[vidarh]

If you need to 'solve' those, you use a reliable protocol instead. Like tcp.

In terms of actual implementation, protocols that does this needs to keep state, regularly notify the other side what they've received, and retry if packets appear to have been lost. Doing it 'simple' is easy, maximising efficiency/performance is harder.

The other answer gives a good example of when you don't actually want to fix the issues you mention.