The 3-way handshake is to create a connection

between a client and a server. To make sure both

sides are ready to communicate, one side has to

acknowledge that the other sider's packet is

received. See the picture below. Receiver's AYN-

ACK packet is to acknowledge sender's SYN packet

is received. ACK packet is to acknowledge SYN-

ACK packet is received. Can both sides 100% sure

that the connection is ready? Can the receiver

know if ACK packet is missing? Can you design a

protocol that both sender and receiver will 100%

sure that the communication channel is ready?