Link Degrade Monitoring Overview
Link degrade monitoring enables you to monitor the quality of
physical links on Ethernet interfaces and take corrective action when
the link quality degrades beyond a certain level. You can configure
this feature by applying the link-degrade-monitor
statement
at the [edit interfaces interface-name]
hierarchy level.
Ethernet links (using Link Fault Signaling (LFS) protocol), Layer 2 and Layer 3 protocols support physical link monitoring. However, these existing mechanisms cannot detect BER ranges that are very low (for example, 10-13 through 10-5).
When you configure link degrade monitoring on your device, this
feature continuously monitors bit error rate (BER) value of the link
and initiates a corrective action (media-based) when the BER value
breaches a user-configured threshold. You can configure the threshold
by using the thresholds
statement at the [edit interfaces interface-name link-degrade-monitor]
hierarchy level.
The feature can detect a BER value as low as 10-13 through 10-5, helping you prevent or
minimize packet drops in physical links.
You can configure autorecovery or manual recovery method for
the degraded link. In the case of manual recovery, you need to use
the request interface link-degrade-recover interface-name
statement to recover the degraded link. If autorecovery is
configured, automatic recovery of the degraded link is attempted at
the user configured intervals, and when the link’s BER value
is within the configured limit, the link is recovered.
When you configure link monitoring (by using the link-degrade-monitor
statement), you can set the following options:
BER threshold value at which the corrective action must be triggered on an interface. Use the
thresholds (set | clear)
statement to configure the BER threshold value or clear the BER threshold value.Link degrade interval value, which determines the number of consecutive link degradation events that are considered before any corrective action is taken. Use the
thresholds interval intervalvalue
statement to configure the interval.Warning threshold value for link degradation. Use the
thresholds warning (set | clear)
statement to configure the warning threshold value or clear the warning threshold value.Action that is taken when the configured BER threshold level is reached. Use the
thresholds actions media-based
statement to configure the action to be taken.Automatic or manual recovery. Use the
recovery (auto | manual)
statement to configure recovery.Time interval after which automatic recovery of the degraded link must be triggered. Use the
recovery timer timer-value
statement to configure the time interval.
Supported Platforms
Table 1 and Table 2 lists the platform series and line cards that support link degrade monitoring.
Platform Series |
MPC Line Cards Supported |
DPC Line Cards Supported |
---|---|---|
MX |
|
On 10-Gigabit Ethernet interfaces:
|
Platform Series |
Line Cards/PICs Supported |
---|---|
PTX3000 and PTX5000 (Junos) |
|
PTX10003 (Junos Evolved) |
10G, 25G, 40G, 50G, 100G, 200G, and 400G interfaces |
PTX10004 (Junos Evolved) |
10G, 25G, 40G, 50G, 100G, 200G, and 400G interfaces |
PTX10008 (Junos Evolved) |
|
PTX10001 (Junos Evolved) |