JPH02237257A - Inter-pbx relaying system - Google Patents

Abstract

PURPOSE:To improve the reliability and performance of a trunk line at low cost by constructing a communication network by means of setting an ISDN public network as the backup of the private trunk line of inter-PBX. CONSTITUTION:When a fault occurred in the private trunk line 2 is detected in a fault detection circuit 5 and is recognized in a fault detection means 14, a switching and controlling means 22 blocking-processes a private line trunk 4 by a private line trunk control means 16. The switching and controlling means 22 gives control for establishing a channel as to a connection interface 34 with PBX stored in ISDN 30 through an interface for connection establishment 32 to an interface trunk control means for connection establishment 18. When the connection establishment control completes, channel generation control is executed through the interface for exchange connection 34 and communication between both PBX is continued through the channel. Thus, the reliability and the performance of the private trunk line can be improved at low cost.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to improve the reliability and performance of dedicated trunk lines at low cost, with regard to improving the relaying method in the event of a dedicated trunk line failure between digital PBXs (digital private branch exchanges). For each of the first and second digital PBXs (digital private branch exchanges) that communicate via a dedicated line trunk that is connected to a dedicated trunk line, a digital line consisting of an ISDN connection establishment interface and a connection interface is provided. A connection establishment interface trunk and a connection interface trunk to be connected, a failure detection means for receiving a detection output of a failure detection circuit of the leased line relay trunk, and a leased line relay trunk control means for providing connection control to the leased line relay trunk; A connection establishment interface trunk control means for establishing a connection of a connection interface trunk, a connection establishment trunk control means for controlling a connection establishment trunk, a connection interface trunk control means for giving connection control to a connection interface trunk, and a leased line relay trunk control means. The connection establishment interface trunk control means and the connection interface trunk control means are provided with switching control means for causing switching control in accordance with the output of the failure detection means.

[Industrial application field]

The present invention relates to an improvement in a relay system when a dedicated trunk line fails between digital PBXs (digital private branch exchanges).

In recent years, along with the increasing sophistication of demands for corporate toll networks (hereinafter referred to as "internal digital communication networks"), the demand for economical construction thereof has also increased. As one means of responding to this problem, it has been proposed to connect PBXs with trunk lines. In this system, if a failure occurs in the trunk line, communication between PBXs has to be interrupted, so we try to ensure the reliability of the relay by duplicating the trunk line using a backup trunk line. There is.

[Conventional technology]

A conventional trunk line system of this type has a configuration as shown in FIG. As shown in this figure, the lth digital PBX
Opposite part of the network 6I and second digital PBX
The opposing portion 8I of the network is usually connected via an analog or digital dedicated trunk line 50, and communication is performed between the two.

4 is a dedicated line M! 1 rank, and a fault detection circuit is provided there. And that dedicated trunk line 50
When a fault occurs in 6., the fault is detected by the fault detection circuit and the opposing part 6. , or 81 is the third digital P
A backup relay path via the opposing portion 9 of the BX network is connected to the first and second opposing portions 6, 8 . The communication is continued via the backup relay route formed between the two terminals.

[Problem to be solved by the invention]

In the backup relay system as described above, the relay line remains unused except in the event of a failure, so its communication capacity is kept relatively small.

Therefore, if backup relaying occurs during the busiest period between PBXs, the backup relay path is formed with a capacity that is 20 to 30% less than the total capacity of the dedicated trunk line, so that the relay call will not exceed the communication capacity of the backup relay path. may exceed. The excess amount will remain in the backup relay route, making it difficult to make calls via the relay line of the company's digital communication network (reducing the performance of the relay line)
.

The present invention was created in view of such problems, and an object of the present invention is to provide a digital PBX-to-PBX relay system that can improve the reliability and performance of trunk lines at low cost.

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the present invention.

As shown in this figure, the present invention provides first and second digital PBXs (digital private branch exchanges) 6,
The following components are provided every 8 to back up the dedicated trunk line 2. Its components are I
SDN (INS) connection establishment interface 32
and a digital line 3 consisting of a connection interface 34
connection establishment interface trunk 10 connected to 6
and a connection interface trunk 12, a failure detection means 14 that receives the detection output of the failure detection circuit 5 of the leased line relay trunk 4, and a leased line relay trunk control means 16 that provides connection control to the leased line relay trunk 4. connection establishment interface trunk control means 18 for providing control over the connection establishment interface trunk 10 for establishing the connection of the connection interface trunk 12;
If the failure occurs in the connection interface trunk control means 20 that provides connection control to the connection interface trunk 12, the leased line relay trunk control means 16, the connection establishment interface trunk control means 18, and the connection interface trunk control means 20, This is a switching control stage 22 that produces switching control according to the output of the detection means 14. Reference numeral 26 denotes a network for connecting subscribers to the dedicated relay line 2 or to the digital line 36 by means of known exchange connection means installed in the control device 24.

[For production]

During communication via dedicated trunk line 2 between digital PBXs,
A fault occurring in the dedicated trunk line 2 is detected by the fault detection circuit 5 of the dedicated medium line 2, and the fault is detected by the fault detection means 14.
When the switching control means 2 is confirmed by
2 performs blocking processing of the leased line relay trunk 4 on the leased line relay 1/rank control stage 16.

Further, the switching control means 22 connects the PB accommodated in the ISDN 30 to the connection establishment interface trunk control means 18 through the connection establishment interface 32.
Control for establishing a communication path regarding the connection interface 34 with X is passed.

When the connection establishment control is completed, communication path formation control via the exchange connection ink face 34 is then performed. Then, communication between the two PBXs is continued via the communication path, that is, the communication path formed as a backup of the dedicated trunk line.

When the failure of the dedicated trunk line 2 is recovered and the recovery is confirmed by the failure detection means 14, the switching control means 22 responds to this and instructs the leased line trunk trunk control means 16 to re-process the relay of the private trunk trunk 4. Let them do it. Communication continues via the dedicated trunk line 2. Further, the switching control means 22 performs a process of closing the connection interface trunk by the connection interface trunk control means 20 and a process of releasing the connection interface 34 by the connection establishment interface trunk control means 18.

In this way, the reliability and performance of a dedicated trunk line can be improved at low cost.

? Embodiment] FIG. 2 shows an embodiment of the present invention. In this figure, 6
is a PBX, and this PBX 6 is connected to a PBX 8 via a dedicated trunk line 2. All PBχ68 have the same configuration. Therefore, the configuration of the PBX 6 will be explained. 4 is a dedicated line relay trunk, 10 is a basic interface trunk (connection establishment interface trunk 10 in FIG. 1), and 12 is a digital relay trunk (connection interface 1-rank 12 in FIG. 1).

A fault detection circuit 5 is provided in the dedicated line relay 1 and rank 4. 24 is a control device, which includes a failure detection means 14, a leased line relay 11 rank control stage 16, a basic interface connection control means 18I (connection establishment interface control means 18), and a rank control means 201 for the digital relay 1. (connection interface control means 20) and a switching control stage 22 are formed. These means 1/l,
16. The specific configuration of 18201 and 22 is the control device 24
It is located in the CPU and main memory that make up the . That is, programs corresponding to each of the above-mentioned means are stored in the main storage device, and when these programs are executed in the CPU, each means corresponding to the program to be executed is formed in the control device 24. It is structured as follows. 26 is a network, and this network 26 is connected by the control device 24 to connect each subscriber in the premises to leased line relays 1 to rank 4 or digital relays 1 to rank 12, and each connection control is made in accordance with known switching connection procedures in response to call origination or failure detection.

The basic interface trunk 101 and digital relay trunk 121 of this PBX are 2B+D basic interface 3 provided in the T SDN public network 30, respectively.
It is connected to the ISDN 30 via the primary group interface 341 (connection interface 34) of 2I (connection establishment interface 32) and 24B. The basic interface 32 and the primary group ink face 341 belong to the interface group 36. Configure. That way IS
PBX6 connected to DN30 has its ISDN and PB
It is connected to the PBX 8 via an interface group 361 having the same configuration as described above, which is provided between the PBX 8 and the PBX 8.

The operation of the corporate digital communication network having the above configuration will be explained below.

The normal communication between PBX6 and PBχ8 is as follows:
Failure monitoring of the dedicated trunk line 2 is constantly carried out via the dedicated trunk line 2 (Sl in FIG. 3).

When a fault occurs in the dedicated trunk line 2, the fault is detected by the fault detection circuit 5 (fault detection 81 in FIG. 3). The fault detection stage 14 that has received the detection confirms the detection and requests the switching control means 22 to switch the relay. The switching control stage 22 is the dedicated line relay 11 rank control means 16
The dedicated trunk line 2 is blocked (84 in Figure 3).
), and sends a connection request to the base tree interface connection control means 18 to connect the interface 341 between the PBXs 6 and 8 (35 in FIG. 3). P by the basic ink face connection control means 18 in response to this connection request.
Interface 34 between BX6 and PBχ8. Processing for establishing a connection proceeds according to the connection procedure shown in FIG. That is, from the PBX 6 to the basic ink face 32.
The call setup data is sent to the ISDN public network 30 via the D channel of , and then sent from the ISDN network 30 to the PBX 8 (100 in FIG. 4). The call setting acceptance data, paging data, and response data are sent from the PBχ8 that responded to the reception of the call setting data to the PBX6 via the ISDN public network 30.
(102, 104, 106 in Figure 4)
). Then, response confirmation data is sent from the PBX 6 to the PBX 8 (108 in FIG. 4), whereby the digital relay trunk 12 of the PBX 6. and PBX8 digital relay trunk 12. The process for connecting the interface 341 between the two is completed (36 in FIG. 3).

Its interface 34. A connection process is started in which the PBX is used as a trunk line between the two PBXs 6 and 8 (37 in FIG. 3). This connection process is performed by the interface 34. Both PBX6 about
．． The digital relay 1 and rank control means 20+ proceed according to the connection procedure shown in FIG. 4 under the control of the switching control stage 22 which has received the notification of completion of connection establishment between the digital relay 1 and the rank control means 20+. That is, this connection procedure uses the ■ signal transmitted and received via the D channel to form a communication path to the ink face 34, but first the call setting data is transferred from the PBX 6 to the PB
It is sent to X8 (110 in FIG. 4).

The call setting reception data, paging data, and response data are sequentially sent from the PBX 8 that received the call setting data to the PBX 6 via the D channel (112 to 114.1 in Fig. 4).
16). Then, by returning the response confirmation data from the PBX 6 to the PBχ8, a navy blue communication path is formed in the interface 34 (38 in FIG. 3). And interface 34. starts communication as a communication path (relay line) between both PBXs 6 and 8 (120 in FIG. 4). This interface 341 is a 238+D interface as described above, and has the same capacity as the dedicated trunk line 2. Interface 34. is used only when a failure occurs, and its cost of use is 1-, if it is for a short time, the PBX
The backup can be performed to the full required capacity with a considerably lower value than that of a relay. Therefore, communication is suspended only when a failure occurs, and the performance of the relay line is improved.

In this way, after the trunk line has been switched, the fault detection circuit 5 of the dedicated line relay trunk 4 detects that the faulty dedicated trunk line has been restored, and a notification thereof is given to the fault detection means 14. When the restoration is approved (S12 in FIG. 3), a request for restoration processing is made to the switching control means 22 (313 in FIG. 3). The switching control means 22 instructs the trunk line trunk 1 and rank control means 16 to perform relay restart processing for the leased line relay trunk 4 (third
314) in the figure, a dedicated line relay operation via the dedicated trunk line 2 is started (815 in FIG. 3). At the same time, the switching control means 22 closes all trunk line connections between the PBXs 6 and 8 using the ink face 34 (3rd time 316). This is a PB that has detected recovery after a failure as shown in Figure 4.
P from X6 via D channel of ink face 341
This is done after confirming the transmission and reception of disconnection data to BX8, release data from PBX8 to PBX6, and release completion data from PBX6 to PBX8 (130, 13 in Figure 4).
2.134).

Then, in response to the completion of the blockage, the switching control stage 22 controls the basic interface connection control means 18. A request to open the rain face 341 is sent to (317 in FIG. 3). Basic interface connection control means 1 in response to this release request
The process for opening the interface 341 by 81 is proceeded according to the opening procedure shown in FIG. 4 (318 in FIG. 3).

First, disconnection data is sent from the PBX 6 to the ISDN public 41130 via the D channel of the basic interface 321, and then to the PBX 8 (140 in FIG. 4).

The release data is sent from the PBX 8 to the PBX 6 via the ISDN public network 30 (FIG. 4, 117) 142). Then, the PBX 6 connects the PBX via the IsDN public network 30.
6 (14 in Figure 4).
4) The opening operation of the interface 341 is completed.

In the above embodiment, the failure detection means 14, the trunk line relay trunk control means 16, the basic interface connection control stage 181, and the digital relay trunk control means 20 are used.
, and the switching control means 22 are configured by the software 1 to control, but they can also be configured by hardware.

[Effects of the Invention] As described above, according to the present invention, it is possible to construct a communication network using the ISDN public network as a backup for the dedicated trunk line between PBXs. PB with relatively high installation cost for hack asop relay
There is no need to install a χ relay route as a fixed asset. It is possible to enjoy improved relay reliability and relay performance at low cost.

[Brief explanation of drawings]

Fig. 1 is a principle block diagram of the present invention, Fig. 2 is a diagram showing an embodiment of the present invention, Fig. 3 is a diagram showing a processing flow for the embodiment, and Fig. 4 is an operation for the embodiment. A diagram showing a sequence, FIG. 5 is a diagram showing a conventional inter-PBX relay system. 1 and 2, 2 is a dedicated trunk line, 4 is a dedicated line trunk 1 to rank, 6 is a digital PBX, 8 is a digital PBX, 10 is a connection establishment interface 1 to rank (basic interface trunk 10), and 12 is for connection. Interface 1 to rank (digital relay trunk 12), 14 is failure detection means, 16 is leased line relay 1-rank control means, 18 is interface trunk control means for connection establishment (basic interface connection control means 18,), 20 is connection interface trunk control means (digital relay 1/rank control means 2)
0, ), 22 is a switching control means.

Claims (1)

[Claims] (1) ISDN connection for each of the first and second digital PBXs (digital private branch exchanges) (6, 8) that communicate via leased trunk trunks (4) connected to leased trunk lines (2); Detection of a failure in the connection establishment interface trunk (10) and the connection interface trunk (12) connected to the digital line consisting of the establishment interface (32) and the connection interface (34), and the leased line relay trunk (4). failure detection means (14) receiving the detection output of the circuit (5); leased line relay trunk control means (16) for providing connection control to said leased line relay trunk (4); and said connection interface trunk (12). connection establishment interface trunk control means (18) for controlling the connection establishment interface trunk (10) for establishing a connection;
), a connection interface trunk control means (20) that provides connection control to the connection interface trunk (12), the leased line relay trunk control means (16), the connection establishment interface trunk control means (18), and the connection The switching control means (22) is provided in the interface trunk control means (20) for producing switching control according to the output of the failure detection means (14), so that when the dedicated trunk line fails, the digital line PBX characterized by backing up dedicated trunk lines
Intermediate relay method.