(Nowadays, many networks are used. BT, eDonkey, Thunder, FTP, online video, etc. all take up a lot of bandwidth. Take an Internet cafe with 200 computers as an example, the export bandwidth is 10M, and the average bandwidth of each internal PC is about 50K. If A few people are insanely downloading, and the bandwidth is occupied, which will affect the network speed of other people. Others are downloading large files, and IP packets can reach a maximum of 1518 BYTE.)