Suggest an editImprove this articleRefine the answer for “What guarantees does UDP provide?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**UDP provides a minimum of guarantees.** This is done deliberately, to ensure **simplicity and minimal latency**. **Key point:** UDP does not guarantee delivery, order, or the integrity of the data transfer; it only provides delivery of individual messages without establishing a connection and with minimal overhead.Shown above the full answer for quick recall.Answer (EN)Image**UDP provides a minimum of guarantees.** This is done deliberately, to ensure **simplicity and minimal latency**. --- ## What guarantees UDP does have ### 1. **Message boundaries are preserved** UDP transfers data as **messages (datagrams)**: - one send = one message - if a message arrives, it arrives **whole** This means: - UDP **does not merge** and **does not split** messages for the application --- ### 2. **"Best effort" delivery** UDP tries to deliver data: - **without promises** - **without retries** - **without acknowledgments** If a message arrives, the application will receive it. If not, UDP **does nothing about it**. --- ## What UDP does NOT guarantee (important) UDP **does not guarantee**: - data delivery - delivery order - the absence of duplicates - the integrity of the data stream - speed control - congestion control - connection establishment All of these tasks, when needed, **must be solved by the application itself**. --- ## Comparing TCP and UDP guarantees | Guarantee | TCP | UDP | |---|---|---| | Delivery | Yes | No | | Order | Yes | No | | Retries | Yes | No | | Flow control | Yes | No | | Congestion control | Yes | No | | Message boundaries | No (stream) | Yes (messages) | --- ## Why UDP is still used Because sometimes what matters more is: - **minimal latency** - **predictable delivery time** than perfect reliability. That is why UDP is used for: - VoIP - video streaming - online games - DNS --- ## In short, for the interview > **UDP does not guarantee the delivery, order, or integrity of data transmission; it only provides delivery of individual messages without establishing a connection and with minimal overhead.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.