JPS6351586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for disconnecting calls from subscribers accommodated in the own network in a packet switching network.

Conventionally, when a packet switching network detects a disconnection request from a subscriber, it immediately generates a disconnection request packet, and each packet switch discards all previous data packets that had been accumulated due to flow control. The disconnection request packet was forwarded to the other exchange.

For this reason, if the transmitting terminal immediately requests disconnection after completing its own transmission without receiving a response from the other party, there is a high possibility that the transmitted data will be lost. In the case of data sent to a terminal, there was a drawback that data was definitely lost.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to erase all previously received data from the other party when a disconnection request is detected from a subscriber to the own network. By starting the packet call disconnection process with sufficient timing for the packet to arrive at the receiving terminal, the above drawbacks can be solved, eliminating the need for delivery confirmation at the subscriber level, and reducing the time between packet calls and the receiving exchange. To provide a new call disconnection method that simplifies the disconnection procedure between subscribers by eliminating the need for confirmation, and can guarantee the transmission of data even in packet calls with other packet networks. be.

The above object of the present invention is to provide a packet switching network with a delay generation circuit activated by a call disconnection request signal in an exchange, and when a disconnection request from a subscriber accommodated in the own network is detected, disconnection is performed toward the subscriber. A call disconnection method characterized in that the process proceeds and the disconnection process to the other party is started after the delay generation circuit has sufficient timing for all data from the subscriber to reach the other party's receiving terminal. , achieved by.

Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings and compared with a conventional example.

FIG. 1 is a block diagram showing an example of application of the present invention, and FIG. 2 is a diagram showing a conventional cutting sequence.

In FIG. 1, subscriber S1 belonging to exchange A
If data is being sent from subscriber S2 belonging to exchange B, exchange A
In the conventional method, when a disconnection request is detected from the server, the disconnection request is immediately issued as shown in Figure 2.
Exchange B is still transmitting data 2 and data DT
3 is waiting for the transmission to start at timing C. In this case, exchange B
Since DT3 is discarded and a disconnection procedure is immediately entered, data loss occurs between subscriber S1 and subscriber S2.

FIG. 3 is a block diagram showing an embodiment of a call disconnection method according to the present invention, and FIG. 4 is a diagram showing a disconnection sequence according to the present invention. In the present invention,
As shown in Figure 3, there is a subscriber S in the sending exchange A.
A delay generating circuit D activated by a call disconnection request signal from 1 is provided. The delay generation circuit D is
Specifically, for example, a determination circuit that is activated by a call disconnection signal and generates a timing signal by determining the time sufficient for all previously received data to reach the other party's receiving terminal; It is constituted by a plurality of timers predetermined in accordance with the transmission time, and a selection circuit such as a multiplexer that selects a timer corresponding to the data from among the plurality of timers by the discrimination circuit. .

In the method according to the present invention shown in FIGS. 3 and 4,
Subscriber S1 side is released as before, but subscriber S
The disconnection process in the direction from subscriber S1 to subscriber S2 is delayed by timing (Tt). Timing T is a guaranteed timing for the final data to arrive at the destination receiving terminal S2, and this timing is generated by the delay generating circuit D, thereby guaranteeing that all data will arrive at the destination receiving terminal. Further, the timing t is the timing from when the transmitting terminal completes sending the final data until it issues a disconnection request, and by taking this difference, invalidity pending is eliminated.

Specifically, the delay generation circuit D is activated by firmware incorporated in the central control unit of the exchange and counts the timing T. The firmware incorporated in the central control unit monitors this delay generation circuit D and determines the timing T for the call.
After confirming that the period has elapsed, a call disconnection signal is sent. A schematic flow of this firmware is shown in FIG.

Referring to FIG. 5, when this firmware is activated, it first determines a timer value in step 51 according to the type of call and the amount of data to be transmitted, and then in step 52.
Then, the timer value is set in the delay generation circuit D, and the identification number assigned to the corresponding call is received from the delay generation circuit D. Next, in step 53, it is determined whether or not counting has ended using the identification number, and if it has ended, a disconnection signal is transmitted in step 54.

As explained above, when a disconnection request from a subscriber accommodated in the own network is detected, the present invention immediately disconnects the terminal, while disconnecting to the other party with sufficient timing. By doing so, all data can be delivered to the other party without confirming delivery at the subscriber level or with other networks, while keeping the holding time of the line towards the subscriber of the own network short. It has the effect of

Although the present invention has been described above with reference to one preferred embodiment thereof, this is merely an example, and the present invention is not limited to the embodiment described herein, and there may be cases where it deviates from its scope. Various modifications and changes can be made without any problems. For example, in the present embodiment, the delay generation circuit D is configured of a discrimination circuit, a plurality of timers, and a selection circuit, but the present invention is not limited to this, and various other modifications can be easily made. Furthermore, when exchange B becomes a transmitting terminal, a delay generation circuit D is installed in exchange B.
Needless to say, it should be equipped with the following.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a connection in a normal packet network, FIG. 2 is a diagram showing an example of a call disconnection sequence according to the prior art, and FIG. 3 is a block diagram showing an example of a call disconnection method according to the present invention. FIG. 4 is a block diagram showing an example of a call disconnection sequence according to the present invention, and FIG. 5 is a schematic flowchart of firmware used in this system. S1, S2...general subscribers accommodated in the packet switching network, A, B...exchange stations in the packet switching network, C...time when DT3 is supposed to start transmitting,
D...Delay generation circuit, DT1, DT2, DT3...
Data packet sent from sender to receiver, T
... Guaranteed timing for sending data 3 to completion, t...
Timing from completion of transmission to disconnection request from the sending terminal.

Claims (1)

[Claims] 1. In a packet switching network that does not have a procedure for confirming the delivery of data packets other than flow control signals between the transmitting exchange and the receiving exchange, the transmitting exchange is provided with a delay generation circuit activated by a call disconnection request signal, and the transmission When the side exchange detects a call disconnection request, the call disconnection signal is sent from the transmitting side exchange to the receiving side exchange after the delay generation circuit takes a timing to guarantee the completion of transmission of the already transmitted data packet to the receiving side terminal. A call disconnection method in a packet switching network characterized by sending a call to a receiving exchange.