What is the optimal size of a UDP packet for maximum throughput?

Question

I need to send packets from one host to another over a potentially lossy network. In order to minimize packet latency, I\'m not considering TCP/IP. But, I w

Answer 1

IP header is >= 20 bytes but mostly 20 and UDP header is 8 bytes. This leaves you 1500 - 28 = 1472 bytes for you data. PATH MTU discovery finds the smallest possible MTU on the way to destination. But this does not necessarily mean that, when you use the smallest MTU, you will get the best possible performance. I think the best way is to do a benchmark. Or maybe you should not care about the smallest MTU on the way at all. A network device may very well use a small MTU and also transfer packets very fast. And its value may very well change in the future. So you can not discover this and save it somewhere to use later on, you have to do it periodically. If I were you, I would set the MTU to something like 1440 and benchmark the application...