At present, telecommunications in many places are set to be disconnected every 48 or 24 hours. The explanation is: in order to release redundant ports and avoid network congestion. I've been here for three years, and they set it up from the router in the telecom room, and it can't be changed (at least I called the telecom director, and he said it was nothing, just changing the port of a company, which was too troublesome).
So I added my own route and dialed automatically when I was disconnected ~ ~ ~