How can reliable data delivery be ensured when using the UDP protocol?

UDP is a connectionless protocol without delivery guarantees, so to ensure reliable data delivery over UDP, additional mechanisms need to be implemented at the application level:

• Acknowledgments (ACKs): the receiver sends a confirmation upon receiving a packet.
• Retransmission: if an acknowledgment is not received within a timeout, the sender retransmits the packet.
• Packet numbering: to track order and detect missing packets.
• Buffering and assembly: to correctly assemble data from multiple packets.

In Go, this can be implemented manually, for example, by sending packets with sequence numbers and waiting for acknowledgments, or by using ready-made libraries that add reliability on top of UDP.

An example of simplified logic:

// Pseudocode
for seq := 0; seq < totalPackets; seq++ {
    sendPacket(seq, data)
    waitForAck(seq)
    if timeout {
        resendPacket(seq, data)
    }
}