Dictionary · Networking Fundamentals
UDP
UDP — User Datagram Protocol
Transport · Beginner
A transport protocol that sends independent datagrams without a handshake or retransmission. Delivery, order, and duplicate protection are left to the application or simply not required.
This is the lightweight option. Name lookups, voice, and some streaming prefer a late packet dropped over an old packet arriving late after a retry.
Picture it
There is no handshake and no automatic retry. The application asks again, or it simply continues, if a datagram is lost.
Example: A clock-sync message or a short name lookup can use this transport because the client will simply ask again if needed.
Common misconception
- Connectionless does not mean it has no port numbers. Applications still use source and destination ports.