What is "TCP Application Buffer?"

[Maurizio Pagani]

Hi Everybody,

Someone, do you know what is in deep "TCP Application Buffer"? I'll want
tuning my system but i'm reading on the web, that when i modify this
parameter:

.         tcp_rmem

.         tcp_wmem

in particular, this:

tcp_app_win - INTEGER

Reserve max(window/2^tcp_app_win, mss) of window for application buffer.
Value 0 is special, it means that nothing is reserved.

Default: 31

But unfortunatly, i don't know what is "application buffer". Someone can
help me?

Thanks a lot in advance.

Maurizio