Ethernet OAM three brothers-efm, CFM and y.1731

Ethernet OAM The main functions can be divided into the following two parts:

· fault Management

§  Detect network connectivity by timing or manually sending detection packets.

§  provide similarIPin the networkPing(Packet Internet Groper) andTracerouteof thefunction, fault diagnosis and location of Ethernet.

§  in conjunction with the Protection switching protocol, the Ethernet OAM trigger device or link switching after connectivity failure is detected .

· Performance Management

Performance management mainly refers to the network transmission of packet loss, delay, jitter and other parameters of the measurement, also includes the network of various types of traffic (such as the number of bytes received, the number of error frames, etc.) statistics (usually implemented at the user access point).

EFMprinciple Description, but also on the interface of two direct connected devices, link layer

EFM as an Ethernet access " last kilometer " of the OAM mechanism, which provides operators with a mechanism for monitoring the status of the link in real time, locating the fault link position and the fault type quickly.

OAMPDU(OAM Protocol Data Units,OAMProtocol Data Unit), the format of this thing, to use the time to check, do not have to memorize. InformationOAMPDU(Information OAMPDU)EFMPeer -to-peer discoveryEvent AnnouncementsOAMPDU(Event Notification OAMPDU), monitoringfar-back loopbackOAMPDU(Loopback Control OAMPDU)Connection Mode

EFM There are two types of connection modes: Active mode and passive mode.

CFMPrinciple DescriptionMEP-MIP-MEPCFMVersion InformationFollowieee802.1ag/draft7.0and theIEEE Std 802.1ag-2007. Maintenance DomainMD(Maintenance Domain)

Maintenance Domain MD indicates the network covered by connectivity error detection, whose boundaries are defined by a series of maintenance endpoints configured on the port.

802.1ag the interaction of protocol messages and CFM basic functionality is based on the maintenance domain, so a reasonable maintenance domain plan can help network administrators quickly locate the point of failure.

Maintain EndpointsMEP

the maintenance endpoint has directionality and is divided into Inward Type and Outward type , four kinds of messages

CCM ( Continuitycheck Message )

LBR ( loopbackreply )

LBM ( Loopbackmessage )

LTR ( linktracereply )

LTM ( linktrace Message )

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Ethernet OAM three brothers-efm, CFM and y.1731