The NewReno implementation. More...
#include "tcp-congestion-ops.h"
Public Member Functions | |
TcpNewReno () | |
TcpNewReno (const TcpNewReno &sock) | |
Copy constructor. | |
~TcpNewReno () override | |
Ptr< TcpCongestionOps > | Fork () override |
Copy the congestion control algorithm across sockets. | |
std::string | GetName () const override |
Get the name of the congestion control algorithm. | |
uint32_t | GetSsThresh (Ptr< const TcpSocketState > tcb, uint32_t bytesInFlight) override |
Get the slow start threshold after a loss event. | |
void | IncreaseWindow (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) override |
Try to increase the cWnd following the NewReno specification. | |
Public Member Functions inherited from ns3::TcpCongestionOps | |
TcpCongestionOps () | |
TcpCongestionOps (const TcpCongestionOps &other) | |
Copy constructor. | |
~TcpCongestionOps () override | |
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 | CongestionStateSet (Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCongState_t newState) |
Trigger events/calculations specific to a congestion state. | |
virtual void | CwndEvent (Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCAEvent_t event) |
Trigger events/calculations on occurrence of congestion window event. | |
virtual Ptr< TcpCongestionOps > | Fork ()=0 |
Copy the congestion control algorithm across sockets. | |
virtual std::string | GetName () const =0 |
Get the name of the congestion control algorithm. | |
virtual uint32_t | GetSsThresh (Ptr< const TcpSocketState > tcb, uint32_t bytesInFlight)=0 |
Get the slow start threshold after a loss event. | |
virtual bool | HasCongControl () const |
Returns true when Congestion Control Algorithm implements CongControl. | |
virtual void | IncreaseWindow (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) |
Congestion avoidance algorithm implementation. | |
virtual void | Init (Ptr< TcpSocketState > tcb) |
Set configuration required by congestion control algorithm. | |
virtual void | PktsAcked (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked, const Time &rtt) |
Timing information on received ACK. | |
Public Member Functions inherited from ns3::Object | |
Object () | |
Constructor. | |
~Object () override | |
Destructor. | |
void | AggregateObject (Ptr< Object > other) |
Aggregate two Objects together. | |
void | Dispose () |
Dispose of this Object. | |
AggregateIterator | GetAggregateIterator () const |
Get an iterator to the Objects aggregated to this one. | |
TypeId | GetInstanceTypeId () const override |
Get the most derived TypeId for this Object. | |
template<typename T > | |
Ptr< T > | GetObject () const |
Get a pointer to the requested aggregated Object. | |
template<> | |
Ptr< Object > | GetObject () const |
Specialization of () for objects of type ns3::Object. | |
template<typename T > | |
Ptr< T > | GetObject (TypeId tid) const |
Get a pointer to the requested aggregated Object by TypeId. | |
template<> | |
Ptr< Object > | GetObject (TypeId tid) const |
Specialization of (TypeId tid) for objects of type ns3::Object. | |
void | Initialize () |
Invoke DoInitialize on all Objects aggregated to this one. | |
bool | IsInitialized () const |
Check if the object has been initialized. | |
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter > | |
SimpleRefCount () | |
Default constructor. | |
SimpleRefCount (const SimpleRefCount &o) | |
Copy constructor. | |
uint32_t | GetReferenceCount () const |
Get the reference count of the object. | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
Assignment operator. | |
void | Ref () const |
Increment the reference count. | |
void | Unref () const |
Decrement the reference count. | |
Public Member Functions inherited from ns3::ObjectBase | |
virtual | ~ObjectBase () |
Virtual destructor. | |
void | GetAttribute (std::string name, AttributeValue &value) const |
Get the value of an attribute, raising fatal errors if unsuccessful. | |
bool | GetAttributeFailSafe (std::string name, AttributeValue &value) const |
Get the value of an attribute without raising errors. | |
virtual TypeId | GetInstanceTypeId () const =0 |
Get the most derived TypeId for this Object. | |
void | SetAttribute (std::string name, const AttributeValue &value) |
Set a single attribute, raising fatal errors if unsuccessful. | |
bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
Set a single attribute without raising errors. | |
bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
Connect a TraceSource to a Callback with a context. | |
bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
Connect a TraceSource to a Callback without a context. | |
bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected with a context. | |
bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected without a context. | |
Static Public Member Functions | |
static TypeId | GetTypeId () |
Get the type ID. | |
Static Public Member Functions inherited from ns3::TcpCongestionOps | |
static TypeId | GetTypeId () |
Get the type ID. | |
Static Public Member Functions inherited from ns3::Object | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::ObjectBase | |
static TypeId | GetTypeId () |
Get the type ID. | |
Protected Member Functions | |
virtual void | CongestionAvoidance (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) |
NewReno congestion avoidance. | |
virtual uint32_t | SlowStart (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) |
Tcp NewReno slow start algorithm. | |
Protected Member Functions inherited from ns3::Object | |
Object (const Object &o) | |
Copy an Object. | |
virtual void | DoDispose () |
Destructor implementation. | |
virtual void | DoInitialize () |
Initialize() implementation. | |
virtual void | NotifyNewAggregate () |
Notify all Objects aggregated to this one of a new Object being aggregated. | |
Protected Member Functions inherited from ns3::ObjectBase | |
void | ConstructSelf (const AttributeConstructionList &attributes) |
Complete construction of ObjectBase; invoked by derived classes. | |
virtual void | NotifyConstructionCompleted () |
Notifier called once the ObjectBase is fully constructed. | |
Additional Inherited Members | |
Related Functions inherited from ns3::ObjectBase | |
static TypeId | GetObjectIid () |
Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. | |
The NewReno implementation.
New Reno introduces partial ACKs inside the well-established Reno algorithm. This and other modifications are described in RFC 6582.
ns3::TcpNewReno is accessible through the following paths with Config::Set and Config::Connect:
No Attributes are defined for this type.
No TraceSources are defined for this type.
Size of this type is 32 bytes (on a 64-bit architecture).
Definition at line 211 of file tcp-congestion-ops.h.
ns3::TcpNewReno::TcpNewReno | ( | ) |
Definition at line 104 of file tcp-congestion-ops.cc.
References NS_LOG_FUNCTION.
ns3::TcpNewReno::TcpNewReno | ( | const TcpNewReno & | sock | ) |
Copy constructor.
sock | object to copy. |
Definition at line 110 of file tcp-congestion-ops.cc.
References NS_LOG_FUNCTION.
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override |
Definition at line 116 of file tcp-congestion-ops.cc.
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protectedvirtual |
NewReno congestion avoidance.
During congestion avoidance, cwnd is incremented by roughly 1 full-sized segment per round-trip time (RTT).
tcb | internal congestion state |
segmentsAcked | count of segments acked |
Reimplemented in ns3::TcpHighSpeed, ns3::TcpHtcp, ns3::TcpHybla, ns3::TcpLedbat, ns3::TcpLp, and ns3::TcpScalable.
Definition at line 188 of file tcp-congestion-ops.cc.
References NS_LOG_FUNCTION, and NS_LOG_INFO.
Referenced by ns3::TcpLedbat::CongestionAvoidance(), ns3::TcpLp::CongestionAvoidance(), IncreaseWindow(), ns3::TcpVeno::IncreaseWindow(), and ns3::TcpYeah::IncreaseWindow().
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overridevirtual |
Copy the congestion control algorithm across sockets.
Implements ns3::TcpCongestionOps.
Reimplemented in ns3::TcpHighSpeed, ns3::TcpHtcp, ns3::TcpHybla, ns3::TcpIllinois, ns3::TcpLedbat, ns3::TcpLp, ns3::TcpScalable, ns3::TcpVegas, ns3::TcpVeno, ns3::TcpWestwoodPlus, and ns3::TcpYeah.
Definition at line 252 of file tcp-congestion-ops.cc.
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overridevirtual |
Get the name of the congestion control algorithm.
Implements ns3::TcpCongestionOps.
Reimplemented in ns3::TcpHighSpeed, ns3::TcpHtcp, ns3::TcpHybla, ns3::TcpIllinois, ns3::TcpLedbat, ns3::TcpLp, ns3::TcpScalable, ns3::TcpVegas, ns3::TcpVeno, and ns3::TcpYeah.
Definition at line 238 of file tcp-congestion-ops.cc.
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overridevirtual |
Get the slow start threshold after a loss event.
Is guaranteed that the congestion control state (TcpAckState_t
) is changed BEFORE the invocation of this method. The implementer should return the slow start threshold (and not change it directly) because, in the future, the TCP implementation may require to instantly recover from a loss event (e.g. when there is a network with an high reordering factor).
tcb | internal congestion state |
bytesInFlight | total bytes in flight |
Implements ns3::TcpCongestionOps.
Reimplemented in ns3::TcpHighSpeed, ns3::TcpHtcp, ns3::TcpIllinois, ns3::TcpScalable, ns3::TcpVegas, ns3::TcpVeno, ns3::TcpWestwoodPlus, and ns3::TcpYeah.
Definition at line 244 of file tcp-congestion-ops.cc.
References NS_LOG_FUNCTION.
Referenced by ns3::TcpVeno::GetSsThresh().
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static |
Get the type ID.
Definition at line 95 of file tcp-congestion-ops.cc.
References ns3::TypeId::SetParent().
Referenced by TcpFastRetrTestSuite::TcpFastRetrTestSuite(), TcpPacingTestSuite::TcpPacingTestSuite(), TcpRenoCongAvoidTestSuite::TcpRenoCongAvoidTestSuite(), TcpRtoTestSuite::TcpRtoTestSuite(), TcpSlowStartTestSuite::TcpSlowStartTestSuite(), and ThreeGppHttpClientServerTestSuite::AddHttpObjectTestCase().
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overridevirtual |
Try to increase the cWnd following the NewReno specification.
tcb | internal congestion state |
segmentsAcked | count of segments acked |
Reimplemented from ns3::TcpCongestionOps.
Reimplemented in ns3::TcpIllinois, ns3::TcpLedbat, ns3::TcpVegas, ns3::TcpVeno, and ns3::TcpYeah.
Definition at line 213 of file tcp-congestion-ops.cc.
References CongestionAvoidance(), NS_LOG_FUNCTION, and SlowStart().
Referenced by ns3::TcpVegas::IncreaseWindow(), and ns3::TcpVeno::IncreaseWindow().
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protectedvirtual |
Tcp NewReno slow start algorithm.
Defined in RFC 5681 as
During slow start, a TCP increments cwnd by at most SMSS bytes for each ACK received that cumulatively acknowledges new data. Slow start ends when cwnd exceeds ssthresh (or, optionally, when it reaches it, as noted above) or when congestion is observed. While traditionally TCP implementations have increased cwnd by precisely SMSS bytes upon receipt of an ACK covering new data, we RECOMMEND that TCP implementations increase cwnd, per:
cwnd += min (N, SMSS) (2)
where N is the number of previously unacknowledged bytes acknowledged in the incoming ACK.
The ns-3 implementation respect the RFC definition. Linux does something different:
</blockquote>u32 tcp_slow_start(struct tcp_sock *tp, u32 acked) { u32 cwnd = tp->snd_cwnd + acked; if (cwnd > tp->snd_ssthresh) cwnd = tp->snd_ssthresh + 1; acked -= cwnd - tp->snd_cwnd; tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp); return acked; }As stated, we want to avoid the case when a cumulative ACK increases cWnd more than a segment size, but we keep count of how many segments we have ignored, and return them.
- Parameters
tcb internal congestion state segmentsAcked count of segments acked
- Returns
- the number of segments not considered for increasing the cWnd
Reimplemented in ns3::TcpHybla.
Definition at line 163 of file tcp-congestion-ops.cc.
References NS_LOG_FUNCTION, and NS_LOG_INFO.
Referenced by IncreaseWindow(), ns3::TcpIllinois::IncreaseWindow(), ns3::TcpLedbat::IncreaseWindow(), ns3::TcpVegas::IncreaseWindow(), ns3::TcpVeno::IncreaseWindow(), and ns3::TcpYeah::IncreaseWindow().