JPH08186568A - Atm communication system - Google Patents

Abstract

PURPOSE: To monitor whether or not a working band fulfils a contract value every bundle of plural virtual paths by providing a means to monitor the sum total of communication quantity of the bundle of plural virtual paths each having a communication channel with the virtual path set. CONSTITUTION: The VP band monitoring circuit 11 of a station device houses the virtual paths VP1-VP4. When a cell passage recognition circuit 51 recognizes the virtual path identifier of an ATM cell passing the virtual paths VP1-VP4 through which a main signal passes and sends the result to a counter circuit 52, the circuit 52 counts the number of passing cells of each virtual path identifier, and accumulates the result in a counter value memory circuit 53. While, a contract value storage circuit 55 stores the value of a parameter contract for the upper limit value of sum of the maximum bands of the paths VP1-VP4 and the working bands of the paths VP1-VP4 passing a device 2, and a comparator 54 inspects whether or not the passing cell violates those contracts. When it violates the contract, a control signal is sent to a cell abortion control circuit 56, and the abortion of the ATM cell or the cutoff processing of all paths is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a communication network using an asynchronous transfer mode (hereinafter referred to as ATM: Asynchronous Transfer Mode). The present invention is a CA using ATM.
TV (Cable Television) services and VOD (Video On De)
mand) Service and other multimedia communication services.

[0002]

2. Description of the Related Art Research and development relating to multimedia services in ordinary homes and businesses are being actively conducted. A conventional example will be described with reference to FIG. FIG. 7 is an overall configuration diagram of a conventional example. A station device 1 installed in a station owned by a telecommunications carrier and a subscriber device 2 installed in a subscriber's premises that receives a communication service by contracting with the telecommunications carrier include an optical fiber and other communication cables. Connected by. To the subscriber device 2, m terminal devices 31 to 3m are connected,
On the station device 1 side, n service providing nodes 4 that provide information providing services, interactive communication services, etc. to subscribers.
1 to 4n are connected. The subscriber has required service providing nodes 41 to 4n based on the contract with the communication carrier.
Receive communication services between.

When a service is provided using a system called ATM as a transmission system of this system, a virtual path (between the terminal devices 31 to 3m or the subscriber device 2 and the service providing nodes 41 to 4n ( VP: Vir
tual path) is provided, and information is transferred using a fixed-length information packet called an ATM cell.

Another conventional example will be described with reference to FIG. FIG. 8 is an overall configuration diagram of another conventional example. In this conventional example, a passive optical coupler or other splitter 90 is newly inserted between the station device 1 and the subscriber devices 21 to 2k in the configuration shown in FIG. By providing this splitter 90, there is an advantage that one station device 1 can accommodate a larger number of subscriber devices 21 to 2k as compared with the system of FIG.

Generally, the configuration of FIG. 7 is called a single star system (single star system: SS system), and the configuration of FIG. 8 is called a passive double star system (passive double star system: PDS system).

Next, an example of the connection form of the virtual path of the conventional example will be described with reference to FIG. FIG. 9 is a diagram showing a conventional virtual path connection configuration. In this conventional example, three terminal devices 31 to 33 are connected to one subscriber device 2, and these terminal devices 31 to 33 are four service providing nodes 41.
It is assumed that the communication service is received from ~ 44.
A virtual path required for each service is fixedly provided in advance, and a required virtual path is selected and used from these virtual paths when the service is provided. That is, not all the virtual paths that are provided in advance are used at the same time, but only the virtual paths necessary for providing the communication service are selected and used.

On the other hand, the station device 1 or the subscriber device 2 is provided with a UPC (Usage Parameter Control) circuit for monitoring whether each virtual path is used within the contract band. The UPC circuit is a circuit having a function of performing forced cell discard and other necessary measures when each virtual path is used in violation of the contract.

[0008]

SUMMARY OF THE INVENTION In this conventional example,
From the viewpoint of the bandwidth used by the virtual path between the subscriber and the communication carrier, a contract regarding the maximum bandwidth of each virtual path is required. The contract is a contract for a maximum bandwidth that can be used by each virtual path, which is provided in advance with some communication carriers. However, the subscriber does not use all the virtual paths that are set in advance at the same time, only some of the virtual paths required to provide communication services are used at the same time, and services are provided from only limited operators at the same time. It is believed that receiving is common.

Therefore, in addition to the contract, the contract concerning the upper limit value of the sum of the virtual path use bands passing through one subscriber unit as a contract is effective for the efficiency of accommodation design. The contract is a contract regarding the total bandwidth of virtual paths used simultaneously by the subscriber or the subscriber device. By setting this contract as a contract value that matches the reality, it is possible to reduce waste of communication resources.

In the conventional system, it is possible to independently monitor the used bandwidth for each virtual path, but there is no means for monitoring the used bandwidth for each unit in which a plurality of virtual paths are bundled.
Therefore, UPC was only possible for contracts, not UPC for contracts. If, in the conventional example method, the terminal makes a service request exceeding the contract while protecting the contract to each service providing node, the station apparatus side does not have a method of monitoring this, In the worst case, a buffer overflow may occur in the station device, the subscriber device, or the like.
In particular, the buffer overflow in the station device affects not only the subscriber device that has made an excessive service request, but means for preventing this is necessary.

The present invention has been made against such a background, and provides an ATM communication system capable of monitoring whether or not the used bandwidth for each bundle of a plurality of virtual paths respects the contract value. The purpose is to It is an object of the present invention to provide an ATM communication system that can effectively use a virtual path band.

[0012]

According to the present invention, a subscriber unit accommodating at least one terminal unit, a station unit accommodating at least one subscriber unit, and the station unit and the subscriber unit are connected. Communication line and one or more service providing nodes connected to the station device, a virtual path is set in the communication line, and the maximum communication amount per hour (Bi, i) used for each virtual path is set. Is an ATM communication system provided with means for monitoring a virtual path number).

Here, the feature of the present invention resides in the sum of the communication volume of a plurality of n virtual paths among the above virtual paths (ΣBi, i is 1 to n).
Is equipped with a means of monitoring.

With this, it is possible to deal with the breach of the contract that cannot be grasped only by monitoring the maximum bandwidth used for each virtual path. By being able to monitor contract violations, virtual path bandwidth can be used effectively.

It is desirable that the bundle of the plurality of virtual paths of n is set for each subscriber device. Thereby, the monitoring target can be set for each subscriber device.

It is preferable that the means for monitoring the total include means provided in the station device for recognizing the arrival time of a cell and the virtual path identifier of the cell for each of a plurality of virtual paths. The means for monitoring the total sum measures the total sum (Σmi, i is 1 to n) of the number m of cells that have arrived at the plurality of virtual paths n within a predetermined time according to the output of the recognizing means. Means and
It is provided with means for storing a threshold value set in advance based on a contract, means for comparing the threshold value with the measurement value of the measuring means, and means for controlling cell discard according to the comparison result of the comparing means. Is desirable. It is preferable that the means for controlling the discarding comprises means for blocking all virtual paths of the subscriber device through which the virtual path passes when the comparison result exceeds a threshold value.

As a result, it is possible to prevent the adverse effect of the contract violation from reaching unrelated third parties.

[0018]

It is generally difficult for a single terminal device to simultaneously use a plurality of services provided by multimedia. Therefore, even if virtual paths from multiple service providing nodes are set in one terminal device, the sum of the maximum usable bandwidth of each virtual path is simply added to the sum of the virtual path bandwidths available to that terminal device. Therefore, it is not the case to carry out various designs. If various designs or contracts are made based on such an idea, a large amount of ineffective bandwidth is actually generated.
Therefore, in addition to the contract for the maximum used bandwidth of each virtual path, it is required to make a contract for the sum of the maximum used bandwidth in one bundle of virtual paths.

This bundle can be, for example, a virtual path contained in one subscriber unit. This allows subscribers to detect and take action when they violate the contract of the maximum bandwidth in the bundle of virtual paths while satisfying the contract for the maximum value of the maximum bandwidth of each virtual path. it can.

Various methods are conceivable as countermeasures. For example, when the contract of the maximum bandwidth used in the bundle of virtual paths is violated, all virtual paths accommodated in the corresponding subscriber device are violated. May be shut off.
As a result, it is possible to prevent the adverse effects of the breach of contract from reaching unrelated third parties.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of the first embodiment of the present invention. See FIG. 9 for the overall configuration.

According to the present invention, a subscriber unit 2 accommodating the terminal units 31 to 33 and a station unit 1 accommodating the subscriber unit 2 are provided.
And a communication line 7 connecting the station device 1 and the subscriber device 2, and service providing nodes 41 to 41 connected to the station device 1.
44 and virtual paths VP1 to VP12 on the communication line 7.
Is set, and means for monitoring the maximum communication amount per hour (Bi, i is a virtual path number) used for each of the virtual paths VP1 to VP12 is an ATM communication system provided in the station device 1.

Here, the feature of the present invention lies in that a bundle of virtual paths VP1 to VP12 has its virtual path VP.
As shown in FIG. 1, the station apparatus 1 is provided with a VP band monitoring circuit 11 as a means for monitoring the total sum of communication amounts of 1 to VP 12 (ΣBi, i is 1 to n). Further, the station device 100 performs the distribution operation for each virtual path VP1 to VP12 by multiplexing and demultiplexing the ATM circuit and the interface circuit 12 terminating the connection line to the communication line 7 and the service providing nodes 41 to 44. A demultiplexing circuit (ATM-SW) 10 and a VP band monitoring circuit 11 are provided. The bundle of virtual paths VP1 to VP12 is set for each subscriber device 2.

Next, the VP band monitoring circuit 11 as means for monitoring the total sum provided in the station device 1 will be described with reference to FIG. FIG. 2 is a block diagram of the VP band monitoring circuit 11. The VP band monitoring circuit 11 is provided in the station device 1 and includes a cell passage recognition circuit 51 as means for recognizing the arrival time of a cell and the virtual path identifier of the cell for each of the virtual paths VP1 to VP12.

Further, the VP band monitoring circuit 11 sums up the number m of cells arriving at the virtual paths VP1 to VP12 within a predetermined time according to the output of the cell passage recognition circuit 51 (Σmi, i is from 1 to n). Counter circuit 52 and counter value storage circuit 5 as means for measuring
3, a contract value storage circuit 55 as a means for storing a threshold value set in advance based on a contract, a comparison circuit 54 as a means for comparing the threshold value with the measurement value of the counter value storage circuit 53, and this comparison circuit. The cell discard control circuit 56 is provided as means for controlling cell discard according to the comparison result of 54.

The cell discard control circuit 56, when the comparison result exceeds the threshold value, all the virtual paths VP1 to V for the subscriber unit 2 through which the virtual paths VP1 to VP12 pass.
The cell discard circuit 57 is provided as a means for shutting off P12.

Next, the operation of the first embodiment of the present invention will be described. First, the VP band monitoring circuit 11 will be described. The VP band monitoring circuit 11 accommodates the virtual paths VP1 to VP4. As shown in FIG. 2, the cell passage recognition circuit 51
Virtual path identifiers (VPI: Virtual Path I) of ATM cells passing on the virtual paths VP1 to VP4 through which the main signal passes.
dentifier) recognition. The result is the counter circuit 5
2, the counter circuit 52 measures the number of passing cells for each virtual path identifier, and stores the measurement result in the counter value storage circuit 53. On the other hand, in the contract value storage circuit 55, at least contract: individual virtual paths VP1, VP2, VP
3. Maximum bandwidth of VP4, contract: Two types of parameter contract values are stored: the upper limit value of the sum of used bands of the virtual paths VP1 to VP4 passing through one subscriber unit 2. The comparison circuit 54 checks whether the passing cell violates these contracts. If the passing cell violates the contract, a control signal is sent to the cell discard control circuit 56, and the cell discard circuit 57 discards the ATM cell or takes necessary measures. In the first embodiment of the present invention, when the contract is violated, all virtual paths VP1 to VP4 passing through the subscriber unit 2 are cut off. In this way, it becomes possible to monitor and control the bandwidth of the virtual paths VP1 to VP4 as a bundle of virtual paths.

FIG. 3 shows a configuration compatible with the SS system. FIG. 3 is a specific configuration diagram of the first embodiment of the present invention. The first embodiment of the present invention corresponds to the SS system. Station device 1
As an SLT (Subscriber Line Terminal) 63 and an ONU (Optical Network Unit) 62 as a subscriber device 2, an optical fiber cable is connected between them. ONU
A set top box to which a TV terminal or the like is connected or a terminal device 31 for INS64 service is connected to 62. Further, on the SLT 63 side, the CAT that provides the CATV service as the service providing nodes 41 to 44.
V center 64, VOD server 65 that provides video on demand service, ISM that provides ISDN service
The exchange 66 is connected.

FIG. 4 shows the internal structure of the SLT 63. FIG.
FIG. 3 is a block configuration diagram of an SLT 63 according to the first embodiment of the present invention. As an interface circuit with the service providing node side, a CATV interface 74 having an interface function with the CATV center 64, a VOD interface 75 having an interface function with the VOD server 65, I
A V interface 76 having an interface function with the SM switch 66 is installed. Also, V interface 7
A CLAD 77 for generating or disassembling ATM cells or a demultiplexing circuit 10 for performing a distribution operation for each of the virtual paths VP1 to VP12 are placed for a signal passing through the A. ONU
A maximum of eight units 80 called OSU having an interface function with the 62 side are installed. The configuration of these units 80 will be described. Unit 80 is ON
WDM (Wavelength Division Multiplex) with U62
ing), a module 82 for performing a wavelength division multiplexing transmission system, E / O circuits 81 and 83 for converting signals between electric signals and optical signals, and an LT circuit 8 for terminating communication lines.
4. A signal distribution circuit 85 for distributing CATV signals and other signals, a cell copy circuit 86 having a CATV service program selection function, a program signal copy function, and the like.
Consists of

When the terminal devices 31 to 33 make a service request in violation of the contract, there is a risk that a buffer overflow will occur in the demultiplexing circuit 10 in the SLT 63. However, in the SLT 63 configured as above. VP
By incorporating the band monitoring circuit 11 before and after the demultiplexing circuit 10, it becomes possible to prevent a buffer overflow in the demultiplexing circuit 10.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a specific configuration diagram of the second embodiment of the present invention. FIG. 6 shows the SL of the second embodiment of the present invention.
It is a block configuration diagram of T63. The second embodiment of the present invention is
It corresponds to the PDS system. SL as station device 1
T63 is installed. Here, in the case of the 16-branch PDS system as shown in FIG. 5, one interface device on the SLT 63 side and 16 ONUs 62 as subscriber devices are connected by a splitter 90 called an optical coupler. Each O
To the NU 62, a set top box to which a TV terminal or the like is connected or terminal devices 31 to 36 for INS64 service are connected. Further, on the SLT 63 side, as a service providing node, C which provides the CATV service is provided.
ATV center 64, VOD server 65 that provides video on demand service, I that provides ISDN service
The SM switch 66 is connected.

FIG. 6 shows the internal structure of the SLT 63. As an interface circuit with the service providing node side, C
CAT having an interface function with the ATV center 64
A V interface 74, a VOD interface 75 having an interface function with the VOD server 65, and a V interface 76 having an interface function with the ISM exchange 66 are installed. Also, a CL for generating and disassembling ATM cells for signals passing through the V interface 76.
A demultiplexing circuit 10 for performing a distribution operation for each of AD77 and virtual paths VP1 to VP12 is placed. A total of eight units 80 called OSU having an interface function with the ONU 62 side are installed. These units 80
The configuration of will be described. The unit 80 is a module 82 for performing a wavelength division multiplexing transmission method called WDM with the ONU 62, and an E / E for performing signal conversion between electric signals and optical signals.
O circuits 81 and 83, an LT circuit 84 for terminating a communication line, a signal distribution circuit 85 for distributing CATV signals and other signals, a cell having a CATV service program selection function, a program signal copy function, and the like. Copy circuit 8
It consists of 6.

When the terminal devices 31 to 36 make a service request in violation of the contract, there is a risk that a buffer overflow will occur in the demultiplexing circuit 10 in the SLT 63, but in the SLT 63 configured as above. To V
By incorporating the P band monitoring circuit 11 before and after the demultiplexing circuit 10, a buffer overflow in the demultiplexing circuit 10 can be prevented.

In the first and second embodiments of the present invention,
As a coping method when the breach of the contract is detected, it has been described that all the virtual paths accommodated in the subscriber device 2 accommodating the virtual path are blocked, but various coping methods can be considered. For example, a method may be considered in which priorities are set to virtual paths in advance and the virtual paths are partially cut off sequentially, or a method of discarding the same number of cells from all virtual paths.

[0035]

As described above, according to the present invention,
It is possible to monitor whether or not the used bandwidth of each bundle of a plurality of virtual paths respects the contract value. As a result, it is possible to prevent a buffer overflow in the station device that may occur when the contract is used in excess of the total value of the virtual path bandwidth, and it is possible to block adverse effects on other than the virtual path. In addition, the virtual path band can be effectively used.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a VP band monitoring circuit.

FIG. 3 is a specific configuration diagram of the first embodiment of the present invention.

FIG. 4 is a block configuration diagram of an SLT according to the first embodiment of the present invention.

FIG. 5 is a specific configuration diagram of the second embodiment of the present invention.

FIG. 6 is a block configuration diagram of an SLT according to a second embodiment of the present invention.

FIG. 7 is an overall configuration diagram of a conventional example.

FIG. 8 is an overall configuration diagram of another conventional example.

FIG. 9 is a diagram showing a virtual path connection configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Station device 2, 21-2k Subscriber device 10 Demultiplexing circuit 11 VP band monitoring circuit 12 Interface circuit 31-3m Terminal device 41-4n Service provision node 51 Cell passage recognition circuit 52 Counter circuit 53 Counter value storage circuit 54 Comparison circuit 55 contract value storage circuit 56 cell discard control circuit 57 cell discard circuit 62 ONU 63 SLT 64 CATV center 65 VOD server 66 ISM switch 74 CATV interface 75 VOD interface 76 V interface 77 CLAD 80 unit 81, 83 E / O circuit 82 module 84 LT circuit 85 Signal distribution circuit 86 Cell copy circuit 90 Splitter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical location H04Q 3/00 (72) Inventor Eiji Maekawa 1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph Phone Co., Ltd.

Claims (5)

[Claims] 1. A subscriber device accommodating at least one terminal device, a station device accommodating at least one subscriber device, a communication line connecting the station device and the subscriber device, and the station device. A virtual path is set in the communication line, and the maximum communication amount per hour (Bi, i is the virtual path number) used for each virtual path is monitored. The ATM communication system provided with means for monitoring the total amount of traffic (ΣBi, i is 1 to n) of the virtual path bundle of a plurality of n virtual paths among the virtual paths. An ATM communication system characterized in that 2. The ATM communication system according to claim 1, wherein the bundle of the plurality of virtual paths of n is set for each subscriber device. 3. The means for monitoring the sum total, which is provided in the station apparatus, and includes means for recognizing the arrival time of a cell and the virtual path identifier of the cell for each of a plurality of virtual paths. ATM communication method. 4. The means for monitoring the sum total (sum of the number m of cells arriving at the plurality of virtual paths n within a predetermined time according to the output of the recognizing means (Σ
mi, i is 1 to n), a means for storing a threshold value set in advance based on a contract, a means for comparing the threshold value with a measurement value of the measuring means,
The ATM communication system according to claim 3, further comprising means for controlling cell discard according to a comparison result of the comparing means. 5. The ATM according to claim 4, wherein the means for controlling the discarding comprises means for blocking all virtual paths of a subscriber device through which the virtual path passes when the comparison result exceeds a threshold value. Communication method.