Configuring AIS

Context

In Figure 1, the MEPs configured on the access interfaces of CE1 and CE2 reside in level-6 MD1. The MEPs configured on PE1 and PE2 reside in level-3 MD2. When a fault occurs, a MEP in level-3 MD2 first detects the fault and sends an alarm to the NMS. After a certain period, a MEP in level-6 MD1 also detects the fault and sends the same alarm to the NMS. Therefore, the AIS function needs to be configured on the PEs to prohibit the MEP in the MD of a higher level from sending alarms to the NMS.

Only the S5720-EI, S5720-HI, S5720I-SI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730-HI, S5730S-EI, S5730-SI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720-LI, S6720S-EI, S6720S-LI, S6720S-SI, S6720-SI, S6730-H, S6730S-H, S6730-S, and S6730S-S support AIS.

Millisecond-level connectivity check cannot be performed for a link between CEs configured with alarm suppression.

When the device processes many AIS packets, the CPU usage will become high. When the device is enabled with AIS, it is recommended that nestling layers in an MD should be reduced and the number of interfaces associated with VLANs in an MA should be reduced.

Figure 1 Configuring AIS in the VLAN

Procedure

Performing the following operations on the PE.
1. Run system-view
2. Run cfm md md-name
3. Run ma ma-name
4. Run map vlan vlan-id
5. Run ais enable
  
  AIS is enabled in the MA.
  
  By default, AIS is disabled.
6. (Optional) Run ais link-status
  
  AIS is configured to monitor interfaces in the MA.
  
  By default, AIS does not monitor any interface.
7. (Optional) Run ais interval interval-value
  
  The interval at which AIS PDUs are sent is set.
  
  By default, the interval at which AIS PDUs are sent is 1s.
  
  If the range of VLANs to which AIS PDUs are sent is set, you are advised to set the interval at which AIS PDUs are sent to 60s.
8. Run ais level level-value
  
  The level of AIS PDUs to be sent is set.
9. Run ais vlan { pe-vid pe-vid ce-vid { low-ce-vid [ to hig-ce-vid ] } &<1–10> | vid { low-vid [ to high-vid ] } &<1–10> } mep mep-id
  
  The range of VLANs to which AIS PDUs are to be sent is set.
Performing the following operations on the CE.
1. Run system-view
2. Run cfm md md-name
3. Run ma ma-name
4. Run map vlan vlan-id
5. Run ais enable
  
  AIS is enabled in the MA.
  
  By default, AIS is disabled.
6. Run ais suppress-alarm
  
  Alarm suppression is enabled in the MA.
  
  By default, alarm suppression is disabled in a MEP.
  
  In an MD nesting scenario, if alarm suppression is enabled in the MD of a high level, a MEP in this MD does not send alarms that a MEP in an MD of a low level has sent to the NMS after receiving an AIS PDU.