JP2001111568A - Multiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase data quantity that can be handled by a multiplexer integrating communication services. SOLUTION: A multiplexer 9 is provided with a plurality of cell buses 10a and 10b and a fault monitoring means 13 monitoring a fault in the buses 10a and 10b. The multiplexer 9 is provided with a plurality of bus interfaces 11a to 11d, which construct a cell from received data in a prescribed format, transmit and receive the cell by using a cell bus 10a or 10b decided as normal by the means 13 between the buses 10a and 10b and stop cell transmission and reception by a cell bus, from which a fault is detected by the means 13 between the buses 10a and 10b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexing apparatus for connecting various communication services used by a user to connect to a network owned by a communication carrier.

[0002]

2. Description of the Related Art In recent years, the number of telecommunications carriers that carry out a communication business using a network has increased, and when data is transmitted from a certain point to another point, there is a case where the data is transmitted through a plurality of telecommunications carriers' networks. .

[0003] Further, with the diversification of the telecommunications business, the types of communication services that can be provided by telecommunications carriers and available to users are increasing. Examples of this communication service include:
There are communication using a dedicated line, communication using a frame relay system (FR), communication using an asynchronous transfer mode (ATM), communication using a time division multiplexing system (TDM), communication using an IP address on the Internet, and telephone. Each user may use a plurality of communication services among the various communication services described above.

FIG. 4 is a block diagram showing a conventional network connection relationship between a communication carrier and a user.

In this example, the user 1 is directly connected to the network 2n of the communication carrier 2, the user 3 is directly connected to the network 4n of the communication carrier 4, and the network 2n is connected to the network 4n. It is connected by the network 5n of the communication carrier 5.

When user 1 transmits data to user 3, the data is received by user 3 via networks 2n, 5n, and 4n.

FIG. 5 exemplifies a connection state in a case where the communication carrier 5 directly provides a communication service to the user 1 without passing through the communication carrier 2 in the state of FIG. .

When the user 1 uses a communication service provided by the communication carrier 5, it is necessary to connect the user 1 to the network 5n via the access network 6. Here, in order to simplify the connection by the access network 6, a multiplexing device (for home use) 7 for integrating communication services used by the user is arranged. In addition, a multiplexing device (for intra-office use) that integrates communication services provided by the communication carrier 5.
8 is arranged. The multiplexing device 7 and the multiplexing device 8 are connected by the access network 6.

The multiplexing devices 7 and 8 temporarily convert the data received by the interfaces for various communication services into cells, provide the cells to the interface on the destination side via the internal cell bus, and provide the cells for the communication services of the destination. And provide it to the destination. Here, the cell is usually a fixed-length (53-byte) information transfer unit, and is composed of a 5-byte cell header and a 48-byte information field.

In general, the multiplexing devices 7 and 8 have two cell buses, a working bus and a protection bus, to provide redundancy, and a failure occurs when a failure occurs in the working cell bus. Switching to a non-reserved cell bus prevents information loss.

Here, the conventional example will be summarized. An example of a bus abnormality detection method will be described. L for cell bus interface
SI (CUBIT) has a master: slave = 1: n configuration. The master periodically sends an internal bus monitoring cell and the like to each slave and itself, and upon receiving a cell addressed to itself, the slave replies to the master. The master notifies all or at least one or more slaves or the self-response result of the internal bus monitoring cell to the redundant control unit.

The redundant control unit collects the reply result from the master, and if there is no reply from at least one or all of the slaves and the master for a predetermined time set by the redundant control unit, it is determined that the internal bus is abnormal. Then, the data transmission / reception system is switched from the abnormal internal bus to the spare internal bus. As a result, switching to the standby system is performed at the same time, thereby preventing signal interruption.

FIG. 6 is a flow chart for explaining an operation procedure when an N-system failure occurs in this N / E-system configuration.

That is, the following are disadvantages of the conventional example.

1) In order to switch between working and standby, 1
It can be used only in the capacity of the main. It is also possible to use an n + 1 redundant system using n lines, which increases the capacity but complicates the control.

2) When switching, the signal is interrupted.

3) Distribution of control signals for bus switching is required for each package in the device, which complicates the structure and operation.

[0018]

As described above, the conventional multiplexing apparatus operates to integrate various communication services. However, since the multiplexing apparatus is used while switching between the internal working and protection cell buses, The communication capacity that can be handled is limited to the communication capacity of one cell bus.

However, as described above, the communication services that users and businesses desire to use tend to increase as the information society advances. Therefore, it is desired to increase the communication capacity that can be handled by the multiplexer.

The present invention has been made in view of the above circumstances, and has as its object to provide a multiplexing apparatus that can increase the communication capacity.

[0021]

The multiplexing apparatus according to the present invention includes a plurality of cell buses, and the faults of the plurality of cell buses are monitored by fault monitoring means. Further, the multiplexing device of the present invention forms a cell from the received data of a predetermined format, transmits and receives cells using a cell bus which is normal by the failure monitoring means among the plurality of cell buses, and A plurality of bus interfaces are provided for stopping transmission / reception of cells by the cell bus in which a failure has been detected by the failure monitoring means.

In the multiplexing apparatus of the present invention, cells can be transmitted and received using any cell bus having a normal bus interface.

Therefore, the total communication capacity of the normal cell bus is the communication capacity that can be handled as an apparatus.

Further, in the plurality of bus interfaces according to the present invention, the total capacity of cells transmitted / received on the normal cell bus by the fault monitoring means does not exceed the total transmittable / receiveable capacity of the normal cell bus. Control may be performed as follows.

[0025]

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

Here, a multiplexing apparatus which can use all normal cell buses among the cell buses provided therein will be described.

FIG. 1 is a block diagram illustrating the configuration of a multiplexing apparatus according to the present embodiment. The same parts as in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof is omitted. Now, only the different parts will be described in detail.

The multiplexing device 9 is a device for integrating communication services used by the user 1 at home, and is 1 Gbit / s.
And two cell buses 10a and 10b each having a communication capacity of

Each of the bus interfaces 11a to 11d
Acquires a cell addressed to itself on the cell buses 10a and 10b, and converts the data to a predetermined format when data conversion is required. Then, the access network interface circuit 12a, the control unit 12b, and the terminal
c, 12d.

Each of the bus interfaces 11a to 11a
1d is the cell bus 10a by the bus fault monitoring circuit 13;
The presence or absence of the failure of 10b is monitored. When data is received from the associated parts 12a to 12d, if the data is not a cell, the data is converted into a cell, and the cell is provided to the cell bus which is determined to be normal by the bus failure monitoring circuit 13. .

Each of the bus interfaces 11a to 11a
1d, when both the cell buses 10a and 10b are normal, one cell bus may be used for cell transfer in a predetermined direction and the other cell bus may be used for cell transfer in the other direction. However, even in this case, if a failure occurs in any of the cell buses 10a and 10b, the normal cell bus is used for bidirectional cell transfer. On the other hand, the cell buses 10a, 10a
b before each cell bus 10 fails.
a and 10b may be used as bidirectional.

Further, each bus interface 11a-
11d has a function of limiting the total amount of data flowing into a normal cell bus to be equal to or less than the total capacity of the normal bus, and giving priority to data that should not be delayed, such as a voice signal in a telephone when limiting the total amount of data flowing into the cell bus. And a function to wait for data which is less affected by delay, such as personal computer data, to flow into the cell bus, and to bypass cells on the failed cell bus to a normal cell bus.

Access network interface circuit 12a
Executes transmission of data to the access network 6 and reception of data from the access network 6, and the bus interface 11
The access interface 14 is constituted by being combined with a. Here, assuming that the access network 6 is duplicated, the two access interfaces 1
4 is provided in the multiplexer 9.

The control section 12b executes control processing such as bus control in the multiplexer 9.

The terminal interfaces 12c and 12d are:
Terminals 15c and 15 that provide communication services in the house
The device is responsible for the interface with the device d.

FIG. 2 is a block diagram showing a connection relationship between the in-home multiplexer 9 and the in-station multiplexer according to the present embodiment.

Various terminals 15 used by the user 1
When the data from a to 15d is received by the bus interfaces 18, 19, 11c and 11d via the terminal interfaces 16, 17, 12c and 12d of the in-home multiplexer 9, the data which needs to be converted is stored in the cell. The data is converted and flown into normal cell buses 10a and 10b.

Therefore, in this state, the in-home multiplexer 9 can handle data of the total capacity (2 Gbit / s) of the two cell buses 10a and 10b. As described above, the bus interface 1
In steps 8, 19, 11c, and 11d, a process is performed in which the total amount of cells flowing into a normal cell bus is limited as needed, and a cell having a higher priority flows into the cell bus when the restriction is performed.

Here, when a failure occurs in any of the cell buses 10a and 10b, the cell flows from the bus interfaces 18, 19, 11c and 11d to only the normal cell bus. Also, as described above, in the bus interfaces 18, 19, 11c, and 11d,
A process of diverting cells on the failed cell bus to a normal cell bus is executed.

The cells that have flowed into the normal cell bus are acquired by the access network interface 14 which is in the operating state, and data conversion is performed if necessary.
It is transmitted to the intra-station multiplexing device 20 via the communication medium 6a (for example, HSD, ATM megalink, ISDN, dedicated line, wireless, etc.) in the operation state of the access network 6.

Here, when a failure occurs in the communication medium 6a in the operation state of the access network 6, the backup communication medium 6b is switched to the operation state, and the same data transmission processing is continuously executed.

In the in-station multiplexing device 20, data received from the in-home multiplexing device 9 via the access network 6 is acquired by the access network interface 14 which is in operation, and if necessary, Is converted to a cell,
It flows into a normal cell bus among the cell buses 21a and 21b.

Thereafter, in the intra-station multiplexing device 20, the same handling of cells as in the in-home multiplexing device 9 is performed.

That is, the bus interfaces 22 to 2
5, cells on the cell buses 21a and 21b are acquired, and data conversion is performed if necessary. Then, any of the interfaces 26 to 29 for the various communication services 51 to 54 provided on the network 5n is provided to the network 5n.

The above processing is performed by the user 1 to the network 5
This is a process related to the transmission of data to the network n, but the process of transmitting data from the network 5n to the user 1 is substantially the same as described above except that the direction is reversed, and therefore the description is omitted.

The intra-station multiplexing device 20 can be connected to a plurality of home multiplexing devices 9, and the internal cell buses 21a and 21b have a larger capacity than the cell buses 10a and 10b.

As described above, the multiplexing devices 9 and 20 according to the present embodiment include a plurality of cell buses, and when the plurality of cell buses are normal, operate in a direction-dependent or bidirectional parallel manner. . On the other hand, if a failure occurs in any of the cell buses, the operation of the failed cell bus is stopped.

Therefore, the data amount of the total capacity of the normal cell bus can be handled, and it is possible to cope with an increase in communication services and data.

The multiplexing device 9 according to the present embodiment
In 20, the cell on the failed cell bus is bypassed to the normal cell bus, so that even if a failure occurs, it is possible to prevent the information from being disconnected.

The multiplexing device 9 according to the present embodiment
In 20, the total amount of cells flowing into the cell bus from the terminal interface, the access network interface circuit 12a, and the control unit 12b is limited to the total capacity of the normal cell bus. In this case, cells having a large influence of the data delay are preferentially flown into the cell bus, and cells having a small influence are placed in a waiting state. Therefore, it is possible to prevent the quality of transmitted / received data from deteriorating.

In the multiplexing apparatus according to the present embodiment, the case where the number of cell buses is two has been described. However, the number of cell buses is not limited to this and may be three or more.

In this embodiment, a case has been described in which a function of limiting the total amount of cells flowing into the cell bus and a function of controlling the priority order of cells flowing into the cell bus are added to the bus interface. However, the present invention is not limited to this. For example, these functions may be provided in a terminal or an access network interface circuit.

In this embodiment, the case where the bus fault monitoring circuit 13 is provided in each bus interface is described. However, the present invention is not limited to this, and a fault is detected for each cell bus. It is also possible to provide a bus failure monitoring circuit that performs the monitoring and notify the monitoring result to each bus interface.

Here, the present embodiment will be summarized. An example of a bus abnormality detection method will be described. The internal bus failure detecting means has the same configuration as that of the above-described conventional example.

Next, a specific detour procedure (including a bus parallel operation method) when a failure occurs and an example in which the amount of data sent from each package to the bus when a bus error occurs is described.

The redundant control unit is composed of m internal buses, and at least one or more internal buses are used during operation.

The redundant system control unit determines an internal bus registered in advance and used for each virtual path (VP) or virtual channel (VC), and distributes it. When a failure occurs, the data allocated to the failed bus is reallocated to a normal bus among the m buses.

When the entire band of the internal bus is used, the VP or VC is given a priority, and when the VP or VC having a high priority is accommodated in the faulty bus, the VP or VC is assigned a low priority. Move the VP or VC to the fault bus,
Move the higher priority VP or VC to the normal bus.

This priority control is performed by the internal bus redundant system control unit.
The priority management of P or VC is performed and controlled.

The priority setting means for limiting the amount of data to be sent to the data bus is provided by the internal bus redundancy control unit.
It has a priority management table in P or VC units.

The reason why the data amount can be limited is that the priority is assigned to each VP or VC with high importance, so that even when an internal bus failure occurs, the VP or VC that goes down has the priority. This is because it is low and damage can be minimized.

FIG. 3 shows a system 0 (1 / m) with an m bus structure.
6 is a flowchart illustrating an operation procedure at the time of a failure.

That is, the advantages of this embodiment are as follows.

1) When buses 0 and 1 are normal, n
Operation is possible with twice the capacity.

2) During switching, the cell is temporarily changed to the cell BUF.
There is no momentary interruption because it can be stored in

[0066]

As described above, in the present invention,
Parallel operation with a normal cell bus becomes possible.

Therefore, it is possible to communicate up to the capacity obtained by adding the capacity of all normal cell buses, and the type of communication service, the amount of data to be handled, and the service destination can be increased.

Further, in the present invention, since a cell having a capacity equal to or greater than the sum of the capacity of all normal cell buses is prevented from flowing into the cell bus, it is possible to prevent information loss due to the disappearance of the cell. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of a multiplexing device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a connection relationship between the in-home multiplexer and the in-station multiplexer according to the embodiment;

FIG. 3 is a flowchart illustrating an operation procedure when a system 0 (1 / m) fault occurs in an m bus structure.

FIG. 4 is a block diagram showing a conventional network connection relationship between a communication carrier and a user.

FIG. 5 is a block diagram illustrating a connection state in a case where a new communication carrier directly provides a communication service to a user 1;

FIG. 6 is a flowchart illustrating an operation procedure when an N system failure occurs in the N / E system configuration.

[Explanation of symbols]

1, 3, user 2, 4, 5 ... communication carrier 2n, 4n, 5n ... network 6 ... access network 7, 8, 9, 20 ... multiplexer 10a, 10b, 21a, 21b ... cell bus 11a to 11d, 18 Bus interface 12a Access network interface 12b Control unit 12c, 12d, 16, 17 Terminal interface 13 Bus failure monitoring circuit 14 Access network interface 15a-15d Terminal 26-29 Interface

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenji Ansai F-term (reference) 5K028 AA11 CC05 KK01 KK35 MM14 QQ02 5K030 GA08 GA12 GA19 HA10 HB14 HB29 JA01 JA10 JT02 KA13 KX03 LC01 MA11 MB01 MB09 5K035 AA05 BB04 CC03 CC10 DD01 EE01 JJ03 LL03 LL04

Claims (2)

[Claims] A cell is configured from a plurality of cell buses (10a, 10b), a failure monitoring means (13) for monitoring a failure of the plurality of cell buses (10a, 10b), and a received data of a predetermined format, Among a plurality of cell buses (10a, 10b), a cell is transmitted and received using a cell bus which is regarded as normal by the failure monitoring means (13),
Failure monitoring means (13) of the plurality of cell buses (10a, 10b)
A plurality of bus interfaces (11a, 11b, 11c, 1
A multiplexing device comprising: 1d). 2. The multiplexing device according to claim 1, wherein said plurality of bus interfaces (11a, 11b, 11c, 11d).
Is characterized in that the total capacity of cells transmitted and received on the normal cell bus by the fault monitoring means (13) is controlled so as not to exceed the total transmittable and receivable capacity of the normal cell bus. Multiplexing device.