Quality of service

traffic prioritization and measure of network performance

computer networking architecture for classifying traffic and applying different routing policies to each classification of traffic

architecture of quality of service of computer networking

IEEE task group active from 1995 to 1998

ALTQ (ALTernate Queueing) is the network scheduler for Berkeley Software Distribution. ALTQ provides queueing disciplines, and other components related to quality of service (QoS), required to realize resource sharing. It is most commonly implemented on BSD-based routers. ALTQ is included in the base distribution of FreeBSD, NetBSD, and DragonFly BSD, and was integrated into the pf packet filter of OpenBSD but later replaced by a new queueing subsystem (it was deprecated with OpenBSD 5.5 release, and completely removed with 5.6 in 2014).