JPS6226615B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a message transmission regulation system in a store-and-forward network.

In conventional store-and-switch networks, for example, when a certain destination terminal is out of order and a large number of messages to that destination terminal are input from the originating store-and-switch station,
Since these messages cannot be sent to the destination terminal, the storage device of the terminating store and switch center
The network is filled with only messages to the destination terminal, and the storage/switching station becomes abnormally congested.

Therefore, not only will other normal terminals housed in the store and forwarding station be unable to communicate, but if a request to send a message to the failed destination terminal occurs, the store and forwarding station on the sending side will not be able to communicate with the other normal terminals. There is a danger that the station's storage device will also be filled with messages for the destination terminal, and that this will spread throughout the store-and-forward network like an avalanche, resulting in no communication at all.

SUMMARY OF THE INVENTION An object of the present invention is to provide a message transmission regulation system that eliminates the above-described drawbacks of the prior art and can prevent abnormal congestion in a store-and-forward network due to terminal failure.

A feature of the present invention is that each store and forwarding station constituting the store and forwarding network is provided with a counter capable of recording the number of messages retained for each terminal in the network, and the value of the counter is The message transmission regulation method is updated based on periodic reports from the switching center, and is capable of regulating message transmission to terminals whose counter value exceeds a predetermined value.

Embodiments of the present invention will be described below based on the drawings.

The figure is a control system diagram of an embodiment of the message transmission regulation system according to the present invention.

Here, 1a and 1b are packet switching devices related to storage and switching centers A and B, 2a and 2b are storage devices thereof, and 3-1, 3-2 and 3-3 and 3-4 are packet switching devices, respectively. Terminals housed in devices 1a and 1b, 4a-1 to 4a-4 and 4b
-1 to 4b-1 are terminals 3-1 to 3-, respectively.
This counter corresponds to No. 4 and is provided in the packet switching devices 1a and 1b.

These constitute the store and exchange network,
Normally, a store and forward network may include other store and forward stations, relay exchange stations, etc. in addition to these, but these are omitted from the drawings as there is no change in principle even if they are omitted for the purpose of explaining the present invention. It has been done.

In addition, counters 4a-1 to 4a-4, 4b-1
~4b-4 are respectively packet switching devices 1
It may be provided as hardware within a and 1b, or
A corresponding area may be provided in the main storage device, and writing and reading may be performed in this area under software control.

First, control on the destination side will be explained.

For example, when the packet switching device 1b receives a message MES addressed to the terminal 3-3 as the destination terminal from the packet switching device 1a, the packet switching device 1b stores the message in the storage device 2.
At the same time, the counter 4b-3 is incremented by +1 ().

Further, when the message MES is taken out from the storage device 2b and transmitted to the terminal 3-3, the counter 4b-3 is counted down by -1 ().

Therefore, the value of counter 4b-3 is
-3 means the number of retained messages that should be sent.

Note that the same applies to the counter 4b-4.

In this way, the packet switching device 1b constantly records the number of accumulated messages of its own terminals 3-3, 3-4 in the counters 4b-3, 4b-4, and accumulates this at a predetermined period. The information is reported to each packet switching device (in this embodiment, only 1a) in the switching network.

This cycle may be selected in accordance with the communication density so that the number of accumulated messages at another station can be grasped within a time delay that does not cause any practical problems with that at the station concerned.

Next, control on the calling side will be explained.

The packet switching device 1a is the packet switching device 1.
When receiving the values of counters 4b-3 and 4b-4 from terminal b, it updates the values of own counters 4a-3 and 4a-4 corresponding to terminals 3-3 and 3-4 ().

In this way, the packet switching device 1a can ascertain the number of messages retained in all the partner station terminals (3-3 and 3-4 in this embodiment).

Therefore, for example, terminal 3 as the originating terminal
When there is a request to send a message from the terminal 1 to the terminal 3-3, the value of the counter 4a-3 is checked, and if the value is greater than or equal to a predetermined value, a signal indicating that the message cannot be received is returned in response to the sending/receiving request. , prevents messages from being accepted ().

Note that if the value is below the predetermined value, the message is accepted as usual and the operation to send it to the terminal 3-3 is performed.

This predetermined value is selected in advance at a value that is considered unlikely to cause abnormal network congestion during the busiest communication period, taking into account the processing capacity of each storage and forwarding center, the total number of terminals in the network, and the amount of communication. Ru.

In the above description, the case where the packet switching device 1a is the originating station and the packet switching device 1b is the terminating station has been described, but the same control is performed in the reverse case.

That is, the packet switching device 1a updates the values of the counters 4a-1 and 4a-2 each time a message is sent and received, and periodically reports this to the packet switching device 1b, and updates the values of the counters 4b-1 and 4b-2.
The packet switching device 1a described above updates the value of
As in the case of , message sending can be regulated.

As described in detail above, according to the present invention, it is possible for the originating station to grasp the messages accumulated at a desired destination station, so that message transmission can be restricted according to the amount of messages accumulated at a desired destination station. The store-and-forward network will not be brought into an abnormally congested state due to a terminal failure, etc., and the reliability and serviceability of the store-and-forward network will be significantly improved.

[Brief explanation of the drawing]

The figure is a control system diagram of an embodiment of the message transmission regulation system according to the present invention. 1a, 1b...Packet switching device, 2a, 2b
...Storage device, 3-1 to 3-4...Terminal, 4a-
1-4a-4, 4b-1-4b-4...Counter.

Claims (1)

[Scope of Claims] 1. Each store and forward station constituting a store and forward network is provided with a counter capable of recording accumulated messages for all terminals in the network, and the value of the counter is set in the store that accommodates the terminal. The information is updated based on periodic reports from the switching center, and each storage and switching center checks the value of the counter associated with the destination terminal each time it receives a message transmission request from the originating terminal. A message transmission regulation method is characterized in that it restricts the transmission of messages to terminals that are in use. 2. In what is stated in claim 1,
The counter utilizes the main memory of the store and forwarding center,
A message transmission regulation method in which an area corresponding to a terminal is provided, and the number of accumulated messages is recorded in the area corresponding to the terminal by software processing.