JP2000228665A - Atm switching network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize the band of a detour destination by attaching a virtual channel bundle identifier to each of a virtual channel connection and collectively managing virtual channel connections having different detour priorities in the same direction. SOLUTION: A detour priority low VC connection 31 set to a terminal 8A connected to a line IF 23 of an ATM exchange 2 from a terminal 7A connected to the line IF 13 of an ATM exchange 1 and a detour priority high VC connection 32 are managed as one VC bundle. Also, a VC bundle monitoring path 33 is set between a line IF 14 and a line IF 24 and detour sections are defined. And, VC connections having different detour priorities in the same direction are collectively managed and detoured by attaching a VC bundle identifier for identifying each VC connection of a bundle of VC connections. Thus, it is possible to effectively utilize the band of a detour destination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (Asynchro
(Nous Transfer Mode, Asynchronous Transfer Mode) The present invention relates to a switching network, and more particularly, to a detour control of a communication route.

[0002]

2. Description of the Related Art FIG. 10 shows a plurality of ATM switches SW1 to SW1.
FIG. 5 is a schematic diagram of an ATM network including SW4, in which a virtual path (Virtual Path) VP1 is provided between exchanges SW1 to SW4.
To VP4 are set. In this network, the originating exchange SW1-transit exchange SW is used as a working route.
A 2-destination exchange SW3 is set, and an originating exchange SW1-relay exchange SW4-destination exchange SW3 is set as a backup route. The backup route is independent of the working route.

The originating exchange SW1 has a routing table T
A spare outgoing VCI / VPI (Virtual Channel)
Identifier / Virtual Path Identifier, virtual channel identifier / virtual path identifier) table, and the destination exchange SW3 stores in the routing table TBL the spare incoming V
It has a CI / VPI table.

When a failure occurs in the transit exchange SW2 on the working route, the originating exchange SW1 and the destination exchange SW3 connect to the VC.
(Virtual Channel) Receive notification of connection failure. The outgoing exchange SW1 and the destination exchange SW3, which have been notified of the failure, switch the routing table TBL to switch the VC connection in communication from the working route to the backup route.

[0005]

In the above-mentioned prior art, even if there is a request to make a detour between arbitrary exchanges through which a bundled VC connection passes, the detour can only be made between the originating exchange and the destination exchange. There was an inconvenience.

In the prior art described above, the detour source (working) route and the detour destination (spare) route both use the band without waste when no fault occurs, and the detour destination route when a fault occurs. Even if there is a request to disconnect a VC connection with a low detour priority in the middle and use the bandwidth to detour a VC connection with a high detour priority of the detour source route, the VC connection of the detour destination route is disconnected. There was a disadvantage that it could not be cut.

Conventionally, since the upper 5 bits of the VCI are used to bundle VC connections, there is an inconvenience that a great restriction is imposed on network design.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and effectively manages VC connections on the same route having different detour priorities, thereby effectively utilizing a detour destination band. It is an object of the present invention to provide an ATM switching network capable of performing such operations.

[0009]

An ATM switching network according to the present invention is an ATM switching network in which a bypass priority can be set for each virtual channel connection, and one virtual channel connection is used to bundle the virtual channel connections. A virtual channel bundle identifier for identifying a bundle of virtual channel connections is assigned to each virtual channel connection, and virtual channel connections on the same route having different detour priorities are bundled, managed and bypassed.

According to the present invention, a virtual channel connection of the same route having different bypass priorities is bundled and managed, so that the bandwidth of the bypass destination can be effectively used.
A TM exchange network is obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an ATM switching network in which a bypass priority can be set for each virtual channel connection. An ATM switching network in which a virtual channel bundle identifier for identifying a bundle of virtual channel connections is assigned to each book, and virtual channel connections of the same route having different detour priorities can be bundled and managed. The virtual channel connections having different bypass priorities can be bundled and bypassed.

According to a second aspect of the present invention, in the first aspect, a virtual path identifier is used as a virtual channel bundle identifier, and the network design can be performed in units of a virtual path identifier. Have.

According to a third aspect of the present invention, in the first aspect of the present invention, a virtual channel connection for monitoring a failure of a virtual channel connection bundle between arbitrary exchanges through which a bundled virtual channel passes is provided. By setting, a detour section is defined, a detour section can be defined between arbitrary exchanges, and it has an effect of enabling a flexible redundancy design.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a virtual channel connection bundle is monitored by monitoring a virtual channel connection bundle failure. This eliminates the need to monitor faults of all virtual channel connections, and has the effect of reducing the cost of equipment without degrading the performance of fault monitoring.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the detour priority in the bundle of the detour source virtual channel connections is based on the detour priority given to the virtual channel connection. Virtual channel connections with high priority are detoured, virtual channel connections with low detour priority are disconnected, and a bundle of virtual channel connections at the detour destination with high detour priority maintains communication and one with low detour priority Is to cut,
There is an effect that the band at the detour destination can be effectively utilized when no detour occurs.

According to a sixth aspect of the present invention, in the first aspect of the present invention, when a virtual channel connection having a high bypass priority is registered in a virtual channel bundle in which a detour is defined, a virtual source virtual path is registered. The sum of the bandwidths of the virtual channel connection with a high priority of detour in the channel bundle and the virtual channel connection of the high priority of detour in the virtual channel bundle of the detour destination should not exceed the total sum of the circuit bandwidth of the detour destination, This has the effect that it is possible to guarantee a communication band on a detour when a detour occurs.

According to a seventh aspect of the present invention, in the first aspect of the present invention, a bundle of virtual channel connections is bypassed to the ISDN, which has an effect of enabling a flexible network design. .

According to an eighth aspect of the present invention, in the first aspect, the detour is controlled by the maintenance console device and the network monitoring device, and the detour operation can be performed by the user's will. Having.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 shows an ATM according to the present invention.
1 is an example of a network configuration of a switching network, in which a detour section is defined between an ATM exchange 1 and an ATM exchange 2; A
Although the TM exchange 3 and the ATM exchange 4 only perform relay exchange, they are exchanges having functions equivalent to those of the ATM exchanges 1 and 2.

ATM exchanges 1 and 2 are monitoring / control devices 1
1 and 21, cell switching devices 12 and 22, and a plurality of line interface devices (IFs) 13-15 and 23-25. The monitoring / control devices 11 and 21 perform fault monitoring in the device, various controls, and interfaces with the maintenance console device 5 and the network monitoring device 6. The cell switching devices 12 and 22 perform header conversion and exchange of cells. The line IFs 13 to 15 and 23 to 25 provide connection interfaces with the lines. The maintenance console 5 performs maintenance and control of the ATM switch alone, and the network monitoring device 6 performs monitoring and control relating to the entire network.

The monitoring / control devices 11 and 21 transmit the bundle of the virtual channel connections of the bypass source (the bundle of VCs to V
Detour registration tables 11a and 21a for associating a detour destination virtual channel bundle with the detour destination virtual channel bundle, and a VCC registration table 1 for holding the registration status of a VC connection (VCC).
1b, 21b and a VC connection for monitoring a failure of a bundle of VC connections (hereinafter, referred to as a VC bundle monitoring path)
Bundle monitoring path registration table 11 holding the registration status of the
c, 21c.

The terminal 7A connected to the line IF 13 of the ATM exchange 1 to the terminal 8A connected to the line IF 23 of the ATM exchange 2 have a single bypass priority low VC connection 31 and a high bypass priority high VC connection 32. V
It is managed as a C bundle. Line IF14 and Line IF2
4, a VC bundle monitoring path 33 is set, and a detour section is defined.

Further, a bypass priority low VC connection 41 and a bypass priority high VC connection 42 set from the terminal 7B connected to the line IF 13 of the ATM switch 1 to the terminal 8B connected to the line IF 23 of the ATM switch 2 are connected. 1
Are managed as one VC bundle. A VC bundle monitoring path 43 is set between the line IF 15 and the line IF 25 to define a detour section.

Next, a detour operation of the ATM switching network having this configuration will be described. First, registration of a VC connection will be described. To register a VC connection, the maintenance console device 5 or the network monitoring device 6 is used.

The registration information of the VC connection is registered in the cell switching devices 12 and 22 and the line IFs 13 to 15 and 23 to 25 via the monitoring and control devices 11 and 21. If the registration is successful, it is stored in the VCC registration tables 11b and 21b in the monitoring / control devices 11 and 21.

FIG. 2 shows the VCC registration table 11b in the ATM exchange 1, and FIG. 3 shows the VCC registration table 21b in the ATM exchange 2. The bypass priority is specified for each connection. The VC bundle identifier (VC bundle ID) can be designated for each arbitrary exchange. In this example, no VC bundle is defined on the terminal side. A VC bundle having a VC bundle ID of “5” and a VC bundle ID of “10” is defined on the network side. A VC connection with a high bypass priority and a VC with a low bypass priority for each VC bundle
Connections are registered one by one. In general, a network is often designed by assigning the same VPI to VCs having the same route, and thus the VPI may be used as the VC bundle ID.

Next, the definition of the detour section will be described.
The detour section is defined by registering a VC bundle monitoring path. A VC bundle monitoring path is registered from the maintenance console device 5 or the network monitoring device 6 to the exchanges at both ends of the detour section. Information necessary for registering the VC bundle monitoring path is a VC bundle ID, a line IF, a VPI, and a VCI.

This information is registered in the line IFs 13 to 15 from the monitoring / control device 11 via the cell switching device 12.
If the registration is successful, it is stored in the VC bundle monitoring path registration table 11c in the monitoring / control device 11. FIG. 4A shows a VC bundle monitoring path registration table 11c in the ATM exchange 1 when the detour source VC bundle monitoring path 33 and the detour destination VC bundle monitoring path 43 are registered, and the VC bundle in the ATM exchange 2 is shown in FIG. FIG. 4B shows the monitoring path registration table 21c.

The VC bundle monitoring path is a VC connection terminated at the line IF by a VC connection having the same VC bundle ID as the VC bundle to be monitored.
Consider it a failure of the whole bundle. As a result, all the Vs in the VC bundle
It is not necessary to monitor the failure of the C connection. VP
I and VCI can take any values.

Next, the detour registration will be described. The user can use the maintenance console device 5 or the network monitoring device 6
From the VC bundle ID to be the detour source and the VC bundle I to be the detour destination
Specify D.

The specified information is transmitted to the monitoring / control devices 11 and 12.
1 are stored in the detour registration tables 11a and 21a.
FIG. 5 shows a detour registration table 11a, A in the ATM switch 1.
3 shows a detour registration table 21a in the TM exchange 2; This example shows a case where the VC bundle with the VC bundle ID “5” is designated as the detour source, and the VC bundle with the VC bundle ID “10” is designated as the bypass destination.

At the time of detour registration, the following feasibility determination is made in order to guarantee the communication quality at the time of detour. At the time of the detour, the VC connection having the high detour priority in the detour source VC bundle and the VC connection having the high detour priority in the detour destination VC bundle communicate on the route of the detour destination VC bundle. The detour registration is permitted only when the bandwidth of the VC connection having the high detour priority of the detour priority and the VC connection having the high detour priority in the detour destination VC bundle fall within the detour destination line IF.

When a VC connection is registered in a VC bundle for which detour registration has been completed, call admission control shown in FIG. 6 is performed. When registering a VC connection, a means for comparing the sum of the bandwidth of the VC connection with the line bandwidth is generally used. However, when registering a VC connection with a high bypass priority, in addition to the comparing means, the VC bundle in the bypass source is added. A comparison is made between the sum of the bandwidth of the VC connection having the high detour priority and the VC connection having the high detour priority in the VC bundle of the detour destination and the sum of the bandwidth of the line interface accommodating the detour VC bundle.

That is, in the flowchart shown in FIG. 6, if the detour priority is high (step S1), the VC connection with the high detour priority in the detour source VC bundle and the VC with the detour priority in the detour destination VC bundle are high. The sum of the sum of the connection bandwidth and the sum of the bandwidth of the line interface accommodating the bypass VC bundle is compared (step S2).

As a result, if the sum of the bandwidths of the line interfaces accommodating the detour destination VC bundle is larger, registration is permitted (step S3), and if smaller, the registration is rejected (step S4). If the bypass priority is low (step S1), the sum of the bandwidths of the VC connections is compared with the line bandwidth (step S5). If the line bandwidth is large, registration is permitted (step S3). (Step S4).

Next, the detour switching operation will be described. The line IF in which the VC bundle monitoring path is registered is OAM (Operation, Ad
The failure monitoring is performed on the VC bundle monitoring path according to the minimization and maintenance protocol F5.

That is, CC (Continuity Check) error, VC-RDI (Remote Defect Indica)
reception, far-end reception failure) reception, VC-AIS (Alarm Indi)
If the VC bundle monitoring path fails due to reception and line failure, the line IF
The failure is notified to the control devices 11 and 21.

For example, when a failure occurs in the ATM exchange 3, the line IF 14 of the ATM exchange 1 detects the failure,
The failure is notified to the monitoring / control device 11. When the monitoring / control device 11 receives the failure notification, the bypass destination VC bundle monitoring path 43
After confirming that no fault has occurred,
It instructs the cell switching device 12 to delete the VC connection having a low bypass priority in the C bundle. In this example, the bypass priority low VC connection 41 in the bypass VC bundle is deleted.

Next, the V having the high detour priority in the detour source VC bundle
It instructs the cell switching device 12 to switch the C connection to the route of the bypass VC bundle. In this example, the high priority VC connection 32 within the bypass VC bundle is reassigned. A
The same operation is performed in the TM exchange 2, and the detour operation is completed.

Next, a description will be given of the switching back operation at the time of failure recovery. When the VC bundle monitoring path recovers from the failure, the line IF
Notifies the monitoring / control devices 11 and 21 of the failure recovery. For example, when the failure of the ATM exchange 3 is recovered, A
The line IF 14 of the TM exchange 1 detects the recovery from the failure and notifies the monitoring / control device 11 of the recovery from the failure.

Upon receiving the failure recovery notification, the monitoring / control device 11 first instructs the cell switching device 12 to switch the bypassed VC connection having a high bypass priority to the route of the bypass source VC bundle. In this example, the high priority VC connection 32 in the detour source VC bundle is switched back. Next, the detour destination VC
It instructs the cell switching device 12 to register a VC connection with a low bypass priority in the bundle. In the present example, the detour-priority low-VC connection 41 in the detour destination VC bundle is registered. The same operation is performed in the ATM exchange 2, and the detour operation is completed.

In the above description, an example has been described in which the bypass operation is performed upon occurrence and recovery of a failure. However, the bypass operation may be performed according to a user instruction from the maintenance console device 5 and the network monitoring device 6.

(Embodiment 2) FIG. 7 shows a network configuration of an ATM switching network according to Embodiment 2 of the present invention.
This figure shows a configuration in which VCs are bundled and detoured to a DN (Integrated Services Digital Communication Network).

In this embodiment, in addition to the configuration of the first embodiment, an ISDN connected to the
Add line interface devices (IF) 16, 26,
ISDN is stored in the VC bundle monitoring path registration tables 11c and 21c.
Fields for the other party's telephone number, bulk mode, and outgoing / incoming mode.

The detour operation of the ATM switching network configured as described above will be described. First, registration of a VC connection will be described.
Is the same as

Next, regarding the definition of the detour section, the method of defining the detour section is basically the same as in the first embodiment.
However, the VC registered on the ISDN line IF16, 26
The bundle monitoring path is held in the monitoring / control devices 11 and 21 until the actual detour operation occurs, and the cell switching devices 12 and 2
2. Not registered in the line IF.

FIG. 8A shows the bypass source VC bundle monitoring path 33.
(VC bundle ID = 5), the bypass destination VC bundle monitoring path 43 (VC
ATM exchange 1 when bundle ID = 15) is registered
8 shows the VC bundle monitoring path registration table 11c in FIG.
(B) shows the VC bundle monitoring path registration table 21c in the ATM exchange 2. A detour section is defined between the ISDN line IF 16 and the ISDN line IF 26. Detour destination VC
The bundling monitoring path 43 includes a partner telephone number to be connected at the time of detour,
As the bandwidth on the ISDN, information on the number of bulks and information on a calling / receiving mode for identifying a calling side and a called side are registered.

Next, the detour registration will be described. The detour registration operation is the same as in the first embodiment. FIG.
Detour registration table 11 in ATM switch 1 for SDN
3A shows the detour registration table 21a in the ATM switch 2 for ISDN detour. In this example, the VC whose VC bundle ID is “5”
The case where the bundle is designated as the detour source and the VC bundle with the VC bundle ID “10” is designated as the bypass destination is shown.

At the time of detour registration, the following feasibility determination is made in order to guarantee the communication quality at the time of detour. This is also the same as in the first embodiment, but since the detour destination is an ISDN line, no VC connection is previously established at the detour destination, so that the detour priority of the detour source VC bundle is high. Detour registration is permitted only when the total bandwidth of the VC connection falls within the detour destination ISDN line IF.

Further, the method of call acceptance processing when a VC connection is registered in a VC bundle for which detour registration has been performed is also the same as in the first embodiment. However, since the detour destination is an ISDN line, no VC connection is registered in the detour destination VC bundle. Therefore, it is necessary to pay attention only to the fact that the sum of the VC connection bands in the detour destination VC bundle is always zero.

Next, the detour switching operation will be described. For example, when a failure occurs in the ATM exchange 3, the line IF 14 of the ATM exchange 1 detects the failure and the monitoring / control device 1
Notify 1 of the failure. Upon receiving the failure notification, the monitoring / control device 11 makes a call to the ISDN line IF 16.

When the call control is successful, the monitoring / control device 11
Registers the bypass destination VC bundle monitoring path 43 in the ISDN line IF 16. Next, a VC with a high detour priority in the detour source VC bundle
It instructs the cell switching device 12 to switch the connection to the route of the bypass VC bundle. In this example, the detour-source VC bundle detour priority high VC connection 32 is reassigned. A
The same operation is performed in the TM exchange 2 upon an incoming call,
The detour operation is completed. The reason for registering the VC bundle monitoring path in the detour destination is to detect a failure in the detour destination.

Next, a description will be given of a switching operation at the time of recovery from a failure. When the failure of the ATM switch 3 is recovered, the line IF 14 of the ATM switch 1 detects the recovery and notifies the monitoring / control device 11 of the recovery. Upon receiving the failure recovery notification, the monitoring / control device 11 first instructs the cell switching device 12 to switch the detoured VC connection having the higher detour priority to the route of the detour source VC bundle. In this example, the high-delay-priority VC connection 32 in the detour-source VC bundle is switched back.

Next, the bypass destination VC bundle monitoring path 43 is set to the ISD
Delete it from the N-line IF 16 and instruct it to disconnect the call. AT
The same operation is performed in the M exchange 2 upon the disconnection of the call, and the return operation is completed.

In the above description, an example in which the detour operation is performed upon occurrence and recovery of a failure has been described. However, the detour operation may be performed by a user's instruction from the maintenance console device or the network monitoring device. When a failure occurs at the detour destination, a switchback operation is performed.

[0057]

As described above, according to the present invention, in order to bundle VC connections, V
By assigning a VC bundle identifier for identifying a bundle of C connections, VC connections on the same route having different detour priorities are bundled, managed, and detoured, so that the detour destination band can be effectively used. Effects can be obtained.

[Brief description of the drawings]

FIG. 1 shows a network configuration example of an ATM switching network according to a first embodiment of the present invention.

FIG. 2 is a VCC registration table in the ATM exchange 1 shown in FIG.

FIG. 3 is a VCC registration table in the ATM exchange 2 shown in FIG.

4A is a VC bundle monitoring path registration table in the ATM exchange 1 shown in FIG. 1, and FIG.
C bundle monitoring path registration table

FIG. 5 is a detour registration table in the ATM exchanges 1 and 2 shown in FIG.

FIG. 6 is a flowchart showing a processing procedure of call admission control at the time of registering a VC connection to a bypass-registered VC bundle;

FIG. 7 shows a network configuration example of an ATM switching network according to a second embodiment of the present invention;

8A is a VC bundle monitoring path registration table in the ATM exchange 1 shown in FIG. 7, and FIG.
C bundle monitoring path registration table

9 is a detour registration table in the ATM exchanges 1 and 2 shown in FIG. 7;

FIG. 10 shows a network configuration example of a conventional ATM switching network.

[Explanation of symbols]

 1-4 ATM switch 5 Maintenance console device 6 Network monitoring device 7A, 7B, 8A, 8B Terminal device 9 ISDN 11, 21 Monitoring / control device 11a, 21a Detour registration table 11b, 21b VCC registration table 11c, 21c VC bundle monitoring path Registration table 12,22 Cell switching device 13-15,23-25 Line interface device 16,26 ISDN line interface device 31 Detour source VC bundle detour priority low VC connection 32 Detour source VC bundle detour priority high VC connection 33 Detour source VC bundle monitoring path 41 Detour destination VC bundle detour priority low VC connection 42 Detour destination VC bundle detour priority high VC connection 43 Detour destination VC bundle monitoring path

Claims (8)

[Claims] 1. An ATM switching network in which a bypass priority can be set for each virtual channel connection, wherein the bundle of virtual channel connections is identified for each virtual channel connection in order to bundle the virtual channel connections. An ATM switching network, which assigns virtual channel bundle identifiers for the same purpose and bundles and manages and bypasses the virtual channel connections on the same route having different bypass priorities. 2. The ATM switching network according to claim 1, wherein a virtual path identifier is used as the virtual channel bundle identifier. 3. A detour section is defined by setting a virtual channel connection for monitoring a failure of the bundle of virtual channel connections between arbitrary exchanges through which the bundled virtual channel connections pass. 2. The ATM switching network according to claim 1. 4. The ATM switching network according to claim 1, wherein the failure of the virtual channel connection for monitoring the failure of the virtual channel connection bundle automatically bypasses the virtual channel connection bundle. 5. A virtual channel connection having a high bypass priority in a bundle of virtual channel connections of a detour source based on a bypass priority assigned to a virtual channel connection, and a virtual channel connection having a low bypass priority is disconnected. 2. The ATM switching network according to claim 1, wherein, among a bundle of virtual channel connections at a detour destination, one having a high detour priority maintains communication, and one having a low detour priority is disconnected. 6. Registering a virtual channel connection with a high detour priority in a virtual channel bundle in which detour is defined, in the detour source virtual channel bundle and in the detour destination virtual channel bundle. 2. The ATM switching network according to claim 1, wherein the sum of the bandwidths of the virtual channel connections having the high bypass priority does not exceed the sum of the circuit bandwidths of the bypass destination. 7. A bundle of virtual channel connections is called IS
2. The AT according to claim 1, wherein the AT is detoured to a DN.
M switching network. 8. The detour control from a maintenance console device and a network monitoring device.
2. The ATM switching network according to claim 1.