ALTQ(4)

NAME

     ALTQ -- Alternate queuing of network packets

DESCRIPTION

     The ALTQ framework provides several disciplines for queuing outgoing net-
     work 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) manpages 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_RED	 build the ``Random Early Drop'' 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 consumer.
     ALTQ_PRIQ	 build the ``Priority Queuing'' discipline.
     ALTQ_NOPCC  required for SMP builds.
     ALTQ_DEBUG  enable additional debugging facilities.

     Note that ALTQ-disciplines can not 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) and required to use a cer-
     tain network card with ALTQ have been applied to the following hardware
     drivers an(4), ath(4), awi(4), bfe(4), dc(4), em(4), fxp(4), hme(4),
     lnc(4), wi(4), de(4), rl(4), sis(4), vr(4) and xl(4).

     The ndis(4) framework also has support for ALTQ and thus all encapsulated
     drivers.

     The tun(4) pseudo driver also does support ALTQ and includes the required
     modifications.

SEE ALSO

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