26
The relationship between the interval field value in the CCM messages, the interval between CCM
messages and the timeout time of the remote MEP is illustrated in
Table 9
Relationship of interval field value, interval between CCM messages, and timeout time of the
remote MEP
Interval field value
Interval between CCM
messages
Timeout time of the remote MEP
3
100 milliseconds
350 milliseconds
4
1 second
3.5 seconds
5
10 second
35 seconds
6
60 seconds
210 seconds
7
600 seconds
2100 seconds
Configuring LB on MEPs
The LB function can verify the link state between the local MEP and the remote MEP or MIP.
Follow these steps to configure LB on a MEP:
To do...
Use the command...
Remarks
Enable LB
cfd loopback service-instance
instance-id
mep
mep-id
{
target-mep
target-mep-id
|
target-mac
mac-address
} [
number
number
]
Required
Disabled by default.
Available in any view
Configuring LT on MEPs
LT can trace the path between the source and target MEPs, and can also locate link faults by sending LT
messages automatically. The two functions are implemented in the following way:
•
To trace the path between the source MEP and target MEPs
○
The source MEP first sends LTM messages to the target MEP.
○
Based on the LTR messages in response to the LTM messages, the path between the two MEPs
can be identified.
•
To locate link faults by sending LT messages automatically
○
After LT messages automatic sending is enabled, if the source MEP fails to receive the CCM
frames from the target MEP within 3.5 times the transmission interval, the link between the two
is considered faulty and LTM frames—with the target MEP as the destination and the TTL field in
the LTM frames set to the maximum value 255—will be sent out.
○
Based on the LTRs that the MIPs return, the fault source can be located.
Follow these steps to configure LT on MEPs: