Some communication scenarios need both sides to send and receive data simultaneously. Half-duplex (one direction at a time) adds latency and complexity for interactive applications.
A communication mode where both endpoints can send and receive data simultaneously, enabling true bidirectional communication.
- Both endpoints have independent send and receive channels
- Data can flow in both directions at the same time
- Each direction is independent — can have different data rates
- Enables techniques like piggybacking (ACK on reverse-direction data)
- TCP is full-duplex: both sides can send data simultaneously
- Simultaneous bidirectional data flow
- Each direction is independent
- Enables piggybacking of ACKs on data
- Used by TCP and most modern network protocols
- Built from: TCP — is full-duplex
- Related: Piggybacking — relies on full-duplex
- Contrasts with: Half-Duplex — one direction at a time
- Contrasts with: Simplex — one direction only
- Not all links support full-duplex (some wireless is half-duplex due to single radio)
- Full-duplex Ethernet requires point-to-point links (no shared medium)
- Asymmetric data rates: one side may send much more than the other