HTB - Hierarchy Token Bucket 手册

man tc-htb

 

HTB(8)                                                                             Linux                                                                             HTB(8)

NAME
       HTB - Hierarchy Token Bucket

SYNOPSIS
       tc qdisc ... dev dev ( parent classid | root) [ handle major: ] htb [ default minor-id ]

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

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 under鈥[m
       lying bandwidth of the outgoing interface.

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

CLASSIFICATION
       Within the one HRB instance many classes may exist. Each of these classes contains another qdisc, by default 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.

       (i)    Consult filters attached to the class. If sent to a leafnode, we are done.  Otherwise, restart.

       (ii)   If none of the above returned with an instruction, enqueue at this node.

       This algorithm makes sure that a packet always ends up somewhere, even while you are busy building your configuration.

LINK SHARING ALGORITHM
       FIXME

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

       parent major:minor | root
              This mandatory parameter determines the place of the HTB instance, either at the root of an interface or within an existing class.

       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.

       default minor-id
              Unclassified traffic gets sent to the class with this minor-id.

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

       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.

       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.

       prio priority
              In the round-robin process, classes with the lowest priority field are tried for packets first. Mandatory.

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

       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

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

       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.

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.

SEE ALSO
       tc(8)

       HTB website: http://luxik.cdi.cz/~devik/qos/htb/

AUTHOR
       Martin Devera <[email protected]>. This manpage maintained by bert hubert <[email protected]>

iproute2                                                                      10 January 2002                                                                        HTB(8)

 

 

 

示例命令

 

tc qdisc del dev eth0 root
tc qdisc add dev eth0 root handle 1: htb default 2
tc class add dev eth0 parent 1: classid 1:1 htb rate 1000Mbit
tc class add dev eth0 parent 1:1 classid 1:2 htb rate 1000Mbit

 

使用burst参数控制突发流量