master-tcp
Contents
The Transmission Control Protocol (TCP) is intended for use as a highly reliable host-to-host protocol between hosts in packet-switched computer communication networks, and in interconnected systems of such networks.
TCP header format
basic data transfer
reliability
- sequence number
- acknowledgement
flow control
- window size
multiplexing
- socket (ip, port)
connections
Each connection is uniquely specified by a pair of sockets identifying its two sides.(source ip, source port),(destination ip, destination port)
- sockets
- sequence numbers
- window size
TCP 建立连接目的
交换通信双方的 ISN (Initial Sequence Number) 凡是占据序列号的任何TCP报文，一定对方确认，如果没有收到确认，会一直重传，直到达到规定的上限次数。 syn , data , fin 占据 sequence number 需要确认. ack 不占据 sequence number 不需要确认.