drcl.inet.core.queue
Class RED

java.lang.Object
  drcl.DrclObj
      drcl.comp.queue.QLogic
          drcl.inet.core.queue.RED

All Implemented Interfaces:

java.lang.Cloneable, ObjectDuplicable, java.io.Serializable

Direct Known Subclasses:

FRED

public class RED

extends QLogic

The Random Early Detection (RED) queue logic.

See Also:

Serialized Form

Field Summary

protected Port	avgQSizePort Port to output average queue size change event
protected double	bw Link bandwidth (bps), for computing ptc.
protected long	count # of packets since last early drop.
protected static java.lang.String	DTYPE_FORCED
protected static java.lang.String	DTYPE_NONE
protected static java.lang.String	DTYPE_UNFORCED
static java.lang.String	EVENT_AVG_QSIZE Name of the average queue size change event.
protected double	idletime Start of the current idle period.
protected boolean	mark The mark flag, true for marking CE bit instead of early dropping.
protected double	max_p Maximum dropping probability.
protected int	mean_pktsize Mean packet size (byte), for computing ptc.
protected int	old 0 when average queue first exceeds thresh.
protected double	ptc Output rate of the link in packets/second.
protected double	qavg Computed average queue size.
protected double	qw Weight for computing average queue size given to current queue size sample.
static boolean	RED_EWMA
static boolean	RED_HOLT_WINTERS
protected double	th_max Maximum threshold of average queue size.
protected double	th_min Minimum threshold of average queue size.
protected RandomNumberGenerator	ug The random number generator used in this RED.
protected double	v_a For computing dropping probability (=max_p*(qavg - min_th)/(max_th-min_th) = v_a * qavg + v_b).
protected double	v_b For computing dropping probability (=max_p*(qavg - min_th)/(max_th-min_th) = v_a * qavg + v_b).
protected double	v_prob Computed dropping probability for the incoming packet, for diagnosis purpose.
protected double	v_slope Variable used in HOLT WINTERS filter for computing average queue size.
protected boolean	wait The wait flag, true for waiting between dropped packets.

Fields inherited from class drcl.comp.queue.QLogic

capacity, DEFAULT_ADVICE, EVENT_QSIZE, host, qlen, qsize, qSizePort

Constructor Summary

RED()

RED(Component host_, java.lang.String avgpid_)

RED(Component host_, java.lang.String avgpid_, java.lang.String qpid_)

Method Summary

java.lang.String	adviceOn(java.lang.Object obj_, int psize_) Returns advice (in String) on whether or not to drop the packet.
void	dequeueHandler(java.lang.Object obj_, int psize_) Handles the event of dequeuing the object of the given size.
protected boolean	drop_early(Packet pkt_)
void	duplicate(java.lang.Object source_) Duplicates the content of the source object to this object.
protected java.lang.String	edv_print(java.lang.String prefix_)
void	enqueueHandler(java.lang.Object obj_, int psize_) Handles the event of enqueuing the object of the given size.
double	getBandwidth()
double	getInvProb()
double	getMaxThresh()
int	getMeanPacketSize()
double	getMinThresh()
long	getSeed()
double	getWeight()
java.lang.String	info(java.lang.String prefix_) Prints the content (states) of this queue management instance.
boolean	isMarkEnabled()
boolean	isWait()
void	reset() Resets this object to the initial state.
protected void	run_estimator(boolean advice_) Computes the average queue size.
void	setAvgQSizePort(java.lang.String avgqspid_)
void	setBandwidth(double bw_)
void	setInvProb(double value)
void	setMarkEnabled(boolean enabled_) If enabled, RED marks the congestion bit of, instead of advising to drop, packets.
void	setMaxThresh(double max)
void	setMeanPacketSize(int size_)
void	setMinThresh(double min)
void	setRandomNumberGenerator(RandomNumberGenerator ug_)
void	setRandomNumberGenerator(RandomNumberGenerator ug_, long seed_)
void	setREDParam(int psize_, double bw_, double th_max_, double th_min_, double inv_max_p_, double qw_) Sets up all RED parameters.
void	setSeed(long seed_)
void	setWait(boolean enabled_)
void	setWeight(double weight)

Methods inherited from class drcl.comp.queue.QLogic

dropHandler, getCapacity, getCurrentQLength, getCurrentQSize, getHost, info, isEmpty, isFull, set, setCapacity, setHost, setQSizePort

Methods inherited from class drcl.DrclObj

clone, toString

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

RED_EWMA

public static boolean RED_EWMA

RED_HOLT_WINTERS

public static boolean RED_HOLT_WINTERS

DTYPE_NONE

protected static final java.lang.String DTYPE_NONE

DTYPE_FORCED

protected static final java.lang.String DTYPE_FORCED

See Also:

Constant Field Values

DTYPE_UNFORCED

protected static final java.lang.String DTYPE_UNFORCED

See Also:

Constant Field Values

EVENT_AVG_QSIZE

public static final java.lang.String EVENT_AVG_QSIZE

Name of the average queue size change event.

See Also:

Constant Field Values

avgQSizePort

protected Port avgQSizePort

Port to output average queue size change event

mean_pktsize

protected int mean_pktsize

Mean packet size (byte), for computing ptc.

bw

protected double bw

Link bandwidth (bps), for computing ptc.

th_min

protected double th_min

Minimum threshold of average queue size.

th_max

protected double th_max

Maximum threshold of average queue size.

max_p

protected double max_p

Maximum dropping probability.

qw

protected double qw

Weight for computing average queue size given to current queue size sample.

wait

protected boolean wait

The wait flag, true for waiting between dropped packets.

mark

protected boolean mark

The mark flag, true for marking CE bit instead of early dropping.

ptc

protected double ptc

Output rate of the link in packets/second.

v_a

protected double v_a

For computing dropping probability (=max_p*(qavg - min_th)/(max_th-min_th) = v_a * qavg + v_b).

v_b

protected double v_b

For computing dropping probability (=max_p*(qavg - min_th)/(max_th-min_th) = v_a * qavg + v_b).

qavg

protected double qavg

Computed average queue size.

v_slope

protected double v_slope

Variable used in HOLT WINTERS filter for computing average queue size.

v_prob

protected double v_prob

Computed dropping probability for the incoming packet, for diagnosis purpose.

count

protected long count

# of packets since last early drop.

old

protected int old

0 when average queue first exceeds thresh.

idletime

protected double idletime

Start of the current idle period. Is Double.NaN if not idle.

ug

protected RandomNumberGenerator ug

The random number generator used in this RED.

Constructor Detail

RED

public RED()

RED

public RED(Component host_,
           java.lang.String avgpid_)

Parameters:

avgpid_ - ID of the average queue size change event port that will be created at the host component.

RED

public RED(Component host_,
           java.lang.String avgpid_,
           java.lang.String qpid_)

Parameters:

avgpid_ - ID of the average queue size change event port that will be created at the host component.

qpid_ - ID of the instant queue size change event port that will be created at the host component.

Method Detail

reset

public void reset()

Description copied from class: QLogic

Resets this object to the initial state. Subclasses must call super.reset() when overriding this method.

Overrides:

reset in class QLogic

duplicate

public void duplicate(java.lang.Object source_)

Description copied from class: QLogic

Duplicates the content of the source object to this object. If the host component is already set, this method also creates the queue size change event port of the same ID as that in source_. Subclasses must call super.duplicate() when overriding this method.

Specified by:

duplicate in interface ObjectDuplicable

Overrides:

duplicate in class QLogic

info

public java.lang.String info(java.lang.String prefix_)

Description copied from class: QLogic

Prints the content (states) of this queue management instance.

Overrides:

info in class QLogic

Parameters:

prefix_ - prefix of each line in the printout.

run_estimator

protected void run_estimator(boolean advice_)

Computes the average queue size. The code contains two alternate methods for this, the plain EWMA and the Holt-Winters method.

drop_early

protected boolean drop_early(Packet pkt_)

adviceOn

public java.lang.String adviceOn(java.lang.Object obj_,
                                 int psize_)

Returns advice (in String) on whether or not to drop the packet. Returns false if not to drop the packet.

Overrides:

adviceOn in class QLogic

Returns:

the advice; null if advicing not to drop the object.

enqueueHandler

public void enqueueHandler(java.lang.Object obj_,
                           int psize_)

Description copied from class: QLogic

Handles the event of enqueuing the object of the given size.

Overrides:

enqueueHandler in class QLogic

dequeueHandler

public void dequeueHandler(java.lang.Object obj_,
                           int psize_)

Description copied from class: QLogic

Handles the event of dequeuing the object of the given size.

Overrides:

dequeueHandler in class QLogic

setWait

public void setWait(boolean enabled_)

isWait

public boolean isWait()

setMarkEnabled

public void setMarkEnabled(boolean enabled_)

If enabled, RED marks the congestion bit of, instead of advising to drop, packets.

isMarkEnabled

public boolean isMarkEnabled()

setMeanPacketSize

public void setMeanPacketSize(int size_)

getMeanPacketSize

public int getMeanPacketSize()

setMaxThresh

public void setMaxThresh(double max)

getMaxThresh

public double getMaxThresh()

setMinThresh

public void setMinThresh(double min)

getMinThresh

public double getMinThresh()

setInvProb

public void setInvProb(double value)

getInvProb

public double getInvProb()

setWeight

public void setWeight(double weight)

getWeight

public double getWeight()

getBandwidth

public double getBandwidth()

setBandwidth

public void setBandwidth(double bw_)

setREDParam

public void setREDParam(int psize_,
                        double bw_,
                        double th_max_,
                        double th_min_,
                        double inv_max_p_,
                        double qw_)

Sets up all RED parameters. For each parameter, the default value is used if zero is given.

setSeed

public void setSeed(long seed_)

getSeed

public long getSeed()

setRandomNumberGenerator

public void setRandomNumberGenerator(RandomNumberGenerator ug_)

setRandomNumberGenerator

public void setRandomNumberGenerator(RandomNumberGenerator ug_,
                                     long seed_)

setAvgQSizePort

public void setAvgQSizePort(java.lang.String avgqspid_)

edv_print

protected java.lang.String edv_print(java.lang.String prefix_)