Configuring Single-ended Frame Loss Measurement in VLL Networking

In VLL networking, CFM is enabled. CCMs are not used to monitor link connectivity, preventing them from using excessive network bandwidth resources. If frame loss measurement needs to be performed for a link, single-ended frame loss measurement can be configured to monitor the link quality.

Context

Single-ended frame loss measurement in VLL networking can be either on-demand or proactive. On-demand single-ended frame loss measurement is manually initiated for diagnosis of frame loss in a limited time. It can be singular or periodic measurement. Proactive single-ended frame loss measurement is carried out continuously to permit proactive reporting of fault or performance results.

To implement one-time or periodic single-ended frame loss measurement for a PW or an AC, configure on-demand single-end frame loss measurement in VLL networking.
To implement continuous single-ended frame loss measurement for a PW, configure proactive single-ended frame loss measurement in VLL networking.

Service packets are prioritized based on 802.1p priorities and are transmitted using different policies. As shown in Figure 1, the 802.1p priority values contained in traffic passing through the P on the VLL are 1 and 2.

Frame loss measurement is performed for the link between PE1 and PE2. Assume that traffic (with the priority value of 2) that is not involved in frame loss measurement is sent out after frame loss measurement is enabled. The traffic is forwarded preferentially because its priority is high. As a result, the traffic (with the priority value of 1) that is involved in frame loss measurement fails to reach PE2 in time, causing incorrect frame loss statistics.

802.1p-priority-based single-ended frame loss measurement can be configured for the VLL for accurate proactive frame loss tests.

Figure 1 Networking diagram for Y.1731 priority-based frame loss measurement on a VLL

Procedure

Configure on-demand single-ended frame loss measurement.
- Configure on-demand single-ended frame loss measurement for a PW.
  1. Perform the following steps on the PEs at both ends of a PW where single-ended frame loss measurement will be implemented:
    1. Run system-view
      
      The system view is displayed.
    2. Run cfm mdmd-name
      
      The MD view is displayed.
    3. Run mama-name
      
      The MA view is displayed.
    4. Associate the MA with a service.
      LDP VLL scenarios
      
      Run map mpls l2vc[ peer-address ] l2vc-id { raw | tagged }
      
      The MA is bound to a specified L2VC.
      
      BGP VLL scenarios
      
      Run mapmpls l2vpnl2vpn-namecece-idce-offsetce-offset-id
      
      The MA is bound to a specified PW.
    5. Run mep mep-id
      
      The MEP is configured.
    6. Run remote-mep mep-id mep-id
      
      An RMEP is configured.
    7. Run mep ccm-send enable
      
      The CCM transmission function is enabled.
    8. Run remote-mep ccm-receive [ mep-id mep-id ] enable
      
      The CCM reception function is enabled.
    9. (Optional) Run measure-point mep mep-id pw
      
      A measurement point for collecting Y.1731 statistics is configured.
  2. Configure a test instance on the device.
    1. On the receiving device of a PW where single-ended frame loss measurement will be implemented:
      
      Run test-id test-id [ testid-file ]mep mep-id [ description description ]
      
      A test instance is configured on the device.
    2. On the transmitting device of a PW where single-ended frame loss measurement will be implemented:
      
      Run test-id test-id [ testid-file ]mep mep-id [ mac mac-address | remote-mepmep-id ] [ description description ]
      
      A test instance is configured on the device.
  3. On the receiving device of a PW where single-ended frame loss measurement will be implemented:
    
    Run loss-measure single-ended receive test-id test-id-value
    
    The LMM reception function is configured on the device.
  4. On the transmitting device of a PW where single-ended frame loss measurement will be implemented:
    
    Run loss-measure single-ended send test-id test-id-value interval { 1000 | 10000 } count count-value
    
    On-demand single-ended frame loss measurement is configured for a PW.
  5. Run commit
    
    The configuration is committed.
- Configure on-demand single-ended frame loss measurement for an AC.
  1. Perform the following steps on the devices at both ends of an AC where single-ended frame loss measurement will be implemented:
    1. Run system-view
      
      The system view is displayed.
    2. Run cfm md md-name
      
      The MD view is displayed.
    3. Run ma ma-name
      
      The MA view is displayed.
    4. Perform the following steps on the devices where the MEPs reside:
      - On the CE, run map vlan vlan-id
        
        The MA is bound to a VLAN.
      - On the PE, associate the MA with a service.
        
        LDP VLL scenarios
        
        Run map mpls l2vc[ peer-address ] l2vc-id { raw | tagged }
        
        The MA is bound to a specified L2VC.
        
        BGP VLL scenarios
        
        Run mapmpls l2vpnl2vpn-namecece-idce-offsetce-offset-id
        
        The MA is bound to a specified PW.
    5. Run mep mep-id
      
      The MEP is configured.
    6. Run remote-mep mep-id mep-id
      
      An RMEP is configured.
    7. Run mep ccm-send enable
      
      The CCM transmission function is enabled.
    8. Run remote-mep ccm-receive [ mep-id mep-id ] enable
      
      The CCM reception function is enabled.
    9. Run measure-point mep mep-id ac
      
      An AC interface is configured as the measurement point.
  2. Configure a test instance on the device.
    1. On the receiving device of an AC where single-ended frame loss measurement will be implemented:
      
      Run test-id test-id [ testid-file ]mep mep-id [ 8021p 8021p-value ] [ description description ]
      
      A test instance is configured on the device.
    2. On the transmitting device of an AC where single-ended frame loss measurement will be implemented:
      
      Run test-id test-id [ testid-file ] mepmep-id [mac mac-address |remote-mep mep-id ] [ 8021p 8021p-value ] [ description description ]
      
      A test instance is configured on the device.
  3. On the receiving device of an AC where single-ended frame loss measurement will be implemented:
    
    Run loss-measure single-ended receive test-id test-id-value
    
    The LMM reception function is configured on the device.
  4. On the transmitting device of an AC where single-ended frame loss measurement will be implemented:
    
    Run loss-measure single-ended send test-id test-id-value interval { 1000 | 10000 } count count-value
    
    On-demand single-ended frame loss measurement is configured for an AC.
  5. Run commit
    
    The configuration is committed.
Configure proactive single-ended frame loss measurement.
1. Perform the following steps on the devices at both ends of a PW where proactive single-ended frame loss measurement will be implemented:
  1. Run system-view
    
    The system view is displayed.
  2. (Optional) Run y1731 pm-mode enable
    
    PM is enabled to manage Y.1731 proactive performance statistics.
  3. Run cfm mdmd-name
    
    The MD view is displayed.
  4. Run mama-name
    
    The MA view is displayed.
  5. Associate the MA with a service.
    - LDP VLL scenarios
      
      Run map mpls l2vc[ peer-address ] l2vc-id { raw | tagged }
      
      The MA is bound to a specified L2VC.
    - BGP VLL scenarios
      
      Run mapmpls l2vpnl2vpn-namecece-idce-offsetce-offset-id
      
      The MA is bound to a specified PW.
  6. Run mep mep-id
    
    The MEP is configured.
  7. Run remote-mep mep-id mep-id
    
    An RMEP is configured.
  8. Run mep ccm-send enable
    
    The CCM transmission function is enabled.
  9. Run remote-mep ccm-receive [ mep-id mep-id ] enable
    
    The CCM reception function is enabled.
  10. Run measure-pointmepmep-idpw
    
    A measurement point for collecting Y.1731 statistics is configured.
  11. (Optional) Run loss-measure single-ended local-ratio-thresholdmep mep-id upper-limit upper-limit lower-limit lower-limit [ 8021p 8021p-value ]
    
    Lower and upper thresholds are set for the near-end frame loss rate in proactive single-ended frame loss measurement for a specified MEP.
  12. (Optional) Run loss-measure single-ended local-ratio-threshold test-id test-id-value upper-limit upper-limit lower-limit lower-limit
    
    Lower and upper thresholds are set for the near-end frame loss rate in proactive single-ended frame loss measurement in a specified test instance.
  13. (Optional) Run loss-measure single-ended remote-ratio-threshold mep mep-id upper-limit upper-limit lower-limit lower-limit [ 8021p 8021p-value ]
    
    Lower and upper thresholds are set for the far-end frame loss rate in proactive single-ended frame loss measurement for a specified MEP.
  14. (Optional) Run loss-measure single-ended remote-ratio-threshold test-id test-id-value upper-limit upper-limit lower-limit lower-limit
    
    Lower and upper thresholds are set for the far-end frame loss rate in proactive single-ended frame loss measurement in a specified test instance.
2. Configure a test instance on the device.
  1. On the receiving device of a PW where single-ended frame loss measurement will be implemented:
    
    Run test-id test-id [ testid-file ]mep mep-id [ description description ]
    
    A test instance is configured on the device.
  2. On the transmitting device of a PW where single-ended frame loss measurement will be implemented:
    
    Run test-id test-id [ testid-file ]mep mep-id [ mac mac-address | remote-mepmep-id ] [ description description ]
    
    The test instance is configured on the device.
3. On the receiving device of a PW where proactive single-ended frame loss measurement will be implemented:
  Run loss-measure single-ended receive test-idtest-id-value
  
  The LMM reception function is configured on the device.
4. On the transmitting device of a PW where proactive single-ended frame loss measurement will be implemented:
  Run loss-measure single-ended continual send test-id test-id-value interval interval-value [ period period ]
  
  Proactive single-ended frame loss measurement is configured for a PW.
5. Run commit
  The configuration is committed.

Verifying the Configuration

Run the display y1731 statistic-type single-loss [ test-id test-id-value ] [ count count-value ] command on the device that initiates single-ended frame loss measurement to check statistics about single-ended frame loss.