you can found on SE0000180675 document each FIC FE of NE20 support 4k pppoe user and session ,NE20 faced a problem when the number of PPPOE users increased (around 150-180 online users). Our PPPOE user randomly complain about receiving “Error
678: the remote computer did not respond” on their machines in this stage.
678: the remote computer did not respond”
1. FIC FE interface now is working properly with pppoe session lower than 180 user
2. NE20 router use VRP 5.30 with last release patch. in release note mention that support 4K pppoe session and user with FIC FE interface board.
3.by check the configuration we found that Ethernet0/0/1.31 being used for PPPoE, which is a FIC interface on RPU.this interface capability is low,sometimes it's cannot meet the requirement.
1.check the FIC FE interface board to be correct
2.check the VRP version and patch release note for PPPOE support.
3.check the configuration and topology of network to be correct
Don't use the FE interface on RPU board for service because its capability is low