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An ME is created and bound to a bidirectional co-routed TE tunnel.
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9.3.3 (Optional) Configuring CC and CV for an LSP
The CC and CV functions provided by MPLS-TP OAM can be configured for an LSP to check
its continuous connectivity and forwarding correctness.
Context
CC and CV are two different MPLS-TP OAM functions. CC checks loss of continuity (LOC)
defects between two MEPs in a MEG. CV is used to detect consistency of configurations on two
MEPs in a MEG or in different MEGs. The purpose of CC greatly differs from that of CV. The
details are as follows:
l
CC is a pro-active OAM operation. It detects connectivity between any two MEPs in a
MEG. A MEP sends CCMs to its RMEP at intervals. If the RMEP does not receive CCMs
within a period 3.5 times the specified interval, it considers that the connectivity between
the two MEPs is faulty and will report an alarm and enter the Down state. Then, automatic
protection switching (APS) will be triggered on both MEPs. After receiving a CCM from
the MEP, the RMEP will clear the alarm and exit from the Down state.
l
CV is also a pro-active OAM operation. It enables a MEP to report alarms when the EMP
receives unexpected packets. For example, if a CV-enabled device receives a packet from
an LSP and finds that this packet is mistakenly transmitted by the LSP, the device will
report an alarm indicating a forwarding error.
Transport networks have strict requirements on data forwarding correctness. In addition,
MPLS-TP requires that the data plane be able to work without IP support, which means
that packet forwarding is based on label switching only. Therefore, the correctness of label-
based forwarding must be guaranteed.
In real world situations, CC and CV are usually used together. Therefore, these two functions
are integrated on the NE80E/40E. Perform the following steps on the MEP and RMEP:
Procedure
Step 1
Run:
system-view
The system view is displayed.
Step 2
Run:
mpls-tp meg
meg-name
A MEG is created and the MEG view is displayed.
Step 3
(Optional) Run either of the following commands:
NOTE
Ensure that the same CCM transmission interval is set on the MEP and RMEP; otherwise, an alarm will be
generated.
l
To configure the interval between CCM transmissions, run:
cc interval
interval-value
CCM transmission intervals and their application scenarios are as follows:
HUAWEI NetEngine80E/40E Router
Configuration Guide - Reliability
9 MPLS-TP OAM Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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