TCP Packet Routing Lab

Network

Latency: 80msPacket Loss: 1%Window Size: 32

Legend

In-flight packet

Acknowledged

Lost (needs retransmit)

TCP Packet Visualizer – Network Protocols & Handshakes

TCP (Transmission Control Protocol) is the backbone of reliable internet communication, ensuring that every byte sent from one host arrives at the destination in order and without corruption. This visualizer animates the TCP three-way handshake, shows packet header fields including sequence and acknowledgment numbers, and lets you introduce packet loss to watch retransmission and congestion control algorithms respond. By seeing protocol behavior frame by frame, you gain the intuition that raw RFC documents rarely provide.

What you can do in this simulation

Animate the TCP three-way handshake (SYN, SYN-ACK, ACK) between two virtual hosts
Inspect packet header fields: source/destination ports, sequence numbers, flags, and window size
Simulate packet loss and watch TCP detect the gap and retransmit the missing segment
Observe slow-start and congestion-avoidance phases as the congestion window grows
Compare TCP's reliable delivery with a UDP-style connectionless alternative

Concepts covered

TCP · three-way handshake · packet headers · congestion control · reliable delivery · network protocols

Related simulations

Browse all Technology simulations →

Free to use in your browser — no signup required. Found a bug or have an idea to make it better? Tell us.

Please wait

Loading technology simulations

The requested content is still loading.

Finished experimenting?

Save one completion to this browser's signed guest ledger, or directly to your account when signed in.