JPS62202633A - Call disconnection method in packet exchange network - Google Patents

Abstract

PURPOSE:To eliminate the need for the retrieval of a call memory at an incoming station by adding a call disconnect request packet to call identification information and sending the result to an incoming station after an incoming reception packet is received when a call disconnection requests comes before the end of call setting. CONSTITUTION:When a call disconnection request packet J is sent from a terminal equipment 1 before a call is confirmed between a call terminal equipment 1 and an incoming terminal equipment 3, an exchange processing section 6 identifies the call connection state from a call memory 7 a logic based on a logic channel number A1. Since the call setting is not finished, the call disconnection request packet J is preserved. In receiving an inter-station call setting request packet B, an incoming station 8 applies call setting processing and sends an incoming reception packet E to a call station 5. The call station 5 adds the incoming ink number set in the packet D and the call identification information including the outgoing link number of its own station to the call disconnection request packet J during preservation and sends the result to the incoming station 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a call disconnection method in a packet switching network that converts information into packet units as predetermined unit blocks, and in particular, the present invention relates to a call disconnection method in a packet switching network that converts information into packet units as predetermined unit blocks. The present invention relates to a call disconnection method in a packet switching network in response to a call disconnection request generated in an unconfirmed number state.

[Conventional technology]

FIG. 3 is a block diagram showing a conventionally commonly used packet switching network. In the figure, 1 is a calling terminal that issues a communication request, and 2 is a calling station connected to the calling terminal 1, which has a switching processing section 2a and a call memory 2b for holding the call status. ing. 3 is a called terminal that is a communication partner of the calling terminal l; 4 is a called station to which the called terminal 3 is connected; like the calling station 2, it maintains the call status with the exchange processing unit 4a. It is equipped with a call memory 4b. The called station 4 and the calling station 2 are connected to each other directly or via another station. The operation of the packet switching network with the above configuration will be explained below.

When the calling terminal 1 calls the called terminal 3 and transmits packets of information between the two, first the calling terminal l
is logical channel number AI and call setup request code A2
A call setup request packet A containing destination information such as ``A'' is transmitted to the calling station 2. When the calling station 2 receives the call setup request packet l-A, the switching processing unit 2a installed therein
Call memory 2b provided to hold call status
The received call setting request packet A is allocated to the call setting request packet A, and a calling link number A3 for identifying this call is added and stored. Note that the call memory 2b includes a storage area for the logical channel number AI specified by the calling terminal 1 and the above-mentioned calling link number A.

In addition to the storage area for , it has a storage area for the terminating link number A4 that will be supplied later from the called station 4.

Next, the exchange processing unit 2a identifies the called terminal 3 and the called station 4 that accommodates this called terminal 3 from the destination information specified by the call setup request bucket A supplied from the calling terminal 1. Then, it transmits an inter-office call setup request packet I-B to the identified called station 4.

This inter-office call setting request packet B includes, in addition to the above-described call setting request packet A2, the originating link number A3 and the terminating link number A4, the terminating station number Bl and the originating station number B2. However, the incoming link number A4 remains empty because it has not yet been sent from the called station 4.

On the other hand, when the switching processing unit 4a of the called station 4 receives the inter-office call setup request (Pakeso) B sent from the calling station 2, it identifies the called terminal 3 from the contents and sends it to the called station 4. and called terminal 3
Determine the logical channel number B3 to be used for communication with. Then, the exchange processing unit 4a allocates a call memory 4b for holding the state of the call, and stores the originating link number B4 for identifying the call in the allocated call memory 4b. Further, in this call memory 4b, the outgoing link number A3 included in the inter-office call setup request packet B sent from the calling station 2 is stored as the incoming link number B.

Next, the exchange processing unit 4a transmits an incoming call packet C including a logical channel number B3 and an incoming call code CI to the called terminal 3, thereby indicating that a connection request has arrived. Use to inform.

Here, if the called terminal 3 is ready to receive a call, the called terminal 3 sends a call acceptance packet D, which is a call acceptance code D1 including the call code C1 and a logical channel number B3, to the called terminal 3. We will notify you by transmitting to. The switching processing unit 4a of the called station 4 identifies the logical channel number B3 included in the received call acceptance packet D sent from the called terminal 3. Then, the outgoing link number B4 and the incoming link number B are read from the call memory 4b with which the identified logical channel number B3 matches, and the incoming call acceptance packet is added with the incoming station number B and the outgoing station number B2. It is transmitted together with D to the calling station 2 as an interoffice reception packet E.

When the calling station 2 receives the inter-office acceptance packet I-E, the calling station 2 stores the incoming call acceptance packet E in the incoming link number A4 of the call memory 2b that matches the outgoing link number A3 indicated by the incoming link number B5 included therein. The outgoing link number B4 sent by is stored as the incoming link number A4. When the storage of the outgoing link number is completed in this way, the exchange processing unit 2a transmits the connection completion packet I-F to the calling terminal 1, and the logical channel number AI included in this connection completion packet F is transmitted to the calling terminal 1. and connection completion code F.

to notify the completion of the connection. By executing such processing, a call is established between the calling terminal 11, the calling station 2, the called station 4, and the called terminal 3.

In this way, when the call setup is completed, the logical channel number A between calling terminal 1 and calling station 2 is
, is used as a call identifier and packets G, , G2 are used for transmission and reception. Also, between the calling station 2 and the called station 4, the calling station 2 sends a packet using the incoming link number A4 as a call identifier.
-H, and the called station 4 performs transmission and reception by transmitting a packet H, to the calling station 2 using the incoming link number B as an identifier. Further, transmission and reception is performed between the called station 4 and the called terminal 3 using Paquette It and Iz with the logical channel number B3 as an identifier.

Next, the normal procedure for disconnecting a call will be described for the case where the calling party disconnects the call. The calling terminal 1 as the call disconnection requesting party uses logical channel number A.

A call disconnection request bucket containing the call disconnection request bucket) J is sent to the calling station 2. When the calling station 2 receives this call disconnection request bucket) J, the calling station 2 receives the logical channel number A contained therein.

The call memory 2b storing the same logical channel number A is read out. Then, the outgoing link number A3 and the incoming link number A4 stored in the call memory 2b are extracted, and an inter-office call disconnection request bucket (K) is generated by adding the incoming station number BI + It station number B2 and the call disconnection request packet J. and transmits it to the called station 4. When the called station 4 receives this inter-office call disconnection request packet K, the switching processing unit 4
A reads the call memory 4b which stores the outgoing link number B4 which is the same as the incoming link number A4 included in the interoffice call disconnection request packet K. Then, the logical channel number B3 stored in the call memory 4b is extracted, a call disconnection instruction packet L is generated, and the packet L is transmitted to the called terminal 3. When the called terminal 3 receives this call disconnection instruction packet I-L, it disconnects the call and transmits a call disconnection confirmation packet M containing the logical channel number B to the called station 4. In the called station 4 that has received the call disconnection confirmation packet M, the switching processing unit 4a selects the logical channel number B3 included in the call disconnection confirmation packet M.
The call memory 4b that stores the logical channel number B, which is the same as that of The inter-office call disconnection confirmation packet l-N generated by adding B2 and the call disconnection confirmation packet M is transmitted to the calling station 2, and at the same time, the call memory 4b is released.

When the calling station 2 receives the inter-office call disconnection confirmation packet N, the switching processing unit 2a stores the same outgoing link number A as the incoming link number B included in the inter-office call disconnection confirmation packet N. The call memory 7a is read out. The logical channel number A1 stored in this call memory 7a
The call disconnection confirmation packet O generated by reading the call disconnection confirmation packet O is sent to the calling terminal 1, and the call memory 2b is released, thereby completing the normal disconnection of the call.

show.

Next, as shown in Figure 4, the calling terminal 1
When a call disconnection request packet J is generated, the call is disconnected according to the following procedure. First, when the calling station 2 receives the call disconnection request packet J, the switching processing unit 2a receives the logical channel number A included in the call disconnection request packet J.
An attempt is made to obtain the incoming link number A4 by reading the call memory 2b which stores the same logical ring channel number as I. However, at this point, the originating link number B4 has not yet been sent from the called station 4, so it is unknown. Therefore, the exchange processing unit 2a transmits the inter-office call disconnection request bucket (K) with the incoming link number A4 empty to the called station 4. Since the incoming link number A4 included in the inter-office call disconnection request packet/node K does not indicate anything, the switching processing unit 4a of the called station 4 scans its own call memory and determines the originating link number. The corresponding call memory 4b is obtained by searching the call memory having the incoming link number Bs that matches A. Then, by reading the contents of the call memory 4b determined by this search, the logical channel number B3 is extracted, a call disconnection instruction packet L-L is generated, and the generated call disconnection instruction packet L-L is transmitted to the called terminal 3.

When the called terminal 3 receives this call disconnection instruction bucket L, it disconnects the call and transmits a call disconnection confirmation bucket M containing the logical channel number B to the called station 4. Ear cut @
The called station 4 that received the confirmation bucket) M sends a message to the switching processing unit 4a.
reads the call memory 4b that stores the same logical channel number B3 as the logical channel number B3 included in the call disconnection confirmation packet node M, and reads the outgoing link number B, the incoming link number B, and the incoming link number B stored therein. The inter-office call disconnection confirmation bucket l-N generated by adding the destination station number B71, the originating station number B2, and the call disconnection confirmation packet M is transmitted to the calling station 2, and at the same time, the call memory 4b is released.

When the calling station 2 receives the inter-office call disconnection confirmation packet N, the switching processing unit 2a stores the outgoing link number A, which is the same as the incoming link number B5 included in this inter-office call disconnection confirmation packet N. The call memory 7a is read out. The logical channel number A stored in this call memory 7a,
The call disconnection confirmation packet 0 generated by reading is sent to the calling terminal 1, and the call memory 2b is released, thereby completing the call disconnection.

[Problem that the invention seeks to solve]

Since conventional packet switching networks are configured as described above, the calling station's calling link number is stored in the call memory of the calling station only when the call setup between the calling terminal and the called terminal is completed. Stored as the incoming link number. For this,
During call setup, when a call disconnection request is issued from a calling terminal, even if the calling station reads its own call memory, it cannot know the originating link number of the called station. Therefore,
The calling station will transmit an interoffice call disconnection request packet with the terminating link number in an empty state to the called station. As a result, the called station searches the call memory that has the called link number that matches the calling link number included in the inter-office call disconnection request packet, reads the logical channel number stored therein, and outputs the logical channel number stored therein. A call disconnection instruction packet to be transmitted to the floor terminal 3 must be generated. Therefore, there is a problem in that the processing load required for the switching processing section of the called station to scan the call memory and read out the logical channel number becomes extremely large.

This invention was made to solve the above-mentioned problems.If the calling terminal issues a disconnection request before the call between the calling terminal and the called terminal is set up, the It is an object of the present invention to provide a call disconnection method in a packet switching network in which the processing required for a switching processing unit of a station to obtain a logical channel number for a called terminal to be disconnected is greatly reduced.

[Means for solving problems]

A call disconnection method in a packet switching network according to the present invention includes:
When the calling station receives a call disconnection request packet sent from the calling terminal, it determines the contents of the call memory that stores call identification information for the calling terminal, and determines whether this call identification information is one of the call identification information. If the call terminating link number is not determined, it is assumed that the call setup between the calling terminals is not completed, and transmission of the call disconnection request packet to the called station is deferred, and the calling terminal transmits the call to the called terminal. When an incoming call acceptance packet sent through a station is received, the originating link number of the called station set in this incoming call acceptance packet is set as the incoming link number, and this incoming link number and the own station's originating link number are set. The call is disconnected by adding the pending call disconnection request packet to the call identification information including the originating link number and transmitting it to the called station, and transmitting a call disconnection confirmation packet to the calling terminal. be.

Additionally, if the arrival of the call acceptance request sent from the called terminal to the calling station via the called station is delayed for more than a set time, a call disconnection confirmation packet is issued instead of the pending call disconnection request packet. It is sent to the call terminal. In addition, if the packet sent from the called station is a packet other than call setup and call disconnection that has call identification information that does not exist in the calling station, the calling station uses the call identification information contained in this packet. A call disconnection request packet having call identification information in which the originating link number is replaced with the terminating link number and the terminating link number is replaced with the originating link number is generated and transmitted to the called station.

[For production]

In the call disconnection method in a packet-switched network according to the present invention, when a calling station receives a call disconnection request packet sent from a calling terminal before the call setup is completed, it stores call identification information for the calling terminal. The call setup status is determined by determining the contents of the call memory, that is, by determining whether the incoming link number as one of the call identification information has been determined, and if the call setup has not yet been completed, the called station Since the calling station uses the calling link number included in the incoming call acceptance packet sent from the incoming call acceptance packet as the incoming link number and transmits the pending call disconnection request packet to the called station, the called station uses its own call memory. There is no need to search and determine the corresponding called terminal,
Accordingly, the processing required for the called station to obtain the ethical channel number for the called terminal to be disconnected is greatly reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, reference numeral 5 denotes a calling station to which the calling terminal 1 is connected, serving as a first packet switching means.

This calling station 5 has an exchange processing unit 6 and a call memory 7, and this call memory 7 stores the calling link number Aff+
Incoming link number A4. It has an area for storing logical channel number AI, call status A, and call disconnection request flag A6. Reference numeral 8 denotes a called station as a second packet switching means that accommodates the called terminal 3. This called station 8 has an exchange processing section 9 and a call memory 10, and this call memory 10 has an area for storing an originating link number B4+, an incoming link number B, and a logical channel number B3. .

In the packet switching network configured in this way, the calling station 1
When transmitting information in packets between the calling station 3 and the called station 3, the calling station 1 first sends a call setup request packet l-A containing destination information such as logical channel number A+ and call setup request code A2. It is transmitted to the calling station 5. When the calling station 5 receives the call setup request bucket (A) sent from the calling terminal l, the switching processing unit 6 acquires the call memory 7 and stores the call setup request and the calling link number Az determined by the calling station. The logical channel number AI specified by packet A and the call status A indicating the connection state of the call are stored.

However, at this point, the incoming link number A4 is undetermined. In addition, the exchange processing unit 6 (call setting request bucket)
Called number B11 Called link number A4 + Called station number B
An inter-office call setup request packet B to which call identification information between the calling station and the calling station 8 is added is sent to the calling station 8, which is made up of the calling station 8 and the sending link number A3.

Here, if the calling terminal l issues a call disconnection request before the call setup is completed, the logical channel number A, the call disconnection request code J,
A call disconnection request packet J consisting of the following is transmitted to the calling station 5.

When the calling station 5 receives the call disconnection request code J1, the switching processing unit 6 stores the call memory 7 which stores the same logical channel number as the logical channel number A included in the call disconnection request code J1. The call connection state is identified by reading out the determined contents of the call memory 7. However, at this point, since the call setup is not yet completed and the incoming link number has not yet been determined, the call disconnection request plug A6 is set and the call disconnection request packet J is put on hold.

On the other hand, in the called station 8, which received the inter-office call setup request bucket) B sent from the calling station 4, the switching processing unit 9 acquires a vacant call memory 10, and the station decides It stores the incoming link number B determined according to the outgoing link number A included in the interoffice call setup request packet B of the outgoing link number B4, and the logical channel number B3 determined by the own station. In addition, this exchange processing unit 9 sends a call packet C including a logical channel number B3 and a call packet CI to the called terminal 3.
By transmitting this, the logical channel number B3 is used to notify that a connection request has arrived.

Here, if the called terminal 3 has completed preparations for receiving the call, it sends the called reception packet D, in which the call reception code C1 is added to the call reception code D1 and the logical channel number B3, to the called station 8. Notification by transmission. The switching unit 9 of the called station 8 identifies the logical channel number B3 included in the called reception bucket I-D sent from the called terminal 3.

Then, the outgoing link number B4 and the incoming link number B are read out from the call memory 10 with which the identified logical channel number B3 matches, and the incoming call acceptance packet is added with the incoming station number B and the outgoing station number B2. It is transmitted together with D to the calling station 5 as an interoffice reception packet E.

When the calling station 2 receives the inter-office acceptance packet E, the calling station 2 transfers the incoming link number A4 of the call memory 7 to the incoming link number A4, which matches the outgoing link number A3 indicated by the incoming link number B included therein, using the incoming call acceptance packet E. Outgoing link number B sent to you
Store 4. Furthermore, the switching processing unit 6 of the calling station 5 learns that the call disconnection request packet J is on hold by determining the contents of the call disconnection request flag A6 stored in the call memory 7. In this way, when the exchange processing unit 6 confirms that the call disconnection request bucket) J is on hold, the outgoing link number A3゜incoming link number A3゜incoming link number stored in the call memory 7
4, and enter the incoming station number Bl1 and the originating station number B2.
and an inter-office call disconnection request packet (to which the call disconnection request packet J is added) K is generated and transmitted to the called station 8, and after transmitting a call disconnection request packet Q containing the logical channel number A to the called terminal. Free the call memory 7.

On the other hand, in the called station 8 which received the inter-office call disconnection request packet K, the switching processing unit 9 identifies the corresponding call memory 10 based on the incoming link number A4 included in the inter-office call disconnection request packet K, Logical channel number B3 and call disconnection instruction code L
, a call disconnection request bucket) L is transmitted to the called terminal 3. The called terminal 3 that has received the call disconnection instruction packet L transmits a call disconnection confirmation packet M consisting of a logical channel number B3 and a call disconnection confirmation code M1 to the called station 8 in response. The called station 8, which has received the call disconnection confirmation packet M, completes the call disconnection by releasing the call memory 10 corresponding to the logical channel number B3 included in the call disconnection confirmation packet M.

FIG. 2 is a block diagram for explaining another embodiment of the call disconnection method in a packet switching network according to the present invention. In the figure, reference numeral 11 denotes a timer monitoring section provided in the calling station 5, and by connecting it to the exchange processing section 6, detects that the inter-office reception packet E cannot be received within a certain period of time.

In the packet switching network configured in this way, the called station 8
If the inter-office acceptance packet E transmitted from to the calling station 5 disappears for some reason, the timer monitoring unit 11 provided in the calling station 5 receives the inter-office acceptance packet E within a certain period of time. It is detected that the exchange processing unit 6 cannot be used, and the exchange processing unit 6 is notified. Upon receiving the notification from the timer monitoring unit 11, the exchange processing unit 6 generates a call disconnection confirmation packet l-Q consisting of a call disconnection confirmation code M1 and a logical channel number A1, supplies it to the calling terminal l, and stores it in the call memory. Release 7.

On the other hand, since the called terminal 3 has already set up a call, it uses the logical channel number B3 and the data code (including data).
A data packet P consisting of P is transmitted to the called station 8.

When the called station 8 receives the data packet P, since the call has already been set up, the switching unit 9 sends the call identification information, which is the originating link number B4 + the incoming link number B61, the called station number BI + the originating station number. B2 is added to the incoming call acceptance packet D and the result is transmitted to the calling station 5 as an interoffice data code)Q. The calling station 5 which received the inter-office data packet Q,
Since the exchange processing unit 6 has already released the call memory 10 that has information that matches the identification information of the call, the calling station number B2 of the inter-office data bucket Q that was just received is set as the receiving station number B.
, the incoming link number B is set to the outgoing link number B4, the station number B is set to the outgoing link number B4, the outgoing link number B is set to the incoming link number B, and the replaced call identification information and new information within the own station are set. An inter-office call disconnection request packet R consisting of the generated inter-office data packet Q is transmitted to the called station 8.

On the other hand, in the called station 8 which has received the inter-office call disconnection request packet R, the switching processing unit 9 identifies the corresponding call memory 10 based on the incoming link number Bs included in the inter-office call disconnection request packet R, and Channel number B, call disconnection instruction code L
, the called terminal 3 receives the call disconnection request bucket L-L consisting of the logical channel number B and the call disconnection confirmation bucket L-L consisting of the call disconnection confirmation code M1 to the called station 8 in response. do. The called station 8, which has received the call disconnection confirmation packet M, completes the call disconnection by releasing the call memory 10 corresponding to the logical channel numbers B and 1 included in the call disconnection confirmation packet M.

〔Effect of the invention〕

As described above, according to the present invention, when a calling station receives a call disconnection request packet sent from a calling terminal, it determines the contents of the call memory storing call identification information from the calling terminal. However, if the incoming link number, which is one of the call identification information, is not determined, it is assumed that the call setup between the calling and receiving terminals is not completed, and the transmission of the call disconnection request packet to the called station is suspended. When receiving an incoming call acceptance packet sent from the calling terminal via the called station, the outgoing link number of the called station set in this incoming call acceptance packet is set as the incoming link number, and , transmits the pending call disconnection request packet to the call identification information including the incoming link number and the outgoing link number of the own station to the called station, and sends a call disconnection confirmation packet to the calling terminal. The call is then transmitted and the call is disconnected. Additionally, if the arrival of the call acceptance packet sent from the called terminal via the called station is delayed for more than a set time, the calling station sends a call disconnection confirmation request packet in place of the pending call disconnection request packet. The call is disconnected by sending the message to the calling terminal. In addition, if the packet sent from the called station is a packet other than call setup and call disconnection that has call identification information that does not exist in the calling station, the calling station uses the call identification information contained in this packet. The call is disconnected by replacing the originating link number with the terminating link number and replacing the terminating link number with the originating link number, generating a call disconnection request packet with call identification information and transmitting it to the called station. . Therefore, even if the calling terminal sends a call disconnection request packet without establishing a call between the calling terminal and the called terminal, the called station searches the call memory provided within its own station as before. This eliminates the need for the step of obtaining a logical channel number for the called terminal that is the target of call disconnection, and this has the effect of significantly reducing the processing at the called station.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a call disconnection method in a packet switching network according to an embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment, and FIGS. FIG. 2 is a block diagram for explaining a call disconnection method. 1 is a calling terminal, 3 is a called terminal, 5 is a calling station, 6.9 is a switching processing unit, 7.10 is a call memory, 8 is a called station, and 11 is a timer monitoring unit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. (2 others) -

Claims (3)

[Claims] (1) A calling terminal and a called terminal that can perform data communication for each unit of data called a packet, a calling station that accommodates the calling terminal, and a calling station that accommodates the called terminal and directly or another station. and a called station connected to the calling station via the calling station, and the called station assigns an originating link number assigned by the calling station during execution of a call setup sequence between the calling and receiving terminals. The outgoing link numbers are exchanged between the two stations to become the outgoing link number and incoming link number of the other station, and the call identification information including this incoming link number and the outgoing link number within the own station is stored in the call memory within the own station. In a packet switching network, when the calling station receives a call disconnection request packet sent from the calling terminal, it The content of the call memory that stores call identification information for the call terminal is determined, and if the preferred link number, which is one of the call identification information, has not been determined, the call setup between the calling and receiving terminals is incomplete. If the call disconnection request packet is suspended from being transmitted to the called station, and an incoming call acceptance packet sent from the calling terminal via the called station is received, the call acceptance packet is The set originating link number of the called station is set as the incoming link number, and the pending call disconnection request packet is added to the call identification information including this incoming link number and the originating link number of the own station. A call disconnection method in a packet switching network, characterized in that the call is disconnected by transmitting a call disconnection confirmation packet to a called station and to the calling terminal. (2) If the arrival of the call acceptance packet sent from the called terminal via the called station is delayed for more than the set time, the calling station sends a call disconnection confirmation packet in place of the pending call disconnection request packet. 2. A call disconnection method in a packet switching network according to claim 1, wherein the call disconnection method is transmitted to a calling terminal. (3) If the packet sent from the called station is a packet other than call setup and call disconnection that has call identification information that does not exist in the calling station, the calling station uses the call identification information contained in this packet as A call disconnection request packet having call identification information with the originating link number replaced with the terminating link number and the terminating link number replaced with the originating link number is generated and transmitted to the called station. A method for disconnecting a call in a packet switching network according to item 1.