# RACK TCP Stack: Netflix's TCP Recent ACKnowledgment (Recent ACK) and Tail
# Loss Probe (TLP) for improved Retransmit TimeOut response. RACK uses the
# notion of time, instead of packet or sequence counts, to detect TCP losses
# for connections supporting per-packet timestamps and selective acknowledgment
# (SACK). Connections that do not support SACK are automatically serviced by
# the default, base FreeBSD TCP stack. Use "sysctl
# net.inet.tcp.functions_available" to show available TCP stacks loaded by the
# kernel. FYI: introduced in FreeBSD 12; the kernel must be rebuilt with
# additional TCP stacks (makeoptions WITH_EXTRA_TCP_STACKS=1) and the high
# precision TCP timer (options TCPHPTS). Look lower on this page for instructions.
# https://tools.ietf.org/html/draft-ietf-tcpm-rack-04
#
#net.inet.tcp.functions_default=rack