Figure 9-3 Mep And Mip - Raisecom ISCOM2600G-HI (A) Series Configuration Manual

Raisecom
ISCOM2600G-HI (A) Series Configuration Guide

Figure 9-3 MEP and MIP


As shown in Figure 9-3, the MIP is the internal node of a service instance, which is
automatically created by the device. MIP cannot actively send CFM packets but can process
and response to LinkTrace Message (LTM) and LoopBack Message (LBM) packets.

MEP and MIP are called Maintenance Point (MP).
CFM functions
CFM can provide following OAM functions:

The function is implemented by periodically sending Continuity Check Messages (CCMs).
One MEP sends CCM and other MEPs in the same service instance can verify the RMEP
status when receiving this packet. If the ISCOM2600G-HI series switch fails or a link is
incorrectly configured, MEPs cannot properly receive or process CCMs sent by RMEPs. If no
CCM is received by a MEP during 3.5 CCM intervals, it is believed that the link fails. Then a
fault Trap will be sent according to configured alarm priority.

This function is used to verify the connectivity between two MPs through the source MEP
sending LoopBack Message (LBM) and the destination MP sending LoopBack Reply (LBR).
The source MEP sends a LBM to a MP who needs to acknowledge a fault. When receiving the
LBM, the MP sends a LBR to the source MEP. If the source MEP receives this LBR, it is
believed that the route is reachable. Otherwise, a connectivity fault occurs.

The source MEP sends LinkTrace Message (LTM) to the destination MP and all MPs on the
LTM transmission route will send a LinkTrace Reply (LTR) to the source MEP. By recording
valid LTR and LTM, this function can be used to locate faults.

This function is used to inhibit alarms when a fault is detected at the server layer (sub-layer,
as shown in Figure 9-2). When detecting a fault, the MEP (including the server MEP) sends
an AIS frame to the client MD. By transmitting ETH-AIS frames, the device can inhibit or
stop an alarm on MEP (or server MEP).
MIP
MP
Fault detection (Continuity Check, CC)
Fault acknowledgement (LoopBack, LB)
Fault location (LinkTrace, LT)
Alarm Indication Signal (AIS)
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