JPH04170839A - Communication adaptability testing system for isdn terminal - Google Patents

Abstract

PURPOSE:To automatically change testing procedure for B-channel and D-channel by inputting a transmission message sent from a test control means and a return message from an ISDN terminal to be tested, and comparing them with a stored transmission message for verification and a stored return message for verification. CONSTITUTION:For instance, when the test control means 3 sends the transmission message to the ISDN terminal 2 to be tested on the premise of B-channel communication, a protocol deciding means 5 inputs it, and compares it with plural kinds of the transmission messages stored beforehand in a verification message storage means 4, and grasps what protocol is being executed. Besides, the protocol deciding means 5 inputs the return message from the ISDN terminal 2 to be tested for the transmission message as well, and compares it with plural kinds of the stored return messages. The ISDN terminal 2 is decided by checking these two results of comparison. Thus, the testing procedure is automatically changed for the B-channel communication and the D-channel communication.

Description

[Detailed Description of the Invention] [Summary] Concerning the communication compatibility testing method for ISDN terminals connected to the S/T point of the ISDN subscriber interface, the test procedure is adapted for B-channel communication using return messages from the ISDN terminal under test. The purpose of the present invention is to provide a communication compatibility test method that automatically switches between the ISDN terminal and the D channel communication.
A test control means capable of performing a communication compatibility test whether a DN terminal communicates using a B channel or a D channel of an ISDN subscriber line, and the test control means A verification device for accumulating multiple sets of verification transmission messages and verification return messages each having the same content as a transmission message sent to the ISDN terminal under test and a return message from the ISDN terminal under test in response to the transmission message. a message storage means, a transmitted message sent from the test control means during the test, and a test target J for the transmitted message;
A return message from the SDN terminal is input and compared with the verification transmission message and verification return message stored in the verification message storage means, and the
A protocol determining means is provided for determining whether the terminal is an N terminal, a terminal for B channel communication, or a terminal for D channel communication, and for causing the test control means to select a communication compatibility test method that conforms to the determination result. Configure.

[Industrial application field]

The present invention relates to a communication compatibility testing method for an ISDN terminal connected to an S/T point of an ISDN subscriber interface.

In recent years, progress has been made in the construction of integrated services digital networks (ISDN), and in addition to circuit switching and packet switching using the B channel, packet switching using the D channel has also come to be performed. As is well known, an ISDN subscriber line consists of two B channels and one D channel, and up to eight terminals of various media, such as telephones, facsimile machines, and data communication equipment, can be connected to one subscriber line. It is possible to connect the terminal. These terminals (hereinafter referred to as IS
The DN terminal (hereinafter referred to as DN terminal) is connected to the S/T point of the ISDN subscriber interface and connected to the subscriber line via the network terminal (NT), but the communication method is circuit switching using the B channel. communication or communication by packet exchange (hereinafter referred to as B-channel communication or B-ch communication)
There are cases where terminals perform packet communication using the D channel (hereinafter referred to as D channel communication or D-ch communication), and there are many terminals that can use both B channel communication and D channel communication.

When connecting these ISDN terminals to an ISDN line,
Communication procedures (protocols) must conform to established standards, and communication compatibility tests are conducted to verify this. The communication suitability test is performed in each state of call control.
This is to verify whether the SDN terminal has performed the state transition specified in the technical standards for the received message, and this is done by verifying the response contents to all messages received after the call setup request (SETUP). be exposed.

This communication compatibility test is generally performed by connecting a protocol tester having a network termination device simulator function to the SZT point, which is the interface between the ISDN terminal and the network termination device.

The communication compatibility test using a conventional protocol tester is as described in B above.
The main focus is on call control for channel communications, and the call control for D-channel communications requires some protocol, so it was necessary to replace the internal program of the protocol tester. Therefore, the tester should check the attributes of the terminal under test in advance, and if the terminal under test is a terminal that performs D-channel communication, replace the program as described above, or check the compatibility of both B-channel communication and D-channel communication. It was necessary to create a test program that can test D channel communication, and to perform switching operations when testing D channel communication. For this reason, preparations and operations are complicated, placing a burden on the tester.

In view of the above, there is a need for a communication compatibility testing method that allows a protocol tester to automatically switch between testing the communication compatibility of B channel communication and D channel communication using one program.

[Conventional technology]

FIG. 3 is a connection diagram of the ISDN terminal, and FIG. 4 is a test sequence diagram.

Figure 3 (1) shows eight ISDN terminals (hereinafter referred to as TE) 2-1 connected to the S/T point of the subscriber interface.
~2-8 is the network terminal device (hereinafter referred to as NT) 15 via I
It shows the state connected to the SDN exchange 16,
TE11~2. A termination circuit 8 is connected to the line that connects the two lines in multiple ways. In addition, FIG. 3(2) shows the TE2-t
This shows a state in which the protocol tester 1' is connected in order to perform the communication compatibility tests of 2-8.

Figure 4 (1) is TE2 visit ~ 2-8 in Figure 3 (2).
This shows a control sequence when performing B channel communication between one of the NT or protocol tester 1'.

In the case of a test, the protocol tester 1' plays the role of the NT, so the signal between the NT and the TE in FIG. 4(2) becomes a signal transmitted and received between the protocol tester 1' and the TE. All the signals in the figure are sent and received on the D channel, except for the communication on the B channel (■), or among these,
The preamble part (■ to ■) is the transition before reaching the test state, and the test is carried out at ■ and 0, and the postamble part (@-
Q) will be processed after the test is completed.

Now, if we are to test the protocol of incoming calls to the TE, we will use the protocol tester 1' (in the case of testing, do all NTs in Figure 4 mean the protocol tester 1'?
(referred to as NT in the following explanation) starts the TE allocation procedure from the initial state, but first, in step (), the identification information (ID) of the terminal in the UI (unnumbered system information) is restored, and then the A setting request signal 5ETUP is sent to the incoming TE (see ◯ in Fig. 4, hereinafter simply written as ◯). In response, the TE specifies the termination point identifier T E I (Terminal
The NT requests the TE (End-point Identifier) (■), and allocates a TEI to the TE (■). The TE then sends the signal S A M B E (Set
Asynchronous Balanced Mode
Extended) is sent to the NT (■), and the NT responds with an acknowledgment U A (Unnumbered A).
ck, ) is returned (■).

In this state, the TE is called, and the TE sends an ALERT indicating that the call is in progress to the NT. Next, when the TE responds, the TE sends a response signal C0NN to the NT (■),
The confirmation signal C0NN ACK is returned from the NT (■). Here, the B channel is connected in both directions, allowing communication on the B channel ([phase]).

In the case of a test, communication on the B channel is not normally performed, but test messages are sent and received between the NT and TE via the D channel while communicating on the B channel (■
,■). When the test is completed, the NT sends the signal REL to release the B channel (@), and the TE sends the REL COM signal to notify the completion of channel release and call number release.
P is returned (0) and the test ends. If you wish to repeat the test, repeat the steps above from ■.

Figure 4 (2) and Figure 4 (3) are C in Figure (1).
The protocols after 0NN (■) are shown for B channel communication and D channel communication. As is clear from both figures, the call control protocols for B channel communication and D channel communication are different. Among these, the test for call control of B channel communication in Fig. 4 (2) is the same as Fig. 4 (1), so the explanation will be omitted, and the following will be described below.
Call control of channel communication will be explained with reference to FIG. 4 (3).

In the case of D channel communication, when the TE sends C0NN to the NT (o), the NT sends a release signal REL without returning C0NNACK, and the TE that receives this sends back a reception confirmation signal REL COMP. Do (■, 0).

Here, the NT uses the D channel link access procedure (L
APD), and sends SABME 5 API 16, which is service identification information (@l).

In response, the TE returns the UA (■) and a layer 2 link is established. Next, the NT sends a C N (Call Incoming) packet to notify the incoming call, and the TE sends a CA (Call Accept) packet for confirmation.
ed) Packets are returned and packet communication via the D channel becomes possible (@, @). In the case of a test, packet communication using this D channel is not particularly necessary, and once the test is finished, the established link can be used to communicate with the CQ packet from the TE and the N channel.
Disconnect by sending/receiving CF packet from T (@, @
).

As mentioned above, since the protocols for B channel communication and D channel communication are different, in a communication integrity test, for example, when the NT receives C○NN (@=■) from the TE for B channel communication, the NT receives C0NNACK (@ =■) is not returned, the TE detects an abnormality, and when the TE of D channel communication sends C○NN <@), the TE detects an error.
If a C0NN ACK is returned, the TE side determines that there is an abnormality.

Therefore, in the conventional technology, for example, if the non-test TE performs D channel communication when testing is performed assuming protocol tester 1 = (NT equivalent) or B channel communication, the result shown in FIG. 4 (2) C○NN ACK (@
) is detected as an abnormality, and the test is terminated at this stage. Thereafter, it is necessary to replace the test program in the protocol tester 1' with one suitable for D channel communication call connection and perform the test again. For this reason, T.E.
When testing, it is necessary to check the attributes of each TE in advance and perform the test while replacing or switching programs for B channel communication and D channel communication according to each attribute. However, it takes time and effort to prepare in advance, and especially when testing multiple TEs in succession, program selection and operation become complicated, resulting in confusion among testers.

[Problem to be solved by the invention]

Conventional protocol testers are configured to test communication compatibility mainly for call control of B channel communication, so when testing call control of packet communication using D channel, different parts of the sequence are tested. It is necessary to prepare a test program modified to suit D-channel communication, and when testing TE for D-channel communication, it is necessary to replace or switch the test program to the one for D-channel communication. In addition to requiring time and effort to prepare in advance, such as investigating the attributes of the TE to be tested, the method also has the disadvantage that program selection and operation are complicated, especially when testing multiple TEs in succession.

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication compatibility test method that automatically switches the test procedure between B channel communication and D channel communication based on a return message from an ISDN terminal under test.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, l is a protocol test unit that tests the communication compatibility of the ISDN terminal 2 connected to the S/T point of the ISDN subscriber interface, 2 is the ISDN terminal, and 3 is the B of the ISDN subscriber line where the ISDN terminal 2 is connected. 4 is a test control means capable of performing a communication compatibility test for both communication using the D channel and communication using the D channel; 4 is the ISDN terminal under test 2 from the test control means 3
Verification message storage means for storing a plurality of sets of verification transmission messages and verification return messages each having the same content as a transmission message sent to and a return message from the ISDN terminal under test 2 in response to the transmission message; Reference numeral 5 denotes a verification transmission message stored in the verification message storage means 4 by inputting a transmission message sent from the test control means 3 and a return message from the ISDN terminal under test 2 in response to the transmission message when the test is carried out. and the verification return message to determine whether the ISDN terminal under test 2 is a terminal for B-channel communication or a terminal for D-channel communication, and the test control means 3 is configured to match the determination result. This is a protocol determination means for selecting a communication compatibility test method.

[For production]

In FIG. 1, a case will be described in which the test control means 3 executes the test using one of the ISDN terminals 2 as the terminal under test.

The test control means 3 can perform a communication compatibility test both when the ISDN terminal under test 2 performs B channel communication and when it performs D channel communication, and depending on the judgment result of the protocol judgment means 5. It is possible to switch the communication compatibility test procedure to one suitable for call control of either B channel communication or D channel communication.

Generally, a communication suitability test is carried out by moving the terminal under test to a specified state and checking the response of the ISDN terminal under test 2 when a test message is sent there. That is, when the test control means 3 sends out a transmission message, the return message changes depending on whether the ISDN terminal performs B channel communication or D channel communication, and then the test control means 3 sends out the transmission message. , verify the contents of the return message from the ISDN terminal under test.

For example, if the test control means 3 sends a specific message assuming B channel communication, if the ISDN terminal under test 2 is a terminal that performs B channel communication, a normal response will be returned or D channel communication will be performed. If it is a terminal, the response will be different from normal, so communication compatibility can be verified.

In the above case, in the conventional communication compatibility test, the test would be terminated at this stage when the latter returned message was received, but in the present invention, the communication compatibility test is changed by changing the communication compatibility procedure as follows. You are now able to proceed.

For example, when the test control means 3 sends a message to the ISDN terminal under test 2 assuming B channel communication,
The protocol determination means 5 inputs this and compares it with a plurality of types of transmitted messages stored in advance in the verification message storage means 4 to determine whether the protocol is being carried out. Further, the protocol determining means 5 also inputs a return message sent back from the ISDN terminal under test 2 in response to the above-mentioned sent message, and also inputs a return message sent back from the ISDN terminal under test 2 to the verification message storage means 4.
Compare with multiple types of returned messages stored in . By examining the results of these two comparisons, it can be confirmed that the ISDN terminal under test 2 is sending a normal return message in response to the message sent for B channel communication assumed by the test control means 3. The ISDN terminal under test 2 is a B-channel communication terminal, and if it has returned a response message from a D-channel communication terminal in response to a message sent for B-channel communication, then the ISDN terminal under test 2 is a B-channel communication terminal.
It can be determined that terminal 2 is a terminal that performs D channel communication.

When the protocol determination means 5 reports the above determination result to the test control means 3, the test control means 3 switches to the communication compatibility test for D channel communication, and the ISDN terminal under test 2
Run the test again from the required rung. Thereby, the test control means 3 can continue the communication compatibility test without discontinuing it, and can test the communication compatibility of the ISDN terminal 2 under test.

〔Example〕

FIG. 2 is a configuration diagram of an embodiment of the present invention, and shows an example of the configuration of a protocol tester (claim 2) that performs a communication compatibility test of an ISDN terminal.

Throughout the figures, the same objects are indicated by the same symbols, l is a protocol tester, 6 is a call control message transmitter that sends messages sent from the protocol tester 1, and 7 is a part that disassembles messages received from the protocol tester 1. 8 is a terminal circuit, 9 to 14 are each part of the test control unit 3, and 9 is a basic unit that manages the entire test and controls the selection of test contents, execution, continuous testing, etc. The control unit, IO, is a protocol control unit that controls the ISDN terminal under test 2 to transition to a test state, generates and specifies messages to be sent, returns after the test, and manages time, and 11 controls response time. 12 is a response determination unit, 13
is a keyboard, and 14 is a display.

First, the ISD to be tested is
The overall operation when testing N terminal 2 will be explained.

When conducting a test, the tester inputs test conditions and the like into the basic control section 9 using the keyboard 13 and display 14, and the basic control section 9 selects, controls, and manages test items in accordance with the input. The protocol control unit IO transmits the transmitted message to the call control message transmitting unit 6 while generating messages and managing time according to instructions from the basic control unit 9.
is sent to the ISDN terminal under test 2 via. IS under test
When the DN terminal 2 sends a return message in response to the transmitted message, the call control message receiving section 7 receives and analyzes this, and transmits the return message to the response determination section 12. The response determination unit 12 checks whether this returned message is the specified response or not, and determines whether the test result is pass or fail.
Report to the basic control unit 9.

Upon receiving this report, the basic control unit 9 terminates the test or
Or move on to the next exam.

In the above, the content and sequence of the transmission message transmitted from the protocol control unit 10 and the return message from the ISDN terminal under test 2 in the normal state are the same as those in FIG. 4 explained in the prior art, so the explanation will be omitted, and the following will be explained below. The operation of the main parts of the present invention will be mainly explained with reference to FIGS. 2 and 4.

In FIG. 2, the verification message storage section 4 stores the verification transmission messages and verification messages that have the same contents as the messages that may be sent from the protocol control section 10 and the messages that may be returned from the ISDN terminal under test 2. received messages are stored in advance. When a test is started on the protocol tester 1 or the ISDN terminal under test 2 in this state, the protocol control unit 10 sends and receives messages to and from the ISDN terminal under test 2, and then the ISDN terminal under test 2 is ) until C0NN transmission (■).

During this time, the protocol determination section 5 inputs the message transmitted from the protocol control section 10 and the message returned from the ISDN terminal under test 2 through the monitor, and checks the transmitted verification message stored in the verification message storage section 4 and the message sent back from the ISDN terminal under test 2. Compare it with the received verification message to understand the progress of the call control protocol.

For example, if the protocol that the protocol tester I is trying to test is the incoming operation of packet communication by the D channel, the transmission capability information element (not shown) is included in 5ETUP■ of FIG. 4 (1). Since it is indicated that the communication is packet communication, the protocol determination unit 5
inputs 5ETUP■ sent from the protocol control unit IO and compares it with the verification transmission message stored in the verification message storage unit 4, thereby determining that the test content is a packet communication operation using the D channel. judge. After that, from the ISDN terminal 2 under test, C0NN■
4 (3) is received, the protocol determination section 5 compares the verification return message stored in the verification message storage section 4 with the received C0NN.
It is checked whether or not there is channel identification information (CHID, not shown) in the message indicating that the packet communication is via the D channel. As a result, if the information indicating D-channel communication is confirmed, the protocol determination unit 5 determines that the ISDN terminal under test 2 is compatible with D-channel communication, and the response determination unit 5
2 and the protocol control unit 10 are notified of this. As a result, the protocol control unit 10 will proceed as shown in (3) in FIG.
The test is completed by sending and receiving messages according to the following sequence.

The above is a case where there is a match between communication compatibility and D channel communication, but for example, the transmission capability information element in 5ETUP■ sent from the protocol control unit IO indicates that it is voice (telephone) information handled in B channel communication. is indicated, and the ISDN terminal under test 2 or D in the C0NN message ■
If you want to show information that indicates channel communication,
The protocol determining unit 5 determines that the communication compatibility does not match, and notifies the response determining unit 12 and the protocol control unit IO that the ISDN terminal under test 2 is operating for D channel communication. This allows the protocol control unit IO
Switch the communication compatibility test to D channel communication, re-execute the sequence in Figure 4 (1) from ■ to ■ as D channel communication, and then move to the sequence after ■ in Figure 4 (3). Confirm communication suitability for D channel communication.

As described above, in the present invention, the test, which was conventionally canceled when there was a mismatch in communication compatibility, is changed by changing the test conditions by messages sent and received between the protocol tester 1 and the ISDN terminal under test 2. Since you can test again with conditions that match the settings of terminal 2,
It is possible to efficiently test multiple ISDN terminals 2 in succession.

Although the present invention has been explained in detail with reference to FIGS. 2 and 4, FIG. 2 merely shows an example of the present invention, and FIG. 4 shows the basic sequence of the ISDN terminal protocol. It is merely an indication of the Therefore, the structure and sequence of the present invention are not limited to only those shown in FIG. 2 and FIG.
It is clear that the method can also be applied to sequences different from those shown in the figure.

〔Effect of the invention〕

As described above, according to the present invention, the communication suitability test for B channel call control that has been conventionally performed can be applied to call control for D channel packet communication without replacing or switching the test program. In addition, it eliminates the need for preliminary investigation of the attributes of the ISDN terminal under test and program changes during testing, which improves test efficiency, especially when testing the communication compatibility of multiple ISDN terminals in succession. It has a great effect on improving.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is an ISDN terminal connection diagram, and FIG. 4 is a test sequence diagram. In the figure, 1 ----------... Protocol test section 2 ----
1-・-・ISDN terminal 3 ・・・・・・・・・-・・-
Test control means 4 --- Verification message storage means 5 --- Protocol determination means. Figure 1 Test nokenos diagram Figure 4 NT TENT
TE(shi()ININ and SOJpi1no

Claims (1)

[Claims] 1. In a communication compatibility test method for an ISDN terminal (2) connected to an S/T point of an ISDN subscriber interface, the ISDN terminal (2) uses the B channel of an ISDN subscriber line. A test control means (3) capable of performing a communication compatibility test both when communicating and when communicating using a D channel; and the test control means (3).
) to the ISDN terminal under test (2) and the I under test for the transmitted message.
a verification message storage means (4) for storing multiple sets of verification transmission messages and verification return messages each having the same content as the return message from the SDN terminal (2);
When conducting a test, a transmission message sent from the test control means (3) and a test object I for the transmission message.
A return message from the SDN terminal (2) is input and compared with the verification transmission message and verification return message stored in the verification message storage means (4), and it is determined whether the ISDN terminal under test (2) is on the B channel. Protocol determining means (5) for determining whether the terminal is for communication or for D channel communication, and for causing the test control means (3) to select a communication compatibility test method that conforms to the determination result.
A communication compatibility test method for an ISDN terminal, characterized in that the content of the communication compatibility test can be automatically switched and executed according to the communication content of the ISDN terminal under test. 2. The test control means according to claim 1 (
3), a verification message storage means (4), and a protocol determination means (5).