NAME

fireqos-params-class - optional class parameters

SYNOPSIS

rate | commit | min speed

ceil | max speed

minrate speed

{ qdisc qdisc-name | pfifo|bfifo|sfq|fq_codel|codel|none } [options “qdisc-options”]

prio { 0..7 | keep | last }

{ linklayer linklayer-name } | { adsl {local|remote} encapsulation } | ethernet | atm

mtu bytes

mpu bytes

tsize size

overhead bytes

r2q factor

burst bytes

cburst bytes

quantum bytes

priority | balanced

input | output

DESCRIPTION

All of the options apply to interface and class statements.

Units for speeds are defined in fireqos.conf(5).

input, output

For bidirectional interfaces, input and output define the direction for which the parameters following it are applied.

Only the following parameters are affected (all the others are applied to both input and output):

minrate
rate, min, commit
ceil, max

If one of the above is not defined for either input or output, its default will be used.

rate, commit, min

When a committed rate of speed is provided to a class, it means that the bandwidth will be given to the class when it needs it. If the class does not need the bandwidth, it will be available for any other class to use.

For interfaces, a rate must be defined.

For classes the rate defaults to 1/100 of the interface capacity.

ceil, max

Defines the maximum speed a class can use. Even there is available bandwidth, a class will not exceed its ceil speed.

For interfaces, the default is the rate speed of the interface.

For classes, the defaults is the ceil of the their interfaces.

minrate

Defines the default committed speed for all classes not specifically given a rate in the config file. It forces a recalculation of tc(8) r2q.

When minrate is not given, FireQOS assigns a default value of 1/100 of the interface rate.

qdisc qdisc-name, pfifo, bfifo, sfq, fq_codel, codel, none

The qdisc defines the method to distribute class bandwidth to its sockets. It is applied within the class itself and is useful in cases where a class gets saturated. For information about these, see the Traffic Control Howto

A qdisc is only useful when applied to a class. It can be specified at the interface level in order to set the default for all of the included classes.

To pass options to a qdisc, you can specify them through an environment variable or explicitly on each class.

Set the variable FIREQOS_DEFAULT_QDISC_OPTIONS_qdiscname in the config file. For example, for sfq:

FIREQOS_DEFAULT_QDISC_OPTIONS_sfq="perturb 10 quantum 2000".

Using this variable each sfq will get these options by default. You can still override this by specifying explicit options for individual qdiscs, for example to add some sfq options you would write:

class classname sfq options "perturb 10 quantum 2000"

The options keyword must appear just after the qdisc name.

prio (class)

Note

There is also a match parameter called prio, see fireqos-params-match(5).

HTB supports 8 priorities, from 0 to 7. Any number less than 0 will give priority 0. Any number above 7 will give priority 7.

By default, FireQOS gives the first class priority 0, and increases this number by 1 for each class it encounters in the config file. If there are more than 8 classes, all classes after the 8th will get priority 7. In balanced mode (see balanced, below), all classes will get priority 4 by default.

FireQOS restarts priorities for each interface and class group.

The class priority defines how the spare bandwidth is spread among the classes. Classes with higher priorities (lower prio) will get all spare bandwidth. Classes with the same priority will get a percentage of the spare bandwidth, proportional to their committed rates.

The keywords keep and last will make a class use the priority of the class just above / before it. So to make two consecutive classes have the same prio, just add prio keep to the second one.

linklayer linklayer-name, ethernet, atm

The linklayer can only be given on interfaces. It is used by the kernel to calculate the overheads in the packets.

adsl

adsl is a special linklayer that automatically calculates ATM overheads for the link.

local is used when linux is running PPPoE.

remote is used when PPPoE is running on the router.

Note

This special case has not yet been demonstrated for sure. Experiment a bit and if you find out, let us know to update this page. In practice, this parameter lets the kernel know that the packets it sees, have already an ethernet header on them.

encapsulation can be one of (all the labels on the same line are aliases):

IPoA-VC/Mux or ipoa-vcmux or ipoa-vc or ipoa-mux,
IPoA-LLC/SNAP or ipoa-llcsnap or ipoa-llc or ipoa-snap
Bridged-VC/Mux or bridged-vcmux or bridged-vc or bridged-mux
Bridged-LLC/SNAP or bridged-llcsnap or bridged-llc or bridged-snap
PPPoA-VC/Mux or pppoa-vcmux or pppoa-vc or pppoa-mux
PPPoA-LLC/SNAP or pppoa-llcsnap or pppoa-llc or pppoa-snap
PPPoE-VC/Mux or pppoe-vcmux or pppoe-vc or pppoe-mux
PPPoE-LLC/SNAP or pppoe-llcsnap or pppoe-llc or pppoe-snap

If your adsl router can give you the mtu, it would be nice to add an mtu parameter too. For detailed info, see here.

mtu

Defines the MTU of the interface in bytes.

FireQOS will query the interface to find its MTU. You can overwrite this behaviour by giving this parameter to a class or interface.

mpu

Defines the MPU of the interface in bytes.

FireQOS does not set a default value. You can set your own using this parameter.

tsize

FireQOS does not set a default size. You can set your own using this parameter.

overhead

FireQOS automatically calculates the bytes overhead for ADSL. For all other technologies, you can specify the overhead in the config file.

r2q

FireQOS calculates the proper r2q factor, so that you can control speeds in steps of 1/100th of the interface speed (if that is possible).

Note

The HTB manual states that this parameter is ignored when a quantum have been set. By default, FireQOS sets quantum to interface MTU, so r2q is probably is ignored by the kernel.

burst

burst specifies the number of bytes that will be sent at once, at ceiling speed, when a class is allowed to send traffic. It is like a ‘traffic unit’. A class is allowed to send at least burst bytes before trying to serve any other class.

burst should never be lower that the interface mtu and class groups and interfaces should never have a smaller burst value than their children. If you do specify a higher burst for a child class, its parent may get stuck sometimes (the child will drain the parent).

By default, FireQOS lets the kernel decide this parameter, which calculates the lowest possible value (the minimum value depends on the rate of the interface and the clock speed of the CPU).

burst is inherited from interfaces to classes and from group classes to their subclasses. FireQOS will not allow you to set a burst at a subclass, higher than its parent. Setting a burst of a subclass higher than its parent will drain the parent class, which may be stuck for up to a minute when this happens. For this check to work, FireQOS uses just its configuration (it does not query the kernel to check how the value specified in the config file for a subclass relates to the actual value of its parent).

cburst

cburst is like burst, but at hardware speed (not just ceiling speed).

By default, FireQOS lets the kernel decide this parameter.

cburst is inherited from interfaces to classes and from group classes to their subclasses. FireQOS will not allow you to set a cburst at a subclass, higher to its parent. Setting a cburst of a subclass higher than its parent, will drain the parent class, which may be stuck for up to a minute when this happens. For this check to work, FireQOS uses just its configuration (it does not query the kernel to check how the value specified in the config file for a subclass relates to the actual value of its parent).

quantum

quantum specifies the number of bytes a class is allowed to send at once, when it is borrowing spare bandwidth from other classes.

By default, FireQOS sets quantum to the interface mtu.

quantum is inherited from interfaces to classes and from group classes to their subclasses.

priority, balanced

These parameters set the priority mode of the child classes.

priority: priority is the default mode, where FireQOS assigns an incremental priority to each class. In this mode, the first class takes prio 0, the second prio 1, etc. When a class has a higher prio than the others (higher = smaller number), this high priority class will get all the spare bandwidth available, when it needs it. Spare bandwidth will be allocate to lower priority classes only when the higher priority ones do not need it.
balanced: balanced mode gives prio 4 to all child classes. When multiple classes have the same prio, the spare bandwidth available is spread among them, proportionally to their committed rate. The value 4 can be overwritten by setting FIREQOS_BALANCED_PRIO at the top of the config file to the prio you want the balanced mode to assign for all classes.

The priority mode can be set in interfaces and class groups. The effect is the same. The classes that are defined as child classes, will get by default the calculated class prio based on the priority mode given.

These options affect only the default prio that will be assigned by FireQOS. The default is used only if you don’t explicitly use a prio parameter on a class.

Note

There is also a match parameter called priority, see fireqos-params-match(5).