Nicolas Williams wrote:
> We could implement auto-tuning in ssh/sshd, as a stopgap, I suppose, but
> that would be a new project and probably wouldn't get off the ground
> soon enough.
One problem of implementing this in user land is that we
don't allow shrinking of the receive buffer (which in turns
control the TCP receive window). The reason is that TCP
should not shrink the receive window (moving the right edge
of the receive window left). In order to reduce the receive
window, TCP needs to keep the right edge fixed until it can
be moved right when the window is now of the reduced size.
We don't have this hence we don't allow shrinking of the
receive buffer.
The above means that an app cannot use setsockopt(SO_RCVBUF)
to fine tune the TCP window, which can only be changed in
one direction. If there is a mistake, it cannot be corrected.
--
K. Poon.
kacheong.poon at sun.com
