maintenancedomain, each service instance is called a maintenanceassociation. A
maintenanceassociationcan be thought as a full mesh of maintenance endpoints(MEPs)
havingsimilar characteristics. MEPs are activeCFM entities generating and responding
toCFM protocol messages.There is also a maintenance intermediate point (MIP),which
isa CFM entity similar tothe MEP, but more passive(MIPs only respond to CFM messages).
MEPscan be up MEPs or down MEPs. A link can connect a MEP at level5 to a MEP at
level7. The interfaceat level 5 is an up MEP (because the other end of the link is at MEP
level7) and the interface at level7 is a down MEP (because the other end of the link is
atMEP level 5).
Ina Metro Ethernet network, CFM is commonly used at twolevels:
•Bythe service provider to check the connectivity among its provideredge (PE) routers
•Bythe customer to check the connectivity among its customer edge (CE)routers
NOTE: Theconfigured customer CFM levelmust be greater than service
providerCFM level.
Inmany Metro Ethernet networks, CFM is used to monitor connectivityover a VPLS and
bridgenetwork.
Related
Documentation
MXSeries Ethernet Services Routers SolutionsPage•
•EthernetOperations, Administration, and Maintenanceon page 103
•Example:Configuring Ethernet CFM over VPLS on page105
•Example:Configuring Ethernet CFM on Bridge Connections on page112
•Example:Configuring Ethernet CFM on Physical Interfaceson page 116
Example:Configuring Ethernet CFM over VPLS
Inthis example, both the customer and service provider are running EthernetCFM over
aVPLS and a multiprotocol label switching (MPLS)network. The network is shown in
Figure15 on page 106. The customer has configuredEthernet CFM on MX Series routers
L2-CE1and L2-CE2. The service provider has configured Ethernet CFM on MX Series
routersPE1, P, and PE2.
NOTE: Theconfigurations in this exampleare only partial examples of
completeand functional router configurations.Do not copy these
configurationsand use them directly on an actual system.
Theservice provider is using CFM level 5 and the customer is using CFM level7. The
boundariesare marked with “up mep” and “down mep” CFM terminology in the figure.
105Copyright© 2010, Juniper Networks,Inc.
Chapter10: IEEE 802.1ag OAM Connectivity-FaultManagement