sysctl kernel parameters for full gigabit throughput on NetBSD

sysctl.conf

# documentation
# https://calomel.org/freebsd_network_tuning.html
# https://mail-index.netbsd.org/tech-net/2015/08/03/msg005317.html
# http://proj.sunet.se/E2E/tcptune.html
#
# Warning: this is aimed at a **client** setup, a server with
# many connexions could exhaust its memory with values this high
#
kern.sbmax=16777216
net.inet.tcp.recvbuf_auto=1
net.inet.tcp.sendbuf_auto=1
net.inet.tcp.sendbuf_max=16777216 
net.inet.tcp.recvbuf_max=16777216
net.inet.tcp.sendspace=3217968
net.inet.tcp.recvspace=3217968
net.inet.tcp.init_win=10