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

     The ALTQ 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

     pf(4), pf.conf(5), ipfw(8), pfctl(8), altq(9)

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 .