Cfd Functions - HP A5830 series Configuration Manual

Figure 6 demonstrates a grading example of the CFD module. Six devices exist, labeled A through F,
respectively,. Suppose each device has two ports, and MEPs and MIPs are configured on some of these
ports. Four levels of MDs are designed in this example. The bigger the number, the higher the level and
the larger the area covered. In this example, Port 1 of device B is configured with the following MPs: a
level 5 MIP, a level 3 inward-facing MEP, a level 2 inward-facing MEP, and a level 0 outward-facing
MEP.
Figure 6 Levels of MPs
MEP list
A MEP list is a collection of local MEPs allowed to be configured and remote MEPs to be monitored in
the same MA. It lists all MEPs configured on different devices in the same MA. The MEPs all have unique
MEP IDs. When a MEP receives from a remote device a CCM that carries a MEP ID not included in the
MEP list of the MA, it drops the message.

CFD functions

CFD works effectively only in properly-configured networks. Its functions, which are implemented through
the MPs, include the following:
CC
•
Loopback (LB)
•
Linktrace (LT)
•
Continuity check
Connectivity faults are usually caused by device faults or configuration errors. Continuity check checks
the connectivity between MEPs. This function is implemented through periodic sending of CCMs by the
MEPs. As a multicast message, a CCM sent by one MEP is intended to be received by all other MEPs in
the same MA. If a MEP fails to receive the CCMs within 3.5 times the sending interval, the link is
considered faulty, and a log is generated. When multiple MEPs send CCMs at the same time, the
multipoint-to-multipoint link check is achieved. CCM frames are multicast frames.
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