ALTQ(4) | Device Drivers Manual | ALTQ(4)

# NAME

`altq` — alternate queuing framework

# SYNOPSIS

`options ALTQ`
`options ALTQ_BLUE`
`options ALTQ_CBQ`
`options ALTQ_CDNR`
`options ALTQ_FIFOQ`
`options ALTQ_FLOWVALVE`
`options ALTQ_HFSC`
`options ALTQ_LOCALQ`
`options ALTQ_PRIQ`
`options ALTQ_RED`
`options ALTQ_RIO`
`options ALTQ_WFQ`

# DESCRIPTION

The `altq` system is a framework which provides several disciplines for queuing outgoing network packets. While traffic shaping is perhaps the most prominent example, `altq` provides also other measures related to QoS. The framework has been integrated to the pf(4) packet filter since NetBSD 4.0.

At the implementation level `altq` modifies the interface packet queues. Therefore the driver modifications described in altq(9) are required in order to use a certain network card with `altq`.

# FILES

    /dev/altq

# SEE ALSO

pf(4), altq.conf(5), altqd(8), altq(9)

Kenjiro Cho, Fitting theory into reality in the ALTQ case, https://www.iijlab.net/~kjc/papers/fittingtheory.pdf, Taipei, Taiwan, March, 2004, Asia BSD conference.

# HISTORY

The `altq` system first appeared in March 1997 and found its home in the KAME project (https://www.kame.net). It was imported into NetBSD 1.6.

# CAVEATS

Please note that you must compile pf(4) in the kernel, using the PF module(7) alongside `altq` built in the kernel will not work.

March 7, 2026 | NetBSD 11.99