A Discrete-Event Network Simulator
API
tcp-hybla.cc
Go to the documentation of this file.
1/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2/*
3 * Copyright (c) 2014 Natale Patriciello <natale.patriciello@gmail.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 */
19
20#include "tcp-hybla.h"
21#include "tcp-socket-state.h"
22
23#include "ns3/log.h"
24
25namespace ns3 {
26
27NS_LOG_COMPONENT_DEFINE ("TcpHybla");
29
30TypeId
32{
33 static TypeId tid = TypeId ("ns3::TcpHybla")
35 .AddConstructor<TcpHybla> ()
36 .SetGroupName ("Internet")
37 .AddAttribute ("RRTT", "Reference RTT",
41 .AddTraceSource ("Rho",
42 "Rho parameter of Hybla",
44 "ns3::TracedValueCallback::Double")
45 ;
46 return tid;
47}
48
50 : TcpNewReno (),
51 m_rho (1.0),
52 m_cWndCnt (0)
53{
54 NS_LOG_FUNCTION (this);
55}
56
58 : TcpNewReno (sock),
59 m_rho (sock.m_rho),
60 m_cWndCnt (sock.m_cWndCnt)
61{
62 NS_LOG_FUNCTION (this);
63}
64
66{
67 NS_LOG_FUNCTION (this);
68}
69
70void
72{
73 NS_LOG_FUNCTION (this);
74
75 m_rho = std::max ((double) tcb->m_minRtt.GetMilliSeconds () / m_rRtt.GetMilliSeconds (), 1.0);
76
77 NS_ASSERT (m_rho > 0.0);
78 NS_LOG_DEBUG ("Calculated rho=" << m_rho);
79}
80
81void
83 const Time &rtt)
84{
85 NS_LOG_FUNCTION (this << tcb << segmentsAcked << rtt);
86
87 if (rtt == tcb->m_minRtt)
88 {
89 RecalcParam (tcb);
90 NS_LOG_DEBUG ("min rtt seen: " << rtt);
91 }
92}
93
96{
97 NS_LOG_FUNCTION (this << tcb << segmentsAcked);
98
99 NS_ASSERT (tcb->m_cWnd <= tcb->m_ssThresh);
100
101 if (segmentsAcked >= 1)
102 {
103 /*
104 * slow start
105 * INC = 2^RHO - 1
106 */
107
108 double increment = std::pow (2, m_rho) - 1.0;
109 uint32_t incr = static_cast<uint32_t> (increment * tcb->m_segmentSize);
110 NS_LOG_INFO ("Slow start: inc=" << increment);
111
112 tcb->m_cWnd = std::min (tcb->m_cWnd + incr, tcb->m_ssThresh);
113
114 NS_LOG_INFO ("In SlowStart, updated to cwnd " << tcb->m_cWnd <<
115 " ssthresh " << tcb->m_ssThresh <<
116 " with an increment of " << increment * tcb->m_segmentSize);
117
118 return segmentsAcked - 1;
119 }
120
121 return 0;
122}
123
124void
126{
127 NS_LOG_FUNCTION (this << tcb << segmentsAcked);
128
129 uint32_t segCwnd;
130 double increment;
131
132 while (segmentsAcked > 0)
133 {
134 /*
135 * congestion avoidance
136 * INC = RHO^2 / W
137 */
138 segCwnd = tcb->GetCwndInSegments ();
139 increment = std::pow (m_rho, 2) / static_cast<double> (segCwnd);
140
141 m_cWndCnt += increment;
142 segmentsAcked -= 1;
143 }
144
145 if (m_cWndCnt >= 1.0)
146 {
147 // double to int truncates every time.
148 uint32_t inc = static_cast<uint32_t> (m_cWndCnt);
149 m_cWndCnt -= inc;
150
151 NS_ASSERT (m_cWndCnt >= 0.0);
152
153 /* This leaves space for a tcp pacing implementation; it would be easy
154 to setup a limit on the maximum increment of the cWnd per ACK received.
155 The remaining increment is leaved for the next ACK. */
156
157 tcb->m_cWnd += inc * tcb->m_segmentSize;
158
159
160 NS_LOG_INFO ("In CongAvoid, updated to cwnd " << tcb->m_cWnd <<
161 " ssthresh " << tcb->m_ssThresh <<
162 " with an increment of " << inc * tcb->m_segmentSize);
163 }
164}
165
168{
169 return CopyObject<TcpHybla> (this);
170}
171
172std::string
174{
175 return "TcpHybla";
176}
177
178
179} // namespace ns3
#define min(a, b)
Definition: 80211b.c:42
#define max(a, b)
Definition: 80211b.c:43
Implementation of the TCP Hybla algorithm.
Definition: tcp-hybla.h:47
virtual ~TcpHybla(void) override
Definition: tcp-hybla.cc:65
Time m_rRtt
Reference RTT.
Definition: tcp-hybla.h:80
virtual Ptr< TcpCongestionOps > Fork() override
Copy the congestion control algorithm across sockets.
Definition: tcp-hybla.cc:167
virtual uint32_t SlowStart(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) override
Tcp NewReno slow start algorithm.
Definition: tcp-hybla.cc:95
TracedValue< double > m_rho
Rho parameter.
Definition: tcp-hybla.h:79
virtual std::string GetName() const override
Get the name of the congestion control algorithm.
Definition: tcp-hybla.cc:173
void RecalcParam(const Ptr< TcpSocketState > &tcb)
Recalculate algorithm parameters.
Definition: tcp-hybla.cc:71
static TypeId GetTypeId(void)
Get the type ID.
Definition: tcp-hybla.cc:31
double m_cWndCnt
cWnd integer-to-float counter
Definition: tcp-hybla.h:81
virtual void PktsAcked(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked, const Time &rtt) override
Timing information on received ACK.
Definition: tcp-hybla.cc:82
TcpHybla(void)
Create an unbound tcp socket.
Definition: tcp-hybla.cc:49
virtual void CongestionAvoidance(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) override
NewReno congestion avoidance.
Definition: tcp-hybla.cc:125
The NewReno implementation.
uint32_t m_segmentSize
Segment size.
Time m_minRtt
Minimum RTT observed throughout the connection.
uint32_t GetCwndInSegments() const
Get cwnd in segments rather than bytes.
TracedValue< uint32_t > m_cWnd
Congestion window.
TracedValue< uint32_t > m_ssThresh
Slow start threshold.
Simulation virtual time values and global simulation resolution.
Definition: nstime.h:103
int64_t GetMilliSeconds(void) const
Get an approximation of the time stored in this instance in the indicated unit.
Definition: nstime.h:383
AttributeValue implementation for Time.
Definition: nstime.h:1308
a unique identifier for an interface.
Definition: type-id.h:59
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:922
#define NS_ASSERT(condition)
At runtime, in debugging builds, if this condition is not true, the program prints the source file,...
Definition: assert.h:67
Ptr< const AttributeAccessor > MakeTimeAccessor(T1 a1)
Definition: nstime.h:1309
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
#define NS_LOG_DEBUG(msg)
Use NS_LOG to output a message of level LOG_DEBUG.
Definition: log.h:273
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by ",...
#define NS_LOG_INFO(msg)
Use NS_LOG to output a message of level LOG_INFO.
Definition: log.h:281
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:45
Time MilliSeconds(uint64_t value)
Construct a Time in the indicated unit.
Definition: nstime.h:1252
Ptr< const TraceSourceAccessor > MakeTraceSourceAccessor(T a)
Create a TraceSourceAccessor which will control access to the underlying trace source.
Every class exported by the ns3 library is enclosed in the ns3 namespace.
Ptr< const AttributeChecker > MakeTimeChecker(const Time min, const Time max)
Helper to make a Time checker with bounded range.
Definition: time.cc:522