JPH02186743A - Call resetting system in packet exchange - Google Patents

Abstract

PURPOSE:To shorten a delay time following an operation which is to set a totally new cell even if the call is disconnected and to retraensmit data by resetting the call only between packet exchanges where a fault has occurred at the time of the fault of a line. CONSTITUTION:A call identifier and a terminating-side device number are previously given to the network utility part of a connection complement packet 3. The fault of the line has occurred between the packet exchanges PS2 and PS4, and data (6) is transmitted from an originating terminal PT 1 to a transmitting terminal PT 2 till sequence number (1, 0). Then, the call resetting is executed between the PS2 and the PS-4, and the alternative route PS2-PS3-PS-4 is set. The call identifier, the terminating-side device number, the transmission packet sequence number (1) and the reception packet sequence number (0), all of which are made communication, are inputted to the network utility part of the call request packets 1 and 3 for resetting the call, and data (7) can be transmitted from PS2 by the sequence number (0, 2).

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a call reconfiguration method in packet switching.

[Conventional technology]

Conventionally, in packet switching equipment, if a call is terminated midway through, the call is set up again from the beginning and the data is retransmitted.

[Problem to be solved by the invention]

In the conventional method described above, if a line failure occurs, the call is disconnected, a completely new call is set up, and the data is retransmitted. This increases the number of call disconnection and call setup procedures, increases delay time, and reduces content. Since the exchange is not involved in the retransmission of the same data, there is a problem in that it is unclear how far the data has been sent or where to start retransmitting it.

[Means to solve the problem]

The call reconfiguration method in packet switching of the present invention has a function of setting a call identification number, which can recognize a packet-switched call, as a utility in a call setup packet, and a function of setting a call identification number that can recognize a packet-switched call as a utility in a call setup packet. Equipped with a function to set the call identifier, destination equipment number, and packet sequence number assigned to the packet before call reconfiguration as a utility when reconfiguring the call, and to prevent line failures in the network during communication. In this configuration, a call is re-established between some stations where a line failure has occurred, without notifying subscribers accommodated in the network that the call has been terminated.

[Effect]

In the call resetting method in packet switching of the present invention, a call resetting information utility is included in the connection completion packet in advance, and a destination device number and a call identifier are added. If communication becomes impossible due to a line failure between stations, a detour route is determined in advance and the call is reconnected only between the stations.
Set the destination device number, call identifier, transmission packet sequence number, and reception packet sequence number that were communicated in the network utility section of the call request packet and connection completion packet, and transmit the data from the continuation based on these information. do.

〔Example〕

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

Referring to FIG. 1, FIG. 2, and FIG. 3 showing an embodiment of the present invention, the packet switch (switching center) PSl that received the call request packet 1 from the X.25 line transfers this packet to the packet switch PS2.゜When sending to PS4, a call identifier must be added. This call identifier and destination device number are given in advance to the network utility section of the connection completion packet 3. Usually a packet switch
While data was being transmitted along the route S1-PS2-PS4, a line failure occurred between the packet switches PS2 and PSJ, and data (6) was not sent from the originating terminal PTI to the terminating terminal PT2 until sequence number (10). It is being Therefore, the call is reconfigured between the packet switches PS2 and PSJ, and a predetermined detour route is established between PS2 and PS3.
Set. The call identifier 1M side equipment number, transmission packet sequence number (1), and reception packet sequence number (0) that have been communicated so far are sent to the network utility section of the call request packet 1 and connection completion packet 3 of this call resetting. In addition, with this information, data (7) can be sent from the packet switch PS2 with sequence number (2, O>. In FIG. 1, 2 is an incoming call packet, 4 is an incoming call acceptance packet, 5, 6.7 and 8.9 were sent respectively.

Received packet sequence number (0, O), (1°0),
This is data of (2, O), (3, O), (4, 0>).

Also, in the call reconfiguration information utility shown in FIGS. 2 and 3, octet 0 is the parameter length.

〔Effect of the invention〕

As explained above, according to the present invention, when a line failure occurs, the call is re-established only between the packet switching centers where the failure has occurred, so that even if the call is disconnected, a completely new call is established and data is retransmitted. The delay time associated with this can be reduced. Also,
Since the switching center handles everything, normal communication can continue between terminals.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an operation sequence in one embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing a call resetting information utility of a packet in the same embodiment.

Claims (1)

[Claims] A function to set a call identifier and a destination device number that can recognize a packet-switched call as a utility in a call setup packet, and a function to set a call identifier and a destination device number when resetting a call between some stations in a network. Equipped with a function to set the number and the packet sequence number assigned to the packet before call resetting as a utility, even if a line failure occurs in the network during communication, the subscriber accommodated in the network A call resetting method in packet switching characterized by resetting a call between some stations where a line failure has occurred without notifying that the call has been terminated.