Global MTU config

[Green-Sky]

Toxcore needs to have the concept of MTU for an interface, either derrived dynamically per connection, or simpler set by the user globally.

A friend has bee having issues with friend file transfers just not working and resetting the connection because of too large packets. And I have heard of this issue before too.

[zoff99]

for filetransfers i would suggest implementing FTv2a which solves most of the issues with filetransfers and is tested properly with edge cases.
yes it's not the optimal solution, but in lack of any other solution, it is the best there is for now.

it solves:

• resuming
• tox client devs putting data into the wrong FT
• FT breaking because of connection issues
• and some more stuff ...

https://github.com/zoff99/c-toxcore/blob/zoff99/zoxcore_local_fork/docs/filetransfer_v2.md
https://github.com/zoff99/c-toxcore/blob/zoff99/zoxcore_local_fork/docs/filetransfer_v2a.md
zoff99@810dc1e

[Green-Sky]

too large packets

For the example I gave your solution also would not work. The problem is more fundamental.