JPH01238234A - Line back up system - Google Patents

Abstract

PURPOSE:To prevent the trouble of a part except a host from becoming the breakdown of all terminals by using an integrated digital service network(ISDN) and a preliminary DP between the host and a decentralized processor(DP) as a back up circuit. CONSTITUTION:A buffer circuit connected to a back up adapter BA4 is disposed between the host 1 and the DVs 7, 8 by the use of the preliminary DP 3, ISDN 5 of a buffer. At the time of the trouble of the line 21, the message path of the DVs 7, 8 is formed by the ISDN 5 and the DP 2 and when the trouble of the DP 2 is decided according to a non response, a similar message path is formed by a BA 4 in which a switch 16 is disconnected through the DP3, the ISDN 5 and them. Thereby, the breakdown of all terminals is avoided to a single trouble except the time of the trouble of the host.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides an online system that uses ISDN (Integrat) for backup in the event of a line or equipment failure.
ed Digital 5 services Netwo
Regarding a line backup method using rk).

[Conventional technology]

The conventional method, as described in Japanese Patent Application Laid-open No. 60-150347, backs up the working line by setting an alternative communication path on the backup exchange line including the line termination equipment by dialing on the center side. I was doing it.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the prevention of all DVs from going down due to a DP going down in a terminal system in which a distributed processor (hereinafter abbreviated as DP) is connected to a plurality of terminal devices (hereinafter abbreviated as DV), and the backup effect is The problem was limited to when a specific part of the system failed.

The purpose of the present invention is to employ ISDN as a backup line, and to provide backup so that a single failure of the central processing unit (hereinafter abbreviated as HO5T) and below, including the DP mentioned above, will not cause the entire DV to go down. It is in.

[Means to solve the problem]

The above purpose is to connect 15DN as a backup line between HOST and DP, connect a backup DP in addition to HOST on the HOST side subscriber line of the ISDN, connect the backup DP directly to HOS1', and and D
A backup adapter (hereinafter abbreviated as BA) is installed between the DVs, the BA is connected to the DP side subscriber line of the ISDN together with the DP, and the connection destination for sending and receiving data from the DV is connected to the DP.
This is achieved by providing a changeover switch for switching between the side and the 15DN subscriber line side.

[For production]

If the DP is operating normally in response to a current line failure, the HOS
T sends a call setup message to the DP and sets up a backup channel on the 15DN. HO for DP failure
The ST transmits a call setup message to the BA, and after receiving the message, the BA transmits a call setup message to the backup DP.

After setting up a backup communication path between the backup DP and BA by sending a response message from the backup DP to the BA, the BA switches the connection of the changeover switch,
Connect the DV to the 15DN subscriber line side. As a result, the DV can be accessed via BA, ISDN, and backup DP.
It is connected to the OST and will never go down. Also, HOS
By making the I5DN subaddresses of T and backup DP different, and DP and BA different, the above call setup will not malfunction. In addition, by dividing the DV into the connection to the DP and the connection to the BA, the DV connected to the DP can operate between the DP and the BA, and even in the event of a BA failure, so all DV
will never go down.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows an example of an online system to which the present invention is applied.

HOSTl is connected to DP2 via working line 21, D°P
2 is connected to DV6, DV7, BA by DV signal line 25, and BA is connected to DV8, DV9 by DV signal line 26.
2. Backup DP3 is connected to HOST1 via HOST-DP signal line 22.

HOSTl, DP2. The backup DP3 and BA4 each have l5DN transmitting/receiving sections 11, 12, 13°14,
The I5DN transmitter/receiver is connected to the I5DN 5 via the I5DN subscriber line 23.24.

Note that a HOST1 and a backup DP3 are connected to the 15DN subscriber line 23, and each has a different SDN subaddress A and B. l5DN subscriber line 24 has a DP
2 and BA4 are connected, each having a different l5DN subaddress C and D.

BA4 has a changeover switch 16 in addition to the l5DN transmitting/receiving section 14.
and a speed conversion section 15, and the common terminal side of the changeover switch 16 is connected to a DV signal line 26.

The selection terminal side is connected to the DV signal line 25 and the speed converter 15,
Usually, the DV signal line 25 side is in contact with the common terminal. The speed converter 15 is connected to the B channel signal line 27 of the I5DN transmitter/receiver 16.

FIG. 2 shows the configuration of the SDI transmitter/receiver, and FIG. 3 shows a flowchart of the backup switching operation.

The operation shown in FIG. 1 will be explained with reference to FIGS. 2 and 3.

(1) Detects a working line failure on the HOSTl side and starts backup switching operation. First, l5DN of HOSTl
The transmitting/receiving unit 11 transmits a call setting message including a B channel communication path setting instruction to the DP2 via the 15DN5.

(2) If DP2 is in normal state, DP2 (7) IS
HO
A communication path between STl and DP2 is set up on the ISDN B channel, and HOSTl, DP2, and each DV are connected via l5DN.
data communication between the two.

(3) If DP2 is in a failure state, the HOS from DP2
Either there is no response to T1, or the l5DN transmitter/receiver 12 of DP2 sends a disconnection message to HOS T1 as the destination.
Send via DN. Thereafter, the HO5TI transmits a call setup message from the l5DN transmitter 11 to BA4 via the l5DN.

(4) In response to receiving the call setup message from HOST1, BA2 sends the call setup message containing the B channel communication path setup instruction to the backup DP3 as the destination.
Transmit from N transmission/reception 14 via engineering 5DN5.

(5) The backup DP3 sends a response message from the l5DN transmitting/receiving unit 13 via the l5DN5 with BA4 as the destination.
A communication path between the two is set up on the ISDN B channel.

(6) Upon receiving the response message from the backup DP3, the BA4 switches the connection of the changeover switch 16 to the speed converter 15 side, thereby connecting the HO3TI, backup DP3, I5DN5, BA4. DV8 and D
A data communication path between V9s is set up, preventing all DVs from going down. If the Naori V signal can be communicated in the same synchronization as the ISDN B channel, the speed converter 15 is not necessary, making it more economical.

After the processing in (6) above is completed, the completion of the backup switching operation may be notified to the HOSTI by transmitting a response message from the BA4 to the HOSTI destination.

Also, assuming that the function of the backup DP3 is supported in (3) above, the destination (address) of BA4 to be connected to the backup DP3 is transmitted from the HOS T1, and a call is made from the backup DP3 side to the BA4. It can also be set.

〔Effect of the invention〕

According to the present invention, the entire DV does not go down in response to a single failure of a communication path or a component device other than the HOST, and there is an advantage that a no-down system configuration can be established.

Furthermore, since the BA has a simple configuration consisting of only a changeover switch and a speed conversion function, it can be realized at low cost, and is more economical than installing two DPs.

By using 15DN as a backup line, processing capacity is improved over systems that use existing analog switching networks.

Note that automatic switching is also possible since switching is performed simply by starting from HOST.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram showing an example of an online system to which the present invention is applied, FIG. 2 is a diagram showing the l5DN transmitter/receiver shown in FIG. 1, and FIG. 3 is a diagram shown in FIG. 1. 3 is a flowchart for explaining backup switching operation of the online system. 1...HOST, 2...DP, 3...Backup DP, 4-BA, 5-I SDN, 6-9-DV. 11-14...15DN transmitting/receiving section, 15... Speed converting section, 16... Changeover switch.

Claims (1)

[Claims] 1. A distributed processor (hereinafter abbreviated as DP) connected to a central processing unit (hereinafter abbreviated as HOST) through a communication line, and the D
In an online system consisting of a plurality of terminal devices (hereinafter abbreviated as DV) connected to P, there is an ISDN (Integrated Digital Network) between the HOST and the DP.
lServicesNetwork), connect the corresponding ISD
Between the HOST side subscriber line of N and the HOST,
A backup DP with different identification addresses on the subscriber line is connected to the DP, and a backup adapter (hereinafter referred to as BA) is connected between the DP and the DV with different identification addresses on the DP side subscriber line. (abbreviated as ),
The BA connects the connection destination of the transmitted and received data from the DV to the D.
A line backup system characterized in that a changeover switch is provided to switch between the P side and the DP side subscriber line side of the ISDN.