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man/man8/bridge.8
View file @ 5699275b
......@@ -91,7 +91,7 @@ bridge \- show / manipulate bridge addresses and devices
.BR "bridge vlan" " { " add " | " del " } "
.B dev
.IR DEV
.B vid
.B vid
.IR VID " [ "
.BR pvid " ] [ " untagged " ] [ "
.BR self " ] [ " master " ] "
......@@ -159,7 +159,7 @@ return code will be non zero.
- Bridge port.
.TP
.B fdb
.B fdb
- Forwarding Database entry.
.TP
......@@ -384,7 +384,7 @@ If omitted the default value is used.
.BI via " DEVICE"
device name of the outgoing interface for the
VXLAN device driver to reach the
remote VXLAN tunnel endpoint.
remote VXLAN tunnel endpoint.
.SS bridge fdb append - append a forwarding database entry
This command adds a new fdb entry with an already known
......
man/man8/ip-addrlabel.8
View file @ 5699275b
......@@ -7,8 +7,8 @@ ip-addrlabel \- protocol address label management
.in +8
.ti -8
.B ip
.RI "[ " OPTIONS " ]"
.B addrlabel
.RI "[ " OPTIONS " ]"
.B addrlabel
.RI " { " COMMAND " | "
.BR help " }"
.sp
......@@ -66,4 +66,3 @@ flush all address labels in the kernel. This does not restore any default settin
.SH AUTHOR
Manpage by Yoshifuji Hideaki / 吉藤英明
man/man8/ip-neighbour.8
View file @ 5699275b
......@@ -33,9 +33,9 @@ ip-neighbour \- neighbour/arp tables management.
.SH DESCRIPTION
The
The
.B ip neigh
command manipulates
command manipulates
.I neighbour
objects that establish bindings between protocol addresses and
link layer addresses for hosts sharing the same link.
......
man/man8/ip-ntable.8
View file @ 5699275b
......@@ -55,7 +55,7 @@ ip-ntable - neighbour table configuration
.SH DESCRIPTION
.I ip ntable
controls the parameters for the neighbour tables.
controls the parameters for the neighbour tables.
.SS ip ntable show - list the ip neighbour tables
......@@ -98,4 +98,4 @@ default value (3) to 8 packets.
.BR ip (8)
.SH AUTHOR
Manpage by Stephen Hemminger
Manpage by Stephen Hemminger
man/man8/ip-rule.8
View file @ 5699275b
......@@ -62,7 +62,7 @@ ip-rule \- routing policy database management
.SH DESCRIPTION
.I ip rule
manipulates rules
manipulates rules
in the routing policy database control the route selection algorithm.
.P
......
man/man8/ip-xfrm.8
View file @ 5699275b
......@@ -121,7 +121,7 @@ ip-xfrm \- transform configuration
.ti -8
.IR ALGO " :="
.RB "{ " enc " | " auth " } "
.RB "{ " enc " | " auth " } "
.IR ALGO-NAME " " ALGO-KEYMAT " |"
.br
.B auth-trunc
......
man/man8/ip.8
View file @ 5699275b
......@@ -12,7 +12,7 @@ ip \- show / manipulate routing, devices, policy routing and tunnels
.sp
.ti -8
.B ip
.B ip
.RB "[ " -force " ] "
.BI "-batch " filename
.sp
......
man/man8/routel.8
View file @ 5699275b
.TH "ROUTEL" "8" "3 Jan, 2008" "iproute2" "Linux"
.SH "NAME"
.LP
.LP
routel \- list routes with pretty output format
.br
routef \- flush routes
.SH "SYNTAX"
.LP
.LP
routel [\fItablenr\fP [\fIraw ip args...\fP]]
.br
.br
routef
.SH "DESCRIPTION"
.LP
.LP
These programs are a set of helper scripts you can use instead of raw iproute2 commands.
.br
The routel script will list routes in a format that some might consider easier to interpret then the ip route list equivalent.
......@@ -18,15 +18,15 @@ The routel script will list routes in a format that some might consider easier t
The routef script does not take any arguments and will simply flush the routing table down the drain. Beware! This means deleting all routes which will make your network unusable!
.SH "FILES"
.LP
\fI/usr/bin/routef\fP
.br
\fI/usr/bin/routel\fP
.LP
\fI/usr/bin/routef\fP
.br
\fI/usr/bin/routel\fP
.SH "AUTHORS"
.LP
.LP
The routel script was written by Stephen R. van den Berg <srb@cuci.nl>, 1999/04/18 and donated to the public domain.
.br
This manual page was written by Andreas Henriksson <andreas@fatal.se>, for the Debian GNU/Linux system.
.SH "SEE ALSO"
.LP
.LP
ip(8)
man/man8/rtacct.8
View file @ 5699275b
......@@ -47,4 +47,3 @@ Time interval to average rates. Default value is 60 seconds.
.SH SEE ALSO
lnstat(8)
man/man8/rtmon.8
View file @ 5699275b
......@@ -10,11 +10,11 @@ This manual page documents briefly the
command.
.PP
.B rtmon
listens on
.I netlink
listens on
.I netlink
socket and monitors routing table changes.
.I rtmon
.I rtmon
can be started before the first network configuration command is issued.
For example if you insert:
......@@ -61,7 +61,7 @@ to display logged output from file.
.SH SEE ALSO
.BR ip (8)
.SH AUTHOR
.B rtmon
.B rtmon
was written by Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>.
.PP
This manual page was written by Michael Prokop <mika@grml.org>,
......
man/man8/ss.8
View file @ 5699275b
......@@ -12,7 +12,7 @@ to
It can display more TCP and state informations than other tools.
.SH OPTIONS
When no option is used ss displays a list of
When no option is used ss displays a list of
open non-listening sockets (e.g. TCP/UNIX/UDP) that have established connection.
.TP
.B \-h, \-\-help
......@@ -189,10 +189,10 @@ List all the tcp sockets in state FIN-WAIT-1 for our apache to network 193.233.7
.BR /usr/share/doc/iproute-doc/ss.html " (package iproute­doc)",
.br
.BR RFC " 793 "
- https://tools.ietf.org/rfc/rfc793.txt (TCP states)
- https://tools.ietf.org/rfc/rfc793.txt (TCP states)
.SH AUTHOR
.I ss
.I ss
was written by Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>.
.PP
This manual page was written by Michael Prokop <mika@grml.org>
......
man/man8/tc-bfifo.8
View file @ 5699275b
......@@ -6,37 +6,37 @@ bfifo \- Byte limited First In, First Out queue
.SH SYNOPSIS
.B tc qdisc ... add pfifo
.B [ limit
.B [ limit
packets
.B ]
.P
.B tc qdisc ... add bfifo
.B [ limit
.B [ limit
bytes
.B ]
.SH DESCRIPTION
The pfifo and bfifo qdiscs are unadorned First In, First Out queues. They are the
simplest queues possible and therefore have no overhead.
simplest queues possible and therefore have no overhead.
.B pfifo
constrains the queue size as measured in packets.
constrains the queue size as measured in packets.
.B bfifo
does so as measured in bytes.
Like all non-default qdiscs, they maintain statistics. This might be a reason to prefer
Like all non-default qdiscs, they maintain statistics. This might be a reason to prefer
pfifo or bfifo over the default.
.SH ALGORITHM
A list of packets is maintained, when a packet is enqueued it gets inserted at the tail of
a list. When a packet needs to be sent out to the network, it is taken from the head of the list.
a list. When a packet needs to be sent out to the network, it is taken from the head of the list.
If the list is too long, no further packets are allowed on. This is called 'tail drop'.
.SH PARAMETERS
.TP
.TP
limit
Maximum queue size. Specified in bytes for bfifo, in packets for pfifo. For pfifo, defaults
to the interface txqueuelen, as specified with
Maximum queue size. Specified in bytes for bfifo, in packets for pfifo. For pfifo, defaults
to the interface txqueuelen, as specified with
.BR ifconfig (8)
or
.BR ip (8).
......@@ -48,20 +48,20 @@ The range for this parameter is [0, UINT32_MAX] bytes.
Note: The link layer header was considered when counting packets length.
.SH OUTPUT
The output of
The output of
.B tc -s qdisc ls
contains the limit, either in packets or in bytes, and the number of bytes
and packets actually sent. An unsent and dropped packet only appears between braces
contains the limit, either in packets or in bytes, and the number of bytes
and packets actually sent. An unsent and dropped packet only appears between braces
and is not counted as 'Sent'.
In this example, the queue length is 100 packets, 45894 bytes were sent over 681 packets.
In this example, the queue length is 100 packets, 45894 bytes were sent over 681 packets.
No packets were dropped, and as the pfifo queue does not slow down packets, there were also no
overlimits:
.P
.nf
# tc -s qdisc ls dev eth0
# tc -s qdisc ls dev eth0
qdisc pfifo 8001: dev eth0 limit 100p
Sent 45894 bytes 681 pkts (dropped 0, overlimits 0)
Sent 45894 bytes 681 pkts (dropped 0, overlimits 0)
.fi
If a backlog occurs, this is displayed as well.
......@@ -72,5 +72,3 @@ If a backlog occurs, this is displayed as well.
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>
This manpage maintained by bert hubert <ahu@ds9a.nl>
man/man8/tc-cbq-details.8
View file @ 5699275b
......@@ -5,54 +5,54 @@ CBQ \- Class Based Queueing
.B tc qdisc ... dev
dev
.B ( parent
classid
.B | root) [ handle
major:
classid
.B | root) [ handle
major:
.B ] cbq avpkt
bytes
.B bandwidth
rate
.B [ cell
.B [ cell
bytes
.B ] [ ewma
log
.B ] [ mpu
bytes
.B ]
.B ]
.B tc class ... dev
dev
.B parent
.B parent
major:[minor]
.B [ classid
.B [ classid
major:minor
.B ] cbq allot
bytes
.B [ bandwidth
rate
.B ] [ rate
.B [ bandwidth
rate
.B ] [ rate
rate
.B ] prio
priority
.B [ weight
weight
.B ] [ minburst
.B ] [ minburst
packets
.B ] [ maxburst
packets
.B ] [ maxburst
packets
.B ] [ ewma
.B ] [ ewma
log
.B ] [ cell
bytes
.B ] avpkt
bytes
.B [ mpu
bytes
bytes
.B ] [ bounded isolated ] [ split
handle
.B & defmap
defmap
.B ] [ estimator
.B ] [ estimator
interval timeconstant
.B ]
......@@ -60,7 +60,7 @@ interval timeconstant
Class Based Queueing is a classful qdisc that implements a rich
linksharing hierarchy of classes. It contains shaping elements as
well as prioritizing capabilities. Shaping is performed using link
idle time calculations based on the timing of dequeue events and
idle time calculations based on the timing of dequeue events and
underlying link bandwidth.
.SH SHAPING ALGORITHM
......@@ -71,10 +71,10 @@ When shaping a 10mbit/s connection to 1mbit/s, the link will
be idle 90% of the time. If it isn't, it needs to be throttled so that it
IS idle 90% of the time.
From the kernel's perspective, this is hard to measure, so CBQ instead
derives the idle time from the number of microseconds (in fact, jiffies)
that elapse between requests from the device driver for more data. Combined
with the knowledge of packet sizes, this is used to approximate how full or
From the kernel's perspective, this is hard to measure, so CBQ instead
derives the idle time from the number of microseconds (in fact, jiffies)
that elapse between requests from the device driver for more data. Combined
with the knowledge of packet sizes, this is used to approximate how full or
empty the link is.
This is rather circumspect and doesn't always arrive at proper
......@@ -84,9 +84,9 @@ perhaps because of a badly implemented driver? A PCMCIA network card
will also never achieve 100mbit/s because of the way the bus is
designed - again, how do we calculate the idle time?
The physical link bandwidth may be ill defined in case of not-quite-real
network devices like PPP over Ethernet or PPTP over TCP/IP. The effective
bandwidth in that case is probably determined by the efficiency of pipes
The physical link bandwidth may be ill defined in case of not-quite-real
network devices like PPP over Ethernet or PPTP over TCP/IP. The effective
bandwidth in that case is probably determined by the efficiency of pipes
to userspace - which not defined.
During operations, the effective idletime is measured using an
......@@ -104,59 +104,59 @@ CBQ throttles and is then 'overlimit'.
Conversely, an idle link might amass a huge avgidle, which would then
allow infinite bandwidths after a few hours of silence. To prevent
this, avgidle is capped at
this, avgidle is capped at
.B maxidle.
If overlimit, in theory, the CBQ could throttle itself for exactly the
amount of time that was calculated to pass between packets, and then
pass one packet, and throttle again. Due to timer resolution constraints,
this may not be feasible, see the
this may not be feasible, see the
.B minburst
parameter below.
.SH CLASSIFICATION
Within the one CBQ instance many classes may exist. Each of these classes
contains another qdisc, by default
contains another qdisc, by default
.BR tc-pfifo (8).
When enqueueing a packet, CBQ starts at the root and uses various methods to
When enqueueing a packet, CBQ starts at the root and uses various methods to
determine which class should receive the data. If a verdict is reached, this
process is repeated for the recipient class which might have further
means of classifying traffic to its children, if any.
CBQ has the following methods available to classify a packet to any child
CBQ has the following methods available to classify a packet to any child
classes.
.TP
(i)
.B skb->priority class encoding.
Can be set from userspace by an application with the
Can be set from userspace by an application with the
.B SO_PRIORITY
setsockopt.
The
The
.B skb->priority class encoding
only applies if the skb->priority holds a major:minor handle of an existing
only applies if the skb->priority holds a major:minor handle of an existing
class within this qdisc.
.TP
(ii)
tc filters attached to the class.
.TP
(iii)
The defmap of a class, as set with the
The defmap of a class, as set with the
.B split & defmap
parameters. The defmap may contain instructions for each possible Linux packet
priority.
.P
Each class also has a
Each class also has a
.B level.
Leaf nodes, attached to the bottom of the class hierarchy, have a level of 0.
.SH CLASSIFICATION ALGORITHM
Classification is a loop, which terminates when a leaf class is found. At any
Classification is a loop, which terminates when a leaf class is found. At any
point the loop may jump to the fallback algorithm.
The loop consists of the following steps:
.TP
.TP
(i)
If the packet is generated locally and has a valid classid encoded within its
.B skb->priority,
......@@ -169,40 +169,40 @@ a class which is not a leaf class, restart loop from the class returned.
If it is a leaf, choose it and terminate.
.TP
(iii)
If the tc filters did not return a class, but did return a classid,
try to find a class with that id within this qdisc.
If the tc filters did not return a class, but did return a classid,
try to find a class with that id within this qdisc.
Check if the found class is of a lower
.B level
than the current class. If so, and the returned class is not a leaf node,
restart the loop at the found class. If it is a leaf node, terminate.
If we found an upward reference to a higher level, enter the fallback
If we found an upward reference to a higher level, enter the fallback
algorithm.
.TP
(iv)
If the tc filters did not return a class, nor a valid reference to one,
consider the minor number of the reference to be the priority. Retrieve
a class from the defmap of this class for the priority. If this did not
contain a class, consult the defmap of this class for the
contain a class, consult the defmap of this class for the
.B BEST_EFFORT
class. If this is an upward reference, or no
.B BEST_EFFORT
class. If this is an upward reference, or no
.B BEST_EFFORT
class was defined,
enter the fallback algorithm. If a valid class was found, and it is not a
leaf node, restart the loop at this class. If it is a leaf, choose it and
leaf node, restart the loop at this class. If it is a leaf, choose it and
terminate. If
neither the priority distilled from the classid, nor the
.B BEST_EFFORT
neither the priority distilled from the classid, nor the
.B BEST_EFFORT
priority yielded a class, enter the fallback algorithm.
.P
The fallback algorithm resides outside of the loop and is as follows.
.TP
(i)
Consult the defmap of the class at which the jump to fallback occurred. If
the defmap contains a class for the
Consult the defmap of the class at which the jump to fallback occurred. If
the defmap contains a class for the
.B
priority
of the class (which is related to the TOS field), choose this class and
terminate.
of the class (which is related to the TOS field), choose this class and
terminate.
.TP
(ii)
Consult the map for a class for the
......@@ -212,28 +212,28 @@ priority. If found, choose it, and terminate.
(iii)
Choose the class at which break out to the fallback algorithm occurred. Terminate.
.P
The packet is enqueued to the class which was chosen when either algorithm
The packet is enqueued to the class which was chosen when either algorithm
terminated. It is therefore possible for a packet to be enqueued *not* at a
leaf node, but in the middle of the hierarchy.
.SH LINK SHARING ALGORITHM
When dequeuing for sending to the network device, CBQ decides which of its
When dequeuing for sending to the network device, CBQ decides which of its
classes will be allowed to send. It does so with a Weighted Round Robin process
in which each class with packets gets a chance to send in turn. The WRR process
starts by asking the highest priority classes (lowest numerically -
starts by asking the highest priority classes (lowest numerically -
highest semantically) for packets, and will continue to do so until they
have no more data to offer, in which case the process repeats for lower
have no more data to offer, in which case the process repeats for lower
priorities.
.B CERTAINTY ENDS HERE, ANK PLEASE HELP
Each class is not allowed to send at length though - they can only dequeue a
configurable amount of data during each round.
configurable amount of data during each round.
If a class is about to go overlimit, and it is not
.B bounded
it will try to borrow avgidle from siblings that are not
.B isolated.
.B isolated.
This process is repeated from the bottom upwards. If a class is unable
to borrow enough avgidle to send a packet, it is throttled and not asked
for a packet for enough time for the avgidle to increase above zero.
......@@ -244,7 +244,7 @@ for a packet for enough time for the avgidle to increase above zero.
.SH QDISC
The root qdisc of a CBQ class tree has the following parameters:
.TP
.TP
parent major:minor | root
This mandatory parameter determines the place of the CBQ instance, either at the
.B root
......@@ -259,22 +259,22 @@ For calculations, the average packet size must be known. It is silently capped
at a minimum of 2/3 of the interface MTU. Mandatory.
.TP
bandwidth rate
To determine the idle time, CBQ must know the bandwidth of your underlying
To determine the idle time, CBQ must know the bandwidth of your underlying
physical interface, or parent qdisc. This is a vital parameter, more about it
later. Mandatory.
.TP
cell
The cell size determines he granularity of packet transmission time calculations. Has a sensible default.
.TP
.TP
mpu
A zero sized packet may still take time to transmit. This value is the lower
cap for packet transmission time calculations - packets smaller than this value
are still deemed to have this size. Defaults to zero.
.TP
ewma log
When CBQ needs to measure the average idle time, it does so using an
When CBQ needs to measure the average idle time, it does so using an
Exponentially Weighted Moving Average which smooths out measurements into
a moving average. The EWMA LOG determines how much smoothing occurs. Defaults
a moving average. The EWMA LOG determines how much smoothing occurs. Defaults
to 5. Lower values imply greater sensitivity. Must be between 0 and 31.
.P
A CBQ qdisc does not shape out of its own accord. It only needs to know certain
......@@ -283,35 +283,35 @@ parameters about the underlying link. Actual shaping is done in classes.
.SH CLASSES
Classes have a host of parameters to configure their operation.
.TP
.TP
parent major:minor
Place of this class within the hierarchy. If attached directly to a qdisc
Place of this class within the hierarchy. If attached directly to a qdisc
and not to another class, minor can be omitted. Mandatory.
.TP
.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
major number of the qdisc to which it belongs. Optional, but needed if this
class is going to have children.
.TP
.TP
weight weight
When dequeuing to the interface, classes are tried for traffic in a
When dequeuing to the interface, classes are tried for traffic in a
round-robin fashion. Classes with a higher configured qdisc will generally
have more traffic to offer during each round, so it makes sense to allow
it to dequeue more traffic. All weights under a class are normalized, so
only the ratios matter. Defaults to the configured rate, unless the priority
only the ratios matter. Defaults to the configured rate, unless the priority
of this class is maximal, in which case it is set to 1.
.TP
.TP
allot bytes
Allot specifies how many bytes a qdisc can dequeue
during each round of the process. This parameter is weighted using the
during each round of the process. This parameter is weighted using the
renormalized class weight described above.
.TP
.TP
priority priority
In the round-robin process, classes with the lowest priority field are tried
In the round-robin process, classes with the lowest priority field are tried
for packets first. Mandatory.
.TP
.TP
rate rate
Maximum rate this class and all its children combined can send at. Mandatory.
......@@ -321,7 +321,7 @@ This is different from the bandwidth specified when creating a CBQ disc. Only
used to determine maxidle and offtime, which are only calculated when
specifying maxburst or minburst. Mandatory if specifying maxburst or minburst.
.TP
.TP
maxburst
This number of packets is used to calculate maxidle so that when
avgidle is at maxidle, this number of average packets can be burst
......@@ -329,7 +329,7 @@ before avgidle drops to 0. Set it higher to be more tolerant of
bursts. You can't set maxidle directly, only via this parameter.
.TP
minburst
minburst
As mentioned before, CBQ needs to throttle in case of
overlimit. The ideal solution is to do so for exactly the calculated
idle time, and pass 1 packet. However, Unix kernels generally have a
......@@ -352,21 +352,21 @@ Minidle is specified in negative microseconds, so 10 means that
avgidle is capped at -10us.
.TP
bounded
bounded
Signifies that this class will not borrow bandwidth from its siblings.
.TP
.TP
isolated
Means that this class will not borrow bandwidth to its siblings
.TP
.TP
split major:minor & defmap bitmap[/bitmap]
If consulting filters attached to a class did not give a verdict,
If consulting filters attached to a class did not give a verdict,
CBQ can also classify based on the packet's priority. There are 16
priorities available, numbered from 0 to 15.
priorities available, numbered from 0 to 15.
The defmap specifies which priorities this class wants to receive,
specified as a bitmap. The Least Significant Bit corresponds to priority
zero. The
The defmap specifies which priorities this class wants to receive,
specified as a bitmap. The Least Significant Bit corresponds to priority
zero. The
.B split
parameter tells CBQ at which class the decision must be made, which should
be a (grand)parent of the class you are adding.
......@@ -374,7 +374,7 @@ be a (grand)parent of the class you are adding.
As an example, 'tc class add ... classid 10:1 cbq .. split 10:0 defmap c0'
configures class 10:0 to send packets with priorities 6 and 7 to 10:1.
The complimentary configuration would then
The complimentary configuration would then
be: 'tc class add ... classid 10:2 cbq ... split 10:0 defmap 3f'
Which would send all packets 0, 1, 2, 3, 4 and 5 to 10:1.
.TP
......@@ -384,11 +384,11 @@ can use to classify packets with. In order to determine the bandwidth
it uses a very simple estimator that measures once every
.B interval
microseconds how much traffic has passed. This again is a EWMA, for which
the time constant can be specified, also in microseconds. The
the time constant can be specified, also in microseconds. The
.B time constant
corresponds to the sluggishness of the measurement or, conversely, to the
corresponds to the sluggishness of the measurement or, conversely, to the
sensitivity of the average to short bursts. Higher values mean less
sensitivity.
sensitivity.
......@@ -399,7 +399,7 @@ Sally Floyd and Van Jacobson, "Link-sharing and Resource
Management Models for Packet Networks",
IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
.TP
.TP
o
Sally Floyd, "Notes on CBQ and Guarantee Service", 1995
......@@ -408,7 +408,7 @@ o
Sally Floyd, "Notes on Class-Based Queueing: Setting
Parameters", 1996
.TP
.TP
o
Sally Floyd and Michael Speer, "Experimental Results
for Class-Based Queueing", 1998, not published.
......@@ -421,5 +421,3 @@ for Class-Based Queueing", 1998, not published.
.SH AUTHOR
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>. This manpage maintained by
bert hubert <ahu@ds9a.nl>
man/man8/tc-cbq.8
View file @ 5699275b
......@@ -5,56 +5,56 @@ CBQ \- Class Based Queueing
.B tc qdisc ... dev
dev
.B ( parent
classid
.B | root) [ handle
major:
.B ] cbq [ allot
classid
.B | root) [ handle
major:
.B ] cbq [ allot
bytes
.B ] avpkt
bytes
.B bandwidth
rate
.B [ cell
.B [ cell
bytes
.B ] [ ewma
log
.B ] [ mpu
bytes
.B ]
.B ]
.B tc class ... dev
dev
.B parent
.B parent
major:[minor]
.B [ classid
.B [ classid
major:minor
.B ] cbq allot
bytes
.B [ bandwidth
rate
.B ] [ rate
.B [ bandwidth
rate
.B ] [ rate
rate
.B ] prio
priority
.B [ weight
weight
.B ] [ minburst
.B ] [ minburst
packets
.B ] [ maxburst
packets
.B ] [ maxburst
packets
.B ] [ ewma
.B ] [ ewma
log
.B ] [ cell
bytes
.B ] avpkt
bytes
.B [ mpu
bytes
bytes
.B ] [ bounded isolated ] [ split
handle
.B & defmap
defmap
.B ] [ estimator
.B ] [ estimator
interval timeconstant
.B ]
......@@ -62,7 +62,7 @@ interval timeconstant
Class Based Queueing is a classful qdisc that implements a rich
linksharing hierarchy of classes. It contains shaping elements as
well as prioritizing capabilities. Shaping is performed using link
idle time calculations based on the timing of dequeue events and
idle time calculations based on the timing of dequeue events and
underlying link bandwidth.
.SH SHAPING ALGORITHM
......@@ -85,71 +85,71 @@ CBQ throttles and is then 'overlimit'.
Conversely, an idle link might amass a huge avgidle, which would then
allow infinite bandwidths after a few hours of silence. To prevent
this, avgidle is capped at
this, avgidle is capped at
.B maxidle.
If overlimit, in theory, the CBQ could throttle itself for exactly the
amount of time that was calculated to pass between packets, and then
pass one packet, and throttle again. Due to timer resolution constraints,
this may not be feasible, see the
this may not be feasible, see the
.B minburst
parameter below.
.SH CLASSIFICATION
Within the one CBQ instance many classes may exist. Each of these classes
contains another qdisc, by default
contains another qdisc, by default
.BR tc-pfifo (8).
When enqueueing a packet, CBQ starts at the root and uses various methods to
determine which class should receive the data.
When enqueueing a packet, CBQ 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.
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
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.
Consult filters attached to the class. If sent to a leafnode, we are done.
Otherwise, restart.
.TP
(ii)
Consult the defmap for the priority assigned to this packet, which depends
Consult the defmap for the priority assigned to this packet, which depends
on the TOS bits. Check if the referral is leafless, otherwise restart.
.TP
(iii)
Ask the defmap for instructions for the 'best effort' priority. Check the
Ask the defmap for instructions for the 'best effort' priority. Check the
answer for leafness, otherwise restart.
.TP
(iv)
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.
you are busy building your configuration.
For more details, see
.BR tc-cbq-details(8).
.SH LINK SHARING ALGORITHM
When dequeuing for sending to the network device, CBQ decides which of its
When dequeuing for sending to the network device, CBQ decides which of its
classes will be allowed to send. It does so with a Weighted Round Robin process
in which each class with packets gets a chance to send in turn. The WRR process
starts by asking the highest priority classes (lowest numerically -
starts by asking the highest priority classes (lowest numerically -
highest semantically) for packets, and will continue to do so until they
have no more data to offer, in which case the process repeats for lower
have no more data to offer, in which case the process repeats for lower
priorities.
Classes by default borrow bandwidth from their siblings. A class can be
prevented from doing so by declaring it 'bounded'. A class can also indicate
Classes by default borrow bandwidth from their siblings. A class can be
prevented from doing so by declaring it 'bounded'. A class can also indicate
its unwillingness to lend out bandwidth by being 'isolated'.
.SH QDISC
The root of a CBQ qdisc class tree has the following parameters:
.TP
.TP
parent major:minor | root
This mandatory parameter determines the place of the CBQ instance, either at the
.B root
......@@ -159,7 +159,7 @@ handle major:
Like all other qdiscs, the CBQ 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
.TP
allot bytes
This allotment is the 'chunkiness' of link sharing and is used for determining packet
transmission time tables. The qdisc allot differs slightly from the class allot discussed
......@@ -170,23 +170,23 @@ The average size of a packet is needed for calculating maxidle, and is also used
for making sure 'allot' has a safe value. Mandatory.
.TP
bandwidth rate
To determine the idle time, CBQ must know the bandwidth of your underlying
To determine the idle time, CBQ must know the bandwidth of your underlying
physical interface, or parent qdisc. This is a vital parameter, more about it
later. Mandatory.
.TP
cell
The cell size determines he granularity of packet transmission time calculations. Has a sensible default.
.TP
.TP
mpu
A zero sized packet may still take time to transmit. This value is the lower
cap for packet transmission time calculations - packets smaller than this value
are still deemed to have this size. Defaults to zero.
.TP
ewma log
When CBQ needs to measure the average idle time, it does so using an
When CBQ needs to measure the average idle time, it does so using an
Exponentially Weighted Moving Average which smooths out measurements into
a moving average. The EWMA LOG determines how much smoothing occurs. Lower
values imply greater sensitivity. Must be between 0 and 31. Defaults
a moving average. The EWMA LOG determines how much smoothing occurs. Lower
values imply greater sensitivity. Must be between 0 and 31. Defaults
to 5.
.P
A CBQ qdisc does not shape out of its own accord. It only needs to know certain
......@@ -195,40 +195,40 @@ parameters about the underlying link. Actual shaping is done in classes.
.SH CLASSES
Classes have a host of parameters to configure their operation.
.TP
.TP
parent major:minor
Place of this class within the hierarchy. If attached directly to a qdisc
Place of this class within the hierarchy. If attached directly to a qdisc
and not to another class, minor can be omitted. Mandatory.
.TP
.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
major number of the qdisc to which it belongs. Optional, but needed if this
class is going to have children.
.TP
.TP
weight weight
When dequeuing to the interface, classes are tried for traffic in a
When dequeuing to the interface, classes are tried for traffic in a
round-robin fashion. Classes with a higher configured qdisc will generally
have more traffic to offer during each round, so it makes sense to allow
it to dequeue more traffic. All weights under a class are normalized, so
only the ratios matter. Defaults to the configured rate, unless the priority
only the ratios matter. Defaults to the configured rate, unless the priority
of this class is maximal, in which case it is set to 1.
.TP
.TP
allot bytes
Allot specifies how many bytes a qdisc can dequeue
during each round of the process. This parameter is weighted using the
during each round of the process. This parameter is weighted using the
renormalized class weight described above. Silently capped at a minimum of
3/2 avpkt. Mandatory.
.TP
.TP
prio priority
In the round-robin process, classes with the lowest priority field are tried
In the round-robin process, classes with the lowest priority field are tried
for packets first. Mandatory.
.TP
.TP
avpkt
See the QDISC section.
.TP
.TP
rate rate
Maximum rate this class and all its children combined can send at. Mandatory.
......@@ -238,7 +238,7 @@ This is different from the bandwidth specified when creating a CBQ disc! Only
used to determine maxidle and offtime, which are only calculated when
specifying maxburst or minburst. Mandatory if specifying maxburst or minburst.
.TP
.TP
maxburst
This number of packets is used to calculate maxidle so that when
avgidle is at maxidle, this number of average packets can be burst
......@@ -246,7 +246,7 @@ before avgidle drops to 0. Set it higher to be more tolerant of
bursts. You can't set maxidle directly, only via this parameter.
.TP
minburst
minburst
As mentioned before, CBQ needs to throttle in case of
overlimit. The ideal solution is to do so for exactly the calculated
idle time, and pass 1 packet. However, Unix kernels generally have a
......@@ -269,21 +269,21 @@ Minidle is specified in negative microseconds, so 10 means that
avgidle is capped at -10us. Optional.
.TP
bounded
bounded
Signifies that this class will not borrow bandwidth from its siblings.
.TP
.TP
isolated
Means that this class will not borrow bandwidth to its siblings
.TP
.TP
split major:minor & defmap bitmap[/bitmap]
If consulting filters attached to a class did not give a verdict,
If consulting filters attached to a class did not give a verdict,
CBQ can also classify based on the packet's priority. There are 16
priorities available, numbered from 0 to 15.
priorities available, numbered from 0 to 15.
The defmap specifies which priorities this class wants to receive,
specified as a bitmap. The Least Significant Bit corresponds to priority
zero. The
The defmap specifies which priorities this class wants to receive,
specified as a bitmap. The Least Significant Bit corresponds to priority
zero. The
.B split
parameter tells CBQ at which class the decision must be made, which should
be a (grand)parent of the class you are adding.
......@@ -291,7 +291,7 @@ be a (grand)parent of the class you are adding.
As an example, 'tc class add ... classid 10:1 cbq .. split 10:0 defmap c0'
configures class 10:0 to send packets with priorities 6 and 7 to 10:1.
The complimentary configuration would then
The complimentary configuration would then
be: 'tc class add ... classid 10:2 cbq ... split 10:0 defmap 3f'
Which would send all packets 0, 1, 2, 3, 4 and 5 to 10:1.
.TP
......@@ -301,22 +301,22 @@ can use to classify packets with. In order to determine the bandwidth
it uses a very simple estimator that measures once every
.B interval
microseconds how much traffic has passed. This again is a EWMA, for which
the time constant can be specified, also in microseconds. The
the time constant can be specified, also in microseconds. The
.B time constant
corresponds to the sluggishness of the measurement or, conversely, to the
corresponds to the sluggishness of the measurement or, conversely, to the
sensitivity of the average to short bursts. Higher values mean less
sensitivity.
sensitivity.
.SH BUGS
The actual bandwidth of the underlying link may not be known, for example
in the case of PPoE or PPTP connections which in fact may send over a
The actual bandwidth of the underlying link may not be known, for example
in the case of PPoE or PPTP connections which in fact may send over a
pipe, instead of over a physical device. CBQ is quite resilient to major
errors in the configured bandwidth, probably a the cost of coarser shaping.
Default kernels rely on coarse timing information for making decisions. These
Default kernels rely on coarse timing information for making decisions. These
may make shaping precise in the long term, but inaccurate on second long scales.
See
See
.BR tc-cbq-details(8)
for hints on how to improve this.
......@@ -327,7 +327,7 @@ Sally Floyd and Van Jacobson, "Link-sharing and Resource
Management Models for Packet Networks",
IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995
.TP
.TP
o
Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995
......@@ -336,7 +336,7 @@ o
Sally Floyd, "Notes on Class-Based Queueing: Setting
Parameters", 1996
.TP
.TP
o
Sally Floyd and Michael Speer, "Experimental Results
for Class-Based Queueing", 1998, not published.
......@@ -349,5 +349,3 @@ for Class-Based Queueing", 1998, not published.
.SH AUTHOR
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>. This manpage maintained by
bert hubert <ahu@ds9a.nl>
man/man8/tc-drr.8
View file @ 5699275b
......@@ -92,4 +92,3 @@ as limits are handled by the individual child qdiscs.
.SH AUTHOR
sched_drr was written by Patrick McHardy.
man/man8/tc-htb.8
View file @ 5699275b
......@@ -5,30 +5,30 @@ HTB \- Hierarchy Token Bucket
.B tc qdisc ... dev
dev
.B ( parent
classid
.B | root) [ handle
major:
.B ] htb [ default
classid
.B | root) [ handle
major:
.B ] htb [ default
minor-id
.B ]
.B ]
.B tc class ... dev
dev
.B parent
.B parent
major:[minor]
.B [ classid
.B [ classid
major:minor
.B ] htb rate
rate
.B [ ceil
rate
.B ] burst
rate
.B ] burst
bytes
.B [ cburst
bytes
.B ] [ prio
priority
.B ]
.B ]
.SH DESCRIPTION
HTB is meant as a more understandable and intuitive replacement for
......@@ -37,9 +37,9 @@ 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.
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
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.
......@@ -49,30 +49,30 @@ Shaping works as documented in
.SH CLASSIFICATION
Within the one HTB instance many classes may exist. Each of these classes
contains another qdisc, by default
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.
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.
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
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.
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.
you are busy building your configuration.
.SH LINK SHARING ALGORITHM
FIXME
......@@ -80,7 +80,7 @@ FIXME
.SH QDISC
The root of a HTB qdisc class tree has the following parameters:
.TP
.TP
parent major:minor | root
This mandatory parameter determines the place of the HTB instance, either at the
.B root
......@@ -90,54 +90,54 @@ 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
.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
.TP
parent major:minor
Place of this class within the hierarchy. If attached directly to a qdisc
Place of this class within the hierarchy. If attached directly to a qdisc
and not to another class, minor can be omitted. Mandatory.
.TP
.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
major number of the qdisc to which it belongs. Optional, but needed if this
class is going to have children.
.TP
.TP
prio priority
In the round-robin process, classes with the lowest priority field are tried
In the round-robin process, classes with the lowest priority field are tried
for packets first. Mandatory.
.TP
.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.
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
.TP
burst bytes
Amount of bytes that can be burst at
Amount of bytes that can be burst at
.B ceil
speed, in excess of the configured
.B rate.
.B rate.
Should be at least as high as the highest burst of all children.
.TP
.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,
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
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
......@@ -146,5 +146,3 @@ burst as 100*12kb*8 equals 10mbit.
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>
man/man8/tc-netem.8
View file @ 5699275b
......@@ -2,9 +2,9 @@
.SH NAME
NetEm \- Network Emulator
.SH SYNOPSIS
.B "tc qdisc ... dev"
.B "tc qdisc ... dev"
.IR DEVICE " ] "
.BR "add netem"
.BR "add netem"
.I OPTIONS
.IR OPTIONS " := [ " LIMIT " ] [ " DELAY " ] [ " LOSS \
......@@ -15,15 +15,15 @@ NetEm \- Network Emulator
.I packets
.IR DELAY " := "
.BI delay
.BI delay
.IR TIME " [ " JITTER " [ " CORRELATION " ]]]"
.br
[
[
.BR distribution " { "uniform " | " normal " | " pareto " | " paretonormal " } ]"
.IR LOSS " := "
.BR loss " { "
.BI random
.BI random
.IR PERCENT " [ " CORRELATION " ] |"
.br
.RB " " state
......@@ -44,13 +44,13 @@ NetEm \- Network Emulator
.IR REORDERING " := "
.B reorder
.IR PERCENT " [ " CORRELATION " ] [ "
.B gap
.B gap
.IR DISTANCE " ]"
.IR RATE " := "
.B rate
.IR RATE " [ " PACKETOVERHEAD " [ " CELLSIZE " [ " CELLOVERHEAD " ]]]]"
.SH DESCRIPTION
NetEm is an enhancement of the Linux traffic control facilities
......@@ -139,11 +139,11 @@ in this second example 25% of packets are sent immediately (with correlation of
50%) while the others are delayed by 10 ms.
.SS rate
delay packets based on packet size and is a replacement for
delay packets based on packet size and is a replacement for
.IR TBF .
Rate can be
specified in common units (e.g. 100kbit). Optional
.I PACKETOVERHEAD
specified in common units (e.g. 100kbit). Optional
.I PACKETOVERHEAD
(in bytes) specify an per packet overhead and can be negative. A positive value can be
used to simulate additional link layer headers. A negative value can be used to
artificial strip the Ethernet header (e.g. -14) and/or simulate a link layer
......@@ -152,7 +152,7 @@ the cellsize. Cellsize can be used to simulate link layer schemes. ATM for
example has an payload cellsize of 48 bytes and 5 byte per cell header. If a
packet is 50 byte then ATM must use two cells: 2 * 48 bytes payload including 2
* 5 byte header, thus consume 106 byte on the wire. The last optional value
.I CELLOVERHEAD
.I CELLOVERHEAD
can be used to specify per cell overhead - for our ATM example 5.
.I CELLOVERHEAD
can be negative, but use negative values with caution.
......
man/man8/tc-pfifo_fast.8
View file @ 5699275b
......@@ -13,14 +13,14 @@ is detached.
In this sense this qdisc is magic, and unlike other qdiscs.
.SH ALGORITHM
The algorithm is very similar to that of the classful
The algorithm is very similar to that of the classful
.BR tc-prio (8)
qdisc.
qdisc.
.B pfifo_fast
is like three
.BR tc-pfifo (8)
queues side by side, where packets can be enqueued in any of the three bands
based on their Type of Service bits or assigned priority.
based on their Type of Service bits or assigned priority.
Not all three bands are dequeued simultaneously - as long as lower bands
have traffic, higher bands are never dequeued. This can be used to
......@@ -28,7 +28,7 @@ prioritize interactive traffic or penalize 'lowest cost' traffic.
Each band can be txqueuelen packets long, as configured with
.BR ifconfig (8)
or
or
.BR ip (8).
Additional packets coming in are not enqueued but are instead dropped.
......@@ -36,7 +36,7 @@ See
.BR tc-prio (8)
for complete details on how TOS bits are translated into bands.
.SH PARAMETERS
.TP
.TP
txqueuelen
The length of the three bands depends on the interface txqueuelen, as
specified with
......@@ -46,7 +46,7 @@ or
.SH BUGS
Does not maintain statistics and does not show up in tc qdisc ls. This is because
it is the automatic default in the absence of a configured qdisc.
it is the automatic default in the absence of a configured qdisc.
.SH SEE ALSO
.BR tc (8)
......@@ -55,5 +55,3 @@ it is the automatic default in the absence of a configured qdisc.
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>
This manpage maintained by bert hubert <ahu@ds9a.nl>
man/man8/tc-prio.8
View file @ 5699275b
......@@ -5,21 +5,21 @@ PRIO \- Priority qdisc
.B tc qdisc ... dev
dev
.B ( parent
classid
.B | root) [ handle
major:
.B ] prio [ bands
classid
.B | root) [ handle
major:
.B ] prio [ bands
bands
.B ] [ priomap
band band band...
.B ] [ estimator
.B ] [ estimator
interval timeconstant
.B ]
.SH DESCRIPTION
The PRIO qdisc is a simple classful queueing discipline that contains
an arbitrary number of classes of differing priority. The classes are
dequeued in numerical descending order of priority. PRIO is a scheduler
dequeued in numerical descending order of priority. PRIO is a scheduler
and never delays packets - it is a work-conserving qdisc, though the qdiscs
contained in the classes may not be.
......@@ -51,22 +51,22 @@ From userspace
A process with sufficient privileges can encode the destination class
directly with SO_PRIORITY, see
.BR socket(7).
.TP
.TP
with a tc filter
A tc filter attached to the root qdisc can point traffic directly to a class
.TP
.TP
with the priomap
Based on the packet priority, which in turn is derived from the Type of
Service assigned to the packet.
.P
Only the priomap is specific to this qdisc.
Only the priomap is specific to this qdisc.
.SH QDISC PARAMETERS
.TP
bands
Number of bands. If changed from the default of 3,
.B priomap
must be updated as well.
.TP
.TP
priomap
The priomap maps the priority of
a packet to a class. The priority can either be set directly from userspace,
......@@ -126,7 +126,7 @@ TOS Bits Means Linux Priority Band
The second column contains the value of the relevant
four TOS bits, followed by their translated meaning. For example, 15 stands
for a packet wanting Minimal Monetary Cost, Maximum Reliability, Maximum
Throughput AND Minimum Delay.
Throughput AND Minimum Delay.
The fourth column lists the way the Linux kernel interprets the TOS bits, by
showing to which Priority they are mapped.
......@@ -151,7 +151,7 @@ FTP
TFTP 1000 (minimize delay)
SMTP
SMTP
Command phase 1000 (minimize delay)
DATA phase 0100 (maximize throughput)
......@@ -176,12 +176,10 @@ further qdisc.
.SH BUGS
Large amounts of traffic in the lower bands can cause starvation of higher
bands. Can be prevented by attaching a shaper (for example,
bands. Can be prevented by attaching a shaper (for example,
.BR tc-tbf(8)
to these bands to make sure they cannot dominate the link.
.SH AUTHORS
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>, J Hadi Salim
<hadi@cyberus.ca>. This manpage maintained by bert hubert <ahu@ds9a.nl>
man/man8/tc-red.8
View file @ 5699275b
.TH RED 8 "13 December 2001" "iproute2" "Linux"
.SH NAME
red \- Random Early Detection
red \- Random Early Detection
.SH SYNOPSIS
.B tc qdisc ... red
.B limit
.B limit
bytes
.B [ min
bytes
.B ] [ max
bytes
.B [ min
bytes
.B ] [ max
bytes
.B ] avpkt
bytes
.B [ burst
.B [ burst
packets
.B ] [ ecn ] [ harddrop] [ bandwidth
rate
......@@ -46,51 +46,51 @@ The average queue size is used for determining the marking
probability. This is calculated using an Exponential Weighted Moving
Average, which can be more or less sensitive to bursts.
When the average queue size is below
When the average queue size is below
.B min
bytes, no packet will ever be marked. When it exceeds
.B min,
bytes, no packet will ever be marked. When it exceeds
.B min,
the probability of doing so climbs linearly up
to
.B probability,
to
.B probability,
until the average queue size hits
.B max
bytes. Because
.B probability
bytes. Because
.B probability
is normally not set to 100%, the queue size might
conceivably rise above
conceivably rise above
.B max
bytes, so the
bytes, so the
.B limit
parameter is provided to set a hard maximum for the size of the queue.
.SH PARAMETERS
.TP
.TP
min
Average queue size at which marking becomes a possibility. Defaults to
.B max
/3
.TP
.TP
max
At this average queue size, the marking probability is maximal. Should be at
least twice
.B min
to prevent synchronous retransmits, higher for low
to prevent synchronous retransmits, higher for low
.B min.
Default to
Default to
.B limit
/4
.TP
.TP
probability
Maximum probability for marking, specified as a floating point
number from 0.0 to 1.0. Suggested values are 0.01 or 0.02 (1 or 2%,
respectively). Default : 0.02
.TP
.TP
limit
Hard limit on the real (not average) queue size in bytes. Further packets
are dropped. Should be set higher than max+burst. It is advised to set this
a few times higher than
a few times higher than
.B max.
.TP
burst
......@@ -98,7 +98,7 @@ Used for determining how fast the average queue size is influenced by the
real queue size. Larger values make the calculation more sluggish, allowing
longer bursts of traffic before marking starts. Real life experiments
support the following guideline: (min+min+max)/(3*avpkt).
.TP
.TP
avpkt
Specified in bytes. Used with burst to determine the time constant for
average queue size calculations. 1000 is a good value.
......@@ -126,15 +126,15 @@ bytes, this parameter forces a drop instead of ecn marking.
adaptive
(Added in linux-3.3) Sets RED in adaptive mode as described in http://icir.org/floyd/papers/adaptiveRed.pdf
.nf
Goal of Adaptive RED is to make 'probability' dynamic value between 1% and 50% to reach the target average queue :
Goal of Adaptive RED is to make 'probability' dynamic value between 1% and 50% to reach the target average queue :
.B (max - min) / 2
.fi
.SH EXAMPLE
.P
# tc qdisc add dev eth0 parent 1:1 handle 10: red
limit 400000 min 30000 max 90000 avpkt 1000
# tc qdisc add dev eth0 parent 1:1 handle 10: red
limit 400000 min 30000 max 90000 avpkt 1000
burst 55 ecn adaptive bandwidth 10Mbit
.SH SEE ALSO
......@@ -142,11 +142,11 @@ Goal of Adaptive RED is to make 'probability' dynamic value between 1% and 50% t
.BR tc-choke (8)
.SH SOURCES
.TP
.TP
o
Floyd, S., and Jacobson, V., Random Early Detection gateways for
Congestion Avoidance. http://www.aciri.org/floyd/papers/red/red.html
.TP
.TP
o
Some changes to the algorithm by Alexey N. Kuznetsov.
.TP
......@@ -156,7 +156,5 @@ Adaptive RED : http://icir.org/floyd/papers/adaptiveRed.pdf
.SH AUTHORS
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>, Alexey Makarenko
<makar@phoenix.kharkov.ua>, J Hadi Salim <hadi@nortelnetworks.com>,
Eric Dumazet <eric.dumazet@gmail.com>.
Eric Dumazet <eric.dumazet@gmail.com>.
This manpage maintained by bert hubert <ahu@ds9a.nl>
man/man8/tc-sfq.8
View file @ 5699275b
......@@ -33,11 +33,11 @@ P
.SH DESCRIPTION
Stochastic Fairness Queueing is a classless queueing discipline available for
traffic control with the
traffic control with the
.BR tc (8)
command.
SFQ does not shape traffic but only schedules the transmission of packets, based on 'flows'.
SFQ does not shape traffic but only schedules the transmission of packets, based on 'flows'.
The goal is to ensure fairness so that each flow is able to send data in turn, thus preventing
any single flow from drowning out the rest.
......@@ -62,13 +62,13 @@ Destination address
(iii)
Source and Destination port
.P
If these are available. SFQ knows about ipv4 and ipv6 and also UDP, TCP and ESP.
Packets with other protocols are hashed based on the 32bits representation of their
If these are available. SFQ knows about ipv4 and ipv6 and also UDP, TCP and ESP.
Packets with other protocols are hashed based on the 32bits representation of their
destination and source. A flow corresponds mostly to a TCP/IP connection.
Each of these buckets should represent a unique flow. Because multiple flows may
get hashed to the same bucket, sfqs internal hashing algorithm may be perturbed at configurable
intervals so that the unfairness lasts only for a short while. Perturbation may
get hashed to the same bucket, sfqs internal hashing algorithm may be perturbed at configurable
intervals so that the unfairness lasts only for a short while. Perturbation may
however cause some inadvertent packet reordering to occur. After linux-3.3, there is
no packet reordering problem, but possible packet drops if rehashing hits one limit
(number of flows or packets per flow)
......@@ -88,7 +88,7 @@ divisor
Can be used to set a different hash table size, available from kernel 2.6.39 onwards.
The specified divisor must be a power of two and cannot be larger than 65536.
Default value: 1024.
.TP
.TP
limit
Upper limit of the SFQ. Can be used to reduce the default length of 127 packets.
After linux-3.3, it can be raised.
......@@ -97,12 +97,12 @@ depth
Limit of packets per flow (after linux-3.3). Default to 127 and can be lowered.
.TP
perturb
Interval in seconds for queue algorithm perturbation. Defaults to 0, which means that
Interval in seconds for queue algorithm perturbation. Defaults to 0, which means that
no perturbation occurs. Do not set too low for each perturbation may cause some packet
reordering or losses. Advised value: 60
This value has no effect when external flow classification is used.
Its better to increase divisor value to lower risk of hash collisions.
.TP
.TP
quantum
Amount of bytes a flow is allowed to dequeue during a round of the round robin process.
Defaults to the MTU of the interface which is also the advised value and the minimum value.
......@@ -142,7 +142,7 @@ Specified in bytes. Used with burst to determine the time constant for average q
burst
Used for determining how fast the average queue size is influenced by the real queue size.
.nf
Default value is :
Default value is :
.B (2 * min + max) / (3 * avpkt)
.fi
.TP
......@@ -166,16 +166,16 @@ To attach to device ppp0:
.P
# tc qdisc add dev ppp0 root sfq
.P
Please note that SFQ, like all non-shaping (work-conserving) qdiscs, is only useful
Please note that SFQ, like all non-shaping (work-conserving) qdiscs, is only useful
if it owns the queue.
This is the case when the link speed equals the actually available bandwidth. This holds
for regular phone modems, ISDN connections and direct non-switched ethernet links.
This is the case when the link speed equals the actually available bandwidth. This holds
for regular phone modems, ISDN connections and direct non-switched ethernet links.
.P
Most often, cable modems and DSL devices do not fall into this category. The same holds
for when connected to a switch and trying to send data to a congested segment also
Most often, cable modems and DSL devices do not fall into this category. The same holds
for when connected to a switch and trying to send data to a congested segment also
connected to the switch.
.P
In this case, the effective queue does not reside within Linux and is therefore not
In this case, the effective queue does not reside within Linux and is therefore not
available for scheduling.
.P
Embed SFQ in a classful qdisc to make sure it owns the queue.
......@@ -191,11 +191,11 @@ changed the sfq default of 1024, use the same value for the flow hash filter, to
.P
Example of sfq with optional RED mode :
.P
# tc qdisc add dev eth0 parent 1:1 handle 10: sfq limit 3000 flows 512 divisor 16384
# tc qdisc add dev eth0 parent 1:1 handle 10: sfq limit 3000 flows 512 divisor 16384
redflowlimit 100000 min 8000 max 60000 probability 0.20 ecn headdrop
.SH SOURCE
.TP
.TP
o
Paul E. McKenney "Stochastic Fairness Queuing",
IEEE INFOCOMM'90 Proceedings, San Francisco, 1990.
......@@ -205,7 +205,7 @@ o
Paul E. McKenney "Stochastic Fairness Queuing",
"Interworking: Research and Experience", v.2, 1991, p.113-131.
.TP
.TP
o
See also:
M. Shreedhar and George Varghese "Efficient Fair
......@@ -220,5 +220,3 @@ Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>,
Eric Dumazet <eric.dumazet@gmail.com>.
.P
This manpage maintained by bert hubert <ahu@ds9a.nl>
man/man8/tc-tbf.8
View file @ 5699275b
......@@ -6,11 +6,11 @@ tbf \- Token Bucket Filter
rate
.B burst
bytes/cell
.B ( latency
ms
.B ( latency
ms
.B | limit
bytes
.B ) [ mpu
.B ) [ mpu
bytes
.B [ peakrate
rate
......@@ -22,46 +22,46 @@ burst is also known as buffer and maxburst. mtu is also known as minburst.
.SH DESCRIPTION
The Token Bucket Filter is a classful queueing discipline available for
traffic control with the
traffic control with the
.BR tc (8)
command.
TBF is a pure shaper and never schedules traffic. It is non-work-conserving and may throttle
itself, although packets are available, to ensure that the configured rate is not exceeded.
It is able to shape up to 1mbit/s of normal traffic with ideal minimal burstiness,
itself, although packets are available, to ensure that the configured rate is not exceeded.
It is able to shape up to 1mbit/s of normal traffic with ideal minimal burstiness,
sending out data exactly at the configured rates.
Much higher rates are possible but at the cost of losing the minimal burstiness. In that
case, data is on average dequeued at the configured rate but may be sent much faster at millisecond
case, data is on average dequeued at the configured rate but may be sent much faster at millisecond
timescales. Because of further queues living in network adaptors, this is often not a problem.
.SH ALGORITHM
As the name implies, traffic is filtered based on the expenditure of
As the name implies, traffic is filtered based on the expenditure of
.B tokens.
Tokens roughly correspond to bytes, with the additional constraint
that each packet consumes some tokens, no matter how small it is. This
reflects the fact that even a zero-sized packet occupies the link for
some time.
On creation, the TBF is stocked with tokens which correspond to the amount of traffic that can be burst
On creation, the TBF is stocked with tokens which correspond to the amount of traffic that can be burst
in one go. Tokens arrive at a steady rate, until the bucket is full.
If no tokens are available, packets are queued, up to a configured limit. The TBF now
If no tokens are available, packets are queued, up to a configured limit. The TBF now
calculates the token deficit, and throttles until the first packet in the queue can be sent.
If it is not acceptable to burst out packets at maximum speed, a peakrate can be configured
If it is not acceptable to burst out packets at maximum speed, a peakrate can be configured
to limit the speed at which the bucket empties. This peakrate is implemented as a second TBF
with a very small bucket, so that it doesn't burst.
To achieve perfection, the second bucket may contain only a single packet, which leads to
the earlier mentioned 1mbit/s limit.
To achieve perfection, the second bucket may contain only a single packet, which leads to
the earlier mentioned 1mbit/s limit.
This limit is caused by the fact that the kernel can only throttle for at minimum 1 'jiffy', which depends
on HZ as 1/HZ. For perfect shaping, only a single packet can get sent per jiffy - for HZ=100, this means 100
on HZ as 1/HZ. For perfect shaping, only a single packet can get sent per jiffy - for HZ=100, this means 100
packets of on average 1000 bytes each, which roughly corresponds to 1mbit/s.
.SH PARAMETERS
See
See
.BR tc (8)
for how to specify the units of these values.
.TP
......@@ -71,30 +71,30 @@ available. You can also specify this the other way around by setting the
latency parameter, which specifies the maximum amount of time a packet can
sit in the TBF. The latter calculation takes into account the size of the
bucket, the rate and possibly the peakrate (if set). These two parameters
are mutually exclusive.
are mutually exclusive.
.TP
burst
Also known as buffer or maxburst.
Size of the bucket, in bytes. This is the maximum amount of bytes that tokens can be available for instantaneously.
In general, larger shaping rates require a larger buffer. For 10mbit/s on Intel, you need at least 10kbyte buffer
Size of the bucket, in bytes. This is the maximum amount of bytes that tokens can be available for instantaneously.
In general, larger shaping rates require a larger buffer. For 10mbit/s on Intel, you need at least 10kbyte buffer
if you want to reach your configured rate!
If your buffer is too small, packets may be dropped because more tokens arrive per timer tick than fit in your bucket.
The minimum buffer size can be calculated by dividing the rate by HZ.
Token usage calculations are performed using a table which by default has a resolution of 8 packets.
This resolution can be changed by specifying the
Token usage calculations are performed using a table which by default has a resolution of 8 packets.
This resolution can be changed by specifying the
.B cell
size with the burst. For example, to specify a 6000 byte buffer with a 16
byte cell size, set a burst of 6000/16. You will probably never have to set
this. Must be an integral power of 2.
.TP
mpu
A zero-sized packet does not use zero bandwidth. For ethernet, no packet uses less than 64 bytes. The Minimum Packet Unit
A zero-sized packet does not use zero bandwidth. For ethernet, no packet uses less than 64 bytes. The Minimum Packet Unit
determines the minimal token usage (specified in bytes) for a packet. Defaults to zero.
.TP
rate
The speed knob. See remarks above about limits! See
The speed knob. See remarks above about limits! See
.BR tc (8)
for units.
.PP
......@@ -112,7 +112,7 @@ Specifies the size of the peakrate bucket. For perfect accuracy, should be set t
If a peakrate is needed, but some burstiness is acceptable, this size can be raised. A 3000 byte minburst
allows around 3mbit/s of peakrate, given 1000 byte packets.
Like the regular burstsize you can also specify a
Like the regular burstsize you can also specify a
.B cell
size.
.SH EXAMPLE & USAGE
......@@ -139,5 +139,3 @@ the limit/latency is not effective anymore.
.SH AUTHOR
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>. This manpage maintained by
bert hubert <ahu@ds9a.nl>
man/man8/tc.8
View file @ 5699275b
......@@ -732,4 +732,3 @@ was written by Alexey N. Kuznetsov and added in Linux 2.2.
.SH AUTHOR
Manpage maintained by bert hubert (ahu@ds9a.nl)
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