KR0175457B1 - Maintenance method of subscriber station in asynchronous delivery mode permanent virtual exchange - Google Patents

Abstract

The present invention is an ATM Permanent Virtual Connection (ATM PVC) switch that performs a switching function for a virtual path (VP) in a broadband integrated service digital network (B-ISDN). The present invention relates to a method for maintaining a subscriber station in an ATM PVC exchange that enables a subscriber to maintain a subscriber station connected to the subscriber network in real time. It is possible to maintain the subscriber terminal, the broadband network termination device and the link to which the subscriber terminal is connected in real time, thereby reducing maintenance costs, increasing the reliability of the communication network, and providing information and communication services to the subscriber. The effect is to improve the quality of.

Description

Subscriber terminal maintenance method in asynchronous delivery mode permanent virtual exchange

1 is a block diagram of a broadband integrated information network (B-ISDN) to which the present invention is applied.

2 is an explanatory diagram showing a performance system of an operation and maintenance (OAM) function of a broadband integrated information network (B-ISDN).

Figure 3 is a flow diagram of an embodiment of a subscriber station maintenance method in an asynchronous delivery mode permanent virtual switching exchange according to the present invention.

4 is a structural diagram of a loopback response message of FIG. 3 used in the present invention.

5 (a) and 5 (b) are flowcharts of one embodiment of a method for maintaining a subscriber station in a broadband network termination apparatus (B-NT) according to the present invention.

* Explanation of symbols for main parts of the drawings

11a: Asynchronous Transfer Mode Permanent Virtual Connection (ATM PVC) Switch

11b: Asynchronous Transfer Mode Exchange Hypothesis Connection (ATM PVC) Exchange

12a, 12b: Broadband network termination device (B-NT, B-NT ')

The present invention is an ATM Permanent Virtual Connection (ATM PVC) switch that performs a switching function for a virtual path (VP) in a broadband integrated service digital network (B-ISDN). The present invention relates to a subscriber station maintenance method in an ATM PVC switch that enables a subscriber to maintain a subscriber station connected to a subscriber network in real time.

In general, the broadband integrated telecommunication network (B-ISDN) provides high-speed, broadband services to a large number of subscribers, so that existing public switched telephone networks (PSTN) and integrated service digital networks (ISDN) are available. Easier, more convenient, faster, and more accurate for maintenance of network elements is required.

1 is a block diagram of a broadband integrated information network (B-ISDN) to which the present invention is applied.

As shown in FIG. 1, the B-ISDN to which the present invention is applied is divided into a subscriber network and a service network, and the subscribers and services are concentrated or distributed based on the technology for exchanging and transmitting broadband traffic. By linking providers, we provide a comprehensive range of services with a wide bandwidth distribution.

The service network includes an ATM PVC switch 11a performing a switching function of a virtual path unit and a related operation management (OAM) function, a switching function of a virtual channel and a virtual path, and a related function. The ATM Switched Virtual Connection Switching (ATM SVC) switch 11b performing an OAM function is interconnected.

In addition, the subscriber home network is connected to the ATM PVC switch (11a) to perform the multiplexing / centralization / switch and network termination functions, and performs a switching function for a virtual channel (VC) for a broadband network termination device (B -NT: Broadband Network Termination (B-NT ') (B-NT') 12b that performs for the virtual path (VP).

In addition, the B-NT 11a and the B-NT '11b include a B-ISDN terminal equipment (B-TE: Broadband Terminal Equipment), or a B-ISDN matching device (B-TA: Broadband Terminal Adapter) and B. ISDN terminal equipment (TE) is connected.

FIG. 2 is an explanatory diagram showing the performance of the OAM function of the Broadband Integrated Telecommunication Network (B-ISDN), which is recommended by the International Telecommunication Union (ITU-T).

As shown in FIG. 2, the Exchange Termination (ET) 20, which is an ATM PVC exchange 11a, may perform an OAM function up to B-NT2 21, which is an F4 end point, and the ATM PVC exchange ( In 11b), it is possible to extend the OAN function to B-ISDN terminal equipment (B-TE) and B-ISDN matching equipment (B-TA) which are F5 endpoints.

And, the failure message in the failure management function performed in F4 indicating the OAM flow among the OAM functions performed in the ATM PVC switch 20 (VP-AIS: Virtual Path Alarm Indication Signal), a response message for the VP-AIS (VP-RDI: Virtual Patrh Remote Defect Indication), Loopback and Continuity Check.

However, since the B-NT '12a performs the switching function only by the virtual channel, when a failure is detected in the subscriber station connected to the B-NT' 12a, the VP-AIS message cannot be transmitted to the ATM PVC switch 11a located at the service network side. Send a VC-AIS message.

Therefore, the ATM PVC switch 11a cannot see the state of the B-TE because it cannot see the VC-AIS, which is a failure message generated on the virtual channel connection.

That is, since the ATM PVC switch (ET) 20 can perform the OAM function only up to B-NT2 20, which is the F4 endpoint, there was a problem that the maintenance function for the subscriber station cannot be directly performed.

This will be described in more detail.

The ATM PVC switch 11a cannot directly loopback to the sb interface (i.e., the line connecting the subscriber station and the B-NTs 12a, 12b) and thus cannot directly recognize the failure occurring in the sb interface.

For example, an ordinary ATM switch can perform both VP and VC switching, but an ATM switch used for small subscribers or a backbone network of an ATM network can perform only VP switching to perform a high-speed switch at a low price. (For example, ATM PVC switch 11a).

However, since the ATM PVC switch 11a switches only in VP units, loopback is performed only to the B-NTs 12a and 12b, which are endpoints on the VP, and the failure of the sb line is not known.

On the other hand, there is another method using the AIS as a way to recognize the failure occurred on the sb line in the ATM switch. That is, if a failure occurs on the sb line, the AIS signal is transmitted to the ATM switch so that the ATM switch can recognize it.

However, since most of the B-NTs 12a and 12b perform switching in units of VC, when a failure occurs in the sb line, the B-NTs 12a and 12b transmit VC_AIS toward the exchange.

However, the ATM PVC switch 11a which performs only VP switching cannot recognize the VC_AIS and thus cannot directly perform maintenance functions for the subscriber station as well as the sb line.

Accordingly, the present invention has been made in order to solve the problems of the prior art as described above, the subscriber terminal connected to the subscriber network ATM PVC switch using the OAM cell in the broadband integrated information communication network, broadband network termination equipment and subscriber terminal It is an object of the present invention to provide a subscriber terminal maintenance method in an ATM PVC switch for maintaining the connected link in real time.

According to an aspect of the present invention, there is provided a method for maintaining a subscriber station in an asynchronous delivery mode permanent virtual link exchange applied to a broadband integrated telecommunication network, wherein the asynchronous delivery mode is received from an operator. A first step in which the permanent virtual link exchange transmits a loopback message to the broadband terminator connected to the subscriber per row; When a loopback request is received from the asynchronous delivery mode permanent virtual exchange switch, the broadband terminating device transmits the state information of the most recent subscriber station retrieved from the failure management table to a loopback response message and is transmitted to the asynchronous delivery mode permanent virtual connection exchange. Step 2; And a third step of the asynchronous delivery mode switch receiving the loopback response message from the broadband terminating device, recording state information of the subscriber station in a failure management table, and outputting the state of the subscriber station to an operator terminal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a method for maintaining a subscriber station in an asynchronous delivery mode persistent virtual exchange switch according to the present invention, and performs a switching function for a subscriber station or a subscriber station and a virtual channel in an ATM PVC switch 11a. The B-NT 12a detects the state of the subscriber station by performing a loopback function on the connected link.

As shown in FIG. 3, the subscriber station maintenance method in the ATM PVC exchange 11a according to the present invention firstly, if the operator requests the state of the subscriber station to the ATM PVC exchange 11a (100). The PVC exchange 11a transmits a loopback message (OAM cell) to the B-NT 12a to which the subscriber is connected (101).

Meanwhile, the B-NT 12a receiving the loopback OAM cell from the ATM PVC exchange 11a carries the state information on the subscriber station in the OAM cell for the loopback response and transmits the state information to the ATM PVC exchange 11a. Detailed description thereof will be described later.

After receiving the loopback response message from the B-NT 12a (102), the ATM PVC switch 11a records the state information of the subscriber station in the failure management table (103), and then displays the state of the subscriber station in the operator terminal. Output 104 to allow the operator to take a recovery action for the terminal.

4 is a structural diagram of the loopback response message of FIG. 3 used in the present invention, and shows a message structure in which the B-NT 12a shows status information of each subscriber station in the loopback response message.

Referring to FIG. 4, the loopback response message includes a 5-octet header, a 4-bit OAM type field, a 4-bit Function Type field, and a 45-octet Function Specific field. And a 6-bit reserved field and a 10-bit error detection code (EDC) filter.

The Function Specific field includes a loopback indication field of 1 octet, a correlation tag field of 4 octets, a loopback location ID field of 16 octets, and a loopback location ID field of 28 octets. It consists of a Source ID field and an 8 octet Unused field.

The source ID field allocates 1 bit per terminal / link to display the mounted / unmounted information of each terminal / link in the upper 8 octets and the status information of each terminal / link in the lower 8 octets.

Accordingly, the B-NT 12a receives a loopback message from the ATM PVC exchange 11a, and transmits the status information of each terminal to the 'Source ID field' of the 'Funciton Specific Field' of the OAM cell for loopback response. Field), and the upper 8 octets indicate whether each terminal is mounted one by one bit (that is, mounted: 1, not mounted: 0), and lower 8 The octet indicates the status of each terminal in order of 1 bit (ie, normal: 1, abnormal: 0).

5 (a) and 5 (b) is a flow chart of an embodiment of a subscriber station maintenance method in a broadband network termination apparatus (B-NT) according to the present invention.

As shown in FIGS. 5A and 5B, a subscriber station maintenance method in a broadband network termination apparatus (B-NT) according to the present invention first performs a switching function on a virtual channel. When the B-NT 12a receives the loopback request from the ATM PVC exchange 11a (110), the state information of the latest terminal is retrieved from the failure management table (111), and the loopback response message (see FIG. 4) is added. The transfer to the ATM PVC switch 11a is carried out (112).

In addition, the B-NT 12a monitors the failure of the subscriber terminal connected to it, and when the failure is detected (113), records the fact in the failure management table (114) and isolates the failed subscriber terminal as the failure. After taking the measures (115), the fact that the failure has occurred is output to the operator terminal of the B-NT 12a (116).

As described above, the present invention provides a subscriber station, a broadband network termination device (B-NT), and a subscriber terminal connected to an asynchronous delivery mode permanent virtual exchange switch (ATM PVC switch) in a broadband integrated information communication network (B-ISDN). By maintaining the link in real time, it is possible to reduce maintenance costs, increase the reliability of the communication network, and improve the quality of information and communication services provided to subscribers.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains, and the above-described embodiments and accompanying It is not limited to the drawing.

Claims (3)

A method for maintaining a subscriber station in an asynchronous delivery mode permanent virtual switching exchange applied to a broadband integrated telecommunication network (B-ISDN), wherein the asynchronous delivery mode persistent virtual switching exchange receives a status request for the subscriber station from an operator. A first step of transmitting a loopback message to a broadband terminator connected to the subscriber; When a loopback request is received from the asynchronous delivery mode permanent virtual exchange switch, the broadband terminator transmits the status information of the most recent subscriber station retrieved from the failure management table to a loopback response message and transmits it to the asynchronous delivery mode persistent virtual connection exchange. Step 2; And a third step of receiving the loopback response message from the broadband terminating device, recording the state information of the subscriber station in a failure management table, and outputting the state of the subscriber station to an operator terminal. A method for maintenance of subscriber station in asynchronous delivery mode permanent virtual exchange exchange. The method of claim 1, wherein the broadband termination apparatus monitors a failure of the subscriber station, and if a failure is detected, records the fact of failure in a failure management table, isolates the failed subscriber terminal, and then fails the operator terminal. And a fourth step of outputting the fact of occurrence of subscriber station maintenance in the asynchronous delivery mode permanent virtual exchange switch. The method of claim 1 or 2, wherein the loopback response message of the second step comprises a header, an operation and maintenance field, a function type field, a function special field, a spare field, and an error detection code (EDC) field. The function special field includes a loopback indication field, a correlation tag field, a loopback location identifier (ID) field, a source ID field, and an unused field, and the source ID field is assigned by a predetermined bit per terminal / link. A method of maintaining a subscriber station in an asynchronous delivery mode permanent virtual switching exchange comprising displaying mounted / unmounted information of each terminal / link in a predetermined octet and displaying state information of each terminal / link in a lower predetermined octet.