If the campus network of Nankai University does not use external network traffic for a month and only accesses the internal network, do you still need to pay 20 yuan?
No need. But you must make sure that you can only access the internal network within one month, but not the external network. Just log in and deduct 20 yuan. . . In addition, I would like to remind you that sometimes there will be a delay in traffic calculation, so you'd better not use zero to surf the Internet at the beginning of each month, otherwise you may use up your traffic last month, and if you don't log in for a month, you will lose all your efforts. . .