TCP Retransmission: indicates the Retransmission of packets due to timeout In the semi-closed state, USER B can still send data to user A. Therefore, ACK packets add one to the number sent by the other party to confirm that they received the SEQ packet from the other party When ACK=1, it is used to confirm that the ACK number sent by the other party is valid and the ACK number determines the SEQ number. If host B is not open, it will send an RST packet to break the TCP handshake The first SYN=1,seq=x is a connection request packet with no data. The start byte is 201, the serial number is 201, and the confirmation number is 301ĭata offset is not equal to slice offset, and the concept is differentįor Apache, the default port for IIS is 80, and the default port for FTP server is 21 The serial number is the start field number of the current data segmentįor example, the data segment contains 100 bytes. In IP, each packet is numbered, whereas in TCP, each byte of data is numbered sequentially to keep the data accurate The maximum number of 16-bit ports is all 1s. TCP is a port-based communication protocol The transmission layer controls the error of data to ensure the integrity and accuracy of transmitted dataĪpplications communicate with each other through ports bound to them The front end Network protocol TCP protocol
0 kommentar(er)
