The speed of asyncio UDP is too slow when transferring large file

[msoxzw]

The speed of asyncio UDP is merely a couple of Mbps if a large file, e.g. 65536 KiB, is transferred.

Test file:
https://gist.github.com/msoxzw/8ae5c488edbc2985d41563c4d9c9cc04