JP2970801B2 - ISDN exchange and line test system and test method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maintenance test of a switching system in an ISDN (Integrated Services Digital Network), and more particularly to a test of an ISDN switching system capable of efficiently performing maintenance of a subscriber line and a switching system without interrupting service. It relates to a system and a test method.

[0002]

2. Description of the Related Art A switch is required to continue its service even if a failure occurs, so that high reliability is required. For this reason, preventive maintenance such as switching of a spare device at the time of failure, confirmation of normality of network service, detection of abnormality of a subscriber line, and confirmation of normality is indispensable.

[0003] Japanese Patent Application Laid-Open No. 2-55554 discloses an example of a test method for an ISDN switching system. FIG.
Is a schematic configuration diagram thereof. ISDN terminal under test 10
1 is ISD through network terminating equipment (NT) and subscriber line
Connected to N exchange. Here, the line terminating device (LT) 102 of the ISDN exchange includes protocol processing for layer 1 and performs B1 channel, B2 channel, and D
The channels are respectively B1 channel selection circuits 103, B2
Channel selection circuit 104 and frame demultiplexing circuit 10
5 is connected. Similarly, the ISDN test equipment 106
Is a line termination device (L
T) 107, and the test B1 channel, B2 channel, and D channel are connected to the B1 channel selection circuit 103, the B2 channel selection circuit 104, and the frame demultiplexing circuit 105, respectively.

The B channel for test or test selected by the B channel selection circuits 103 and 104, respectively, is connected to a time division switch (TDNW) 108 and demultiplexed by the frame demultiplexing circuit 105. The test D channel is connected to the layer 2 protocol processing unit 109. The selection operation of the B channel selection circuits 103 and 104 is performed according to a control signal from the selection circuit 110. Time division switch 108,
Layer 2 protocol processing unit 109 and selection circuit 110
Is connected to a processor (CPU) 111 that performs call processing and other controls via a bus line.

[0005] In such a configuration, the ISDN test apparatus 106 sends out a D channel message indicating, for example, a B1 channel test request of the line terminating apparatus 102.
Upon receiving this test request message, the processor 11
1 checks whether the designated B1 channel of the subscriber line is in use or not, and if not used, switches the B1 channel selection circuit 103 to the ISDN test apparatus 106 side, and the ISDN test apparatus 106 Pseudo transmission / pseudo reception test is performed.

[0006]

However, in the conventional ISDN switching system test method, the ISDN test apparatus 106 is used by the B channel selection circuits 103 and 104.
And the line termination device 102 for the subscriber line, the B channel selection circuits 103 and 104 need to be provided by the number of subscriber lines accommodated in the exchange. In particular, in the case of the primary group interface, 24 (B1 to B24) selection circuits are required for each subscriber line, which significantly complicates the configuration of the exchange.

A processor 111 for controlling call processing is provided.
In order for the maintenance test to be performed by the
1 is a process for checking whether or not there is an outgoing or incoming call to the B channel under test, a process for stopping the test when an outgoing or incoming call occurs, a process for checking whether or not a test is being performed for each call, and a test. It is necessary to constantly execute a check process of whether or not the processing has been completed, and there is a problem that a heavy load is imposed on the processor 111.

An object of the present invention is to provide a simple configuration of an IS regardless of the number of subscriber lines and the type of I-interface (basic interface and / or primary rate interface).
IS that can perform maintenance tests on DN exchanges and lines
An object of the present invention is to provide a DN test system.

It is another object of the present invention to provide an ISDN test system and a test method capable of performing a maintenance test of an exchange and a line without imposing a load on a call processor of the ISDN exchange.

[0010]

SUMMARY OF THE INVENTION An ISDN maintenance test system according to the present invention comprises a switch network capable of setting an arbitrary path, a subscriber line terminating means connected to the switch network, and an I interface signal processing means. Test means connected to the switch network for executing a maintenance test of the ISDN exchange and the line. In the operation mode of the ISDN exchange, an operation path is provided between the subscriber line terminating means and the I interface signal processing means. When a test request is received from the test means, a first path between the subscriber line terminating means and the test means and a second path between the test means and the signal processing means for the I interface are provided according to the test request. , Control the switch network.

In the ISDN maintenance test method according to the present invention, an idle B channel which is not used in a subscriber line requested to be tested is searched in a test mode of the ISDN exchange, and an empty B channel and a D channel of the subscriber line are searched. The path setting of the switch network is executed so as to assign to the maintenance test apparatus.

[0012] The maintenance test device is a virtual terminal means for testing the I interface signal processing device and the call processing software of the exchange facing the I interface signal processing device, and sub- jecting to the subscriber line under test. User terminal, network-side terminator, line terminator, and virtual network means for testing the subscriber line. Thus, the outgoing and incoming functions of the subscriber line and the network can be independently tested.

[0013] The maintenance test apparatus is provided with a subscriber line and an I-line.
It is desirable to transparently transmit D channel information to and from the interface signal processing device. More specifically, the D channel between the subscriber interface and the network interface is terminated to layer 2, and the D channel layer 3 information between the subscriber terminal under test and the I interface signal processing device is bypassed.

Further, it is desirable that the maintenance test apparatus performs call control on all the channels of the subscriber line in the test mode. For example, in the test mode, when a subscriber calls the B channel under test,
The test of the B channel is stopped, and the setting of the B channel is performed in response to a call from the subscriber.

[0015]

In the test mode, by performing path control on the switch network, a test apparatus is interposed between the line terminating device connected to the switch network and the signal processing device for the I interface, thereby performing a maintenance test of the exchange and the line. Execute The test apparatus pulls in the D channel and the vacant B channel of the subscriber line requested to be tested, and transparently transmits the D channel layer 3 information between the subscriber line and the I interface signal processing device. , The test of the designated B channel can be executed without stopping the service of the B channel in use. Further, in the test mode, the load on the call processor on the exchange side is reduced because the test apparatus is in charge of the call control of the subscriber line.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of an ISDN exchange test system according to the present invention. ISDN
The exchange is a time-division switch 10, an ISDN test apparatus 1
1, a plurality of line terminating devices (LTs) 12, an I-interface signal device 13, and a processor 14 for performing call processing and other controls. The time-division switch 10, the ISDN test device 11, and the I-interface signal device 13
It is connected to the processor 14 via a bus.

An ISDN test apparatus 11 is connected to the time division switch 10 through a test highway. The time division switch 10 can connect the ISDN test apparatus 11 and the line termination device LT of an arbitrary subscriber line by arbitrary B channels and D channels under the path control of the processor 14. Similarly, the ISDN test apparatus 11 can connect the B channel and the D channel to the I interface signal device 13 through the setting path of the time division switch 10.

The I interface signal device 13 is a layer 1 and layer 2 protocol processing unit, and is connected to either the line terminating device LT or the ISDN test device 11 through a path set in the time division switch 10 by the processor 14. Is done. More specifically, the signal device 13 for the I interface is a line termination device LT in the operation mode.
To the ISDN test apparatus 11 in the test mode. Therefore, in the test mode, the line terminating device L
ISDN between T and the signal device 13 for I interface
The test device 11 is interposed.

In addition to the call processing control, the processor 14 searches for a free B channel of the subscriber line in the test mode, and draws or releases the switch path to the ISDN test apparatus 11 together with the D channel.

The line terminating device 12 of the exchange is connected to a network terminating device (NT) 15 through a subscriber line, and the network terminating device 15 is connected to a subscriber's ISDN terminal 16.
In addition, although the case of the basic interface is shown in the drawings, the present invention is not, of course, limited to this.
It can be applied to the I interface including the next group speed interface.

The ISDN test apparatus 11 includes a virtual network circuit 20
1, a virtual terminal circuit 202 and a control unit 203.
The virtual network circuit 201 can pull in the B channel and the D channel of the subscriber line interface and terminate to the layer 2, and using the virtual network circuit 201, the ISDN subscriber terminal 16, the network terminator 15, the subscriber line, and The normality test of the line termination device 12 is performed. The virtual terminal circuit 202 can pull in the B channel and the D channel of the network interface and terminate to the layer 2, and sends out a pseudo call D channel information for testing under the control of the control unit 203,
Thus, the normality test of the I interface signal device 13 and the call processing software of the processor 14 is performed. Therefore, the virtual network circuit 201 and the virtual terminal circuit 202
Are independently controlled, maintenance tests for the subscriber interface and the network interface can be executed simultaneously.

The control unit 203 is connected between the virtual network circuit 201 and the virtual terminal circuit 202 and, as will be described later, layers a plurality of pseudo call D channel information for testing and call control D channel information of the subscriber line. 3 and can be transmitted from the virtual terminal circuit 202. This allows IS
The DN test apparatus 11 includes a D channel layer 3 between the ISDN terminal under test 16 and the I-interface signal device 13.
The information becomes transparent, and call control such as call setting and call release from the subscriber terminal 16 via the ISDN test apparatus 11 can be performed in the same manner as in operation.

The control unit 203 further includes a virtual network circuit 201
, The call status of the subscriber under test is constantly monitored, and if there is a call from the subscriber to the B channel under test, the test is stopped at that point and the call setting from the subscriber is executed. If there is a call release request for the B channel during the test, the B channel is released.

Operation The tests executed in this embodiment include an in-service test performed without stopping the user service (in-service state) and an out-service test performed by stopping the user service. The in-service test includes a network service normality test, a primary subscriber interface test that has a large effect when the user service is stopped, or a test of only a specific switching service. Switching test of spare equipment in case of occurrence and IS
There is a DN line opening test, etc. An operation example of this embodiment in the in-service test mode and the out-service test mode will be specifically described.

(In Service Test Mode) FIG. 2 is a sequence diagram showing an operation example in the in service test mode in this embodiment. When the ISDN test apparatus 11 issues a test request for a certain subscriber line to the processor 14, the processor 14 first determines whether the B
Find a channel. Here, it is assumed that the B0 channel is in use and the B1 channel is an empty channel.

The processor 14 controls the path of the time-division switch 10 and pulls the free B1 channel and D channel into the ISDN test apparatus 11. More specifically, FIG.
As shown in the figure, the line termination device 12 of the subscriber line is connected to the virtual network circuit 201 of the ISDN test device 11 through the test path P1 of the time division switch 10, and
The virtual terminal circuit 202 of the N test device 11 is connected to the I interface signal device 13 through the test path P2 of the time division switch 10. At this time, the ISDN test equipment 11
As described above, since the D channel layer 3 information is transparent, the D channel information of the B0 channel in use is transferred to the I interface signal device 13 as it is, and the service of the B0 channel is stopped. There is no.

Subsequently, when the processor 14 sends an in-service circuit switching test instruction to the ISDN test apparatus 11, the ISDN test apparatus 11
SETUP, CALL PROC, and SETUP for setting a test call for an empty B1 channel (B1ch-T: T means test) with the interface signaling device 13).
ALERT messages are exchanged as is well known. During this call setup test, the occurrence of other call control messages also
If there is no call for one channel, the pseudo call setting for the B1 channel is completed and the continuity test of the B1 channel can be started.

On the other hand, immediately after the ISDN test apparatus 11 receives the ALERT message from the I-interface signaling device 13, the B0 channel (B0
ch-U: U means a subscriber. ) Disconnection request (DI
SC), as shown in FIG. 2, the pseudo call setup of the B1 channel is interrupted, and the subscriber line interface (the ISDN terminal 16 under test) and the network interface (the I interface signal device 13) are connected. Between ISDN
DISC, RE of B0 channel via test apparatus 11
L, REL COM messages are exchanged, and B
Channel 0 is released.

When the release of the B0 channel is completed, the pseudo call setting of the B1 channel, which has been interrupted, is continued, and the I-interface signaling device 13 transmits a B1 channel CONNN message to the ISDN test device 11, and the ISD
A continuity test is started between the N test device 11 and the I interface signal device 13.

When a call specifying the B1 channel under test is detected from the subscriber during the continuity test using the B1 channel, the ISDN test apparatus 11 transmits a test result and a stop report to the processor 14. As a result, the processor 14 releases the pull-in of the B1 channel, the ISDN test apparatus 11 stops the continuity test with the I-interface signaling device 13, and the DISC, RE for the B1 channel.
Exchange each message of L, REL COM and B1
Release the channel.

When the B1 channel is released, the ISDN test apparatus 11 sends a call setup message (B1ch-U) to the I-interface signaling apparatus 13, and the ISDN test apparatus 11 uses a well-known procedure as shown in FIG. The call setting of the B1 channel is performed via the terminal. When the call setting of the B1 channel is completed, the ISDN test apparatus 11 reports the end of the test to the processor 14, and the processor 14 releases the pull-in of the D channel.

(Out-Service Test Mode) FIG. 3 is a sequence diagram showing an operation example of the out-service test mode in this embodiment. First, when there is a test request for a certain subscriber terminal from the ISDN test apparatus 11, the processor 14
Stops the service of the subscriber line under test, and pulls the D channel and B channel of the subscriber line interface into the ISDN test apparatus 11 by the path control of the time division switch 10. As a result, the subscriber line interface (the ISDN terminal under test 16) is terminated by the virtual network circuit 201, and the network interface (the I interface signal device 13) is terminated by the virtual terminal circuit 202 (pseudo terminal mode).

In the pseudo network mode, a circuit switching test on the subscriber line side for confirming various functions of the ISDN terminal under test 16 is performed. First, the subscriber line interface (I under test I)
Call from SDN terminal 16), SETUP, CALL
PROC, ALERT, and CONN messages are exchanged according to a predetermined procedure, and a continuity test is performed through the B channel for which a call is set. When the B channel continuity test is completed, the ISDN test apparatus 11
DISC, REL, and RELCOM messages are exchanged with the terminal 16 in a predetermined procedure to release the B channel. Then, the ISDN test apparatus 11 reports the results of the transmission test, the reception test, the disconnection test, and the continuity test of the B channel to the processor 14, and ends the test.

In the pseudo terminal mode, a circuit switching test on the network side is performed. First, between the pseudo terminal circuit 201 of the ISDN test apparatus 11 and the signal device 13 for I interface, SETUP, CALL PROC, ALERT,
Each message of CONN is exchanged in a predetermined procedure,
The B channel continuity test can be broken. When the B channel continuity test is completed, the DISC, REL, and REL COM messages are exchanged according to a predetermined procedure to release the B channel, and the ISDN test apparatus 11 issues a transmission test, a reception test, and a disconnection test to the processor 14. , And the result of the continuity test of the B channel and the end of the test. ISDN test equipment 1
When the processor 14 receives the test result and the test completion from the processor 1, the processor 14 releases the suspension of the subscriber service under test and controls the path of the time division switch 10 to release the D channel and the B channel.

Since the virtual network circuit 201 and the virtual terminal circuit 202 of the ISDN test apparatus 11 can operate independently of each other, the subscriber line interface test and the network interface test can be executed simultaneously. It is possible.

[0037]

As described above, the IS according to the present invention
In the test mode, the DN test system interposes a test device between the line terminating device and the signal processing device for the I interface by performing path control of the switch network,
Perform switch and line maintenance tests. Therefore, there is no need to provide a selection circuit for each subscriber line and switch between the test apparatus and the subscriber line as in the related art, and the configuration of the system is greatly simplified.

Further, the test apparatus draws in the D channel and the vacant B channel of the subscriber line requested to be tested, and transparently transmits the D channel layer 3 information between the subscriber line and the I interface signal processing apparatus. , The test of the designated B channel is executed without interrupting the service of the B channel in use. Further, in the test mode, the test apparatus is in charge of call control of the subscriber line, and when a call is made to the B channel under test, the test is stopped and the B channel is released.
Since the control of setting the B channel for the outgoing call is performed, the load on the call processor on the exchange side is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an ISDN exchange test system according to the present invention.

FIG. 2 is a sequence diagram illustrating an operation example of an in-service test mode in the embodiment.

FIG. 3 is a sequence diagram illustrating an operation example of an out-service test mode in the embodiment.

FIG. 4 is a block diagram showing a test method of a conventional ISDN switching system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ISDN test apparatus 10 Time division switch (TDNW) 14 Processor 13 Signaling device for I interface 16 ISDN terminal under test 15 Network terminator (NT) 12 Line terminator (LT) 203 Control unit 202 Virtual terminal circuit 201 Virtual network circuit

Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) H04L 12/00-12/28 H04L 12/50-12/66 H04M 3/08-3/14 H04M 3/22-3 / 36 H04Q 1/20-1/26 H04Q 3/52 H04Q 11/00-11/08

Claims (9)

(57) [Claims] In an ISDN (Integrated Services Digital Network) exchange and circuit maintenance test system, a switch network capable of setting an arbitrary path, a subscriber line termination means connected to the switch network, and the switch I interface signal processing means connected to a circuit network; test means connected to the switch network for performing a maintenance test of the ISDN switch and line; and a subscriber line terminating means in an operation mode of the ISDN switch. And an operation path between the I-interface signal processing means and a first path between the subscriber line terminating means and the test means according to the test request received from the test means, the test means, Controlling the switch network so as to establish a second path with the I-interface signal processing means. Switch control means; and the test means comprises first means for providing a virtual network and second means for providing a virtual terminal, and the subscriber line termination means and the first means by the first path. And connect
A maintenance test system, wherein the second means and the I-interface signal processing means are connected by the second path. 2. The test means terminates the D channel information between the subscriber line terminating means and the signal processing means for I interface up to layer 2 and passes the D channel layer 3 information. The maintenance test system according to claim 1. 3. An ISDN exchange and line comprising a switch network capable of setting an arbitrary path, a subscriber line terminating device and an I interface signal processing device connected to the switch network, and a maintenance test device. In the maintenance test method of (1), the maintenance test device is configured to provide a first virtual network.
And a second means for providing a virtual terminal, wherein in the operation mode of the ISDN exchange, an operation path is set between the subscriber line terminating device and the I-interface signal processing device; In the test mode, a path control of the switch network is executed so that the maintenance test device is interrupted between the subscriber line terminating device and the I-interface signal processing device. A maintenance test method, wherein a path is set between a line terminating device and the first means, and a path is set between the second means and the I-interface signal processing means. 4. The maintenance test device terminates D channel information between the subscriber line terminating device and the I interface signal processing device to layer 2 and passes D channel layer 3 information. The maintenance test method according to claim 3, wherein: 5. The maintenance test device executes a subscriber line switching test between the first means and the subscriber terminal of the subscriber line termination device, and executes the second means and the I interface signal. 4. The maintenance test method according to claim 3, wherein a network switching test is performed with the processing device. 6. An ISDN exchange and line comprising a switch network capable of setting an arbitrary path, a subscriber line terminating device and a signal processing device for an I interface connected to the switch network, and a maintenance test device. The maintenance test method, wherein the maintenance test device is a virtual network means for testing a subscriber terminal, a network side termination device, the subscriber line termination device and a subscriber line facing the subscriber line, Virtual terminal means for testing the I interface signal processing device and the call processing software of the exchange facing the I interface signal processing device, wherein the subscriber line terminating device is in operation mode of the ISDN exchange. An operation path is set between the ISDN exchange and the I-interface signal processing device. Free B not used in requested subscriber line
Searching for a channel, performing a path setting of the switch network so as to allocate the empty B channel and D channel of the subscriber line to the maintenance test device, wherein the maintenance test device has the subscriber line termination device and A maintenance test method, wherein a path is set between the virtual network means and a path is set between the virtual terminal means and the I interface signal processing means. 7. The maintenance test device terminates D channel information between the subscriber line terminating device and the I interface signal processing device to layer 2 and passes D channel layer 3 information. The maintenance test method according to claim 6, wherein: 8. The maintenance test method according to claim 7, wherein said maintenance test apparatus layer 3 multiplexes test pseudo call D channel information and D channel information on said subscriber line. 9. The maintenance test method according to claim 6, wherein said maintenance test device executes call control for all channels of said subscriber line in said test mode.