JPH04291555A - Call reception method in retrial wait state for isdn network - Google Patents

Abstract

PURPOSE:To attain early connection by including oscillation station identification information into transmission information sent from a caller side to a called side, sending the resulting information, allowing the called side to compare the information with opposite station information after lapse of retrial waiting time and receiving the call through the coincidence of both the information sets. CONSTITUTION:A network controller 1 receives a call operation request from an external device and sends it to an ISD network 2. In this case, a caller number information element is used for caller station information inserted into the caller information and its own station number is set to an octet 4 in the element. When a reply is received from the network 2 and the result indicates successful connection, a connection with the external side is notified to make the communication possible. When the connection is not successful, a prescribed retrial number and a current retrial number are compared and when the retrial number is a set number of times or over, a transmission fault is noticed. On the other hand, when a call is received during retrial waiting, the controller 1 extracts the caller station identification information and compares it with the information of an opposite station sent from its own station and gives incoming call reply to the network 2 when the call comes from the opposite station.

Description

[Detailed description of the invention]

(Table of Contents) Industrial Application Fields Prior Art (FIG. 5) Problems to be Solved by the Invention Means for Solving Problems (FIG. 1) Working Example (a) Description of One Embodiment (FIG. 2) 4) (b) Description of other embodiments Effects of the invention

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving a call while an ISDN network is waiting for a retry, for receiving an incoming call from an opposite station while waiting for a retry of a calling operation in a device that communicates using an ISDN network. .

[0003] A plurality of switched line services are provided as switched lines usable for data communication, one of which is the switched service of the ISDN network.

[0004] In a communication device that uses an exchange service, when a communication request is generated, the communication device uses the exchange service to connect with the opposite station with which to communicate, and performs communication.

[0005] When communicating using this exchange service, the time from when a communication request is generated to when communication becomes possible (connection time) greatly affects the response of the entire system. Shortening is required.

[0006]

2. Description of the Related Art FIG. 5 is an explanatory diagram of the prior art. Figure 5 (
As shown in A), one station (ISD
N network control device) 1a is another station (ISDN network control device) 1
In order to communicate with B, one station 1a sets up a call in response to a connection request, sends a call setup message to the other station 1b via the ISDN network 2, and then connects the ISDN network 2 from the other station 1b to the other station 1b. Need to get a response through.

[0007] When using this exchange service, even if a connection is requested to network 2, the connection may end in failure due to congestion in network 2. Therefore, as shown in FIG. 5(B), After waiting for a certain period of time, the call is made again (retry).

[0008] ISDN network control device 1a receives a calling operation request from an external device. ■ISDN network control device 1a
performs a calling operation to network 2 and waits for a response from network 2. If a response is received from the network 2 and the result is a successful connection, the external device is notified that the connection has been completed, the calling operation is completed, 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 greater than the set number, the external device is notified of the call failure and the process ends.

On the other hand, if the number of retries is less than the set number, after the retry waiting time has elapsed, the process returns to step (2) and the call is made again. In this way, conventionally, even if an incoming call was received while waiting for a retry between outgoing calls, the incoming call was ignored to prevent the originally requested station from being connected to a different station. .

0010

[Problems to be Solved by the Invention] However, the prior art has the following problems. ■Incoming calls from the station that has requested a connection (the opposite station to connect to) are also rejected, so even if it is possible to connect to the opposite station, the connection is not made, resulting in a missed connection opportunity and an early connection failure. It was difficult.

[0011] ■When an incoming call from the connected opposite station is rejected, the connected opposite station also enters the retry standby state, and as a result, even if the calling side makes a call after the retry standby time has elapsed, the connected opposite station is in the retry standby state. , the connection is refused and the system is placed in a retry waiting state.

[0012] Furthermore, even if the connected opposite station performs a calling operation after the retry waiting time has elapsed, a similar situation occurs, and a deadlock state occurs in which connection is not possible until one of the stations stops the retry operation. To avoid this, even if the number of retries is limited, the connection will not be completed until the number of retries reaches the limit, and the connection will take time. Furthermore, if the transmission operation is limited to only one direction, the system will operate in one direction, which is not preferable. Therefore, it is an object of the present invention to provide a method for terminating a call in a retry waiting state in an ISDN network, which enables early connection.

[0013]

[Means for Solving the Problems] FIG. 1 is a diagram showing the principle of the present invention. Claim 1 of the present invention is connected to an ISDN network 2,
Upon receiving a connection request, it performs a calling operation and communicates with the opposite connection station and ISD.
Network control is performed to connect via N network 2, and ISDN network 2
In the ISDN network control equipment that receives a notification of incoming call, performs the incoming call operation, and re-originates if the connection with the opposite station fails during the outgoing operation, the ISD
When the transmission information sent from the calling side to the called side by the circuit switching operation of the N network 2 includes the calling station identification information, and an incoming call is received while waiting for a retry between the calls,
The present invention is characterized in that the calling station identification information included in the received transmission information is compared with the information of the opposing station that makes the call after a retry standby period has elapsed, and if the two pieces of information match, the call is received.

[0014] Claim 2 of the present invention provides the following in claim 1:
The transmission information is a call setup message, and is characterized in that the caller's own station number is included in the calling number information element in the call setup message.

[0015]

[Operation] According to claim 1 of the present invention, when making a call, the transmission information sent from the calling side to the called side by the circuit switching operation of the ISDN network 2 includes the calling station identification information, so that the called side can: The originating station can be identified. Then, when an incoming call is received during retry standby between outgoing calls, the calling station identification information included in the received transmission information is compared with the information of the opposing station that will make the outgoing call after the retry standby has elapsed. Since the call is received based on information matching, even if a call is received from the connected opposite station while waiting for a retry, this can be identified.
It is possible to allow incoming calls, enable early connection, and prevent deadlock situations. In claim 2 of the present invention, since the calling party's own station number is included in the calling number information element in the call setup message, it can be easily implemented without changing the protocol of the ISDN network.

[0016]

Embodiment (a) Description of one embodiment FIG. 2 is a block diagram for one embodiment of the present invention. In the figure, the same parts as those shown in FIGS. 1 and 5 are indicated by the same symbols, and 10 is a processor (MPU), which performs the calling operation described later in FIG. 3 in accordance with the connection request, 11 is a RAM (Random Access Memory) that stores data necessary for the operation of the processor 10 such as connected opposite station information; 12 is a ROM ( Lead
1) which stores programs, parameters, etc. for the operation of the processor 10;
3 is a frame synchronization circuit that assembles and disassembles frame signals; 14 is a driver/receiver (DV/receiver);
RV), which sends signals onto the line and receives signals on the line.

FIG. 3 is a flow diagram of a transmission process according to an embodiment of the present invention, and FIG. 4 is an explanatory diagram of an ISDN protocol according to an embodiment of the present invention. (2) The processor 10 receives an outgoing operation request from an external device. (2) The processor 10 makes 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 Figure 4 (A) of the ISDN network control indication recommended in the CCITT Recommendation I series. element in Figure 4 (
The own station number is set as the calling station identification information in octet 4 of the calling number information element shown in B), and is sent to the network 2.

[0018] Then, when a response is received from the network 2 and the result is that the connection is successful, the external device is notified that the connection has been completed, the calling operation is completed, and communication becomes possible. (2) If the connection is unsuccessful, compare the predetermined number of retries with the current number of retries, and if the current number of retries is equal to or greater than the set number, notify the external device that the call has failed and end the process. (2) On the other hand, if the number of retries is less than the set number, the retry waiting process shown in FIG. 3(B) is performed and the process returns to step (2).

Next, regarding the retry waiting process, FIG.
This will be explained using (B). (2) The processor 10 determines whether there is an incoming call. ■If there is no incoming call, the processor 10 checks whether the predetermined retry waiting time has elapsed. If the retry waiting time has not elapsed, the process returns to step ■, and the retry waiting time has elapsed. If so, return to step (2) in FIG. 3(A).

[0020] 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 setup message in the incoming signal, and after the retry waiting time held in the RAM 11 has elapsed. Compare the information with the opposite station that makes the call from your own station (hereinafter referred to as the calling opposite station), and determine whether the station that sent the incoming call request is the opposite station that makes the call from your own station after the retry waiting time has elapsed, and then make the call. If the call is not from the opposite station, proceed to step (3) and ignore the call.

[0021] On the other hand, if the call is received from the originating opposite station, the processor 10 sends a 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 response indicates that the connection is complete, it notifies the external device that the connection has been completed, and ends the process; if the connection is unsuccessful, it returns to step (■). .

In this way, while waiting for a retry, it is determined whether or not there is an incoming call, and if there is an incoming call, it is determined whether the station that sent the incoming call request is the opposite station to which the own station will make the call after the retry waiting time has elapsed. However, if the call is not from the originating opposite station, the incoming call is ignored, and if it is from the originating opposite station, a connection is made. Therefore, early connection is possible and deadlock in the retry state can be prevented.

(b) Description of other embodiments In addition to the embodiments described above, 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 also be included in other information elements. (2) A terminal device, a host computer, etc. can be used as an external device to the ISDN network control device.

The present invention has been explained above using examples, but
Various modifications are possible within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0025]

[Effects of the Invention] As explained above, according to the present invention,
It has the following effects. ■When making a call, the transmission information sent from the calling side to the called party by the circuit switching operation of the ISDN network 2 includes the calling station identification information, so the called party can identify the calling station and While waiting for a retry between
When a call is received, the calling station identification information included in the received transmission information is compared with the information of the opposite station that makes the call after waiting for a retry, and if the two pieces of information match, the call is received. Even if an incoming call is received from the opposite station to be connected while waiting for a retry, this can be identified, the incoming call is permitted, and early connection is possible.

[0026] Since an incoming call is accepted from a connected opposite station that is waiting for a retry, a deadlock state can be prevented and a quick connection can be established.

[Brief explanation of the drawing]

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

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

FIG. 3 is a flowchart 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 the prior art.

[Explanation of symbols]

1 ISDN network control device 2 ISDN network 10 Processor

Claims (2)

[Claims] Claim 1: Connected to the ISDN network (2), receives a connection request, performs a calling operation, and communicates with the opposite connection station and the ISDN network (2).
2), and performs network control to connect via ISDN network (2).
), the ISDN network control equipment performs the incoming call operation and re-originates if the connection with the opposite station fails during the outgoing operation.
When the transmission information sent from the calling side to the called side by the circuit switching operation of the DN network (2) includes the calling station identification information, and an incoming call is received while waiting for a retry between the calls. , the ISDN network is characterized in that the calling station identification information included in the received transmission information and the information of the opposite station that makes the call after the elapse of a retry standby are compared, and if the two pieces of information match, the call is received. How to receive a call while waiting for retry. 2. The IS according to claim 1, wherein the transmitted information is a call setup message, and the caller's own station number is included in the calling number information element in the call setup message.
How to receive a call while waiting for a retry on the DN network.