction,
Level 2 regulations and level 3 regulations).

When YES is determined in step S32, that is, when the occurrence of the congestion state of the message traffic is detected, the congestion control management unit 14 notifies the determined restriction level to the congestion control execution unit 15, and the congestion control execution unit 15 The originating station (in this embodiment, either originating station B2 or originating station C3) that has the largest number of messages to be exchanged for D4 is in accordance with the regulation level (any of level 1 regulation, level 2 regulation, and level 3 regulation). A regulation process is instructed through the input / output unit 11 and the data line L (step S33).

At the transmitting station receiving the regulation processing instruction,
The transmission of the message according to the regulation level is immediately stopped (step S34).

On the other hand, in the relay exchange A1, the congestion control execution unit 15 performs a process of discarding the message input from the originating station.

On the other hand, when the total value of the messages from a certain transmitting station falls below the regulation release threshold, the congestion control management unit 14 determines that the congestion state of the message traffic from the transmitting station has been eliminated (step YE in S35
S), notifies the congestion control execution unit 15 of the resumption of message transmission, and the congestion control execution unit 15 sends the input / output unit 11 and the data line L
An instruction to release the message transmission restriction is issued through (step S36).

Therefore, the transmitting station which has received the transmission restriction release instruction immediately restarts the transmission of the message (step S37).

If NO in step S32, that is, if the occurrence of message traffic congestion is not detected, the process of transmitting a message from the transmitting station is continued (step S38).

If NO in step S35, that is, if the congestion state of the message traffic has not been resolved, the process returns to step S33 to continue the notification of the message transmission stop.

[0030]

As described above, according to the first aspect of the present invention, the relay exchange of data communication constantly monitors the load status of the message transmission processing of each originating station, and determines the traffic congestion state of the message to be exchanged from the result. Establish a regulatory level to indicate
When the load of the message exceeds the regulation level for each type of message, the originating station is notified of the suspension of message transmission, and the message is discarded. The transmitting station that has received the notification performs the transmission stop processing of the corresponding message, and further, when the load of the message falls below the regulation level for each message type, the transmitting station that stopped transmitting the message receives the message. In the second invention, each of the relay exchanges in the data communication performs a message transmission resumption process of the message transmission processing of each of the transmission stations. Monitoring means for monitoring messages and the load at the time of message transmission detected from the monitor information. A restriction level determining means for determining a restriction level for each message by comparing with a set load reference value, and a discard for discarding a message to be exchanged according to the restriction level determined for each message when message traffic congestion occurs By providing processing means, each relay exchange, by providing notification means for notifying the originating station of the transmission stop of the message to be exchanged when congestion of message traffic occurs and exceeds the regulation level, Further, when the message traffic congestion is resolved and the traffic level drops below the regulation level, the notifying unit notifies the message transmitting station of the resumption of the message transmission, thereby transmitting the message that caused the message traffic congestion. The station immediately sends a message to the called station that is experiencing congestion. Will stop, it has the effect that it is possible to eliminate the congestion message traffic.

Further, since the discarded message is not retransmitted at the source station, the performance of the message exchange processing is improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of a message traffic congestion control method and apparatus according to the present invention.

FIG. 2 is a block diagram of a network showing a data communication network to which the present invention is applied and a data flow.

FIG. 3 is a flowchart showing the flow of processing when message traffic congestion occurs and when it is resolved in the network shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 relay exchange A 2, 3 originating station B, C 4 destination station D 11 input / output unit 12 monitor unit 13 threshold value storage unit 14 congestion control management unit 15 congestion control execution unit L, L1,..., L3 data line

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuhiro Kimura 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Hideo Hino 2-4-1-18 Kohoku-ku, Yokohama, Kanagawa No. Japan Electric Aerospace Systems Co., Ltd.

Claims (6)

[Claims] A relay station for data communication constantly monitors the load status of a message transmission process of each originating station, determines a regulation level indicating a traffic congestion state of the message to be exchanged from the result, and determines a type of the message. A message traffic congestion control method comprising: notifying the originating station of the transmission of the message when the load of the message exceeds the regulation level, and performing a discarding process of the message. 2. The message traffic congestion control method according to claim 1, wherein the transmitting station, which has been notified of the transmission stoppage of the message from the transit exchange, performs processing for stopping transmission of the message. 3. When the load of the message falls below the regulation level for each type of the message, the transmitting station that has stopped transmitting the message is notified of the resumption of transmission of the message, and receiving the notification. 2. The method according to claim 1, wherein the transmitting station performs a process of resuming the transmission of the message. 4. Each of the relay exchanges for data communication monitors a load status of a message transmission process of each originating station, and a load at the time of message transmission detected from the monitor information is set to a predetermined load reference value. A restriction level determining means for comparing and determining a restriction level for each message; and a discarding process for discarding the message to be exchanged according to the restriction level determined for each message when the message traffic congestion occurs. And a message traffic control device. 5. The relay switching station according to claim 1, further comprising: notifying means for notifying the transmitting station that the transmission of the message to be exchanged is stopped when the message traffic congestion occurs and exceeds the regulation level. The message traffic control device according to claim 4, wherein 6. The system according to claim 1, wherein when the congestion of the message traffic is resolved and the traffic level falls below the regulation level, the notifying unit notifies the originating station of the message that transmission of the message is to be resumed. 6. The message traffic control device according to claim 5.