Configuring One-way Frame Delay Measurement in VLL Networking

In VLL networking, the clock frequencies between the two ends are synchronized and CFM is enabled to monitor link connectivity. If the unidirectional delay measurement needs to be performed for a link, one-way frame delay measurement can be configured to monitor the quality of the link.

Context

One-way frame delay measurement in VLL networking can be either on-demand or proactive. On-demand one-way frame delay measurement is manually initiated for diagnosis of frame transmission delays in a limited time. It can be singular or periodic measurement. Proactive one-way frame delay measurement is carried out continuously to permit proactive reporting of frame transmission delays or performance results.

To implement singular or periodic one-way frame delay measurement for a PW or an AC, configure on-demand one-way frame delay measurement in VLL networking.
To implement continual one-way frame delay measurement for a PW or an AC, configure proactive one-way frame delay measurement in VLL networking.

802.1p priorities carried by packets on a network are used to differentiate services, and therefore different policies can be deployed for services. As shown in Figure 1, the 802.1p priority values contained in traffic passing through the P on the VLL are 1 and 2.

One-way frame delay 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 delay measurement is sent out after one-way frame delay 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 delay measurement fails to reach PE2 in time, causing incorrect frame delay statistics.

802.1p-priority-based one-way frame delay measurement can be configured for the VLL for accurate proactive frame delay tests.

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

Procedure

Configure on-demand one-way frame delay measurement.
- Configure on-demand one-way frame delay measurement for a PW.
  1. Perform the following steps on the devices at both ends of a PW where one-way frame delay 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. 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
      
      The remote MEP ID 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-pointmepmep-idpw
      A measurement point for collecting Y.1731 statistics is configured.
  2. Configure a test instance.
    1. On the receiving device on a PW where on-demand one-way frame delay measurement will be implemented, run test-idtest-id [ testid-file ]mep mep-id [ 8021p 8021p-value ] [ descriptiondescription ]:
      
      A test instance is configured on the device.
    2. On the transmitting device on a PW where one-way frame delay measurement will be implemented, run test-idtest-id [ testid-file ]mepmep-id [ macmac-address | remote-mepmep-id ] [ 8021p8021p-value ] [ descriptiondescription ]:
      
      A test instance is configured on the device.
  3. On the receiving device on a PW where on-demand one-way frame delay measurement will be implemented, run delay-measure one-way receivetest-idtest-id
    
    The 1DM reception function is configured on the device.
  4. On the transmitting device on a PW where one-way frame delay measurement will be implemented, run delay-measure one-waysendtest-idtest-idinterval { 1000 | 10000 } countcount-value
    
    On-demand one-way frame delay measurement is configured for a PW.
  5. Run commit
    
    The configuration is committed.
- Configure on-demand one-way frame delay measurement for an AC.
  1. Perform the following steps on the devices at both ends of an AC where on-demand one-way frame delay 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
      
      The remote MEP ID 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
      
      A measurement point for collecting Y.1731 statistics is configured for an AC.
  2. Configure a test instance.
    1. On the receiving device on an AC where on-demand one-way frame delay measurement will be implemented, run test-idtest-id [ testid-file ] mep mep-id [ 8021p8021p-value ] [ descriptiondescription ]
      
      A test instance is configured on the device.
    2. On the transmitting device on an AC where one-way frame delay measurement will be implemented, run test-idtest-id [ testid-file ] mepmep-id [macmac-address |remote-mepmep-id ] [ 8021p8021p-value ] [ descriptiondescription ]
      
      A test instance is configured on the device.
  3. On the receiving device on an AC where on-demand one-way frame delay measurement will be implemented, run delay-measure one-way receivetest-idtest-id
    
    The 1DM reception function is configured on the device.
  4. On the transmitting device on an AC where on-demand one-way frame delay measurement will be implemented, run delay-measure one-waysendtest-idtest-idinterval { 1000 | 10000 } countcount-value
    
    On-demand one-way frame delay measurement is configured for an AC.
  5. Run commit
    
    The configuration is committed.
Configure proactive one-way frame delay measurement.
1. Perform the following steps on the devices at both ends of a PW where proactive one-way frame delay measurement will be implemented:
  1. Run system-view
    
    The system view is displayed.
  2. (Optional) Run y1731 pm-mode enable
    
    Performance management (PM) to manage Y.1731 proactive performance statistics is enabled. PM saves the statistics to generated statistics files and then sends the files to the NMS.
  3. Run cfm md md-name
    
    The MD view is displayed.
  4. Run ma ma-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
    
    The remote MEP ID 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. (Optional) Run measure-point mep mep-id pw
    
    A measurement point for collecting Y.1731 statistics is configured.
  11. (Optional) Run delay-measure one-way delay-threshold mep-id mep-id upper-limit upper-limit lower-limit lower-limit [ 8021p 8021p-value ]
    
    Lower and upper thresholds are set for one-way frame delay.
  12. (Optional) Run delay-measure one-way variation-threshold mep-id mep-id upper-limit upper-limit lower-limit lower-limit [ 8021p 8021p-value ]
    
    Lower and upper thresholds are set for one-way frame jitter.
2. Configure a test instance.
  1. To configure a test instance on the receiving device on a PW where on-demand one-way frame delay measurement will be implemented, run the test-idtest-id [ testid-file ]mep mep-id [ 8021p 8021p-value ] [ descriptiondescription ] command.
  2. To configure a test instance on the receiving device on the transmitting device on a PW where one-way frame delay measurement will be implemented, run the test-idtest-id [ testid-file ]mepmep-id [ macmac-address | remote-mepmep-id ] [ 8021p8021p-value ] [ descriptiondescription ] command.
3. On the receiving device on a PW where proactive one-way frame delay measurement will be implemented, run delay-measure one-way continual receive test-id test-id
  The 1DM reception function is configured on the device.
4. On the transmitting device on a PW where proactive one-way frame delay measurement will be implemented, run delay-measure one-way continual test-id test-id-value interval interval-value
  Proactive one-way frame delay measurement is configured for a PW.
5. Run commit
  The configuration is committed.

Verifying the Configuration

Run the display y1731 statistic-type oneway-delay [ test-id test-id-value ] [ count count-value ] command on the device that initiates one-way frame delay measurement to check statistics about the delay in unidirectional frame transmission.