Use of PPG to Minimize Outage Times. (For PPG Based Upgrades)

PON Protection provides PON link and equipment protection during normal operations, but also minimizes outage time during a Software upgrade.  When done properly, a PPG-protected system will only experience traffic outages when the ONTs reboot to load the new software version.  The system will not be affected by switches of the OLT hardware (ESUs and OIU cards) in PPG protected system.

When PPG protection is properly implemented between two OLTs, it provides full redundancy of all OLT hardware and uplinks. This is the preferred configuration for reliability and is the option recommended by Tellabs.
 

 

Figure 1 PPG Protection
 

PPG protected systems also maintain state such as MAC table entries and 802.1x/MAB authentication states, further speeding the process of service restoral after a switch.

PPG protected systems will not need a Golden Card for rollback as you can hold the standby OLT at the old release and old database until you are certain the system is operating properly on the new release.