JPH07336357A - Atm repeating exchange system - Google Patents

Abstract

PURPOSE:To perform the changeover control of an ATM communication route made redundant through an ATM repeating exchange by a simple method in an ATM layer. CONSTITUTION:In this system for which the repeating exchanges 2a and 2b provided with redundant channels 5b to 5e are provided between ATM exchanges 3a and 3b for performing the changeover control of the redundant channels, a routing table is provided inside the respective exchanges 3a, 3b, 2a and 2b and validity information for indicating the validity and invalidity of ATM cells is set and managed corresponding to the fault detection of a supervisory and controlling device 1. The respective exchanges 3a, 3b, 2a and 2b extract and transmit only the cells of validity display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (asynchronous transfer mode) transit switching system, and more particularly to an ATM transit switching system having a redundant trunk line.

[0002]

2. Description of the Related Art FIG. 5 is a schematic block diagram of a conventional ATM transit switching system. In FIG. 5, the transmission side ATM terminal 4a and the reception side ATM terminal 4b are respectively connected to the transmission side ATM switching apparatus 3a and the reception side ATM switching apparatus 3b using ATM communication lines 5a and 5f, respectively.

The ATM relay exchange apparatus 2 has a redundant configuration and is composed of two single ATM relay exchange apparatuses 2a and 2b. ATM communication is performed between the transmission side ATM exchange apparatus 3a and the ATM relay exchange apparatus 2. Two relay lines, lines 5b and 5c, are provided between the ATM relay switching devices 2a and 2b constituting the ATM relay switching device 2 and the transmitting side ATM switching device 3a.

Similarly, the receiving side ATM switching device 3b and the AT
Two relay lines, ATM communication lines 5d and 5e, form the ATM relay exchange device 2 between the M relay exchange device 2 and the ATM relay exchange devices 2a and 2b and the receiving side ATM.
It is provided between the exchange device 3b.

The ATM switching device 3a on the transmission side and the ATM switching devices 2a and 2b on the transmitting side are shown in FIG.
The tables for routing management shown in (A), (B), and (C) are respectively provided, and the input line number and the input logical channel number of the input cell are set to the output line number and the output logical channel number of the output cell. It corresponds to and manages.

In this structure, the ATM communication line 5a
The cell 6a received from the upper logical channel 7a is the logical channel 7 of the ATM communication line 5b in accordance with the routing table of FIG.
b and cells 6b and 6c copied on the logical channel 7c of the ATM communication line 5c are transmitted to the ATM relay exchanges 2a and 2b having a redundant configuration (duplication in FIG. 2).

In the ATM relay exchanges 2a and 2b, the receiving cells 6b and 6c respectively use the logical channel 7d of the ATM communication line 5d as the cell 6d according to the respective routing tables (see FIGS. 6B and 6C). , Again AT
On the logical channel 7e of the M communication line 5e as a cell 6e,
It is transmitted to the receiving side ATM switching apparatus 3b, respectively.

In the receiving side ATM switching device 3b, one of the receiving cells 5d and 5e is selected and transmitted to the receiving side ATM terminal 4b as a cell 6f on the logical channel 7f of the ATM communication line 5f. By doing this, A
A redundant configuration of a relay path including a TM relay switching device and a relay line is adopted.

Here, in the receiving side ATM switching apparatus, the cell 5
Which of the d and 5e is selected and which is discarded is, for example, as described in Japanese Patent Laid-Open No. 3-42940, the receiving side A.
When a cell is transmitted from the TM switching apparatus to the receiving ATM terminal, the transmission side ATM switching apparatus manages the serial number assigned to each cell in advance to detect the cell duplication and discard the duplicate cell. As seen in Japanese Patent Laid-Open No. 4-86043, a selection line for physically selecting one of the ATM communication lines 5d and 5e is provided in the receiving-side ATAM switching device 3b, and a host control unit in the receiving-side ATM switching device 3b is provided. Then, there is a method of controlling a selected line to control a desired ATM communication line.

[0010]

A conventional ATM of this type
In the relay switching system, the receiving side ATM switching device 3b selects and discards the receiving cells 5d and 5e.
In the method of discarding duplicate cells by detecting duplicate cells by using the serial numbers assigned to cells as disclosed in Japanese Patent Laid-Open No. 3-42940 as a means for selecting and discarding them, serial numbers are assigned and managed for each cell. It is necessary, but it needs to be performed in an AAL (ATM adaptation) layer located above the ATM layer, and depending on the type of AAL (for example, AAL type 5), it can be used to assign a serial number to each cell. There is a problem that the field is not standard and cell duplication detection by serial number management cannot be applied.

Further, as disclosed in Japanese Patent Laid-Open No. 4-86043, in the method of selecting one ATM communication line by controlling the selection circuit provided in the receiving side ATM switching device, the transmitting side ATM switching device and the ATM switching device are selected. AT with relay switching device
When one of the M communication line or the duplicated ATM repeater switching device is in a failure state, it is necessary to define a protocol for failure notification and selection circuit control between the ATM repeater switching device and the receiving side ATM switching device. However, there is a problem that protocol processing becomes complicated.

It is an object of the present invention to provide an ATM relay switching system in which switching control of redundant ATM communication paths can be realized by a simple method in the ATM layer.

[0013]

According to the present invention, an ATM
An ATM relay switching system having a plurality of redundant trunk lines provided between first and second ATM switching devices respectively accommodating terminals and having a redundant configuration for relaying communication traffic between these terminals. Management setting means for managing and setting which transmission cell of the transmission cells transmitted from the ATM switching apparatus via each of the trunk lines is selectively derived to the receiving side switching apparatus. An ATM relay system is obtained.

[0014]

The validity / invalidity (validity) of the cell is set and managed for each combination of the trunk line and the logical channel, and the cell transmitted from the ATM switching device on the transmission side via the redundant trunk line is set. It is possible to decide which of them is to be derived alternatively by this effectiveness.

[0015]

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

1 and 3 are system block diagrams of an embodiment of the present invention, and the same portions as those in FIG. 5 are designated by the same reference numerals. In FIG. 1, the sending ATM terminal 4a
And the receiving side ATM terminal 4b uses the ATM communication lines 5a and 5f, respectively.
Each is connected to the TM switching device 3b.

The ATM relay exchange apparatus 2 has a redundant configuration and is composed of two single ATM relay exchange apparatuses 2a and 2b. ATM transmission is performed between the transmitting side ATM exchange apparatus 3a and the ATM relay exchange apparatus 2. Two relay lines of the lines 5b and 5c are ATM relay switches 2 respectively.
Relay exchanges 2a and 2b and transmitting side ATM exchange 3a
It is provided between and.

Similarly, the receiving side ATM switching apparatus 3b and the AT
Two relay lines, ATM communication lines 5d and 5e, form the ATM relay exchange device 2 between the M relay exchange device 2 and the ATM relay exchange devices 2a and 2b and the receiving side ATM.
It is provided between the exchange device 3b.

ATM switching device 3a on the transmitting side, ATM switching devices 2a and 2b on the ATM side, and ATMA switching device 3b on the receiving side.
Respectively have the routing tables shown in FIGS. 2A to 2D inside, and in each routing table,
The input line number and the input logical channel number of the input cell are managed in correspondence with the output line number and the output logical channel number of the output cell, and are valid for each input line number and input logical channel.
The validity of the input cell is managed by displaying invalidity. For valid cells, the cells are output to the output logical channel on the specified output line according to the routing table, and the invalid cells are discarded.

Further, in this embodiment, the supervisory control device 1 connected to the two relay exchange devices 2a and 2b is provided, and the supervisory control device 1 is used by the supervisory control device 1.
a, 2b and ATM communication lines 5b, 5c, 5d, 5e are monitored for each failure, and FIG.
Effective display of each routing table of (D) to (D) can be rewritten.

Now, referring to FIG. 1, the transmitting ATM terminal 4a.
The cell 6a transmitted by means of the ATM switch 3a according to the routing table of FIG. 2 (A) has a logical channel 7b of the ATM communication line 5b and an ATM communication line 5c.
Cells are copied as cells 6b and 6c on the logical channel 7c, and are transmitted to the ATM relay exchanges 2a and 2b, respectively.

In the ATM relay exchange apparatus 2a, as shown in FIG.
The input cell 6b on the logical channel 7b of the ATM communication line 5b is managed as "valid" by the routing table of No. 1 and is transmitted to the receiving side ATM switching device 3b as the cell 6d on the logical channel 7d of the ATM communication line 5d. To be done. In the ATM relay exchange apparatus 2b, since the input cell 6c on the logical channel 7c of the ATM communication line 5c is managed as "invalid" by the routing table of FIG. 2 (C), the cell 6d is the ATM relay exchange apparatus. It is discarded at 2b and is not transmitted to the logical channel 7e of the ATM communication line 5e.

In the receiving side ATM switching apparatus 3b, both the cell on the logical channel 7d of the ATM communication line 5d and the cell on the logical channel 7e of the ATM communication line 5e are set as "valid" and the routing table of FIG. Are managed by the ATM communication line 5f, and all cells are output to the receiving side ATM terminal 4b on the logical channel 7f of the ATM communication line 5f. However, in reality, since only the cell 6d is received from the ATM relay exchange 2a on the logical channel 7d of the ATM communication line 5d, the cell 6d defines the logical channel 7f of the ATM relay line 5f as the cell 6f. It is delivered to the terminal 4b, and the ATM terminal 4a on the sending side and the A terminal on the receiving side
Communication has been established with the TM terminal 4b.

Now, ATM trunk lines 5b, 5d or ATM
When a failure occurs in one of the relay switching apparatuses 2a, the monitoring control apparatus 1 detects the failure and, as shown in FIGS. 4B and 4C, ATM of each routing table of the ATM relay switching apparatuses 2a and 2b. The valid indications on the communication lines 5b and 5c are reversed to "invalid" and "valid", respectively.

After the routing table has been rewritten as described above, as shown in FIG.
The cell 6b on the logical channel 7b of b is discarded by the ATM relay switching apparatus 2a, and the cell 6c on the logical channel 7c of the ATM relay line 5c is changed to the cell 6e of the logical channel 7e of the ATM relay circuit 5e by the ATM relay switching apparatus 2b. It is routed and transmitted to the receiving side ATM switching apparatus 3b.

In the receiving side ATM switching apparatus 3b, the cell 5d
Instead, the cell 6d is transmitted to the receiving side ATM terminal 4b as the cell 6f on the logical channel 7f of the ATM relay line 5f, so that the communication between the transmitting side ATM terminal 4a and the receiving side ATM terminal 4b can be performed even in the event of a failure. It becomes possible to secure.

[0027]

As described above, according to the present invention, a plurality of trunk lines are provided between the sending side ATM switching apparatus and the ATM relay switching apparatus and between the receiving side ATM switching apparatus and the ATM relay switching apparatus. A cell that is provided and copied and transmitted to each relay line by the transmitting side ATM switching device is enabled / disabled in the setting of the routing table of the ATM relay switching device, and selected only by the ATM layer processing in the ATM relay switching device. It was decided to send the data to the receiving side ATM switching apparatus, but the reliable relaying does not depend on the AAL type and does not perform complicated protocol processing between the ATM relay switching apparatus and the receiving side ATM switching apparatus. This has the effect of easily implementing redundant configuration control of the switching device and the trunk line.

[Brief description of drawings]

FIG. 1 is a diagram showing one relay mode in a system block according to an embodiment of the present invention.

FIG. 2A is an example of a routing table of a transmitting side ATM switching apparatus 3a, and FIG. 2B is an ATM transit switching apparatus 2a.
2C is a diagram showing an example of a routing table of the ATM relay switching device 2b, and FIG. 7D is a diagram showing an example of a routing table of the receiving side ATM switching device 3b.

FIG. 3 is a diagram showing another relay mode in the system block according to the embodiment of this invention.

FIG. 4A is another example of the routing table of the transmitting side ATM switching apparatus 3a, and FIG. 4B is the ATM transit switching apparatus 2;
Another example of the routing table of a, (C) is another example of the routing table of the ATM relay exchange 2b,
(D) is a diagram showing another example of the routing table of the receiving side ATM switching apparatus 3b.

FIG. 5 is a schematic block diagram of a conventional ATM transit switching system.

FIGS. 6A, 6B, and 6C are diagrams showing the contents of a table for routing management, respectively.

Claims (4)

[Claims] 1. First and second accommodating ATM terminals, respectively
Is an ATM relay exchange system having a plurality of redundant trunk lines arranged between the ATM switch equipments for relaying communication traffic between these terminals. An ATM relay system, comprising: management setting means for managing and setting which transmission cell among the transmission cells transmitted via the transmission cell is selectively derived to the receiving side switching device. 2. The management setting means has a management table for performing setting management for each combination of the relay line and a logical channel included in the relay line. ATM relay exchange system. 3. The ATM relay according to claim 2, wherein the management table is configured to set and manage the validity of the corresponding transmission cell for each combination of the relay line and the logical channel. Exchange system. 4. The management setting means invalidates the validity information of the corresponding relay line in the management table in response to the occurrence of a failure of the first relay line, and validates the validity information of another one relay line. 4. The ATM according to claim 3, wherein
Relay switching system.