NAME
altq.conf —
ALTQ configuration
file
DESCRIPTION
The
altq.conf file contains a number of lines specifying the
behavior of queueing disciplines. Comments start with a # and extend to the
end of the line.
The
altqd(8) program reads
/etc/altq.conf at startup and sets up queueing disciplines.
BLUE, CBQ (Class-Based Queueing), FIFOQ (First-In First-Out Queue), HFSC
(Hierarchical Fair Service Curve), PRIQ (Priority Queueing), RED (Random Early
Detection), RIO (RED with IN/OUT), WFQ (Weighted Fair Queueing), JoBS (Joint
Buffer Management and Scheduling) and CDNR (Diffserv Traffic Conditioner) can
be configured in this file.
Interface Commands
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[discipline-specific-options]
The
interface command specifies a network interface to be
under control of ALTQ. One interface specification is provided for each
network interface under control of ALTQ. A system configured as a router may
have multiple interface specifications.
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second. This
is the maximum rate that the queueing discipline will allow on this
interface.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes. When tbrsize is omitted, the system automatically
sets the bucket size using heuristics. The token rate is set to the
interface bandwidth specified by the interface
command.
-
-
- sched_type
- Type of a queueing discipline. It must be either
blue, cbq, fifoq,
hfsc, jobs, priq,
red, rio, or wfq. If
the interface has only traffic conditioners and no queueing discipline,
sched_type can be omitted.
Class Command
-
-
- class
- sched_type
if_name class_name
parent_name
[red|rio]
[ecn]
[cleardscp]
[discipline-specific-options]
The
class command specifies a packet scheduling class for CBQ,
HFSC, JoBS or PRIQ. A class specifier must be provided for each packet
scheduling class.
-
-
- sched_type
- Type of queueing discipline. Must correspond to the
discipline name in interface specification.
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- class_name
- Arbitrary name for this class. Must be unique for this
interface.
-
-
- parent_name
- The name of the parent class for this class (for CBQ or
HFSC). Parent class must have been previously defined. PRIQ and JoBS do
not have class hierarchy and parent_name must be
NULL
for PRIQ and JoBS classes.
-
-
- red
- Use RED (Random Early Detection) on this class queue. RED
drops packets with the probability proportional to the average queue
length.
-
-
- rio
- Use RIO (RED with In/Out bit) on this class queue. RIO runs
triple RED algorithms at the same time.
-
-
- ecn
- Use RED/ECN (Explicit Congestion Notification) on this
class queue (experimental implementation). ECN implies RED.
-
-
- cleardscp
- Clear diffserv codepoint in the IP header.
Filter Commands
-
-
- filter
- if_name
class_name [name
fltr_name]
[ruleno
num] filter_values
The
filter command specifies a filter to classify packets into
a scheduling class. A filter specifier determines any statically-defined
packet classification rules.
-
-
- if_name
- Name of a network interface (e.g., fxp0).
-
-
- class_name
- Name of a class or a conditioner to which matching packets
are directed.
-
-
- name
- Add an arbitrary name to the filter for a future
reference.
-
-
- ruleno
- Specifies explicit order of filter matching. Filter
matching is performed from a filter with a larger ruleno. Default is
0.
filter_values should be in the following format:
-
-
- filter_values:
- dst_addr
[netmask
mask] dport
src_addr [netmask
mask] sport
proto [tos
value [tosmask
value]]
[gpi
value]
Here
dst_addr and
src_addr are
dotted-decimal addresses of the destination and the source respectively. An
address may be followed by
netmask keyword.
dport and
sport are port numbers
of the destination and the source respectively.
proto is
a protocol number defined for IP packets (e.g. 6 for TCP).
tos keyword can be used to specify the type of service field
value.
gpi keyword can be used to specify the Security
Parameter Index value for IPsec.
When filter value 0 is used, it is taken as a wildcard.
-
-
- filter6
- if_name
class_name [name
fltr_name]
[ruleno
num]
filter6_values
The
filter6 command is for IPv6.
filter6_value should be in the following format:
-
-
- filter6_values:
- dst_addr[/prefix_len]
dport
src_addr[/prefix_len]
sport proto
[flowlabel
value]
[tclass value
[tclassmask
value]]
[gpi
value]
Here
dst_addr and
src_addr are IPv6
addresses of the destination and the source respectively. An address may be
followed by an optional address prefix length.
dport and
sport are port numbers of the destination and the source
respectively.
proto is a protocol number defined for
IPv6 packets (e.g. 6 for TCP).
flowlabel keyword can be used
to specify the flowlabel field value.
tclass keyword can be
used to specify the traffic class field value.
gpi keyword
can be used to specify the Security Parameter Index value for IPsec.
When filter value 0 is used, it is taken as a wildcard.
CBQ Commands
CBQ (Class Based Queueing) achieves both partitioning and sharing of link
bandwidth by hierarchically structured classes. Each class has its own queue
and is assigned its share of bandwidth. A child class can borrow bandwidth
from its parent class as long as excess bandwidth is available.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[efficient]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be either cbq,
cbq-wrr (weighted-round robin) or
cbq-prr (packet-by-packet round robin).
cbq is equivalent to cbq-wrr.
-
-
- efficient
- Enables CBQ's link efficiency mode. This means that the
scheduler will send a packet from the first overlimit class it encounters
of all classes of the link-sharing structure when all classes are
overlimit. This will also cause the scheduler to use greater than its
assigned bandwidth, if the link is capable of more than the assigned
bandwidth. By default, this mode is turned off. By adding the keyword
efficient to the interface specification line, enables
this mode.
-
-
- class
- sched_type
if_name class_name
parent_name
[admission cntlload|none]
[priority
pri]
[pbandwidth
percent]
[exactbandwidth
bps]
[borrow]
[default]
[control]
[maxburst
count]
[minburst
count]
[maxdelay msec]
[packetsize
bytes]
[maxpacketsize
bytes]
[red|rio]
[ecn]
[flowvalve]
[cleardscp]
The
class command specifies a CBQ class. The classes are
organized as a hierarchy, and every class, except for the root class, has a
parent.
-
-
- sched_type
- must be cbq for a CBQ class.
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- class_name
- Arbitrary name for this class. Must be unique within the
class hierarchy for this interface. The name ctl_class
is a reserved class name.
-
-
- parent_name
- The name of the parent class for this class or
NULL
if this is the root class. Parent class must
have been previously defined.
-
-
- admission
- The type of admission control and QoS type.
cntlload is controlled load service for RSVP, otherwise,
it should be none. The default is
none.
-
-
- priority
- High numbers are higher priority. Max value is 7 and Min
value is 0. Default is 1.
-
-
- pbandwidth
- The percentage of the interface bandwidth allocated to this
class. Generally should add up to 100 percent at each level of the class
hierarchy, although other amounts can be specified for purposes of
experimentation.
-
-
- exactbandwidth
- Specify the bandwidth in bits-per-second instead of
pbandwidth. Note that the bandwidth allocation of CBQ is
not so precise but this is just a way to pass a parameter to CBQ; the user
is supposed to know the detailed internals of CBQ.
pbandwidth is a preferred way to specify the bandwidth
of a class.
-
-
- borrow
- The class can borrow bandwidth from its parent class when
this class is overlimit. If this keyword is not present, then no borrowing
is done, and the packet is delayed or dropped when the class is
overlimit.
-
-
- default
- Specify the default class. When this keyword is present,
all packets that do not match some classification criteria are assigned to
this class. Must be exactly one class on each interface defined as the
default class.
-
-
- control
- Specify the control class. When this keyword is present,
the predefined control class packets (RSVP, IGMP, and ICMP) are assigned
to this class. Note that when the control class is not specified by the
time the default class is created, one is automatically created with
default parameters. Thus, if the control class is specified, it must be
listed before the default class. Must be exactly one class on each
interface defined as the control class.
-
-
- maxburst
- The maximum burst of back-to-back packets allowed in this
class. Default is 16 but the default value is automatically reduced to 4
when the class bandwidth is small (about less than 1Mbps).
-
-
- minburst
- The minimum burst is used to obtain the steady state burst
size. It's the parameter to help compute offtime for the class. Offtime is
the amount of time a class is to wait between packets. Default is 2.
-
-
- maxdelay
- The maxdelay is specified in milliseconds and used to
obtain the max queue size of the class. If not specified, the default max
queue size (30 packets) is used.
-
-
- packetsize
- The average packet size in bytes to be used in CBQ
over-/under-limit computations. Default value is MTU of the
interface.
-
-
- maxpacketsize
- The maximum packet size in bytes for the class. Default
value is MTU of the interface.
-
-
- red
- enables RED on this class queue.
-
-
- rio
- enables RIO on this class queue.
-
-
- ecn
- enables RED/ECN on this class queue.
-
-
- flowvalve
- enables RED/flow-valve (a.k.a. red-penalty-box) on this
class queue.
-
-
- cleardscp
- clears diffserv codepoint in the IP header.
HFSC Commands
HFSC (Hierarchical Fair Service Curve) supports both link-sharing and guaranteed
real-time services. H-FSC employs a service curve based QoS model, and its
unique feature is an ability to decouple delay and bandwidth allocation. HFSC
has 2 independent scheduling mechanisms. Real-time scheduling is used to
guarantee the delay and the bandwidth allocation at the same time.
Hierarchical link-sharing is used to distribute the excess bandwidth. When
dequeueing a packet, HFSC always tries real-time scheduling first. If no
packet is eligible for real-time scheduling, link-sharing scheduling is
performed. HFSC does not use class hierarchy for real-time scheduling.
Additionally, an upper-limit service curve can be specified for link-sharing
to set the upper limit allowed for the class.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be hfsc for HFSC.
-
-
- class
- sched_type
if_name class_name
parent_name
[admission cntlload|none]
[[sc m1 d
m2]] [[rt
m1 d m2]]
[[ls m1 d
m2]] [[ul
m1 d m2]]
[pshare
percent]
[grate
bps]
[bandwidth
bps]
[ulimit
bps]
[default]
[qlimit
count]
[red|rio]
[ecn]
[cleardscp]
The
class command specifies a HFSC class. The classes are
organized as a hierarchy, and every class, except for the root class, has a
parent.
Each HFSC class has 2 service curves, the real-time service curve and the
link-sharing service curve. Service curves are specified by
[
type m1 d m2].
type should be either
sc,
rt,
ls, or
ul.
sc (service curve) is used to set the same values to both
real-time and link-sharing service curves.
rt (real-time) is
used to specify the real-time service curve.
ls
(link-sharing) is used to specify the link-sharing service curve.
ul (upper-limit) is used to specify the upper-limit service
curve for link-sharing.
m1 is the slope of the first
segment specified in bits-per-second.
d is the
x-projection of the intersection point of the 2 segments specified in
milliseconds.
m2 is the slope of the second segment
specified in bits-per-second.
-
-
- sched_type
- must be hfsc for a HFSC class.
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- class_name
- Arbitrary name for this class. Must be unique within the
class hierarchy for this interface. The name root is a
reserved class name for the root class. The root class for the interface
is automatically created by the interface command.
-
-
- parent_name
- The name of the parent class for this class. Keyword
root is used when the parent is the root class. Parent
class must have been previously defined.
-
-
- admission
- The type of admission control and QoS type.
cntlload is controlled load service for RSVP, otherwise,
it should be none. The default is
none.
-
-
- pshare
- Percent of the link share. This specifies a linear
link-sharing service curve as a fraction of the link bandwidth. It is a
short hand of
[ls 0 0 (link-bandwidth * percent /
100)]
.
-
-
- grate
- Guaranteed rate. This specifies a linear real-time service
curve. It is a short hand of
[rt 0 0 bps]
.
-
-
- bandwidth
- This is a short hand of
[sc 0 0
bps]
.
-
-
- ulimit
- Upper limit rate. This specifies a upper-limit service
curve. It is a short hand of
[ul 0 0 bps]
.
-
-
- default
- Specify the default class. When this keyword is present,
all packets that do not match some classification criteria are assigned to
this class. Must be exactly one class on each interface defined as the
default class.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 50.
-
-
- red
- enables RED on this class queue.
-
-
- rio
- enables RIO on this class queue.
-
-
- ecn
- enables RED/ECN on this class queue.
-
-
- cleardscp
- clears diffserv codepoint in the IP header.
PRIQ Commands
PRIQ (Priority Queueing) implements a simple priority-based queueing. A higher
priority class is always served first. Up to 16 priorities can be used with
PRIQ.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be priq for PRIQ.
-
-
- class
- sched_type
if_name class_name
parent_name
[priority
pri]
[default]
[qlimit
count]
[red|rio]
[ecn]
[cleardscp]
-
-
- sched_type
- must be priq for a PRIQ class.
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- class_name
- Arbitrary name for this class. Must be unique for this
interface.
-
-
- parent_name
- Parent class must be
NULL
for
PRIQ.
-
-
- priority
- High numbers are higher priority. Max value is 15 and Min
value is 0. Default is 0. A higher priority class is always served first
in PRIQ. Priority must be unique for the interface.
-
-
- default
- Specify the default class. When this keyword is present,
all packets that do not match some classification criteria are assigned to
this class. Must be exactly one class on each interface defined as the
default class.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 50.
-
-
- red
- enables RED on this class queue.
-
-
- rio
- enables RIO on this class queue.
-
-
- ecn
- enables RED/ECN on this class queue.
-
-
- cleardscp
- clears diffserv codepoint in the IP header.
WFQ Commands
WFQ (Weighted Fair Queueing) implements a weighted-round robin scheduler for a
set of queue. A weight can be assigned to each queue to give a different
proportion of the link capacity. A hash function is used to map a flow to one
of a set of queues, and thus, it is possible for two different flows to be
mapped into the same queue.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[nqueues
count]
[qsize
bytes]
[hash
policy]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be wfq for WFQ.
-
-
- nqueues
- The number of queues in WFQ. Default value is 256.
-
-
- qsize
- The size of each queue in number of bytes. Default value is
64K bytes.
-
-
- hash
- Type of hash policy to select a queue.
dstaddr specifies a hashing policy by IP destination
address. full specifies a hashing policy by IP addresses
and ports. srcport specifies a hashing policy by IP
source port number. srcaddr specifies a hashing policy
by IP source address. Default is dstaddr
FIFOQ Commands
FIFOQ (First-In First-Out Queueing) is a simple tail-drop FIFO queue. FIFOQ is
the simplest possible implementation of a queueing discipline in ALTQ, and can
be used to compare with other queueing disciplines. FIFOQ can be also used as
a template for those who want to write their own queueing disciplines.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[qlimit
count]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be fifoq for FIFOQ.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 50.
RED Commands
RED (Random Early Detection) is an implicit congestion notification mechanism
that exercises packet dropping or packet marking stochastically according to
the average queue length. RED can be viewed as a buffer management mechanism
and can be integrated into other packet scheduling schemes.
-
-
- red
- min_th max_th
inv_pmax
The
red command sets the default RED parameters.
min_th and
max_th are the minimum
and the maximum threshold values.
inv_pmax is the
inverse (reciprocal) of the maximum drop probability. For example, 10 means
the maximum drop probability of 1/10.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[qlimit
count]
[packetsize
bytes]
[weight n]
[thmin n]
[thmax n]
[invpmax
n]
[ecn]
[flowvalve]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be red for RED.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 60.
-
-
- packetsize
- The average packet size in number of bytes. This parameter
is used to calibrate the idle period. Default value is 1000.
-
-
- weight
- The inverse of the weight of EWMA (exponentially weighted
moving average).
-
-
- thmin
- The minimum threshold.
-
-
- thmax
- The maximum threshold.
-
-
- invpmax
- The inverse of the maximum drop probability.
-
-
- ecn
- enables ECN.
-
-
- flowvalve
- enables flowvalve.
RIO Commands
ALTQ/RIO has 3 drop precedence levels defined for the Assured Forwarding of
DiffServ (RFC2597). Since adaptive flows are likely to stay under the medium
drop precedence level under congestion, the medium drop precedence would
protect adaptive flows from unadaptive flows.
The original RIO has 2 sets of RED parameters; one for in-profile packets and
the other for out-of-profile packets. At the ingress of the network, profile
meters tag packets as IN or OUT based on contracted profiles for customers.
Inside the network, IN packets receive preferential treatment by the RIO
dropper. It is possible to provision the network not to drop IN packets at all
by providing enough capacity for the total volume of IN packets. Thus, RIO can
be used to provide a service that statistically assures capacity allocated for
users. This mechanism can be extended to support an arbitrary number of drop
precedence levels. ALTQ supports 3 drop precedence levels.
-
-
- rio
- low_min_th
low_max_th low_inv_pmax
medium_min_th medium_max_th
medium_inv_pmax high_min_th
high_max_th high_inv_pmax
The
rio command sets the default RIO parameters. The
parameters are RED parameters for 3 (low, medium, high) drop precedence.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[qlimit
count]
[packetsize
bytes]
[weight n]
[lo_thmin
n]
[lo_thmax
n]
[lo_invpmax
n]
[med_thmin
n]
[med_thmax
n]
[med_invpmax
n]
[hi_thmin
n]
[hi_thmax
n]
[hi_invpmax
n]
[ecn]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be rio for RIO.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 60.
-
-
- packetsize
- The average packet size in number of bytes. This parameter
is used to calibrate the idle period. Default value is 1000.
-
-
- weight
- The inverse of the weight of EWMA (exponentially weighted
moving average).
-
-
- lo_thmin
- The minimum threshold for low drop precedence.
-
-
- lo_thmax
- The maximum threshold for low drop precedence.
-
-
- lo_invpmax
- The inverse of the maximum drop probability for low drop
precedence.
-
-
- med_thmin
- The minimum threshold for medium drop precedence.
-
-
- med_thmax
- The maximum threshold for medium drop precedence.
-
-
- med_invpmax
- The inverse of the maximum drop probability for medium drop
precedence.
-
-
- hi_thmin
- The minimum threshold for high drop precedence.
-
-
- hi_thmax
- The maximum threshold for high drop precedence.
-
-
- hi_invpmax
- The inverse of the maximum drop probability for high drop
precedence.
-
-
- ecn
- enables ECN.
BLUE Commands
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
[sched_type]
[qlimit
count]
[packetsize
bytes]
[maxpmark
n]
[holdtime
usec]
[ecn]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be blue for BLUE.
-
-
- qlimit
- The maximum queue size in number of packets. Default value
is 60.
-
-
- packetsize
- The average packet size in number of bytes. Default value
is 1000.
-
-
- maxpmark
- specifies the precision of marking probability.
-
-
- holdtime
- specifies the hold time in usec.
-
-
- ecn
- enables ECN.
CDNR Commands
The
conditioner command specifies a diffserv traffic
conditioner. A traffic conditioner is not a queueing discipline but a
component to meter, mark or drop incoming packets according to some rules.
As opposed to a queueing discipline, a traffic conditioner handles incoming
packets at an input interface. If no queueing discipline (e.g., CBQ) is used
for the interface, a null interface command should be used to specify an input
network interface.
-
-
- interface
- if_name
[bandwidth
bps]
[tbrsize
bytes]
The
conditioner command has the following syntax.
-
-
- conditioner
- if_name
cdnr_name ⟨action⟩
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- cdnr_name
- Arbitrary name for this conditioner. Must be unique for
this interface.
-
-
- action
- Action of the conditioner.
An action can be a recursively defined action. The following actions are
defined.
-
-
- pass
-
- pass
- allows the packet to go through without any
modification to the packet.
-
-
- drop
-
- drop
- rejects the packet. The packet is immediately
discarded.
-
-
- mark
- value
- mark
- sets the specified value to the ds field in the IP
header. Then, the packet is allowed to go through.
-
-
- tbmeter
- rate depth ⟨in_action⟩
⟨out_action⟩
- tbmeter
- is a token bucket meter configured with rate and
depth parameters. Rate is token rate in bits-per-second. Depth is
bucket depth in KB. When an incoming packet is in profile (available
token is more than the packet size), tbmeter takes in_action.
Otherwise, tbmeter takes out_action.
-
-
- trtcm
- cmtd_rate cmtd_depth peak_rate
peak_depth ⟨green_action⟩
⟨yellow_action⟩ ⟨red_action⟩
[coloraware|colorblind]
- trtcm
- is a 2-rate 3 color marker for Assured Forwarding. A
trtcm consists of 2 token buckets, one for a committed rate and the
other for a peak rate. When an incoming packet is in the committed
profile, trtcm takes green_action. When the packet is out of the
committed profile but in the peak profile, trtcm takes yellow_action.
Otherwise, tbtcm takes red_action. A trtcm is either color-aware or
color-blind. A color-aware trtcm do not raise the color (ds field
value), that is, a yellow packet can be yellow or red but can not be
blue. Default is color-blind.
-
-
- tswtcm
- cmtd_rate peak_rate avg_interval
⟨green_action⟩ ⟨yellow_action⟩
⟨red_action⟩
- tswtcm
- is a time sliding window 3 color marker for Assured
Forwarding. A tswtcm differs from trtcm in that a tswtcm
probabilistically marks packets. A tswtcm consists of 2 rates, one for
a committed rate and the other for a peak rate. When an incoming
packet is in the committed profile, tswtcm takes green_action. When
the packet is out of the committed profile but in the peak profile,
tswtcm takes yellow_action. Otherwise, tswtcm takes red_action.
cmtd_rate and peak_rate are specified in bits per second. avg_interval
provides the size of time window for averaging incoming rate, and is
specified in milliseconds. 500 msec is ok for normal settings.
JoBS Commands
JoBS (Joint Buffer Management and Scheduling) is a queuing discipline that can
enforce any feasible mix of absolute and proportional guarantees on packet
losses, packet delays, and throughput, for classes of traffic, on a per-hop
basis. No admission control is performed, thus if the set of service
guarantees becomes infeasible, some service guarantees may be relaxed.
-
-
- interface
- if_name
[bandwidth
bps]
[qlimit
count]
[separate]
[tbrsize
bytes]
[sched_type]
-
-
- if_name
- specifies the name of a network interface (e.g.,
fxp0).
-
-
- bandwidth
- specifies the interface bandwidth in bits per second.
-
-
- qlimit
- specifies the maximum queue size in number of packets.
-
-
- separate
- specifies that classes have independent buffers. The
default is to have a shared buffer for all classes. If this option is
specified, qlimit applies to each independent buffer.
-
-
- tbrsize
- specifies the bucket size of a token bucket regulator in
bytes.
-
-
- sched_type
- must be jobs for JoBS.
-
-
- class
- sched_type
if_name class_name
parent_name
[priority
pri]
[default]
[adc
microsecs]
[alc
fraction]
[arc bps]
[rdc prop]
[rlc
prop]
-
-
- sched_type
- must be jobs for a JoBS class.
-
-
- if_name
- Interface name. Must correspond to name in interface
specification.
-
-
- class_name
- Arbitrary name for this class. Must be unique for this
interface.
-
-
- parent_name
- Parent class must be
NULL
for
JoBS.
-
-
- priority
- Priority index used for proportional differentiation. Max
value is 15 and Min value is 0. Default is 0. Priority must be unique for
the interface.
-
-
- default
- Specify the default class. When this keyword is present,
all packets that do not match some classification criteria are assigned to
this class. Must be exactly one class on each interface defined as the
default class.
-
-
- adc
- Specifies an upper bound on delays for that class (in
microseconds). A value of -1 will indicate the absence of delay bound. By
default, no delay bound is offered.
-
-
- alc
- Specifies a upper bound on loss rate for that class (in
fraction of 1, for instance a 1% loss rate bound will be expressed as
0.01). A value of -1 will indicate the absence of loss rate bound. By
default, no loss rate bound is offered.
-
-
- arc
- Specifies a lower bound on the throughput received by that
class (in bits per second). A value of -1 will indicate the absence of
throughput bound. By default, no throughput bound is offered.
-
-
- rdc
- Specifies a proportional delay differentiation factor
between that class and the class with the successive priority index. For
instance, for priority 1, an rdc of 2 specifies that the delays of packets
marked as class 2 will roughly be twice the delays of packets marked as
class 1. A value of -1 indicates the absence of proportional
differentiation on that class. Note that class N if N is the maximum
priority should have a dummy coefficient different from -1 if proportional
delay differentiation is desired on Class N. By default, no proportional
delay differentiation is offered.
-
-
- rlc
- Specifies a proportional loss differentiation factor
between that class and the class with the successive priority index. For
instance, for priority 1, an rlc of 2 specifies that the loss rate of
packets marked as class 2 will roughly be twice the loss rate of packets
marked as class 1. A value of -1 indicates the absence of proportional
differentiation on that class. Note that class N if N is the maximum
priority should have a dummy coefficient different from -1 if proportional
loss differentiation is desired on Class N. By default, no proportional
loss differentiation is offered.
EXAMPLES
CBQ Example
#
# cbq configuration for vx0 (10Mbps ether)
# give at least 40% to TCP
# limit HTTP from network 133.138.1.0 up to 10%, use RED.
# other traffic goes into default class
#
interface vx0 bandwidth 10M cbq
#
class cbq vx0 root_class NULL priority 0 pbandwidth 100
class cbq vx0 def_class root_class borrow pbandwidth 95 default
class cbq vx0 tcp_class def_class borrow pbandwidth 40
filter vx0 tcp_class 0 0 0 0 6
class cbq vx0 csl_class tcp_class pbandwidth 10 red
filter vx0 csl_class 0 0 133.138.1.0 netmask 0xffffff00 80 6
filter vx0 csl_class 133.138.1.0 netmask 0xffffff00 0 0 80 6
#
# sample filter6 command
#
filter6 vx0 csl_class ::0 0 2001:db8:0:123::/64 80 6
HFSC Example
#
# hfsc configuration for hierarchical sharing
#
interface pvc0 bandwidth 45M hfsc
#
# (10% of the bandwidth share goes to the default class)
class hfsc pvc0 def_class root pshare 10 default
#
# bandwidth share guaranteed rate
# CMU: 45% 15Mbps
# PITT: 45% 15Mbps
#
class hfsc pvc0 cmu root pshare 45 grate 15M
class hfsc pvc0 pitt root pshare 45 grate 15M
#
# CMU bandwidth share guaranteed rate
# CS: 20% 10Mbps
# other: 20% 5Mbps
#
class hfsc pvc0 cmu_other cmu pshare 20 grate 10M
filter pvc0 cmu_other 0 0 128.2.0.0 netmask 0xffff0000 0 0
class hfsc pvc0 cmu_cs cmu pshare 20 grate 5M
filter pvc0 cmu_cs 0 0 128.2.242.0 netmask 0xffffff00 0 0
#
# PITT bandwidth share guaranteed rate
# CS: 20% 10Mbps
# other: 20% 5Mbps
#
class hfsc pvc0 pitt_other pitt pshare 20 grate 10M
filter pvc0 pitt_other 0 0 136.142.0.0 netmask 0xffff0000 0 0
class hfsc pvc0 pitt_cs pitt pshare 20 grate 5M
filter pvc0 pitt_cs 0 0 136.142.79.0 netmask 0xffffff00 0 0
HFSC Example (simpler
one with ulimit)
#
interface fxp0 bandwidth 90M hfsc
# reserve 20% for default class
class hfsc fxp0 def_class root pshare 20 default
# shared class for TCP and UDP
class hfsc fxp0 shared_class root bandwidth 72M
# shared class for all TCP
class hfsc fxp0 tcp_shared shared_class bandwidth 40M ulimit 60M
# generic tcp
class hfsc fxp0 tcp_class tcp_shared bandwidth 15M ulimit 50M
filter fxp0 tcp_class 0 0 0 0 6
# http
class hfsc fxp0 http_class tcp_shared bandwidth 25M ulimit 40M
filter fxp0 http_class 0 80 0 0 6
filter fxp0 http_class 0 0 0 80 6
# udp
class hfsc fxp0 udp_class shared_class bandwidth 15M ulimit 20M
filter fxp0 udp_class 0 0 0 0 17
PRIQ Example
#
# priq configuration for fxp0 (100Mbps ether)
# icmp: high priority
# tcp: medium priority
# others: low priority
#
interface fxp0 bandwidth 100M priq
#
class priq fxp0 high_class NULL priority 2
filter fxp0 high_class 0 0 0 0 1
class priq fxp0 med_class NULL priority 1
filter fxp0 med_class 0 0 0 0 6
class priq fxp0 low_class NULL priority 0 default
WFQ Example
interface pvc0 bandwidth 134000000 wfq
FIFOQ Example
interface rl0 bandwidth 10M fifoq
Conditioner Example
#
interface fxp0
#
# a simple dropper
# discard all packets from 192.168.0.83
#
conditioner fxp0 dropper <drop>
filter fxp0 dropper 0 0 192.168.0.83 0 0
#
# EF conditioner
# mark EF to all packets from 192.168.0.117
#
conditioner pvc1 ef_cdnr <tbmeter 6M 64K <mark 0xb8><drop>>
filter fxp0 ef_cdnr 0 0 192.168.0.117 0 0
#
# AF1x conditioner
# mark AF1x to packets from 192.168.0.178
# AF11 (low drop precedence): less than 3Mbps
# AF12 (medium drop precedence): more than 3Mbps and less than 10Mbps
# AF13 (high drop precedence): more than 10Mbps
#
conditioner fxp0 af1x_cdnr <trtcm 3M 32K 10M 64K <mark 0x28><mark 0x30><mark 0x38>>
filter fxp0 af1x_cdnr 0 0 192.168.0.178 0 0
SEE ALSO
altqd(8)
BUGS
This man page is incomplete. For more information read the source.