Juniper Networks JUNOS OS 10.4 - Manual (Page 131)

maintenance domain, each service instance is called a maintenance association. A
maintenance association can be thought as a full mesh of maintenance endpoints (MEPs)
having similar characteristics. MEPs are active CFM entities generating and responding
to CFM protocol messages. There is also a maintenance intermediate point (MIP), which
is a CFM entity similar to the MEP, but more passive (MIPs only respond to CFM messages).
MEPs can be up MEPs or down MEPs. A link can connect a MEP at level 5 to a MEP at
level 7. The interface at level 5 is an up MEP (because the other end of the link is at MEP
level 7) and the interface at level 7 is a down MEP (because the other end of the link is
at MEP level 5).
In a Metro Ethernet network, CFM is commonly used at two levels:
• By the service provider to check the connectivity among its provider edge (PE) routers
• By the customer to check the connectivity among its customer edge (CE) routers
NOTE: The configured customer CFM level must be greater than service
provider CFM level.
In many Metro Ethernet networks, CFM is used to monitor connectivity over a VPLS and
bridge network.
Related
Documentation
Ethernet OAM •
• Ethernet Operations, Administration, and Maintenance on page 109
• Example: Configuring Ethernet CFM over VPLS on page 111
• Example: Configuring Ethernet CFM on Bridge Connections on page 118
• Example: Configuring Ethernet CFM on Physical Interfaces on page 122
Example: Configuring Ethernet CFM over VPLS
In this example, both the customer and service provider are running Ethernet CFM over
a VPLS and a multiprotocol label switching (MPLS) network. The network is shown in
Figure 15 on page 112 . The customer has configured Ethernet CFM on MX Series routers
L2-CE1 and L2-CE2. The service provider has configured Ethernet CFM on MX Series
routers PE1, P, and PE2.
NOTE: The configurations in this example are only partial examples of
complete and functional router configurations. Do not copy these
configurations and use them directly on an actual system.
The service provider is using CFM level 5 and the customer is using CFM level 7. The
boundaries are marked with “up mep” and “down mep” CFM terminology in the figure.
111 Copyright © 2013, Juniper Networks, Inc.
Chapter 10: IEEE 802.1ag OAM Connectivity-Fault Management