JP3080438B2 - ATM channel switching continuity 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 communication path continuity test method for an ATM exchange having a function of exchanging connectionless information.

In recent years, BISDN (Brad band Integrated
ATM as an exchange method for Services Digital Network)
(Asynchronous Transfer Mode) type exchanges have been actively studied for practical use. In this ATM system, information is transferred and transferred in units of cells of a fixed length (normally 53 octets).

In an ATM network, processing is usually performed in a connection-oriented manner. However, a mechanism for supporting connectionless communication is provided, and a continuity test of a communication path of an ATM switch having such a function is required. Is desired.

[0004]

2. Description of the Related Art FIG. 6 is a diagram for explaining the principle of a conventional example. FIG.
In the figure, 50 is provided on an input highway connected to a subscriber, and generates outgoing message processing means for supporting a connectionless message, 51 is a test cell insertion means, 52 is a test cell generation means, and 53 is a VCI (Virtual
An ATM exchange channel for exchanging cells by Channel Identifire), 54 is a test cell extracting means, 55 is a test cell receiving means, and 56 is provided on an output highway (connected to a subscriber) corresponding to the outgoing message processing means 50. Terminating message processing means for supporting connectionless messages; 57, a communication path control section for controlling the path setting of the ATM exchange communication path; and 58, a call processing section for managing the entire switch at the call level. is there.

A general connection-oriented connection process in an ATM exchange will be described. In this case, when the calling subscriber uses the control channel to display the subscriber of the destination information (connection partner) to the exchange and makes a connection request, the exchange uses the destination information to indicate that the other party is idle. Then, when there is no connection, a connection path in the network from the calling subscriber to the destination subscriber is set (routed).

[0006] Thereafter, the cellized message from the calling side is transferred to the other side through the route set in the communication path of the exchange. In this case, the VCI (virtual channel identification information) included in the cell transmitted by the subscriber is:
The data is converted into a VCI corresponding to a path passing through a route set in the ATM exchange communication path, is converted into a VCI of the other party on the output side of the communication path, and is transmitted to an output highway to which the other party is connected.

[0007] In addition to such connection-oriented connection, a connection path to a destination subscriber is not set in advance, and a message is transmitted every time a message to be transmitted by a transmission side (calling side) subscriber is generated. , There is a connectionless communication that is routed each time and transmitted to the other side.

The operation of connectionless communication will be described with reference to FIG. 6. A connectionless cellized message sent from a calling side (a message is often decomposed into a plurality of cells) includes destination information ( DA: De
The destination information and the VCI of the calling subscriber are added to each message.
The VCI, which is the routing determination information in the exchange communication path 53, is rewritten.

Each outgoing message processing means 50 transmits a VCI (VC identifying a subscriber) of each cell constituting a message.
I) is converted into the VCI designated by the call processing unit 58 and input to the ATM exchange communication path 53. ATM switching channel 5
3 is controlled by the channel control unit 57, and V of each input cell is
It controls the output highway by identifying the CI. The output of the ATM exchange communication path 53 is input to the destination message processing means 56, and is converted into the VCI of the destination subscriber.

The function of the outgoing message processing means 50 is as follows.
By monitoring the test message generated from the test message generator 501 by the test message monitor 502, it is monitored whether the operation is normal. Similarly, the test message generating unit 560 and the test message monitoring unit 561 of the destination message processing unit 56 monitor the normality of the function.

[0011] The connectionless information as described above is the AT
It is necessary to test whether or not the signal passes through the M exchange communication path 53 normally. Therefore, the test cell generating means 52 and the test cell inserting means are provided on the input side of the ATM switching channel 53, and the test cell extracting means 54 and the test cell receiving means 55 are provided on the output side.

The test cell generator 52 allocates an unused VCI on a target output highway and generates a test cell. Note that the call processing unit 58 includes the test cell generation unit 5
2 before the assigned unused VCI
Is set to pass through a desired route in the ATM exchange communication path 53.

Thus, the test cell is connected to the ATM exchange communication path 53.
To the assigned output highway through the desired route. The output cells are output to a predetermined one of the test cell extracting means 54 provided corresponding to each output highway. The test cell extracting means 54 provided on the output highway fetches a cell to which an unused VCI assigned in advance for the test cell is added, and the test cell receiving means 55 receives the cell. The call processing unit 58 compares the test cell generated by the test cell generation unit 52 with the test cell received by the test cell reception unit 55, and confirms that the call passes through the ATM communication path by a correct route and can be transmitted and received normally.

[0014]

In the prior art system described above, in order to conduct a continuity test on the communication path of the ATM exchange, test cell generation and monitoring means are required on all input / output highways of the communication path. There is a limitation that an unused VCI must be allocated in the test target route in order to identify a test cell. That is, the unused V
Processing for detecting and assigning CI was required.

A mechanism for monitoring the functions of the originating message processing means 50 and the destination message processing means 56 and a mechanism for testing the ATM exchange communication path have to be provided. .

An object of the present invention is to provide a communication path continuity test method for an ATM exchange which can simplify the processing of a communication path test of an ATM exchange and reduce the amount of hardware.

[0017]

FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, reference numeral 1 denotes a calling side device, 2 denotes a called side device, 3 denotes an ATM switching communication path, and 4 denotes a call processing unit. Reference numerals 10 and 20 denote control units, reference numeral 11 denotes a test message generation unit, reference numeral 12 denotes a test cell insertion unit, reference numeral 13 denotes a source message processing unit, reference numeral 23 denotes a destination message processing unit, and reference numeral 24 denotes a test cell. The extraction unit 25 is a test message receiving unit.

According to the present invention, it is possible to test an ATM exchange communication path by using a mechanism for confirming the normality of functions of a calling message processing section on a calling side and a called message processing section on a called side.

[0019]

In FIG. 1, when confirming the normality of the functions of the originating message processing unit 13 and the destination message processing unit 23 in the originating apparatus 1 and the terminating apparatus 2, respectively, the test message generating unit 11 specifies a specific message as a test message. A VCI that has a DA (destination address) that does not exist (does not use for controlling the path of the actual communication path) and indicates that it is a test cell
Generate a cell with Each test cell is inserted from the test cell insertion unit 12 into the input highway and the output highway, respectively.

The test of the ATM switching communication path 3 is performed by the call processing unit 4
When a communication path test is instructed to the control unit 10 of the originating apparatus 1 under the control of the above, a test message for the communication path test is generated from the test message generation unit 11. In this case, when the message is converted into a cell, the VCI added to the cell is a value indicating the test message, and a value that does not actually exist as a DA (destination) is assigned.

When this test cell is inserted into the input highway from the test cell insertion unit 12, the outgoing message processing unit 13 identifies the DA and VCI included in the cell and detects that it is a cell for a speech path test. . Then, the outgoing message processing unit 13 converts the VCI value of the test cell into a VCI value assigned to the route (path) to be tested on the ATM exchange communication path 3, and outputs DA as it is.

The cell for the channel test is input to the ATM switching channel 3. The ATM exchange communication path 3 switches the cell to a route corresponding to the VCI value included in the cell and transfers the cell to the output highway connected to the route of the destination device 2.

When this cell arrives at the destination message processing unit 23 of the destination device 2, the destination message processing unit 23 recognizes that the cell is a call test cell by identifying the DA (destination) of the cell. , Is converted to a value indicating that the cell is a test cell and output. When this cell is input to the test cell extraction unit 24, the VC included in the cell
Since the value of I indicates the test cell, this cell is extracted and input to the test message receiving unit 25. The test message composed of the cells received by the test message receiving unit 25 is supplied to the call processing unit 4 via the control unit 20.
The call processing unit 4 compares the test message generated from the calling side apparatus 1 with the test message received by the called side apparatus 2 and performs an ATM operation.
It is determined whether or not the exchange communication path 3 is normal.

[0024]

[0025]

[0026]

[0027]

FIG. 2 is a block diagram of an embodiment, FIG. 3 is a diagram showing a format of each layer of a message, FIG. 4 is a block diagram of an outgoing / incoming message processing unit, and FIG. It is a block diagram.

In FIG. 2, reference numerals 1 to 4 correspond to the devices having the same reference numerals in FIG. 1, 1 is a calling server, 2 is a receiving server,
Reference numeral 3 denotes an ATM switching communication path, and reference numeral 4 denotes a call processing unit. In the originating server 1 and the terminating server 2, 10 and 20 are server control units, 11 and 21 are test message generating units, and 12 is a cell multiplexing unit (indicated by MUX, the test cell inserting unit 12 in FIG. 1). , 13 is an outgoing message processing unit, 22 is a cell multiplexing unit, 23 is an incoming message processing unit, 140, 141 and 2
Reference numerals 40 and 241 denote address filters (displayed in AF) having a function of extracting a specified VCI. Also, 1
5 and 25 are test message receiving units, 30 is a communication path control unit, and 4 is a call processing unit.

First, the format of a message in each layer will be described with reference to FIG. The message transmitted and received between the subscribers corresponds to layer 3 (referred to as L3) as shown in the upper part of FIG.
Header, L3 which is information to be transmitted afterwards
This is a configuration in which information and an L3 trailer are sequentially arranged at the rear. The L3 message is converted to an adaptation layer 2 (L2) when transmitted by ATM.

In the L2 format, as shown in the middle part of FIG. 3, the L3 message is divided into blocks of a fixed length (for example, 44 bytes) sequentially from the beginning, and each block is provided with an adaptation layer at the beginning. An L2 header (for example, 2 bytes) used for processing is newly added, and an L2 trailer (for example, 2 bytes) is added to the rear part. In this example, each block of L2 is 44 bytes long.

Next, cells of layer 1 (L1) are formed based on each block created in L2, and the cell format is as shown in the lower part of FIG. That is, L2
L1 header is added to the head of each block (for example, 5 bytes), and after the header, the L2 block is arranged as it is to be an L1 cell. In this example, the length of the L1 cell (ATM cell) is The length is 53 bytes.

In the format shown in FIG. 3, when a connectionless message is transmitted, the cell of L1 is formed through the blocking of the adaptation layer in L2. In this case, when input from the subscriber to the exchange, each cell of L3 has a VC set by each subscriber.
I is added to the header, and the exchange uses the destination address (D) included in the first cell of the cellized message.
A), the route to be transferred to the destination is selected (routing), and the VCI corresponding to the selected route is shown in FIG.
L of each cell as shown in the cell format of layer 1 of
Write in one header (change original VCI).

The configuration of the embodiment of FIG. 2 exchanges cells of a message using the above-described format and executes a communication path continuity test. The operation of the embodiment will be described.
The connectionless message input from the subscriber is converted into a cell and input to the originating server 1, and the cell multiplexing unit 12
Is input to the outgoing message processing unit 13 via the. Here, the destination address (DA) is identified, routed and converted into a corresponding VCI.
It is exchanged on the communication path 3 via F140 and is input to the destination server 2 of the corresponding destination. The destination message processing unit 23 converts the VCI of the cell into the VCI of the other subscriber and sends it.

When monitoring the functions of the outgoing message processing unit 13 and the incoming message processing unit 23, the server control unit 1
When the monitoring messages are converted from the test message generator 11 and the test message generator 21 into cells under the control of 0 and 20, and transmitted in the same manner as in the prior art, the cell multiplexers 12 and 22 are transmitted.
To the respective message processing units 13 and 23, where each VCI value is converted into a specific monitoring value and output. This cell is detected by the address filters 141 and 241 and input to the test message receiving units 15 and 25.

The operation of the continuity test of the communication path 3 in FIG. 2 will be described. Server control unit 1 according to an instruction from call processing unit 4
0 is a test message generator 1 for performing a communication path continuity test
1 is driven. The test message generator 11 is a VCI (for example, all “0”) allocated to test the outgoing message processor 13 as a cell of the test message.
And a test message in which a number not used as a destination address (DA) is set is generated. For example, in a normal destination address (DA), a number is represented by a plurality of digits of a binary-coded decimal value (4 bits), and the value of each digit is 0000 to 1001.
, The 4-bit value of each digit is all “1”.

This test message is input from the cell multiplexing unit 12 to the outgoing message processing unit 13. When performing a channel continuity test, a route (path) to be subjected to the continuity test is instructed from the call processing unit 4 to the server control unit 10, and the outgoing message processing unit 13 transmits a message cell for the channel continuity test. (Identified by the above specific DA) is input, the server control unit 10 transmits the VCI of the cell of the message.
Is converted into the VCI of the communication path to the destination to be tested (specific outgoing highway).

Since the cell of the continuity test message having the converted VCI has the same VCI as a general communication cell, it passes through the address filter 140 and is input to the communication path 3. Under the control of the communication path control unit 30 instructed by the call processing unit 4, the communication path 3 sets the cells of the highway on each input side to V
A path corresponding to the CI is formed and transferred to the destination highway on the output side.

When a cell is input to the destination server 2 connected to the output highway, it is supplied to the destination message processing unit 23 through the cell multiplexing unit 22. The server control unit 20
A path to be subjected to a continuity test is previously specified from the call processing unit 4, and the VCI of the path is supplied to the destination message processing unit 23.

When a cell having the above-mentioned unused destination address (DA) (a cell for a continuity test message) is input to the destination message processing unit 23, the VCI (VCI) assigned to the test message cell "0") and send it out. Address filter (A
F) 241 fetches the cell of the test message, and the test message receiving unit 25 receives this cell.

The call processing unit 4 can check the normality of the continuity operation on the designated communication path by comparing the test message received by the destination server 2 with the test message transmitted by the calling server 1. .

FIG. 4 shows the configuration of the outgoing / incoming message processing unit, and FIG. 5 shows the configuration of the routing unit of the outgoing message processing unit. A. of FIG. Is an outgoing message processing unit; Is the configuration of the destination message processing unit.

The originating message processing unit 13 terminates the protocol of the information input from the subscriber side by the protocol terminating unit 130, and gives the VCI for routing the cell of the message to the communication path by the routing unit 131.
The output is output from the protocol termination unit 135 to the communication path to the communication path.

The mechanism of the routing section 131 of the outgoing message processing section will be described with reference to FIG. An L3 header (see FIG. 3) is stored in the information field of the first cell of the test message to be input. When this cell is input to the DA determination unit 132, the DA (destination address) in the cell is determined. . On the other hand, the contents of the VCI conversion table 134 are written by the server control unit (10 in FIG. 2). In the case of the continuity test of the communication path, as described above, the unused DA is given in advance from the test message generator (11 in FIG. 2), and the VCI conversion table 134 is sent from the server controller.
The VCI of the route to be tested is written as the VCI corresponding to this DA.

According to the DA determined by the DA determining unit 132, V
Referring to the CI conversion table 134, the corresponding VCI
Is read out, and the VCI is supplied to the VCI adding unit 133 and written as the VCI in the header (L1 header) of the cell (the original VCI is converted). Thus, the VCI of the cell of the communication path continuity test message is converted.

Next, FIG. The message processing unit of
Like the originating message processing unit, the protocol termination unit 230
When the cell input from the terminal is input to the routing unit 231, the destination address determining unit 232 identifies which terminal on the subscriber side is the destination. When the destination address is known from this determination, the VCI conversion table 2 is obtained from the address.
34. This table 234 has the same configuration as the VCI conversion table 134 of the above-mentioned outgoing message processing unit. Since the VCI corresponding to the destination address is written, when the VCI is taken out, the VCI adding unit 2
33, a VCI different from the original VCI of the cell is assigned.

The head cell of the call path continuity test message contains the destination address DA which is not used as described above as the destination address (included in the header of L3 included in the information field of the L1 cell). The destination address determination unit 232 determines this. VCI conversion table 234
The VCI (all “0”) of the test cell is written in advance in the address corresponding to this address from the server control unit (20 in FIG. 2), and is determined by the destination address DA determined from the destination address determination unit 232. Referring to FIG.
The CI is extracted, and this VCI
CI (all “0”) is given to the test cell.

In the configuration of the above embodiment, the test message generator and the test message receiver are provided for each highway. However, a common test message generator and a test message receiver are provided, and By inserting and extracting the cellized message into the input / output highway of the test target route according to the instruction, the amount of hardware can be reduced.

[0048]

According to the present invention, the continuity test of the ATM exchange communication path can be performed by using the test device of the message processing unit of the transmission / reception in the ATM network accommodating the connectionless information. There is no need to provide a device, and the hardware configuration can be simplified.
If there is a VCI for which a path is set in the test target route in advance, the VCI can be used for the test cell. Therefore, it is necessary to search for a free VCI for the test cell and set a new path as in the conventional case. The test can be easily executed.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is a diagram showing a format of a message in each layer.

FIG. 4 is a configuration diagram of an outgoing / incoming message processing unit.

FIG. 5 is a configuration diagram of a routing unit of the outgoing message processing unit.

FIG. 6 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Calling side apparatus 2 Calling side apparatus 3 ATM exchange communication path 4 Call processing section 10, 20 control section 11 Test message generating section 12 Test cell inserting section 13 Originating message processing section 23 Terminating message processing section 24 Test cell extracting section 25 Test message Receiver

Continuing on the front page (72) Inventor Takeshi Ken Kawasaki 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Tomoji Kuroyagi 1015 Kamedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) Reference JP-A-3-71751 (JP, A) JP-A-4-1577841 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/24-12/28 H04L 12 / 56

Claims (2)

(57) [Claims] 1. An outgoing message processor for analyzing a destination address of a cellized variable-length message at a preceding stage of a communication path to route a communication path, and a subsequent message processor at a latter stage for routing to a subscriber. comprising, in the speech path continuity test mode of the ATM exchange to exchange co Ne transfection less information with a communication path to be exchanged between destination message processor and the calling message processing unit in accordance with the VCI value of the cell input, the calling Cell insertion means is provided before the message processing unit.
Comprises a specific destination for continuity test speech path to the cell inserting means, interpolation cell for test set the VCI value representing the test
Type, the calling message processing unit detects a cell for the test
The VCI value representing the test is represented by VC representing the route to be tested.
Enter the call path is converted into I values, wearing message processing unit corresponding to the route of the test subject, VCI values representing the test VCI value representing the tested root of the cells output from the speech path And a cell extracting means is provided at the subsequent stage of the incoming message processing unit .
The communication path continuity test method for an ATM exchange, wherein the cell extracting means extracts a cell having a VCI value representing the test. 2. The test object according to claim 1, wherein a cellularized test message generator for a communication path continuity test is provided in common for each input highway, and a cellularized test message receiver is provided in common for each output highway. test of the cell of the test message generating unit from a preceding insertion means of the origination message processing portion connected to the speech path
Insert the cell, the speech path continuity ATM switch and extracting the cells for testing from subsequent extraction means of the destination message processing unit of output highways tested speech path to the cell trials message receiving unit Test method.