The classless qdiscs are:
choke CHOKe (CHOose and Keep for responsive flows, CHOose and
Kill for unresponsive flows) is a classless qdisc designed
to both identify and penalize flows that monopolize the
queue. CHOKe is a variation of RED, and the configuration
is similar to RED.
codel CoDel (pronounced "coddle") is an adaptive "no-knobs"
active queue management algorithm (AQM) scheme that was
developed to address the shortcomings of RED and its
variants.
[p|b]fifo
Simplest usable qdisc, pure First In, First Out behaviour.
Limited in packets or in bytes.
fq Fair Queue Scheduler realises TCP pacing and scales to
millions of concurrent flows per qdisc.
fq_codel
Fair Queuing Controlled Delay is queuing discipline that
combines Fair Queuing with the CoDel AQM scheme. FQ_Codel
uses a stochastic model to classify incoming packets into
different flows and is used to provide a fair share of the
bandwidth to all the flows using the queue. Each such flow
is managed by the CoDel queuing discipline. Reordering
within a flow is avoided since Codel internally uses a
FIFO queue.
fq_pie FQ-PIE (Flow Queuing with Proportional Integral controller
Enhanced) is a queuing discipline that combines Flow
Queuing with the PIE AQM scheme. FQ-PIE uses a Jenkins
hash function to classify incoming packets into different
flows and is used to provide a fair share of the bandwidth
to all the flows using the qdisc. Each such flow is
managed by the PIE algorithm.
gred Generalized Random Early Detection combines multiple RED
queues in order to achieve multiple drop priorities. This
is required to realize Assured Forwarding (RFC 2597).
hhf Heavy-Hitter Filter differentiates between small flows and
the opposite, heavy-hitters. The goal is to catch the
heavy-hitters and move them to a separate queue with less
priority so that bulk traffic does not affect the latency
of critical traffic.
ingress
This is a special qdisc as it applies to incoming traffic
on an interface, allowing for it to be filtered and
policed.
mqprio The Multiqueue Priority Qdisc is a simple queuing
discipline that allows mapping traffic flows to hardware
queue ranges using priorities and a configurable priority
to traffic class mapping. A traffic class in this context
is a set of contiguous qdisc classes which map 1:1 to a
set of hardware exposed queues.
multiq Multiqueue is a qdisc optimized for devices with multiple
Tx queues. It has been added for hardware that wishes to
avoid head-of-line blocking. It will cycle though the
bands and verify that the hardware queue associated with
the band is not stopped prior to dequeuing a packet.
netem Network Emulator is an enhancement of the Linux traffic
control facilities that allow to add delay, packet loss,
duplication and more other characteristics to packets
outgoing from a selected network interface.
pfifo_fast
Standard qdisc for 'Advanced Router' enabled kernels.
Consists of a three-band queue which honors Type of
Service flags, as well as the priority that may be
assigned to a packet.
pie Proportional Integral controller-Enhanced (PIE) is a
control theoretic active queue management scheme. It is
based on the proportional integral controller but aims to
control delay.
red Random Early Detection simulates physical congestion by
randomly dropping packets when nearing configured
bandwidth allocation. Well suited to very large bandwidth
applications.
rr Round-Robin qdisc with support for multiqueue network
devices. Removed from Linux since kernel version 2.6.27.
sfb Stochastic Fair Blue is a classless qdisc to manage
congestion based on packet loss and link utilization
history while trying to prevent non-responsive flows (i.e.
flows that do not react to congestion marking or dropped
packets) from impacting performance of responsive flows.
Unlike RED, where the marking probability has to be
configured, BLUE tries to determine the ideal marking
probability automatically.
sfq Stochastic Fairness Queueing reorders queued traffic so
each 'session' gets to send a packet in turn.
tbf The Token Bucket Filter is suited for slowing traffic down
to a precisely configured rate. Scales well to large
bandwidths.
