862 lines
24 KiB
C++
862 lines
24 KiB
C++
// /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
|
|
/*
|
|
* Copyright © 2011 Marcos Talau
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation;
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
* Author: Marcos Talau (talau@users.sourceforge.net)
|
|
*
|
|
* Thanks to: Duy Nguyen<duy@soe.ucsc.edu> by RED efforts in NS3
|
|
*
|
|
*
|
|
* This file incorporates work covered by the following copyright and
|
|
* permission notice:
|
|
*
|
|
* Copyright (c) 1990-1997 Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the University nor of the Laboratory may be used
|
|
* to endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* PORT NOTE: This code was ported from ns-2 (queue/red.cc). Almost all
|
|
* comments have also been ported from NS-2
|
|
*/
|
|
|
|
#include "ns3/log.h"
|
|
#include "ns3/enum.h"
|
|
#include "ns3/uinteger.h"
|
|
#include "ns3/double.h"
|
|
#include "ns3/simulator.h"
|
|
#include "ns3/abort.h"
|
|
#include "red-queue-disc.h"
|
|
#include "ns3/drop-tail-queue.h"
|
|
|
|
namespace ns3 {
|
|
|
|
NS_LOG_COMPONENT_DEFINE ("RedQueueDisc");
|
|
|
|
NS_OBJECT_ENSURE_REGISTERED (RedQueueDisc);
|
|
|
|
TypeId RedQueueDisc::GetTypeId (void)
|
|
{
|
|
static TypeId tid = TypeId ("ns3::RedQueueDisc")
|
|
.SetParent<QueueDisc> ()
|
|
.SetGroupName("TrafficControl")
|
|
.AddConstructor<RedQueueDisc> ()
|
|
.AddAttribute ("Mode",
|
|
"Determines unit for QueueLimit",
|
|
EnumValue (Queue::QUEUE_MODE_PACKETS),
|
|
MakeEnumAccessor (&RedQueueDisc::SetMode),
|
|
MakeEnumChecker (Queue::QUEUE_MODE_BYTES, "QUEUE_MODE_BYTES",
|
|
Queue::QUEUE_MODE_PACKETS, "QUEUE_MODE_PACKETS"))
|
|
.AddAttribute ("MeanPktSize",
|
|
"Average of packet size",
|
|
UintegerValue (500),
|
|
MakeUintegerAccessor (&RedQueueDisc::m_meanPktSize),
|
|
MakeUintegerChecker<uint32_t> ())
|
|
.AddAttribute ("IdlePktSize",
|
|
"Average packet size used during idle times. Used when m_cautions = 3",
|
|
UintegerValue (0),
|
|
MakeUintegerAccessor (&RedQueueDisc::m_idlePktSize),
|
|
MakeUintegerChecker<uint32_t> ())
|
|
.AddAttribute ("Wait",
|
|
"True for waiting between dropped packets",
|
|
BooleanValue (true),
|
|
MakeBooleanAccessor (&RedQueueDisc::m_isWait),
|
|
MakeBooleanChecker ())
|
|
.AddAttribute ("Gentle",
|
|
"True to increases dropping probability slowly when average queue exceeds maxthresh",
|
|
BooleanValue (true),
|
|
MakeBooleanAccessor (&RedQueueDisc::m_isGentle),
|
|
MakeBooleanChecker ())
|
|
.AddAttribute ("ARED",
|
|
"True to enable ARED",
|
|
BooleanValue (false),
|
|
MakeBooleanAccessor (&RedQueueDisc::m_isARED),
|
|
MakeBooleanChecker ())
|
|
.AddAttribute ("AdaptMaxP",
|
|
"True to adapt m_curMaxP",
|
|
BooleanValue (false),
|
|
MakeBooleanAccessor (&RedQueueDisc::m_isAdaptMaxP),
|
|
MakeBooleanChecker ())
|
|
.AddAttribute ("MinTh",
|
|
"Minimum average length threshold in packets/bytes",
|
|
DoubleValue (5),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_minTh),
|
|
MakeDoubleChecker<double> ())
|
|
.AddAttribute ("MaxTh",
|
|
"Maximum average length threshold in packets/bytes",
|
|
DoubleValue (15),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_maxTh),
|
|
MakeDoubleChecker<double> ())
|
|
.AddAttribute ("QueueLimit",
|
|
"Queue limit in bytes/packets",
|
|
UintegerValue (25),
|
|
MakeUintegerAccessor (&RedQueueDisc::SetQueueLimit),
|
|
MakeUintegerChecker<uint32_t> ())
|
|
.AddAttribute ("QW",
|
|
"Queue weight related to the exponential weighted moving average (EWMA)",
|
|
DoubleValue (0.002),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_qW),
|
|
MakeDoubleChecker <double> ())
|
|
.AddAttribute ("LInterm",
|
|
"The maximum probability of dropping a packet",
|
|
DoubleValue (50),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_lInterm),
|
|
MakeDoubleChecker <double> ())
|
|
.AddAttribute ("TargetDelay",
|
|
"Target average queuing delay in ARED",
|
|
TimeValue (Seconds (0.005)),
|
|
MakeTimeAccessor (&RedQueueDisc::m_targetDelay),
|
|
MakeTimeChecker ())
|
|
.AddAttribute ("Interval",
|
|
"Time interval to update m_curMaxP",
|
|
TimeValue (Seconds (0.5)),
|
|
MakeTimeAccessor (&RedQueueDisc::m_interval),
|
|
MakeTimeChecker ())
|
|
.AddAttribute ("Top",
|
|
"Upper bound for m_curMaxP in ARED",
|
|
DoubleValue (0.5),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_top),
|
|
MakeDoubleChecker <double> (0, 1))
|
|
.AddAttribute ("Bottom",
|
|
"Lower bound for m_curMaxP in ARED",
|
|
DoubleValue (0.0),
|
|
MakeDoubleAccessor (&RedQueueDisc::m_bottom),
|
|
MakeDoubleChecker <double> (0, 1))
|
|
.AddAttribute ("Alpha",
|
|
"Increment parameter for m_curMaxP in ARED",
|
|
DoubleValue (0.01),
|
|
MakeDoubleAccessor (&RedQueueDisc::SetAredAlpha),
|
|
MakeDoubleChecker <double> (0, 1))
|
|
.AddAttribute ("Beta",
|
|
"Decrement parameter for m_curMaxP in ARED",
|
|
DoubleValue (0.9),
|
|
MakeDoubleAccessor (&RedQueueDisc::SetAredBeta),
|
|
MakeDoubleChecker <double> (0, 1))
|
|
.AddAttribute ("LastSet",
|
|
"Store the last time m_curMaxP was updated",
|
|
TimeValue (Seconds (0.0)),
|
|
MakeTimeAccessor (&RedQueueDisc::m_lastSet),
|
|
MakeTimeChecker ())
|
|
.AddAttribute ("Rtt",
|
|
"Round Trip Time to be considered while automatically setting m_bottom",
|
|
TimeValue (Seconds (0.1)),
|
|
MakeTimeAccessor (&RedQueueDisc::m_rtt),
|
|
MakeTimeChecker ())
|
|
.AddAttribute ("Ns1Compat",
|
|
"NS-1 compatibility",
|
|
BooleanValue (false),
|
|
MakeBooleanAccessor (&RedQueueDisc::m_isNs1Compat),
|
|
MakeBooleanChecker ())
|
|
.AddAttribute ("LinkBandwidth",
|
|
"The RED link bandwidth",
|
|
DataRateValue (DataRate ("1.5Mbps")),
|
|
MakeDataRateAccessor (&RedQueueDisc::m_linkBandwidth),
|
|
MakeDataRateChecker ())
|
|
.AddAttribute ("LinkDelay",
|
|
"The RED link delay",
|
|
TimeValue (MilliSeconds (20)),
|
|
MakeTimeAccessor (&RedQueueDisc::m_linkDelay),
|
|
MakeTimeChecker ())
|
|
;
|
|
|
|
return tid;
|
|
}
|
|
|
|
RedQueueDisc::RedQueueDisc () :
|
|
QueueDisc ()
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
m_uv = CreateObject<UniformRandomVariable> ();
|
|
}
|
|
|
|
RedQueueDisc::~RedQueueDisc ()
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::DoDispose (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
m_uv = 0;
|
|
QueueDisc::DoDispose ();
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::SetMode (Queue::QueueMode mode)
|
|
{
|
|
NS_LOG_FUNCTION (this << mode);
|
|
m_mode = mode;
|
|
}
|
|
|
|
Queue::QueueMode
|
|
RedQueueDisc::GetMode (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
return m_mode;
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::SetAredAlpha (double alpha)
|
|
{
|
|
NS_LOG_FUNCTION (this << alpha);
|
|
m_alpha = alpha;
|
|
|
|
if (m_alpha > 0.01)
|
|
{
|
|
NS_LOG_WARN ("Alpha value is above the recommended bound!");
|
|
}
|
|
}
|
|
|
|
double
|
|
RedQueueDisc::GetAredAlpha (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
return m_alpha;
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::SetAredBeta (double beta)
|
|
{
|
|
NS_LOG_FUNCTION (this << beta);
|
|
m_beta = beta;
|
|
|
|
if (m_beta < 0.83)
|
|
{
|
|
NS_LOG_WARN ("Beta value is below the recommended bound!");
|
|
}
|
|
}
|
|
|
|
double
|
|
RedQueueDisc::GetAredBeta (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
return m_beta;
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::SetQueueLimit (uint32_t lim)
|
|
{
|
|
NS_LOG_FUNCTION (this << lim);
|
|
m_queueLimit = lim;
|
|
}
|
|
|
|
void
|
|
RedQueueDisc::SetTh (double minTh, double maxTh)
|
|
{
|
|
NS_LOG_FUNCTION (this << minTh << maxTh);
|
|
NS_ASSERT (minTh <= maxTh);
|
|
m_minTh = minTh;
|
|
m_maxTh = maxTh;
|
|
}
|
|
|
|
RedQueueDisc::Stats
|
|
RedQueueDisc::GetStats ()
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
return m_stats;
|
|
}
|
|
|
|
int64_t
|
|
RedQueueDisc::AssignStreams (int64_t stream)
|
|
{
|
|
NS_LOG_FUNCTION (this << stream);
|
|
m_uv->SetStream (stream);
|
|
return 1;
|
|
}
|
|
|
|
bool
|
|
RedQueueDisc::DoEnqueue (Ptr<QueueDiscItem> item)
|
|
{
|
|
NS_LOG_FUNCTION (this << item);
|
|
|
|
uint32_t nQueued = 0;
|
|
|
|
if (GetMode () == Queue::QUEUE_MODE_BYTES)
|
|
{
|
|
NS_LOG_DEBUG ("Enqueue in bytes mode");
|
|
nQueued = GetInternalQueue (0)->GetNBytes ();
|
|
}
|
|
else if (GetMode () == Queue::QUEUE_MODE_PACKETS)
|
|
{
|
|
NS_LOG_DEBUG ("Enqueue in packets mode");
|
|
nQueued = GetInternalQueue (0)->GetNPackets ();
|
|
}
|
|
|
|
// simulate number of packets arrival during idle period
|
|
uint32_t m = 0;
|
|
|
|
if (m_idle == 1)
|
|
{
|
|
NS_LOG_DEBUG ("RED Queue Disc is idle.");
|
|
Time now = Simulator::Now ();
|
|
|
|
if (m_cautious == 3)
|
|
{
|
|
double ptc = m_ptc * m_meanPktSize / m_idlePktSize;
|
|
m = uint32_t (ptc * (now - m_idleTime).GetSeconds ());
|
|
}
|
|
else
|
|
{
|
|
m = uint32_t (m_ptc * (now - m_idleTime).GetSeconds ());
|
|
}
|
|
|
|
m_idle = 0;
|
|
}
|
|
|
|
m_qAvg = Estimator (nQueued, m + 1, m_qAvg, m_qW);
|
|
|
|
NS_LOG_DEBUG ("\t bytesInQueue " << GetInternalQueue (0)->GetNBytes () << "\tQavg " << m_qAvg);
|
|
NS_LOG_DEBUG ("\t packetsInQueue " << GetInternalQueue (0)->GetNPackets () << "\tQavg " << m_qAvg);
|
|
|
|
m_count++;
|
|
m_countBytes += item->GetPacketSize ();
|
|
|
|
uint32_t dropType = DTYPE_NONE;
|
|
if (m_qAvg >= m_minTh && nQueued > 1)
|
|
{
|
|
if ((!m_isGentle && m_qAvg >= m_maxTh) ||
|
|
(m_isGentle && m_qAvg >= 2 * m_maxTh))
|
|
{
|
|
NS_LOG_DEBUG ("adding DROP FORCED MARK");
|
|
dropType = DTYPE_FORCED;
|
|
}
|
|
else if (m_old == 0)
|
|
{
|
|
/*
|
|
* The average queue size has just crossed the
|
|
* threshold from below to above "minthresh", or
|
|
* from above "minthresh" with an empty queue to
|
|
* above "minthresh" with a nonempty queue.
|
|
*/
|
|
m_count = 1;
|
|
m_countBytes = item->GetPacketSize ();
|
|
m_old = 1;
|
|
}
|
|
else if (DropEarly (item, nQueued))
|
|
{
|
|
NS_LOG_LOGIC ("DropEarly returns 1");
|
|
dropType = DTYPE_UNFORCED;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// No packets are being dropped
|
|
m_vProb = 0.0;
|
|
m_old = 0;
|
|
}
|
|
|
|
if (nQueued >= m_queueLimit)
|
|
{
|
|
NS_LOG_DEBUG ("\t Dropping due to Queue Full " << nQueued);
|
|
dropType = DTYPE_FORCED;
|
|
m_stats.qLimDrop++;
|
|
}
|
|
|
|
if (dropType == DTYPE_UNFORCED)
|
|
{
|
|
NS_LOG_DEBUG ("\t Dropping due to Prob Mark " << m_qAvg);
|
|
m_stats.unforcedDrop++;
|
|
Drop (item);
|
|
return false;
|
|
}
|
|
else if (dropType == DTYPE_FORCED)
|
|
{
|
|
NS_LOG_DEBUG ("\t Dropping due to Hard Mark " << m_qAvg);
|
|
m_stats.forcedDrop++;
|
|
Drop (item);
|
|
if (m_isNs1Compat)
|
|
{
|
|
m_count = 0;
|
|
m_countBytes = 0;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
GetInternalQueue (0)->Enqueue (item);
|
|
|
|
NS_LOG_LOGIC ("Number packets " << GetInternalQueue (0)->GetNPackets ());
|
|
NS_LOG_LOGIC ("Number bytes " << GetInternalQueue (0)->GetNBytes ());
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Note: if the link bandwidth changes in the course of the
|
|
* simulation, the bandwidth-dependent RED parameters do not change.
|
|
* This should be fixed, but it would require some extra parameters,
|
|
* and didn't seem worth the trouble...
|
|
*/
|
|
void
|
|
RedQueueDisc::InitializeParams (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
NS_LOG_INFO ("Initializing RED params.");
|
|
|
|
m_cautious = 0;
|
|
m_ptc = m_linkBandwidth.GetBitRate () / (8.0 * m_meanPktSize);
|
|
|
|
if (m_isARED)
|
|
{
|
|
// Set m_minTh, m_maxTh and m_qW to zero for automatic setting
|
|
m_minTh = 0;
|
|
m_maxTh = 0;
|
|
m_qW = 0;
|
|
|
|
// Turn on m_isAdaptMaxP to adapt m_curMaxP
|
|
m_isAdaptMaxP = true;
|
|
}
|
|
|
|
if (m_minTh == 0 && m_maxTh == 0)
|
|
{
|
|
m_minTh = 5.0;
|
|
|
|
// set m_minTh to max(m_minTh, targetqueue/2.0) [Ref: http://www.icir.org/floyd/papers/adaptiveRed.pdf]
|
|
double targetqueue = m_targetDelay.GetSeconds() * m_ptc;
|
|
|
|
if (m_minTh < targetqueue / 2.0 )
|
|
{
|
|
m_minTh = targetqueue / 2.0;
|
|
}
|
|
if (GetMode () == Queue::QUEUE_MODE_BYTES)
|
|
{
|
|
m_minTh = m_minTh * m_meanPktSize;
|
|
}
|
|
|
|
// set m_maxTh to three times m_minTh [Ref: http://www.icir.org/floyd/papers/adaptiveRed.pdf]
|
|
m_maxTh = 3 * m_minTh;
|
|
}
|
|
|
|
NS_ASSERT (m_minTh <= m_maxTh);
|
|
m_stats.forcedDrop = 0;
|
|
m_stats.unforcedDrop = 0;
|
|
m_stats.qLimDrop = 0;
|
|
|
|
m_qAvg = 0.0;
|
|
m_count = 0;
|
|
m_countBytes = 0;
|
|
m_old = 0;
|
|
m_idle = 1;
|
|
|
|
double th_diff = (m_maxTh - m_minTh);
|
|
if (th_diff == 0)
|
|
{
|
|
th_diff = 1.0;
|
|
}
|
|
m_vA = 1.0 / th_diff;
|
|
m_curMaxP = 1.0 / m_lInterm;
|
|
m_vB = -m_minTh / th_diff;
|
|
|
|
if (m_isGentle)
|
|
{
|
|
m_vC = (1.0 - m_curMaxP) / m_maxTh;
|
|
m_vD = 2.0 * m_curMaxP - 1.0;
|
|
}
|
|
m_idleTime = NanoSeconds (0);
|
|
|
|
/*
|
|
* If m_qW=0, set it to a reasonable value of 1-exp(-1/C)
|
|
* This corresponds to choosing m_qW to be of that value for
|
|
* which the packet time constant -1/ln(1-m)qW) per default RTT
|
|
* of 100ms is an order of magnitude more than the link capacity, C.
|
|
*
|
|
* If m_qW=-1, then the queue weight is set to be a function of
|
|
* the bandwidth and the link propagation delay. In particular,
|
|
* the default RTT is assumed to be three times the link delay and
|
|
* transmission delay, if this gives a default RTT greater than 100 ms.
|
|
*
|
|
* If m_qW=-2, set it to a reasonable value of 1-exp(-10/C).
|
|
*/
|
|
if (m_qW == 0.0)
|
|
{
|
|
m_qW = 1.0 - std::exp (-1.0 / m_ptc);
|
|
}
|
|
else if (m_qW == -1.0)
|
|
{
|
|
double rtt = 3.0 * (m_linkDelay.GetSeconds () + 1.0 / m_ptc);
|
|
|
|
if (rtt < 0.1)
|
|
{
|
|
rtt = 0.1;
|
|
}
|
|
m_qW = 1.0 - std::exp (-1.0 / (10 * rtt * m_ptc));
|
|
}
|
|
else if (m_qW == -2.0)
|
|
{
|
|
m_qW = 1.0 - std::exp (-10.0 / m_ptc);
|
|
}
|
|
|
|
if (m_bottom == 0)
|
|
{
|
|
m_bottom = 0.01;
|
|
// Set bottom to at most 1/W, where W is the delay-bandwidth
|
|
// product in packets for a connection.
|
|
// So W = m_linkBandwidth.GetBitRate () / (8.0 * m_meanPktSize * m_rtt.GetSeconds())
|
|
double bottom1 = (8.0 * m_meanPktSize * m_rtt.GetSeconds()) / m_linkBandwidth.GetBitRate();
|
|
if (bottom1 < m_bottom)
|
|
{
|
|
m_bottom = bottom1;
|
|
}
|
|
}
|
|
|
|
NS_LOG_DEBUG ("\tm_delay " << m_linkDelay.GetSeconds () << "; m_isWait "
|
|
<< m_isWait << "; m_qW " << m_qW << "; m_ptc " << m_ptc
|
|
<< "; m_minTh " << m_minTh << "; m_maxTh " << m_maxTh
|
|
<< "; m_isGentle " << m_isGentle << "; th_diff " << th_diff
|
|
<< "; lInterm " << m_lInterm << "; va " << m_vA << "; cur_max_p "
|
|
<< m_curMaxP << "; v_b " << m_vB << "; m_vC "
|
|
<< m_vC << "; m_vD " << m_vD);
|
|
}
|
|
|
|
// Update m_curMaxP to keep the average queue length within the target range.
|
|
void
|
|
RedQueueDisc::UpdateMaxP (double newAve, Time now)
|
|
{
|
|
double m_part = 0.4 * (m_maxTh - m_minTh);
|
|
// AIMD rule to keep target Q~1/2(m_minTh + m_maxTh)
|
|
if (newAve < m_minTh + m_part && m_curMaxP > m_bottom)
|
|
{
|
|
// we should increase the average queue size, so decrease m_curMaxP
|
|
m_curMaxP = m_curMaxP * m_beta;
|
|
m_lastSet = now;
|
|
}
|
|
else if (newAve > m_maxTh - m_part && m_top > m_curMaxP)
|
|
{
|
|
// we should decrease the average queue size, so increase m_curMaxP
|
|
double alpha = m_alpha;
|
|
if (alpha > 0.25 * m_curMaxP)
|
|
{
|
|
alpha = 0.25 * m_curMaxP;
|
|
}
|
|
m_curMaxP = m_curMaxP + alpha;
|
|
m_lastSet = now;
|
|
}
|
|
}
|
|
|
|
// Compute the average queue size
|
|
double
|
|
RedQueueDisc::Estimator (uint32_t nQueued, uint32_t m, double qAvg, double qW)
|
|
{
|
|
NS_LOG_FUNCTION (this << nQueued << m << qAvg << qW);
|
|
|
|
double newAve = qAvg * pow(1.0-qW, m);
|
|
newAve += qW * nQueued;
|
|
|
|
Time now = Simulator::Now();
|
|
if (m_isAdaptMaxP && now > m_lastSet + m_interval)
|
|
{
|
|
UpdateMaxP(newAve, now);
|
|
}
|
|
|
|
return newAve;
|
|
}
|
|
|
|
// Check if packet p needs to be dropped due to probability mark
|
|
uint32_t
|
|
RedQueueDisc::DropEarly (Ptr<QueueDiscItem> item, uint32_t qSize)
|
|
{
|
|
NS_LOG_FUNCTION (this << item << qSize);
|
|
m_vProb1 = CalculatePNew (m_qAvg, m_maxTh, m_isGentle, m_vA, m_vB, m_vC, m_vD, m_curMaxP);
|
|
m_vProb = ModifyP (m_vProb1, m_count, m_countBytes, m_meanPktSize, m_isWait, item->GetPacketSize ());
|
|
|
|
// Drop probability is computed, pick random number and act
|
|
if (m_cautious == 1)
|
|
{
|
|
/*
|
|
* Don't drop/mark if the instantaneous queue is much below the average.
|
|
* For experimental purposes only.
|
|
* pkts: the number of packets arriving in 50 ms
|
|
*/
|
|
double pkts = m_ptc * 0.05;
|
|
double fraction = std::pow ((1 - m_qW), pkts);
|
|
|
|
if ((double) qSize < fraction * m_qAvg)
|
|
{
|
|
// Queue could have been empty for 0.05 seconds
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
double u = m_uv->GetValue ();
|
|
|
|
if (m_cautious == 2)
|
|
{
|
|
/*
|
|
* Decrease the drop probability if the instantaneous
|
|
* queue is much below the average.
|
|
* For experimental purposes only.
|
|
* pkts: the number of packets arriving in 50 ms
|
|
*/
|
|
double pkts = m_ptc * 0.05;
|
|
double fraction = std::pow ((1 - m_qW), pkts);
|
|
double ratio = qSize / (fraction * m_qAvg);
|
|
|
|
if (ratio < 1.0)
|
|
{
|
|
u *= 1.0 / ratio;
|
|
}
|
|
}
|
|
|
|
if (u <= m_vProb)
|
|
{
|
|
NS_LOG_LOGIC ("u <= m_vProb; u " << u << "; m_vProb " << m_vProb);
|
|
|
|
// DROP or MARK
|
|
m_count = 0;
|
|
m_countBytes = 0;
|
|
/// \todo Implement set bit to mark
|
|
|
|
return 1; // drop
|
|
}
|
|
|
|
return 0; // no drop/mark
|
|
}
|
|
|
|
// Returns a probability using these function parameters for the DropEarly funtion
|
|
double
|
|
RedQueueDisc::CalculatePNew (double qAvg, double maxTh, bool isGentle, double vA,
|
|
double vB, double vC, double vD, double maxP)
|
|
{
|
|
NS_LOG_FUNCTION (this << qAvg << maxTh << isGentle << vA << vB << vC << vD << maxP);
|
|
double p;
|
|
|
|
if (isGentle && qAvg >= maxTh)
|
|
{
|
|
// p ranges from maxP to 1 as the average queue
|
|
// Size ranges from maxTh to twice maxTh
|
|
p = vC * qAvg + vD;
|
|
}
|
|
else if (!isGentle && qAvg >= maxTh)
|
|
{
|
|
/*
|
|
* OLD: p continues to range linearly above max_p as
|
|
* the average queue size ranges above th_max.
|
|
* NEW: p is set to 1.0
|
|
*/
|
|
p = 1.0;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* p ranges from 0 to max_p as the average queue size ranges from
|
|
* th_min to th_max
|
|
*/
|
|
p = vA * qAvg + vB;
|
|
p *= maxP;
|
|
}
|
|
|
|
if (p > 1.0)
|
|
{
|
|
p = 1.0;
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
// Returns a probability using these function parameters for the DropEarly funtion
|
|
double
|
|
RedQueueDisc::ModifyP (double p, uint32_t count, uint32_t countBytes,
|
|
uint32_t meanPktSize, bool isWait, uint32_t size)
|
|
{
|
|
NS_LOG_FUNCTION (this << p << count << countBytes << meanPktSize << isWait << size);
|
|
double count1 = (double) count;
|
|
|
|
if (GetMode () == Queue::QUEUE_MODE_BYTES)
|
|
{
|
|
count1 = (double) (countBytes / meanPktSize);
|
|
}
|
|
|
|
if (isWait)
|
|
{
|
|
if (count1 * p < 1.0)
|
|
{
|
|
p = 0.0;
|
|
}
|
|
else if (count1 * p < 2.0)
|
|
{
|
|
p /= (2.0 - count1 * p);
|
|
}
|
|
else
|
|
{
|
|
p = 1.0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (count1 * p < 1.0)
|
|
{
|
|
p /= (1.0 - count1 * p);
|
|
}
|
|
else
|
|
{
|
|
p = 1.0;
|
|
}
|
|
}
|
|
|
|
if ((GetMode () == Queue::QUEUE_MODE_BYTES) && (p < 1.0))
|
|
{
|
|
p = (p * size) / meanPktSize;
|
|
}
|
|
|
|
if (p > 1.0)
|
|
{
|
|
p = 1.0;
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
uint32_t
|
|
RedQueueDisc::GetQueueSize (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
if (GetMode () == Queue::QUEUE_MODE_BYTES)
|
|
{
|
|
return GetInternalQueue (0)->GetNBytes ();
|
|
}
|
|
else if (GetMode () == Queue::QUEUE_MODE_PACKETS)
|
|
{
|
|
return GetInternalQueue (0)->GetNPackets ();
|
|
}
|
|
else
|
|
{
|
|
NS_ABORT_MSG ("Unknown RED mode.");
|
|
}
|
|
}
|
|
|
|
Ptr<QueueDiscItem>
|
|
RedQueueDisc::DoDequeue (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
|
|
if (GetInternalQueue (0)->IsEmpty ())
|
|
{
|
|
NS_LOG_LOGIC ("Queue empty");
|
|
m_idle = 1;
|
|
m_idleTime = Simulator::Now ();
|
|
|
|
return 0;
|
|
}
|
|
else
|
|
{
|
|
m_idle = 0;
|
|
Ptr<QueueDiscItem> item = StaticCast<QueueDiscItem> (GetInternalQueue (0)->Dequeue ());
|
|
|
|
NS_LOG_LOGIC ("Popped " << item);
|
|
|
|
NS_LOG_LOGIC ("Number packets " << GetInternalQueue (0)->GetNPackets ());
|
|
NS_LOG_LOGIC ("Number bytes " << GetInternalQueue (0)->GetNBytes ());
|
|
|
|
return item;
|
|
}
|
|
}
|
|
|
|
Ptr<const QueueDiscItem>
|
|
RedQueueDisc::DoPeek (void) const
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
if (GetInternalQueue (0)->IsEmpty ())
|
|
{
|
|
NS_LOG_LOGIC ("Queue empty");
|
|
return 0;
|
|
}
|
|
|
|
Ptr<const QueueDiscItem> item = StaticCast<const QueueDiscItem> (GetInternalQueue (0)->Peek ());
|
|
|
|
NS_LOG_LOGIC ("Number packets " << GetInternalQueue (0)->GetNPackets ());
|
|
NS_LOG_LOGIC ("Number bytes " << GetInternalQueue (0)->GetNBytes ());
|
|
|
|
return item;
|
|
}
|
|
|
|
bool
|
|
RedQueueDisc::CheckConfig (void)
|
|
{
|
|
NS_LOG_FUNCTION (this);
|
|
if (GetNQueueDiscClasses () > 0)
|
|
{
|
|
NS_LOG_ERROR ("RedQueueDisc cannot have classes");
|
|
return false;
|
|
}
|
|
|
|
if (GetNPacketFilters () > 0)
|
|
{
|
|
NS_LOG_ERROR ("RedQueueDisc cannot have packet filters");
|
|
return false;
|
|
}
|
|
|
|
if (GetNInternalQueues () == 0)
|
|
{
|
|
// create a DropTail queue
|
|
Ptr<Queue> queue = CreateObjectWithAttributes<DropTailQueue> ("Mode", EnumValue (m_mode));
|
|
if (m_mode == Queue::QUEUE_MODE_PACKETS)
|
|
{
|
|
queue->SetMaxPackets (m_queueLimit);
|
|
}
|
|
else
|
|
{
|
|
queue->SetMaxBytes (m_queueLimit);
|
|
}
|
|
AddInternalQueue (queue);
|
|
}
|
|
|
|
if (GetNInternalQueues () != 1)
|
|
{
|
|
NS_LOG_ERROR ("RedQueueDisc needs 1 internal queue");
|
|
return false;
|
|
}
|
|
|
|
if (GetInternalQueue (0)->GetMode () != m_mode)
|
|
{
|
|
NS_LOG_ERROR ("The mode of the provided queue does not match the mode set on the RedQueueDisc");
|
|
return false;
|
|
}
|
|
|
|
if ((m_mode == Queue::QUEUE_MODE_PACKETS && GetInternalQueue (0)->GetMaxPackets () < m_queueLimit) ||
|
|
(m_mode == Queue::QUEUE_MODE_BYTES && GetInternalQueue (0)->GetMaxBytes () < m_queueLimit))
|
|
{
|
|
NS_LOG_ERROR ("The size of the internal queue is less than the queue disc limit");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace ns3
|