TCP/IP 詳解 卷1 ch17 TCP: Transmission Control Protocol

1. TCP provides a connection-oriented, reliable, byte stream service.

2. TCP lacks selective acknowledgments because the acknowledgment number in the TCP header means that the sender has successfully received up through but not including that byte.

3. flags

URG - urgent pointer

ACK - 确認序号有效

PSH - 接收方應盡快把這個封包交給應用層

RST - 重建連接配接

SYN - 同步序号用來發起一個連接配接

FIN - 發送端完成發送任務

4. 校驗和包括TCP首部和TCP資料