Qtech QSW-3900-48-SFP-DC [240/245] Basic functions of connectivity fault

QTECH Software Configuration Manual

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Figure 2 Inbound MEP

22.3.3.2 MIP

Maintenance association intermediate point (MIP) can handle and respond to CFM packets. The MA and

MD that a MIP belongs to define the VLAN attribute and level of the packets received.

Figure 3 demonstrates a grading example of CFM module. In the figure, there are six devices, labeled as 1 to

6 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, the X port of device 2 is configured with the following MPs : a level 5 MEP, a level 3

inbound MEP, a level 2 inbound MEP, and a level 0 outbound MEP.

Figure 3 Levels of MPs

22.3.4 Basic Functions of Connectivity Fault

Management

CFM works effectively only in well-deployed and well-configured networks. Its functions, which are

implemented through the maintenance points, include :

· Continuity check (CC);

· Loopback (LB)

· Linktrace (LT)

22.3.4.1 Continuity check

Continuity check is responsible for checking connectivity between MEPs. Connectivity fault is usually

caused by device fault or configuration error. This function is implemented through periodic sending of continuity

check messages (CCM) by the MEPs. As a multicast message, a CCM sent by one MEP is intended to be received by