[p2p-hackers] MTU in the real world

[coderman]

On 6/1/05, Eugen Leitl <eugen at leitl.org> wrote:
> A good use of UDP would be for fanning out of a search query to a global P2P search
> engine (using an amplification cascade) -- it would fit into few 100 Bytes,
> needs no ACK, and it could be lossy (nobody expects deterministic results
> from a search engine).

I used UDP for my fully decentralized search implementation because it
was so lightweight and could support many concurrent logical
connections between peers (high node degree was required to make
search effective).

As for using UDP over consumer internet links I found that some
Windows NAT's would simply drop any NAT'd UDP packets over MTU [that
is to say, the Windows NAT would not reassemble fragmented UDP
datagrams].  Most NAT's seemed to handle larger packets fine, so MTU
discovery would probably be worth the effort.