KR20070061273A - Apparatus and method of oam fault notification in ethernet networks - Google Patents

Abstract

An apparatus and a method for informing about an OAM(Operation, Administration and Maintenance) failure in an Ethernet are provided to construct a carrier Ethernet as well as an LAN and a metro network with guaranteed connectivity by providing an Ethernet OAM failure notification function. An MEP(Maintenance End Point) of a physical layer level periodically generates a CC(Continuity Check) frame for checking a connection state of an Ethernet(S210). Each MEP checks whether the CC frames generated by different MEPs have been normally received(S220). If a CC frame is not received, the MEP periodically generates an AIS(Alarm Indication Signal) frame and transmits it to a client equipment of the opposite side of a failure-occurred point(S230). Upon receiving the AIS frames, the MEPs transmit the AIS frames to an adjacent node of an upper level(S240,S250). When the MEP has received the AIS frame, it transmits the AIS frame to an adjacent node of a level to which the MEP itself belongs(S260,S270). The process is repeatedly performed until the AIS frame reaches a client level(S280). When the AIS frame reaches the client level and a failure generation is notified, a failure verification is performed and a necessary measure is taken(S290).

Description

Apparatus and method of OAM fault notification in ethernet networks

1 is a flowchart of an OAM failure notification frame in an OAM failure notification device according to an embodiment of the present invention;

2 is a flowchart illustrating an OAM failure notification method in an Ethernet network according to an embodiment of the present invention.

The present invention relates to the operation, management, and maintenance of a communication network, and more particularly, to the failure of an Ethernet network in performing an operation, management and maintenance (OAM) function in an Ethernet network. An apparatus and method for notifying.

Ethernet is well known as a networking protocol defined by the Institute of Electrical and Electronics Engineers (IEEE) 802 standard. Traditionally, Ethernet has been used to form networks in enterprises such as business networks and campus networks.

However, technologies other than Ethernet have been used to transport network traffic over long distances. Ethernet is designed as a best-effort network with no guarantee of quality of service, which does not support satisfactory OAM for network service providers and cannot guarantee connectivity. to be. In particular, network service providers that provide carrier services do not want to deploy Ethernet technology-based networks into wide area networks (WANs).

In order to solve this problem, researches on implementing Ethernet OAM have been conducted. US Patent Publication No. 2005/0099949 proposes an Ethernet OAM domain and an Ethernet OAM frame format. However, when an Ethernet network failure occurs, it does not provide a way to notify OAM failure. U.S. Patent Publication No. US2005 / 0099955 also discloses a method for isolating OAM disorders. However, this also does not provide an Ethernet OAM failure notification function.

The technical problem to be solved by the present invention is to quickly and efficiently maintain the failures detected by the Ethernet OAM fault detection and verification function to the related maintenance entity while maintaining the Ethernet frame basic specification so as to have connectivity in the Ethernet network. It is to provide an apparatus and method for accurately notifying.

In order to achieve the above technical problem, the OAM failure notification device in the Ethernet network according to the present invention receives a plurality of alarm indication signal (AIS) frame indicating the occurrence of the failure to transmit a plurality of maintenance to the neighboring node of its higher level Maintenance end points (MEPs); And a plurality of maintenance intermediate points (MIPs) for receiving AIS frames and transmitting them to neighboring nodes of a level to which they belong. Periodically generates CC (continuity check) frames to check the network connection status and monitors the Ethernet network for failures.When a failure is detected, maintenance terminations at the physical layer level periodically generate AIS frames to indicate the point of failure. The AIS frame is transmitted to the other side of the client to notify the failure of the Ethernet network.

In addition, OAM failure notification method in the Ethernet network according to the present invention for achieving the above technical problem, the CC that the maintenance end point (MEP, maintenance end point) of the physical layer level to check the connection state of the Ethernet network (continuity check) periodically generating a frame; Periodically generating an alarm indication signal (AIS) frame notifying the occurrence of a failure by the maintenance end that has not received the CC frame and transmitting it to the customer equipment opposite the point of failure; A plurality of maintenance endpoints receiving the AIS frame, transmitting the AIS frame to its higher level neighbor node; And a plurality of maintenance intermediate points (MIPs) receiving the AIS frame, transmitting the AIS frame to neighboring nodes of a level to which they belong.

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

1 is a flowchart of an OAM failure notification frame in an OAM failure notification device according to an embodiment of the present invention.

Referring to FIG. 1, the OAM failure notification device according to the present invention includes a plurality of maintenance intermediate points (MIPs) and a plurality of maintenance end points (MEPs).

In the present embodiment, an Ethernet network including customer equipments 112 and 114, a network 120 belonging to network operator A, and a network 130 belonging to network operator B will be described as an example. On the other hand, there are service provider bridges 122, 124, and 126 in network 120 belonging to network operator A, and service provider bridges 132 and 134 in network 130 belonging to network operator B. .

In the present invention, maintenance entities (ME) are divided into a customer level, a service provider level, an operator level, and a physical level. Each level has a number of maintenance intermediaries and a number of maintenance terminations, respectively. The number of maintenance intermediates and maintenance terminations at each level depends on the connection to other bridges or customer equipment.

First, all bridges and customer equipment that make up the Ethernet network are connected by MEP at the physical layer level.

At the operator level, bridges belonging to the same network operator are connected by MIP instead of MEP, and only bridges connected to other network operators or customer equipment are connected to the operator level MEP. For example, at bridges 122, 124, and 126 belonging to network operator A, the bridge 122 to customer equipment 112 and the bridge 126 to bridge 132 belonging to another network operator B are at operator level. As an end point of, it has operator level MEPs 155, 163, respectively, connected between MIPs 154, 153, 152, 162.

At the service provider level, only the bridge to the customer equipment has the MEP. For example, only the bridge 122 connected to the customer equipment 112 and the bridge 134 connected to the customer equipment 114 have a service provider level MEP as the end of the service provider level.

The present invention relates to fault notification for Ethernet network operation, management and maintenance (OAM) required by a network provider providing a carrier service to deploy an Ethernet technology-based network. Notifications can be linked with fault detection and fault verification functions.

The failure notification technique is used in conjunction with a failure detection technique to notify failures of upstream and downstream nodes. The CC (Continuity Check Message) is to check the connection status of an information channel to confirm that an information path exists. Maintenance End Point (MEP) generates CC frames periodically and checks that there is no abnormality in the transmission path by receiving CC frames generated by other MEPs.

CC frames provide a means for detecting hardware failures and software failures (such as memory corruption or misconfiguration). Failure detection is accomplished by the MEP sending a CC frame to a maintenance entity (ME).

Each MEP has a list of all other MEPs in the ME, and if the reception of CCMs from the MEPs in the list stops, the local bridge assumes that the remote bridge has failed or an unrecoverable failure has occurred in the transmission path. The bridge that detects the failure can notify the network operator and the failure notification service customer immediately and initiate the failure proof phase automatically or by operator command.

When the MEP detects a failure while monitoring a LAN, it generates a multicast alarm indication signal (AIS) away from the failure.

Preferably, when a failure is detected, maintenance terminations at the physical layer level may periodically generate an AIS frame and transmit the AIS frame to the customer equipment opposite to the failure point to notify the failure of the Ethernet network.

Preferably, the AIS can be used as a signal to inform the service instance user of a failure or to suppress an excessive transmission of an SNMP failure notification message to an operator.

When an AIS frame is generated, the MEP and maintenance intermediate point (MIP) send the AIS frame to notify the customer of the failure up to the customer level.

When the MEP receives an AIS frame indicating that a failure has occurred, the MEP transmits the AIS frame to an adjacent node of a higher level of its own level. In this case, the adjacent node becomes MEP or MIP depending on the connection state.

The MIP receives the AIS frame and transmits it to the neighbor node of its level.

Preferably, when a failure is detected, the active MEP may transmit AIS frames at a fixed frame rate.

Preferably, when a failure is detected, the active MEP may transmit the AIS frame at the transmission rate set in the Lifetime TLV field of the OAM frame format.

Preferably, the AIS frame format may be configured by adding a Lifetime field to the common OAM frame format.

In the embodiment of FIG. 1, the AIS is notified when the line fault 140 occurs.

The MEP 151 of the physical layer level at the point where the circuit failure 140 has occurred first transmits an AIS frame to its higher level in order to transmit the AIS to the MEP 158 at the customer level opposite the failure. The MIP 152 at the operator level receives this and transmits it to the MIP 153 and MIP 154 in sequence until it reaches the MEP 155 at the equivalent level.

The operator level MEP 155 transmits the received AIS frame to the service provider level MEP 156, which in turn sends it to the customer level MIP 157.

Finally, the MIP 157 at the customer level sends an AIS to the MEP 158 at the equivalent level in the customer equipment 112 to notify that a failure has occurred, thus initiating failure verification and taking the necessary action.

As described above, the MEP 161 of the physical layer level at the point where the circuit failure 140 is transmitted transmits the AIS to the MEP 164 at the customer level opposite to the failure. However, in this case, since the data is transmitted through a network operated by different network operators, it is transmitted through MIPs 162 and 163 of the service provider level.

When each MEP detects a connectivity failure, it can generate an AIS at a higher level and deliver the AIS frame to the customer level. Because the AIS frame is sent to the group destination Media Access Control (MAC) address, the AIS frame arrives at all MEPs in the ME, as long as the network's current intercommunication capability allows.

The present invention may be implemented in a plurality of bridges as described in the above embodiments, but is not limited thereto and may be implemented in one bridge or a corresponding communication system constituting an Ethernet network.

2 is a flowchart illustrating an OAM failure notification method in an Ethernet network according to an embodiment of the present invention.

Referring to FIG. 2, first, a maintenance terminal (MEP) of a physical layer level periodically generates a CC (continuity check) frame for checking a connection state of an Ethernet network (S210). Each MEP checks whether a CC frame generated by another MEP is normally received (S220). If the CC frame is not received, the MEP periodically generates an alarm indication signal (AIS) frame indicating a failure, and transmits it to the customer equipment opposite to the failure point (S230). As described above, the plurality of MEPs receiving the AIS frame transmits the AIS frame to the neighboring node of its higher level (S240, S250), and when the MIP receives the AIS frame, the AIS frame is sent to the neighboring node of the level to which it belongs. It transmits (S260, S270). This process is repeated until the AIS frame reaches the customer level (S280). When the AIS frame reaches the customer level and is notified of the failure, the failure verification proceeds and takes the necessary measures (S290).

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which may also be implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown not in the above description but in the claims, and all differences within the equivalent and equivalent scope will be construed as being included in the present invention.

According to the present invention, by providing the Ethernet OAM failure notification function using the Ethernet OAM failure detection and verification function while maintaining the basic Ethernet frame standard, it is possible to establish a LAN network and a metro network that guarantees the interconnectivity (connectivity) In addition, there is an effect to build a carrier Ethernet network.

Claims (11)

A plurality of maintenance end points (MEPs) for receiving an alarm indication signal (AIS) frame indicating a failure and transmitting the same to an adjacent node of a higher level thereof; And And a plurality of maintenance intermediate points (MIPs) for receiving the AIS frame and transmitting the received AIS frame to an adjacent node of a level to which the AIS frame belongs. The maintenance layer at the physical layer level among the maintenance terminals periodically generates a CC (continuity check) frame that checks the connection state of the Ethernet network to monitor whether the Ethernet network has a failure, and if the failure is detected, the physical layer The OAM failure notification device of the Ethernet network, characterized in that the maintenance end of the level periodically generates the AIS frame to transmit the AIS frame to the customer equipment opposite the point of failure. The method of claim 1, When the failure is detected, the maintenance terminal in the active state transmits the AIS frame at a fixed frame rate, OAM failure notification device in the Ethernet network. The method of claim 1, When the failure is detected, the maintenance terminal in the active state transmits the AIS frame at the transmission rate set in the Lifetime TLV field of the OAM frame format. The method of claim 1, The AIS frame is an OAM failure notification device in the Ethernet network, characterized in that to configure the AIS frame format by adding the Lifetime field to the common OAM frame format. The method of claim 1, An OAM failure notification device in an Ethernet network, characterized in that the AIS frame is used as a signal for suppressing a simple network management protocol (SNMP) failure notification. Periodically generating, by a maintenance end point (MEP) at a physical layer level, a continuity check (CC) frame for checking a connection state of an Ethernet network; Periodically generating an alarm indication signal (AIS) frame notifying the occurrence of a failure by the maintenance terminal that has not received the CC frame and transmitting it to the customer equipment opposite the point of failure; A plurality of maintenance terminations receiving the AIS frame transmitting the AIS frame to a neighbor node of its higher level; And A plurality of maintenance intermediate points (MIPs) receiving the AIS frame, transmitting the AIS frame to neighboring nodes of a level to which the AIS frame belongs; OAM failure notification in an Ethernet network Way. The method of claim 6, If a failure is detected, the maintenance terminal in the active state transmits the AIS frame at a fixed frame rate. The method of claim 6, If a failure is detected, the maintenance terminal in the active state transmits the AIS frame at the transmission rate set in the Lifetime TLV field of the OAM frame format. The method of claim 6, The AIS frame is an OAM failure notification method in the Ethernet network, characterized in that the AIS frame format by adding a Lifetime field to the common OAM frame format. The method of claim 6, And using the AIS frame as a signal for suppressing a simple network management protocol (SNMP) failure notification. A computer-readable recording medium having recorded thereon a program for executing an OAM failure notification method in an Ethernet network according to any one of claims 6 to 10.

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