JP2558018B2 - Receiving method in ISDN network waiting for retry - Google Patents

Description

Detailed Description of the Invention

(Table of Contents) Industrial Application Field of the Prior Art (FIG. 5) Problem to be Solved by the Invention Means for Solving the Problem (FIG. 1) Operation Example (a) Description of One Example (FIG. 2) To FIG. 4) (b) Description of another embodiment Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN network call waiting method for accepting an incoming call from an opposite station while waiting for a retry of an outgoing call operation in an apparatus for performing communication using an ISDN network. .

As a switched line that can be used for data communication, a plurality of switched line services are provided, one of which is the ISDN network switching service.

In a communication device using the exchange service, when a communication request is generated, the exchange service is used to connect to an opposite station with which communication is to be performed and perform communication.

When communication is performed using this exchange service, the time (connection time) from the generation of a communication request to the time when communication becomes possible is greatly related to the response of the entire system. Shortening is required.

[0006]

2. Description of the Related Art FIG. 5 is an explanatory diagram of a conventional technique. Figure 5
As shown in (A), one station (IS
DN network control device) 1a is another station (ISDN network control device)
In order to communicate with 1b, one station 1a responds to the connection request.
It is necessary to set up a call from the other station 1b via the ISDN network 2 to notify the other station 1b of the call setup message, and obtain a response from the other station 1b via the ISDN network 2.

When using this exchange service, even if a connection is requested to the network 2, the connection may be unsuccessful due to congestion of the network 2 or the like. Therefore, as shown in FIG. After waiting for a certain period of time, the call is retried.

The ISDN network control device 1a receives a calling operation request from an external device. ISDN network control device 1a
Performs a calling operation to the network 2 and waits for a response from the network 2. When the response from the network 2 is received and the result is successful connection, the external device is notified that the connection is completed, the transmission operation is terminated, and communication becomes possible. If the connection is unsuccessful, the predetermined number of retries is compared with the current number of retries, and if the current number of retries is equal to or more than the set number, the external device is notified of the call failure and the process is terminated.

On the other hand, if the number of retries is less than the set number of times, the process returns to the step after the retry waiting time has elapsed, and the call is retransmitted. As described above, conventionally, even if an incoming call is received while waiting for a retry between outgoing calls, the incoming call is ignored in order to prevent the originally requested station from connecting to another station. .

[0010]

However, the prior art has the following problems. Since it rejects incoming calls from the connection-requested station (connecting opposite station), it does not connect even though it can connect to the connecting opposite station, and misses the opportunity to connect, making early connection difficult. Met.

When the incoming call from the connected opposite station is rejected, the connected opposite station also goes into a retry waiting state. As a result, even if the calling side makes a call after the retry waiting time elapses, the connected opposite station is in a retry waiting state. The connection is rejected, and the device enters the retry waiting state again.

Further, even if the connected opposite station makes a transmission operation after the retry waiting time has elapsed, the same situation occurs, and a deadlock state occurs in which connection cannot be established until either one stops the retry operation. To avoid this, even if the number of retries is limited, the connection is not completed and the connection takes time until the number of retries reaches the limited number. Further, if the transmission operation is restricted to be performed in only one direction, the operation of the system becomes one-way, which is not preferable. Therefore, an object of the present invention is to provide an incoming call method in a retry waiting state of an ISDN network that enables early connection.

[0013]

FIG. 1 is a diagram illustrating the principle of the present invention. Claim 1 of the present invention is connected to the ISDN network 2,
Receives a connection request, performs a transmission operation, and connects with the opposite connection station
Network control is performed to connect via the N network 2, and the ISDN network 2
The ISDN network control device, which receives the incoming notification from the terminal, performs the incoming call operation, and redispatches when the connection with the opposite station becomes unsuccessful during the outgoing call operation
In the case where a call is received while the caller identification information is included in the transmission information sent from the caller side to the callee side by the circuit switching operation of the N network 2 and a retry is waited between the call origination,
It is characterized in that the transmitting station identification information included in the received transmission information is compared with the opposite station information which is transmitted after the waiting for retry has been performed, and the reception is performed when the both information match.

According to claim 2 of the present invention, in claim 1,
The transmission information is a call setup message, and the calling station's own station number is entered in the calling number information element in the call setup message.

[0015]

According to the first aspect of the present invention, when the call is originated, the caller identification information is included in the transfer information sent from the caller to the callee by the circuit switching operation of the ISDN network 2. The calling station can be identified. Then, when an incoming call is received during the retry wait between outgoing calls, the sending station identification information included in the received transmission information is compared with the opposite station information that is sent after the retry wait time, and both Since the incoming call is made by matching the information, even if the incoming call from the connected opposite station is received while waiting for the retry, this can be identified, the incoming call is permitted, the early connection is enabled, and the deadlock state is set. Can be prevented. According to the second aspect of the present invention, since the caller's own station number is included in the calling number information element in the call setting message, it can be easily realized without changing the protocol of the ISDN network.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (a) Description of One Embodiment FIG. 2 is a block diagram for one embodiment of the present invention.
In the figure, the same components as those shown in FIGS. 1 and 5 are designated by the same symbols, and 10 is a processor (MPU), which performs a transmission operation described later in FIG. 3 according to a connection request. According to an incoming call notification, an incoming call operation is performed by executing a program, 11 is a RAM (random access memory) for storing data necessary for the operation of the processor 10 such as connected opposite station information, and 12 is a ROM ( Read only memory) for storing programs, parameters, etc. for the operation of the processor 10,
Reference numeral 13 is a frame synchronization circuit, which assembles and disassembles frame signals, and 14 is a driver / receiver (DV).
/ RV), which sends a signal on the line and receives a signal on the line.

FIG. 3 is a flow chart of the transmission processing of one embodiment of the present invention, and FIG. 4 is an explanatory diagram of the ISDN protocol of one embodiment of the present invention. The processor 10 receives a transmission operation request from an external device. The processor 10 sends a call to the network 2 and waits for a response from the network 2. At this time, as the calling station identification information to be inserted into the calling information, the calling number information in the call setup (SETUP) message shown in FIG. 4A of the network control indication of the ISDN network recommended by the CCITT Recommendation I series. Figure 4
The own station number is set as the originating station identification information in the octet 4 in the calling party number information element shown in (B), and transmitted to the network 2.

Then, when a response from the network 2 is received and the result is that the connection is successful, the external device is notified that the connection is completed, the transmission operation is terminated, and communication becomes possible. If the connection is unsuccessful, the predetermined number of retries is compared with the current number of retries, and if the current number of retries is equal to or more than the set number, the external device is notified of the call failure and the process is terminated. On the other hand, when the number of retries is less than the set number of times, the retry waiting process shown in FIG. 3B is performed and the process returns to the step.

Next, the process during waiting for retry will be described with reference to FIG.
This will be described with reference to (B). The processor 10 determines whether there is an incoming call. If there is no incoming call, processor 10
Checks whether or not a predetermined retry waiting time has elapsed. If the retry waiting time has not elapsed, the process returns to the step, and if the retry waiting time has elapsed, the process shown in FIG. Return to step.

On the other hand, when there is an incoming call, the processor 10 extracts the calling station identification information from the calling number information element in the call setting message in the incoming signal, and after the elapse of the retry waiting time held in the RAM 11, the processor 10 itself. By comparing with the information of the opposite station (hereinafter referred to as the originating opposite station) that originates from the station, it is judged whether or not the station that issued the incoming request is the opposite station that originates from the own station after the retry waiting time elapses. If it is not an incoming call from the station, proceed to step and ignore the incoming call.

On the other hand, when the incoming call is from the originating opposite station, the processor 10 makes an incoming call response to the ISDN network 2 and waits for a response from the ISDN network 2. The processor 10 receives the response from the ISDN network 2, and if the content is the connection completion, it notifies the external device of the connection completion, ends the processing, and if the connection is unsuccessful, returns to the step.

In this way, it is determined whether or not there is an incoming call during the retry standby, and if there is an incoming call, it is determined whether the station that issued the incoming call request is the opposite station that sends from its own station after the retry standby time has elapsed. If the incoming call is not from the outgoing opposite station, the incoming call is ignored, and if the incoming call is from the outgoing opposite station, the connection is established. Therefore, early connection is possible, and deadlock in the retry state can be prevented.

(B) Description of Other Embodiments In addition to the above embodiments, the present invention can be modified as follows. Although the calling station identification information is included in the calling number information element in the call setup message, it may be included in other information elements. As the external device of the ISDN network control device, a terminal device or a host computer can be used.

The present invention has been described above with reference to the embodiments.
Various modifications are possible within the scope of the invention, and these modifications are not excluded from the scope of the invention.

[0025]

As described above, according to the present invention,
The following effects are obtained. At the time of calling, since the calling station identification information was included in the transmission information sent from the calling side to the called side by the circuit switching operation of the ISDN network 2, the called side,
When the caller can be identified and the call is received while waiting for a retry between calls, the caller identification information included in the received transmission information and the information of the opposite station that will make a call after the retry wait has passed. By comparing and matching the two information, the incoming call is made, so even if the incoming call from the connected opposite station is received during the retry standby, this can be identified, the incoming call is permitted, and early connection is possible. .

Since the incoming call from the connected opposite station in the retry standby state is accepted, the deadlock state can be prevented and the quick connection can be realized.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a block diagram for one embodiment of the present invention.

FIG. 3 is a flow chart of a transmission process according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of an ISDN protocol according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1 ISDN network controller 2 ISDN network 10 processor

Claims (2)

(57) [Claims] 1. Connected to an ISDN network (2), receiving a connection request, performing a calling operation, and performing network control so as to connect to an opposite connection station via the ISDN network (2), and from the ISDN network (2). The ISDN network control device, which receives the incoming call notification and performs the incoming call operation, and retransmits when the connection with the opposite station becomes unsuccessful during the outgoing call operation, is performed by the circuit switching operation of the ISDN network (2) at the time of outgoing call. In the transmission information sent from the caller to the callee, the caller identification information is included in the call, and when a call is received while waiting for a retry between calls, the call is included in the call transfer information that was received. A method of receiving an incoming call in a retry waiting state of an ISDN network, characterized in that station identification information is compared with information of an opposite station that makes a call after waiting for a retry and the information is matched to make an incoming call. 2. The ISD according to claim 1, wherein the transmission information is a call setup message, and the calling party's own number is included in the calling number information element in the call setup message.
An incoming call method in a retry waiting state of the N network.