JPH0470092A - Private branch exchange - Google Patents

Abstract

PURPOSE:To prevent the failure of a continuous call for a long time by a caller by informing an audible sound to a T point and an analog telephone set during communication when the T point whose two B channels are already used gets an incomming call. CONSTITUTION:The above exchange is a private branch exchange which supports the T point of an IDSN. When a T point trunk 1 whose to B channels are already used gets the new incoming call, a trunk 3 for transmitting a tone transmits the audible sound to both two B channels of the T point and analog telephone sets 5 and 6 during communication in order to communicate the incomming call. Thus, the analog telephone set which receives the information can quickly complete a business with the T point in the communication underway, and respond to the new incoming call.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to private branch exchanges supporting ISDN T-points.

A number of services have been provided as additional services of the conventional ISDN, and one of them is "incoming call notification during one communication". In a conventional private branch exchange compatible with l5DN, if a call is received at point T while two analog telephones are communicating with two B channels at point T, call setup (S ETUP) is performed from SDN Red.
) to receive messages, the called party is alerted (AL) even though two 8-channels are blocked.
ERT) returns the message and continues receiving the call.

As shown in point 2, conventional private branch exchanges do not reject calls even when there is an incoming call to a point T that is already occupied.

Problems to be Solved by the Invention However, in such conventional private branch exchanges, there is no way to notify an analog telephone that is communicating with a point T that there is an incoming call at that point. There was a problem in which people unknowingly made long calls even though they received important calls. Additionally, there was a problem in that the caller had to continue the call until the T point was released by the person communicating with the T point, who was not aware of the incoming call.

The present invention solves these conventional problems by notifying an analog telephone that is communicating with point T that another call has arrived at point T, so that it can quickly respond to a new call. The purpose of the present invention is to provide an excellent private branch exchange that is capable of both handling and preventing unnecessary calls.

Means for Solving the Problems In order to achieve the above object, the present invention provides a private branch exchange that has a main controller and supports a T point, when the T point receives a call setup (S ETUP) message. If the two B channels at point T are already occupied by two analog telephones, the ALE
In addition to returning the RT message, the call path switch of the analog telephone connected to point T is temporarily switched to a tone sending trunk, so that the analog telephone can hear audible tones.

According to the present invention, with the above configuration, when a call is received at a point T where two B channels are already blocked, an audible sound is notified to the analog telephone that is communicating with the point T, so that the analog telephone that has received the notification It becomes possible to release the current call and immediately respond to a new incoming call. Therefore, the calling party can avoid the problem of continuing calling for a long time.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 3 are schematic configuration diagrams of a private branch exchange showing one embodiment of the present invention. In Figure 1, 1 is l5DNH
1 point trunk connected to 7, 2 is a call path switch, 3
4 is a main control unit (CPU), and 5 and 6 are 15DN#! This is an analog telephone connected to 17.

FIG. 1 shows the two B channels of a one-point trunk 1 connected to two analog telephones 5 and 6, which are occupied. At this time, it is assumed that the communication partner of the analog telephone 5 is a, and the communication partner of the analog telephone 6 is b. In the state shown in Figure 2, when a new call setup (SETUP) message C is sent from 15DN Myanmar 7 to JSDN additional service 7 in progress notification to 1 point trunk 1, as shown in Fig. 2, the main control The device 4 sends an ALERT to the l5DN network 7.
At the same time as the instruction to return a message, by switching the communication path switch 2, the communication path of the two analog telephones 5 and 6 connected to the T point is temporarily disconnected from the T point, and the tone transmission trunk 3 and the analog The telephones 5 and 6 are connected, and an audible tone (tone) is notified to the analog telephones 5 and 6 for about 0.5 seconds. After sending the tone,
Return the communication path switch 2 to the original state shown in FIG.

Through this operation, the analog telephone 5 that has learned of the new incoming call
Figure 3 shows a state in which one of the analog telephones 5 quickly terminates communication with the connected party a, releases one B channel, and responds to the incoming call C from the new 15DN network. .

Effects of the Invention As is clear from the above, according to the present invention, when a new call is received on a single point trunk where two B channels are already blocked, communication is made with two B channels at point T. In order to notify the analog telephone of the incoming call by sending an audible tone from the tone transmission trunk to the analog telephone, the analog telephone that receives the notification of the second immediately terminates the business with the currently communicating point T (JSDN network). This has the advantage of being able to respond to new incoming calls. Furthermore, for a caller who makes an incoming call to a point T where two B channels are blocked, it is possible to eliminate the problem of continuing to call unconditionally for a long time.

[Brief explanation of drawings]

1, 2 and 3 are schematic block diagrams of a private branch exchange illustrating different call path conditions in one embodiment of the present invention. 1...1 point trunk supporting ISDN T point,
2... Call path switch, 3... Trunk for tone transmission, 4... Main control unit (CPU), 5, 6... Analog filler, l... ■ SDN network.

Claims (1)

[Claims] It is equipped with a main control device, a communication path switch controlled by the main control device, and a tone sending trunk, and when a call is received at a point T where two B channels are already blocked, the ISDN supplementary service is used. A certain ``call notification''
The private branch exchange is characterized in that the main controller switches the call path switch to send an audible tone from the tone sending trunk to the analog telephone set communicating with the T point.