TCP/IP

应用层

应用层

表示层

会话层

传输层

传输层

网络层

网络层

数据链路层

数据链路层

物理层

物理层

TCP

Segment header IPV4

SRC₃₂

DEST₃₂

Zeros₈

protocol₈

Tcp-Length₁₆

SRC-Port₁₆

DEST-Port₁₆

SEQ-NO₃₂

ACK-NO₃₂

Data-Offset₄

Reserved₃

NS₁

CWR₁

ECE₁

URG₁

ACK₁

PSH₁

RST₁

SYN₁

FIN₁

Window-Size₁₆

Checksum₁₆

Urgent-Pointer₁₆

Options₁₆

Data₁₆

Connection Establishment

1. $Client \xrightarrow[SEQ=random]{\text{SYN}}Server$
2. $Client \xleftarrow[ACK=SEQ+1 \space SEQ=random]{\text{SYN \space ACK}}Server$
3. $Client \xrightarrow[ACK=1]{\text{ACK}}Server$

Data Transmition

1. $Client \xrightarrow[SEQ \space ACK]{\text{PSH \space ACK}}Server$
2. $Client \xleftarrow[ACK=SEQ]{\text{ACK}}Server$

Connection Termination

1. $SideA \xrightarrow[SEQ=ACK \space ACK=ACK]{\text{FIN}}SideB$
2. $SideA \xleftarrow[SEQ=ACK \space ACK=SEQ+1]{\text{FIN}}SideB$
3. $SideA \xrightarrow[ACK=SEQ+1]{\text{ACK}}SideB$

Segment header IPV4

SRC₃₂

DEST₃₂

Zeros₈

protocol₈

Tcp-Length₁₆

SRC-Port₁₆

DEST-Port₁₆

SEQ-NO₃₂

ACK-NO₃₂

Data-Offset₄

Reserved₃

NS₁

CWR₁

ECE₁

URG₁

ACK₁

PSH₁

RST₁

SYN₁

FIN₁

Window-Size₁₆

Checksum₁₆

Urgent-Pointer₁₆

Options₁₆

Data₁₆

UDP