Configuring CC

This section describes how to configure continuity check (CC) in an L2TPv3 scenario.

Context

CC enables a local maintenance association end point (MEP) and a remote maintenance association end point (RMEP) to periodically send continuity check messages (CCMs) to check the continuity of the link between them. When CC is enabled for connectivity fault management (CFM), CFM provides different CCM intervals to meet carriers' requirements for different quality of service (QoS) levels. Table 1 lists the CCM intervals and the RMEP timeout time that each one corresponds to.

If CC detection is configured on a Layer 3 physical main interface, CC detection fails once each time this interface is added to or removed from an Eth-Trunk interface.

**Table 1** CCM intervals
Interval	RMEP Timeout Time
600000 ms	2100000 ms
60000 ms	210000 ms
10000 ms	35000 ms
1000 ms	3500 ms
100 ms	350 ms
50 ms	175 ms
30 ms	105 ms
20 ms	70 ms
10 ms	35 ms
3.3 ms	11.55 ms

Procedure

Run system-view
The system view is displayed.
Run cfm md md-name
The maintenance domain (MD) view is displayed.
Run ma ma-name
The maintenance association (MA) view is displayed.

In L2TPv3 scenario, MA name of CCM packet is in ICC-based mode. Only the NetEngine 8000 F1A supports L2TPv3.
Run ccm-interval interval
An interval at which a MEP in the MA sends or monitors CCMs is configured.

The same interval must be configured on the MEPs in the same MD and MA.
(Optional) Run ccm tlv interface-status
CCMs are configured to carry Interface Status TLV.
(Optional) Run ccm tlv port-status
CCMs to be sent are enabled to carry the Port Status TLV field.
(Optional) Run ccm tlv sender-id
CCMs to be sent are enabled to carry the Sender ID TLV field.
Run mep ccm-send [ mep-id mep-id ] enable
The specified local MEP is enabled to send CCMs.

If you do not specify the mep-id mep-id parameter, all local MEPs in the MA are enabled to send CCMs.
Run remote-mep ccm-receive [ mep-id mep-id ] enable
The specified local MEP in the MA is enabled to receive CCMs from an RMEP in the MA.

If a local MEP has been enabled to receive CCMs from an RMEP and the link between the local MEP and RMEP fails, an RMEP continuity alarm is generated on the local MEP.

If you do not specify the mep-id mep-id parameter, all local MEPs in the MA are enabled to receive CCMs from RMEPs in the MA.
Run commit
The configuration is committed.

Follow-up Procedure

To configure CC in multiple MAs, repeat Step 3 through Step 7.
To configure CC in multiple MDs, repeat Step 2 through Step 7.