If you plan to transfer large files we advice you to adjust system wide TCP keepalive: parameters:

echo "600" > /proc/sys/net/ipv4/tcp_keepalive_time
echo "75" > /proc/sys/net/ipv4/tcp_keepalive_intvl
echo "9" > /proc/sys/net/ipv4/tcp_keepalive_probes

In order to make the changes persistent add it also to the /etc/sysctl.conf