Reprinted: https://my.oschina.net/u/1859679/blog/1835423
Several important points:
1, there is a reason Time_Wait, twice the MST: Guaranteed Close full duplex, ensure packets are old disappeared
2, Time_Wait highly concurrent connections in a short business there will be problems, this time can be optimized.
TCP ack of sync and mechanisms, is a synchronization mechanism to ensure that the other side was confirmed, it will have three-way handshake and a four-way handshake.