Dell Force10 E300, Configuration Manual, Page: 81 / 1262

802.1ag | 81
These roles define the relationships between all devices so that each device can monitor the layers under its
responsibility. Maintenance points drop all lower-level frames and forward all higher-level frames.
Figure 5-2. Maintenance Points
Maintenance End Points
A Maintenance End Point (MEP) is a logical entity that marks the end-point of a domain. There are two
types of MEPs defined in 802.1ag for an 802.1 bridge:
• Up-MEP : monitors the forwarding path internal to an bridge on the customer or provider edge; on
Dell Force10 systems the internal forwarding path is effectively the switch fabric and forwarding
engine.
• Down-MEP : monitors the forwarding path external another bridge.
Configure Up- MEPs on ingress ports, ports that send traffic towards the bridge relay. Configure
Down-MEPs on egress ports, ports that send traffic away from the bridge relay.
Figure 5-3. Up-MEP versus Down-MEP
Ethernet Access
MPLS Core MPLS Access
Customer Network
Customer Network
Customer Domain (7)
Provider Domain (6)
Operator Domain (5) Operator Domain (5)
Operator Domain (5)
MPLS Domain (4)
Service Provider Network
MIP MEP
Customer Network
Service Provider Ethernet Access
towards relay
away from relay
Up-MEP
Down-MEP