strange problem with my pppoe server

hi, i hope my bad english helping me to explain my problem :slight_smile:

i have mikrotik pppoe server and i have a problem

the connection some times dropped automatically from active connection

and sometimes in interfaces appear connection

this problem is not with all computers my computer is always connected without any disconnect

but some computers always disconnect after 1 or 2 minutes

Tip: i’m using API to add and manage my pppoe server

same problem …
I have 3 pcs X86 (2 of them Mikrotik V6.1 & one V5.20) connected to radius manager

I discover that some users disconnected from all of them ( so the problem is not in the version of Mikrotik )

the users connect to our lan in different ways (direct connect from their PCs & from different Routers Dlink, TPlink…)