A Discrete-Event Network Simulator
API
tcp-congestion-ops.cc
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2015 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 #include "tcp-congestion-ops.h"
20 #include "ns3/log.h"
21 
22 namespace ns3 {
23 
24 NS_LOG_COMPONENT_DEFINE ("TcpCongestionOps");
25 
26 NS_OBJECT_ENSURE_REGISTERED (TcpCongestionOps);
27 
28 TypeId
30 {
31  static TypeId tid = TypeId ("ns3::TcpCongestionOps")
32  .SetParent<Object> ()
33  .SetGroupName ("Internet")
34  ;
35  return tid;
36 }
37 
39 {
40 }
41 
43 {
44 }
45 
47 {
48 }
49 
50 void
52 {
53  NS_LOG_FUNCTION (this << tcb << segmentsAcked);
54 }
55 
56 void
57 TcpCongestionOps::PktsAcked (Ptr<TcpSocketState> tcb, uint32_t segmentsAcked,
58  const Time& rtt)
59 {
60  NS_LOG_FUNCTION (this << tcb << segmentsAcked << rtt);
61 }
62 
63 void
65  const TcpSocketState::TcpCongState_t newState)
66 {
67  NS_LOG_FUNCTION (this << tcb << newState);
68 }
69 
70 void
72  const TcpSocketState::TcpCAEvent_t event)
73 {
74  NS_LOG_FUNCTION (this << tcb << event);
75 }
76 
77 bool
79 {
80  return false;
81 }
82 
83 void
85  [[maybe_unused]] const TcpRateOps::TcpRateConnection &rc,
86  [[maybe_unused]] const TcpRateOps::TcpRateSample &rs)
87 {
88  NS_LOG_FUNCTION (this << tcb);
89 }
90 
91 // RENO
92 
94 
95 TypeId
97 {
98  static TypeId tid = TypeId ("ns3::TcpNewReno")
100  .SetGroupName ("Internet")
101  .AddConstructor<TcpNewReno> ()
102  ;
103  return tid;
104 }
105 
107 {
108  NS_LOG_FUNCTION (this);
109 }
110 
112  : TcpCongestionOps (sock)
113 {
114  NS_LOG_FUNCTION (this);
115 }
116 
118 {
119 }
120 
163 uint32_t
164 TcpNewReno::SlowStart (Ptr<TcpSocketState> tcb, uint32_t segmentsAcked)
165 {
166  NS_LOG_FUNCTION (this << tcb << segmentsAcked);
167 
168  if (segmentsAcked >= 1)
169  {
170  tcb->m_cWnd += tcb->m_segmentSize;
171  NS_LOG_INFO ("In SlowStart, updated to cwnd " << tcb->m_cWnd << " ssthresh " << tcb->m_ssThresh);
172  return segmentsAcked - 1;
173  }
174 
175  return 0;
176 }
177 
187 void
189 {
190  NS_LOG_FUNCTION (this << tcb << segmentsAcked);
191 
192  if (segmentsAcked > 0)
193  {
194  double adder = static_cast<double> (tcb->m_segmentSize * tcb->m_segmentSize) / tcb->m_cWnd.Get ();
195  adder = std::max (1.0, adder);
196  tcb->m_cWnd += static_cast<uint32_t> (adder);
197  NS_LOG_INFO ("In CongAvoid, updated to cwnd " << tcb->m_cWnd <<
198  " ssthresh " << tcb->m_ssThresh);
199  }
200 }
201 
211 void
212 TcpNewReno::IncreaseWindow (Ptr<TcpSocketState> tcb, uint32_t segmentsAcked)
213 {
214  NS_LOG_FUNCTION (this << tcb << segmentsAcked);
215 
216  if (tcb->m_cWnd < tcb->m_ssThresh)
217  {
218  segmentsAcked = SlowStart (tcb, segmentsAcked);
219  }
220 
221  if (tcb->m_cWnd >= tcb->m_ssThresh)
222  {
223  CongestionAvoidance (tcb, segmentsAcked);
224  }
225 
226  /* At this point, we could have segmentsAcked != 0. This because RFC says
227  * that in slow start, we should increase cWnd by min (N, SMSS); if in
228  * slow start we receive a cumulative ACK, it counts only for 1 SMSS of
229  * increase, wasting the others.
230  *
231  * // Incorrect assert, I am sorry
232  * NS_ASSERT (segmentsAcked == 0);
233  */
234 }
235 
236 std::string
238 {
239  return "TcpNewReno";
240 }
241 
242 uint32_t
244  uint32_t bytesInFlight)
245 {
246  NS_LOG_FUNCTION (this << state << bytesInFlight);
247 
248  return std::max (2 * state->m_segmentSize, bytesInFlight / 2);
249 }
250 
253 {
254  return CopyObject<TcpNewReno> (this);
255 }
256 
257 } // namespace ns3
258 
#define max(a, b)
Definition: 80211b.c:43
A base class which provides memory management and object aggregation.
Definition: object.h:88
Congestion control abstract class.
virtual void CwndEvent(Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCAEvent_t event)
Trigger events/calculations on occurrence of congestion window event.
virtual void IncreaseWindow(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
Congestion avoidance algorithm implementation.
virtual void CongControl(Ptr< TcpSocketState > tcb, const TcpRateOps::TcpRateConnection &rc, const TcpRateOps::TcpRateSample &rs)
Called when packets are delivered to update cwnd and pacing rate.
virtual void PktsAcked(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked, const Time &rtt)
Timing information on received ACK.
virtual bool HasCongControl() const
Returns true when Congestion Control Algorithm implements CongControl.
static TypeId GetTypeId(void)
Get the type ID.
virtual void CongestionStateSet(Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCongState_t newState)
Trigger events/calculations specific to a congestion state.
The NewReno implementation.
virtual void IncreaseWindow(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
Try to increase the cWnd following the NewReno specification.
virtual uint32_t GetSsThresh(Ptr< const TcpSocketState > tcb, uint32_t bytesInFlight)
Get the slow start threshold after a loss event.
virtual uint32_t SlowStart(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
Tcp NewReno slow start algorithm.
virtual Ptr< TcpCongestionOps > Fork()
Copy the congestion control algorithm across sockets.
virtual void CongestionAvoidance(Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
NewReno congestion avoidance.
std::string GetName() const
Get the name of the congestion control algorithm.
static TypeId GetTypeId(void)
Get the type ID.
uint32_t m_segmentSize
Segment size.
TcpCAEvent_t
Congestion avoidance events.
TcpCongState_t
Definition of the Congestion state machine.
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
T Get(void) const
Get the underlying value.
Definition: traced-value.h:232
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_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
#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
Every class exported by the ns3 library is enclosed in the ns3 namespace.
Information about the connection rate.
Definition: tcp-rate-ops.h:163
Rate Sample structure.
Definition: tcp-rate-ops.h:134