There mikrotik 3.22 as pptp, pppoe server.
At the peak of ~ 1000 connections.
There is a hanging of PPP:
all users a 800 error
attempt to console or winbox to see the number of users online is inconclusive.
It helps only a restart.
those who were connected, and does not closes the connection work properly.
Stuck occur up to 4 times per month, regardless of
load or time of day.
Or there may be a 800 error only for some users pptp,
while others are connected properly