NAME
ALTQ —
alternate queuing of network
packets
SYNOPSIS
options ALTQ
options ALTQ_CBQ
options ALTQ_CODEL
options ALTQ_RED
options ALTQ_RIO
options ALTQ_HFSC
options ALTQ_CDNR
options ALTQ_PRIQ
options ALTQ_FAIRQ
DESCRIPTION
TheALTQ system is a framework which provides several
disciplines for queuing outgoing network packets. This is done by
modifications to the interface packet queues. See
altq(9) for details.
The user interface for ALTQ is implemented
by the pfctl(8) utility, so please refer to the
pfctl(8) and the
pf.conf(5) man pages for a complete description of the
ALTQ capabilities and how to use it.
Kernel Options
The following options in the kernel configuration file are related
to ALTQ operation:
ALTQ- Enable
ALTQ. ALTQ_CBQ- Build the “Class Based Queuing” discipline.
ALTQ_CODEL- Build the “Controlled Delay” discipline.
ALTQ_RED- Build the “Random Early Detection” extension.
ALTQ_RIO- Build “Random Early Drop” for input and output.
ALTQ_HFSC- Build the “Hierarchical Packet Scheduler” discipline.
ALTQ_CDNR- Build the traffic conditioner. This option is meaningless at the moment as the conditioner is not used by any of the available disciplines or consumers.
ALTQ_PRIQ- Build the “Priority Queuing” discipline.
ALTQ_FAIRQ- Build the “Fair Queuing” discipline.
ALTQ_NOPCC- Required if the TSC is unusable.
ALTQ_DEBUG- Enable additional debugging facilities.
Note that ALTQ-disciplines cannot be
loaded as kernel modules. In order to use a certain discipline you have to
build it into a custom kernel. The
pf(4)
interface, that is required for the configuration process of
ALTQ can be loaded as a module.
SUPPORTED DEVICES
The driver modifications described in
altq(9) are required to use a certain network card with
ALTQ. They have been applied to the following
hardware drivers: ae(4),
age(4), alc(4),
ale(4), an(4),
aue(4), axe(4),
bce(4), bfe(4),
bge(4), bxe(4),
cas(4), cxgbe(4),
dc(4), de(4),
ed(4), em(4),
ep(4), epair(4),
et(4), fxp(4),
gem(4), hme(4),
igb(4), ixgbe(4),
jme(4), le(4),
liquidio(4),
msk(4), mxge(4),
my(4), nfe(4),
nge(4), npe(4),
qlxgb(4), re(4),
rl(4), sf(4),
sge(4), sis(4),
sk(4), ste(4),
stge(4), ti(4),
txp(4), udav(4),
vge(4), vr(4),
vte(4), and xl(4).
The ndis(4) framework also has support for
ALTQ and thus all encapsulated drivers.
The tun(4) and
ng_iface(4) pseudo drivers also do support
ALTQ.
SEE ALSO
HISTORY
The ALTQ system first appeared in March
1997 and found home in the KAME project (http://www.kame.net). It was
imported to FreeBSD in 5.3 .