This OID is a counter of the total number of bytes received without errors on this PPP link, as reported in the Link Quality Report. It only increments and resets when the counter wraps or the link restarts, so you calculate the rate of good bytes by sampling it over time. You monitor this to detect when a link starts silently losing packets—if the good-octets counter stalls while data should be flowing, your link is dropping traffic without notifying you. For example, if accPppLqrInGoodOctets stops increasing even though an FTP transfer is ongoing, it indicates received traffic is being lost.