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Resolving PPG Issues with Low Traffic Levels

Document Number

ENG-010706

Problem

Low traffic volume in a PPG may erroneously cause a protection switch, and if the condition persists, the PON Protection Group (PPG) can oscillate between the two PON ports.

Solution

Work around the issue by introducing a 10 Mbps Constant Bit Rate (CBR1) service on one or more ONTs, using a dummy VLAN. This ensures a minimal amount of traffic is present on the PON, even in the absence of user traffic. It is recommended to apply this service to an unused ethernet port, but it may also be configured alongside existing services.

1. Logon to EMS and click on the profile icon (), and choose the Service tab.
   
    

    

2. Give the profile a name: (i.e. PPG-maintain-traffic-level)
3. Choose a dummy VLAN (22), and click the “Tagged/Trunk” radio button.
4. Select Upstream Class of Service to CBR1
5. Set the Upstream Sustained Rate to 10 Mbps.
   
    
6. Click the Apply button. Output similar to the following is displayed.
   
7. In the Profiles dialog, click on the NAC tab.
8. Choose either…
   1. Create a new NAC profile for use with unused Ethernet ports, or
   2. Edit an existing NAC profile to add the CBR service.

9. In this example we will create a new NAC profile named PPG-traffic.
   
    
10. Add the service created (PPG-maintain-traffic-level) to the NAC profile’s Default and/or Guest VLAN service list.
11. Click the Apply button.
12. Exit the profiles dialog

13. In the tree view, navigate to the ONT where the service is to be added.
14. Click the Ports view, choose a port and in the screenshot column choose the NAC profile (PPG-traffic) created in step 9. Output similar to the following is displayed.
    

15. Click on the Apply button.
16. Steps 13-15 may be repeated for other ONTs.