man/man8/tc-htb.8 - maze/iproute2 - Git at Google

 .TH HTB 8 "10 January 2002" "iproute2" "Linux"
 .SH NAME
 HTB \- Hierarchy Token Bucket
 .SH SYNOPSIS
 .B tc qdisc ... dev
 dev
 .B  ( parent
 classid
 .B | root) [ handle
 major:
 .B ] htb [ default
 minor-id
 .B ]

 .B tc class ... dev
 dev
 .B parent
 major:[minor]
 .B [ classid
 major:minor
 .B ] htb rate
 rate
 .B [ ceil
 rate
 .B ] burst
 bytes
 .B [ cburst
 bytes
 .B ] [ prio
 priority
 .B ]

 .SH DESCRIPTION
 HTB is meant as a more understandable and intuitive replacement for
 the CBQ qdisc in Linux. Both CBQ and HTB help you to control the use
 of the outbound bandwidth on a given link. Both allow you to use one
 physical link to simulate several slower links and to send different
 kinds of traffic on different simulated links. In both cases, you have
 to specify how to divide the physical link into simulated links and
 how to decide which simulated link to use for a given packet to be sent.

 Unlike CBQ, HTB shapes traffic based on the Token Bucket Filter algorithm
 which does not depend on interface characteristics and so does not need to
 know the underlying bandwidth of the outgoing interface.

 .SH SHAPING ALGORITHM
 Shaping works as documented in
 .B tc-tbf (8).

 .SH CLASSIFICATION
 Within the one HRB instance many classes may exist. Each of these classes
 contains another qdisc, by default
 .BR tc-pfifo (8).

 When enqueueing a packet, HTB starts at the root and uses various methods to
 determine which class should receive the data.

 In the absence of uncommon configuration options, the process is rather easy.
 At each node we look for an instruction, and then go to the class the
 instruction refers us to. If the class found is a barren leaf-node (without
 children), we enqueue the packet there. If it is not yet a leaf node, we do
 the whole thing over again starting from that node.

 The following actions are performed, in order at each node we visit, until one
 sends us to another node, or terminates the process.
 .TP
 (i)
 Consult filters attached to the class. If sent to a leafnode, we are done.
 Otherwise, restart.
 .TP
 (ii)
 If none of the above returned with an instruction, enqueue at this node.
 .P
 This algorithm makes sure that a packet always ends up somewhere, even while
 you are busy building your configuration.

 .SH LINK SHARING ALGORITHM
 FIXME

 .SH QDISC
 The root of a HTB qdisc class tree has the following parameters:

 .TP
 parent major:minor | root
 This mandatory parameter determines the place of the HTB instance, either at the
 .B root
 of an interface or within an existing class.
 .TP
 handle major:
 Like all other qdiscs, the HTB can be assigned a handle. Should consist only
 of a major number, followed by a colon. Optional, but very useful if classes
 will be generated within this qdisc.
 .TP
 default minor-id
 Unclassified traffic gets sent to the class with this minor-id.

 .SH CLASSES
 Classes have a host of parameters to configure their operation.

 .TP
 parent major:minor
 Place of this class within the hierarchy. If attached directly to a qdisc
 and not to another class, minor can be omitted. Mandatory.
 .TP
 classid major:minor
 Like qdiscs, classes can be named. The major number must be equal to the
 major number of the qdisc to which it belongs. Optional, but needed if this
 class is going to have children.
 .TP
 prio priority
 In the round-robin process, classes with the lowest priority field are tried
 for packets first. Mandatory.

 .TP
 rate rate
 Maximum rate this class and all its children are guaranteed. Mandatory.

 .TP
 ceil rate
 Maximum rate at which a class can send, if its parent has bandwidth to spare.
 Defaults to the configured rate, which implies no borrowing

 .TP
 burst bytes
 Amount of bytes that can be burst at
 .B ceil
 speed, in excess of the configured
 .B rate.
 Should be at least as high as the highest burst of all children.

 .TP
 cburst bytes
 Amount of bytes that can be burst at 'infinite' speed, in other words, as fast
 as the interface can transmit them. For perfect evening out, should be equal to at most one average
 packet. Should be at least as high as the highest cburst of all children.

 .SH NOTES
 Due to Unix timing constraints, the maximum ceil rate is not infinite and may in fact be quite low. On Intel,
 there are 100 timer events per second, the maximum rate is that rate at which 'burst' bytes are sent each timer tick.
 From this, the minimum burst size for a specified rate can be calculated. For i386, a 10mbit rate requires a 12 kilobyte
 burst as 100*12kb*8 equals 10mbit.

 .SH SEE ALSO
 .BR tc (8)
 .P
 HTB website: http://luxik.cdi.cz/~devik/qos/htb/
 .SH AUTHOR
 Martin Devera <devik@cdi.cz>. This manpage maintained by bert hubert <ahu@ds9a.nl>
	.TH HTB 8 "10 January 2002" "iproute2" "Linux"
	.SH NAME
	HTB \- Hierarchy Token Bucket
	.SH SYNOPSIS
	.B tc qdisc ... dev
	dev
	.B ( parent
	classid
	.B \| root) [ handle
	major:
	.B ] htb [ default
	minor-id
	.B ]

	.B tc class ... dev
	dev
	.B parent
	major:[minor]
	.B [ classid
	major:minor
	.B ] htb rate
	rate
	.B [ ceil
	rate
	.B ] burst
	bytes
	.B [ cburst
	bytes
	.B ] [ prio
	priority
	.B ]

	.SH DESCRIPTION
	HTB is meant as a more understandable and intuitive replacement for
	the CBQ qdisc in Linux. Both CBQ and HTB help you to control the use
	of the outbound bandwidth on a given link. Both allow you to use one
	physical link to simulate several slower links and to send different
	kinds of traffic on different simulated links. In both cases, you have
	to specify how to divide the physical link into simulated links and
	how to decide which simulated link to use for a given packet to be sent.

	Unlike CBQ, HTB shapes traffic based on the Token Bucket Filter algorithm
	which does not depend on interface characteristics and so does not need to
	know the underlying bandwidth of the outgoing interface.

	.SH SHAPING ALGORITHM
	Shaping works as documented in
	.B tc-tbf (8).

	.SH CLASSIFICATION
	Within the one HRB instance many classes may exist. Each of these classes
	contains another qdisc, by default
	.BR tc-pfifo (8).

	When enqueueing a packet, HTB starts at the root and uses various methods to
	determine which class should receive the data.

	In the absence of uncommon configuration options, the process is rather easy.
	At each node we look for an instruction, and then go to the class the
	instruction refers us to. If the class found is a barren leaf-node (without
	children), we enqueue the packet there. If it is not yet a leaf node, we do
	the whole thing over again starting from that node.

	The following actions are performed, in order at each node we visit, until one
	sends us to another node, or terminates the process.
	.TP
	(i)
	Consult filters attached to the class. If sent to a leafnode, we are done.
	Otherwise, restart.
	.TP
	(ii)
	If none of the above returned with an instruction, enqueue at this node.
	.P
	This algorithm makes sure that a packet always ends up somewhere, even while
	you are busy building your configuration.

	.SH LINK SHARING ALGORITHM
	FIXME

	.SH QDISC
	The root of a HTB qdisc class tree has the following parameters:

	.TP
	parent major:minor \| root
	This mandatory parameter determines the place of the HTB instance, either at the
	.B root
	of an interface or within an existing class.
	.TP
	handle major:
	Like all other qdiscs, the HTB can be assigned a handle. Should consist only
	of a major number, followed by a colon. Optional, but very useful if classes
	will be generated within this qdisc.
	.TP
	default minor-id
	Unclassified traffic gets sent to the class with this minor-id.

	.SH CLASSES
	Classes have a host of parameters to configure their operation.

	.TP
	parent major:minor
	Place of this class within the hierarchy. If attached directly to a qdisc
	and not to another class, minor can be omitted. Mandatory.
	.TP
	classid major:minor
	Like qdiscs, classes can be named. The major number must be equal to the
	major number of the qdisc to which it belongs. Optional, but needed if this
	class is going to have children.
	.TP
	prio priority
	In the round-robin process, classes with the lowest priority field are tried
	for packets first. Mandatory.

	.TP
	rate rate
	Maximum rate this class and all its children are guaranteed. Mandatory.

	.TP
	ceil rate
	Maximum rate at which a class can send, if its parent has bandwidth to spare.
	Defaults to the configured rate, which implies no borrowing

	.TP
	burst bytes
	Amount of bytes that can be burst at
	.B ceil
	speed, in excess of the configured
	.B rate.
	Should be at least as high as the highest burst of all children.

	.TP
	cburst bytes
	Amount of bytes that can be burst at 'infinite' speed, in other words, as fast
	as the interface can transmit them. For perfect evening out, should be equal to at most one average
	packet. Should be at least as high as the highest cburst of all children.

	.SH NOTES
	Due to Unix timing constraints, the maximum ceil rate is not infinite and may in fact be quite low. On Intel,
	there are 100 timer events per second, the maximum rate is that rate at which 'burst' bytes are sent each timer tick.
	From this, the minimum burst size for a specified rate can be calculated. For i386, a 10mbit rate requires a 12 kilobyte
	burst as 10012kb8 equals 10mbit.

	.SH SEE ALSO
	.BR tc (8)
	.P
	HTB website: http://luxik.cdi.cz/~devik/qos/htb/
	.SH AUTHOR
	Martin Devera <devik@cdi.cz>. This manpage maintained by bert hubert <ahu@ds9a.nl>