Why does the campus network download things quickly, but it is hard to play games? It used to be fine, just these days. Is there a solution?

400K is not slow, playing online games is enough. The key is whether the network administrator of your school will limit the speed on the campus router, that is, limit the uplink and downlink bandwidth of each IP address. If so, the situation of the network card can be well alleviated. The large number of college students depends on whether the bandwidth of WAN port can withstand the peak traffic of school network. For example, if you have 1000M optical fiber access, the minimum for each of the 3000 students in the school is1m. If 3000 people join together, they will definitely get stuck. If 500 people join together, 2M people can basically slow down the network card. So if you want to play games stably in school, you should apply for an ADSL exclusive outside.