The TCP 3-Way Handshake is essential for backend engineers to understand as it establishes a reliable connection between client and server. It involves sequence numbers and acknowledgments to ensure packets are received correctly, preventing data corruption. This handshake process is crucial for efficient communication and debugging in backend engineering.
Why do we need TCP handshake?
The TCP handshake establishes a connection before any data is transmitted, which is crucial for protocols like HTTP/1.1 and HTTP/2. This process sets the foundation for reliable communication. Understanding how packets are assembled and processed by the server is key to troubleshooting issues in network communication. It allows engineers to identify where problems may arise. Each packet sent during a TCP connection must be acknowledged by the server to ensure successful delivery. This acknowledgment process helps maintain data integrity across networks. TCP requires acknowledgment for packets to ensure they are received correctly, preventing corruption. Each packet must have a unique sequence number for proper identification and ordering. Acknowledgment in TCP establishes communication reliability, allowing clients to retransmit packets if not confirmed. This functionality is crucial for data integrity across the Internet. Sequence numbers play a vital role in packet management by allowing the server to reorder received packets correctly. This system is essential for maintaining the correct data flow. Synchronization between client and server is necessary to agree on packet sequence numbers. This ensures both parties can correctly interpret the order of message exchanges.
Steps in 3-Way Handshake
The TCP 3-Way Handshake consists of three main steps that establish a reliable connection between a client and a server. Here’s a breakdown of each step:
SYN (Synchronize): The client sends a SYN packet to the server to initiate a connection. This packet includes the client's initial sequence number (e.g., 700).
SYN-ACK (Synchronize-Acknowledge): The server responds with a SYN-ACK packet. This packet acknowledges the client's SYN request by sending back an acknowledgment number (e.g., 701, which is the client's sequence number plus one) and includes the server's own initial sequence number (e.g., 200).
ACK (Acknowledge): The client sends an ACK packet back to the server, acknowledging the receipt of the server's SYN-ACK. This acknowledgment number is the server's sequence number plus one (e.g., 201).
After these three steps, a TCP connection is established, allowing for data transmission between the client and server. Each step ensures that both parties are synchronized and ready to communicate reliably.