Dell Force10 S4820T S4820T Configuration Guide - Page 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. Customer Network Service Provider Network Customer Network Ethernet Access Operator Domain (5) MPLS Core Customer Domain (7) Provider Domain (6) Operator Domain (5) MPLS Domain (4) MEP MIP MPLS Access Operator Domain (5) 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. Customer Network Service Provider Ethernet Access towards relay Up-MEP Down-MEP away from relay 802.1ag | 81