H3C Technologies H3C S12500 Series Switches - Manual (Page 31)

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An MA serves a VLAN. Packets sent by the MPs in an MA carry the relevant VLAN tag. An MP can
receive packets sent by other MPs in the same MA. The level of an MA equals the level of the MD that the
MA belongs to.
Maintenance point
An MP is configured on a port and belongs to an MA. MPs include maintenance association end points
(MEPs) and maintenance association intermediate points (MIPs).
• MEP
MEPs define the boundary of the MD. Each MEP is identified by an MEP ID.
The MA that a MEP belongs to defines the VLAN of packets sent by the MEP; the level of an MEP
equals the level of the MD that the MEP belongs to, and the level of packets sent by an MEP equals
the level of the MEP. The level of a MEP determines the levels of packets that the MEP can process.
A MEP forwards packets at a higher level and processes packet of its level or lower. The
processing procedure is specific to packets in the same VLAN. Packets of different VLANs are
independent.
MEPs include inward-facing MEPs and outward-facing MEPs. An outward-facing MEP sends
packets to its host port. An inward-facing MEP does not send packets to its host port. Rather, it
sends packets to other ports on the device.
• MIP
A MIP is internal to an MD. It cannot send CFD packets actively; however, it can handle and
respond to CFD packets. By cooperating with MEPs, a MIP can perform a function similar to ping
and traceroute. A MIP forwards packets of a different level without any processing and only
processes packet of its level.
The MA to which a MIP belongs defines the VLAN of packets that the MIP can receive; the level of
a MIP is defined by its generation rule and the MD that the MIP belongs to. MIPs are generated on
each port automatically according to related MIP generation rules. If a port has no MIP, the system
will check the MAs in each MD (from low to high levels), and follow the procedure as described
in Figure 4 to create or not to create MIPs at the relevant level.
Figure 4 Procedure of creating MIPs
Figure 5 demonstrates a grading example of the CFD module. Four levels of MDs (0, 2, 3, and 5) are
designed. The bigger the number, the higher the level and the larger the area covered. MPs are