The following diagram shows the header format of TCP:
The source port number and destination port number set the port numbers.
The sequence number starts at the fourth byte in the message transmitted from
the source node to the destination node, as shown in the figure demonstrating
the three-way handshake protocol. The acknowledgement number is the next
sequence number that the source node expects.
The following is the list of lags that are commonly used in ZeroMQ:
• URG (0x20) : Urgent
• ACK (0x10) : Acknowledgement
• PSH (0x08) : Push
• RST (0x04) : Reset
• SYN (0x02) : Synchronize
• FIN (0x01) : Finish