JPH0358552A - ISDN switching equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to ISDN switching equipment having an ISDN interface, including electronic switching equipment.

BACKGROUND OF THE INVENTION FIG. 3 shows a connection sequence of a conventional ISDN switching device. Terminal 2 is connected to exchange 1 via an ISDN interface, and terminal 3.4.5 is connected to the same ISDN interface.
It is multi-point coupled and connected to the DN interface.

The terminal 2 sends a SETUP message 6 to the exchange fit for a connection request. When the exchange 1 receives the SETUP message, it determines the called extension number from the called number and outputs the SETUP message 7 to the corresponding ISDN extension. At this time, the exchange 1 notifies the originating terminal 2 that the call has been accepted using a CALL PROC message 8.

Terminals 3, 4, and 5 that received the SETUP message 7,
ALERT messages 9 and l2 indicating that the call is in progress, and RE indicating that the incoming call cannot be accepted due to attribute mismatch.
L COMP message l1 is returned to exchange 1.

Exchange l, which received the ALERT message 9, sends an ALERT message to indicate that the called terminal is calling. T
The message 10 is sent back to the originating terminal 2.

When the destination terminal 3 becomes connectable, it outputs a CONN message 13 to the exchange 1. CONN message l3
The exchange 1 that received the CONN message 14 sends the CONN message 14 to the originating terminal 2, and also sends the CONN AC message to the terminal 3.
K message 15 is returned to notify that communication is possible, and R E L C O M is sent to the terminal 5 that was not selected.
F message 16 is sent to disconnect the terminal. The above procedure enables communication between the terminal 2 and the terminal 3.

In this way, even with the conventional ISDN switching device described above, communication between terminals is possible by processing ISDN messages from the terminals in the switching device.

Problems to be Solved by the Invention However, since the conventional ISDN switching device described above does not manage the type of terminal connected to an extension, the SETUP message 7 to the called party as shown in FIG. An error occurred on the interface, and terminals 3 and 4
．． If an abnormal sequence occurs, such as when the exchange 1 retransmits the SETUP message 17 after time T without reaching the SETUP message 17, no status notification will be sent to the originating terminal 2 until the sequence is recovered, and the There was a problem in that the side terminal 2 could not know whether the call was in progress or whether the call was lost in the middle.

The present invention solves these conventional problems,
It is an object of the present invention to provide an excellent ISDN switching device that can notify the originating terminal of the intermediate status even if an abnormal sequence occurs.

Means for Solving the Problems In order to achieve the above object, the present invention generates a pseudo call to an ISDN extension, receives a response message from a terminal to the pseudo call, and establishes a connection based on the content of the message. A that stores terminal attributes, and when a call comes in from another extension or ISDN network, if the terminal attributes of the incoming call match the stored terminal attributes, the call destination is called Tanaka.
L E R. The T message is sent back.

Operation With the above configuration, the present invention generates a pseudo call to an ISDN extension at a predetermined period, and when an A1, ERT message, or CONN message is received from a terminal, it is determined that the attribute terminal is connected. Store in memory. Also, from the terminal, R. EL. When a C O M P message is received, the content of the reason display is a value indicating a terminal attribute mismatch, and the details 1
If the terminal includes gender, it is remembered that the corresponding terminal is connected. As a result, when an ISDN extension receives a call, the exchange compares the terminal attributes requested by the incoming call with the attributes of the terminal connected to the extension, and if the terminal attributes match, sends a pseudo ALERT to the calling party. The sending of the message allows the calling terminal to know that the call is continuing.

Embodiment FIG. 1 shows a connected terminal information collection sequence of an ISDN switching device in an embodiment of the present invention.

A terminal 22 is connected to the exchange 21 via an ISDN interface, and terminals 23, 24, and 25 are connected to the same ISD.
It is multi-point coupled and connected to the N interface.

The above-mentioned exchange 2 has means for generating a pseudo call to an ISDN extension, means for receiving a response message from a terminal to the pseudo call and storing attributes of the connected terminal based on the contents, and a means for generating a pseudo call to an ISDN extension. In response to an incoming call from the network, if the terminal attribute of the incoming call matches the stored terminal attribute, A. L
A means for returning the ERT message is provided.

Next, the operation of the above embodiment will be explained. In FIG. 1, the exchange 21 transmits a SETUP message 26 to the ISDN extension at a predetermined period to generate a pseudo-termination. Terminal 2 that received the SETUP message 26
3, 24, and 25 return to the exchange 21 an ALERT message 27, 29 indicating that a call is in progress, and a REL COMP message 28 indicating that the incoming call cannot be accepted due to an attribute mismatch.

The exchange 21 sends an RE to terminate the call to the terminal 23.25, which sent the ALERT message 27.29.
At the same time as transmitting the L COMP message 30.31, the connected terminal attribute information is stored in the memory based on the received ALERT message 27.29.

FIG. 2 shows the connection sequence. In FIG. 2, terminal 22 sends a SETUP message 32 to exchange 21 to request a connection. When the exchange 21 receives the SETUP message 32, it determines the called extension number from the called number and outputs the SETUP message 33 to the corresponding ISDN extension.

At this time, the exchange 21 sends a CALL PROC message 3 to the originating terminal 22 to inform that the call has been accepted.
4, along with notification. SETUP message 32
The terminal attributes requested by the exchange 21 are compared with the connected extension terminal attributes managed by the exchange 21, and if the terminal attributes match, an ALERT message 35 is returned to the originating terminal 22 to indicate that call processing is continuing. to notify.

The terminals 23, 24 . that received the SETUP message 33
25 are ALERT messages 36 .
38 or a REL COMP message 37 indicating that the incoming call cannot be accepted due to attribute mismatch to the exchange 21.

The exchange 21 that received the ALERT message 36
Since the ALERT message 35 is sent back to the originating terminal 22 at the timing when the SETUP message 32 is received, the ALERT message is not sent back to the originating terminal 22 at this timing.

When the destination terminal 23 becomes connectable, it outputs a CONN message 39 to the exchange 21. The exchange 21 that received the CONN message 39 transmits a CONN message 40 to the originating terminal 22, and returns a CONN ACK message 41 to the terminal 23 to notify that communication is possible, in the same way as a conventional ISDN exchange. A REL COMP message is sent to the terminal 25 that was not selected, and the terminal is disconnected. By the above procedure, the terminal 22
Communication is possible between the terminal 23 and the terminal 23.

In this way, according to the above embodiment, since the exchange 2l manages the attributes of terminals connected to extensions using the pseudo call reception procedure, the exchange 2l manages the attributes of terminals connected to extensions, so that it is possible to It is possible to perform prefetch processing and notify the calling terminal of the call processing status.

Further, according to the above embodiment, the exchange 21! Since the attributes of the terminals connected to the SDN extension are managed, it is possible to implement incoming extension processing according to the terminal attributes.

Effects of the Invention As described above, according to the present invention, I
Since the configuration is configured so that the terminal connected to the SDN extension can be managed by the exchange, when an incoming call occurs to this ISDN extension, when the requested terminal attribute matches the connected terminal attribute, it will indicate that the call is in progress. Send the message to the calling terminal. As a result, even if a temporary call sequence abnormality occurs on the called side, there is an advantage that the calling side terminal can be notified that the calls are continuous.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the connection terminal information collection sequence of the ISDN switching equipment in one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the connection sequence of the ISDN switching equipment of FIG. 1, and FIGS. The figure is an explanatory diagram showing a connection sequence of a conventional ISDN exchange. 21... Switchboard, 22, 23.24.25... Terminal.

Claims (1)

[Scope of Claims] Means for generating a pseudo call on an ISDN extension, means for receiving and analyzing a response message from a terminal to the pseudo call, and storing an attribute of a connected terminal based on the content thereof; means for comparing the terminal attributes stored in the storage means with the terminal attributes of the incoming call when a connection request is made from the extension to the ISDN extension; and if the terminal attributes match, indicating to the destination that the call is in progress; ISDN switching equipment equipped with means for sending messages.