A Discrete-Event Network Simulator
API
ns3::TcpScalable Class Reference

An implementation of TCP Scalable. More...

#include "tcp-scalable.h"

+ Inheritance diagram for ns3::TcpScalable:
+ Collaboration diagram for ns3::TcpScalable:

Public Member Functions

 TcpScalable (void)
 Create an unbound tcp socket. More...
 
 TcpScalable (const TcpScalable &sock)
 Copy constructor. More...
 
virtual ~TcpScalable (void)
 
virtual Ptr< TcpCongestionOpsFork ()
 Copy the congestion control algorithm across sockets. More...
 
virtual std::string GetName () const
 Get the name of the congestion control algorithm. More...
 
virtual uint32_t GetSsThresh (Ptr< const TcpSocketState > tcb, uint32_t bytesInFlight)
 Get slow start threshold following Scalable principle (Equation 2) More...
 
- Public Member Functions inherited from ns3::TcpNewReno
 TcpNewReno ()
 
 TcpNewReno (const TcpNewReno &sock)
 Copy constructor. More...
 
 ~TcpNewReno ()
 
virtual void IncreaseWindow (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
 Try to increase the cWnd following the NewReno specification. More...
 
- Public Member Functions inherited from ns3::TcpCongestionOps
 TcpCongestionOps ()
 
 TcpCongestionOps (const TcpCongestionOps &other)
 Copy constructor. More...
 
virtual ~TcpCongestionOps ()
 
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. More...
 
virtual void CongestionStateSet (Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCongState_t newState)
 Trigger events/calculations specific to a congestion state. More...
 
virtual void CwndEvent (Ptr< TcpSocketState > tcb, const TcpSocketState::TcpCAEvent_t event)
 Trigger events/calculations on occurrence of congestion window event. More...
 
virtual bool HasCongControl () const
 Returns true when Congestion Control Algorithm implements CongControl. More...
 
virtual void PktsAcked (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked, const Time &rtt)
 Timing information on received ACK. More...
 
- Public Member Functions inherited from ns3::Object
 Object ()
 Constructor. More...
 
virtual ~Object ()
 Destructor. More...
 
void AggregateObject (Ptr< Object > other)
 Aggregate two Objects together. More...
 
void Dispose (void)
 Dispose of this Object. More...
 
AggregateIterator GetAggregateIterator (void) const
 Get an iterator to the Objects aggregated to this one. More...
 
virtual TypeId GetInstanceTypeId (void) const
 Get the most derived TypeId for this Object. More...
 
template<typename T >
Ptr< T > GetObject (void) const
 Get a pointer to the requested aggregated Object. More...
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 Get a pointer to the requested aggregated Object by TypeId. More...
 
void Initialize (void)
 Invoke DoInitialize on all Objects aggregated to this one. More...
 
bool IsInitialized (void) const
 Check if the object has been initialized. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 Default constructor. More...
 
 SimpleRefCount (const SimpleRefCount &o)
 Copy constructor. More...
 
uint32_t GetReferenceCount (void) const
 Get the reference count of the object. More...
 
SimpleRefCountoperator= (const SimpleRefCount &o)
 Assignment operator. More...
 
void Ref (void) const
 Increment the reference count. More...
 
void Unref (void) const
 Decrement the reference count. More...
 
- Public Member Functions inherited from ns3::ObjectBase
virtual ~ObjectBase ()
 Virtual destructor. More...
 
void GetAttribute (std::string name, AttributeValue &value) const
 Get the value of an attribute, raising fatal errors if unsuccessful. More...
 
bool GetAttributeFailSafe (std::string name, AttributeValue &value) const
 Get the value of an attribute without raising erros. More...
 
void SetAttribute (std::string name, const AttributeValue &value)
 Set a single attribute, raising fatal errors if unsuccessful. More...
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 Set a single attribute without raising errors. More...
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 Connect a TraceSource to a Callback with a context. More...
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 Connect a TraceSource to a Callback without a context. More...
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected with a context. More...
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 Disconnect from a TraceSource a Callback previously connected without a context. More...
 

Static Public Member Functions

static TypeId GetTypeId (void)
 Get the type ID. More...
 
- Static Public Member Functions inherited from ns3::TcpNewReno
static TypeId GetTypeId (void)
 Get the type ID. More...
 
- Static Public Member Functions inherited from ns3::TcpCongestionOps
static TypeId GetTypeId (void)
 Get the type ID. More...
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Protected Member Functions

virtual void CongestionAvoidance (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
 Congestion avoidance of TcpScalable (Equation 1) More...
 
- Protected Member Functions inherited from ns3::TcpNewReno
virtual uint32_t SlowStart (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked)
 
Tcp NewReno slow start algorithm More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 Copy an Object. More...
 
virtual void DoDispose (void)
 Destructor implementation. More...
 
virtual void DoInitialize (void)
 Initialize() implementation. More...
 
virtual void NotifyNewAggregate (void)
 Notify all Objects aggregated to this one of a new Object being aggregated. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 Complete construction of ObjectBase; invoked by derived classes. More...
 
virtual void NotifyConstructionCompleted (void)
 Notifier called once the ObjectBase is fully constructed. More...
 

Private Attributes

uint32_t m_ackCnt
 Number of received ACK. More...
 
uint32_t m_aiFactor
 Additive increase factor. More...
 
double m_mdFactor
 Multiplicative decrease factor. More...
 

Additional Inherited Members

Detailed Description

An implementation of TCP Scalable.


Introspection did not find any typical Config paths.

Scalable improves TCP performance to better utilize the available bandwidth of a highspeed wide area network by altering NewReno congestion window adjustment algorithm.

When congestion has not been detected, for each ACK received in an RTT, Scalable increases its cwnd per:

    cwnd = cwnd + 0.01                  (1)

Following Linux implementation of Scalable, we use 50 instead of 100 to account for delayed ACK.

On the first detection of congestion in a given RTT, cwnd is reduced based on the following equation:

    cwnd = cwnd - ceil(0.125 * cwnd)       (2)

More information: http://doi.acm.org/10.1145/956981.956989


Attributes

  • AIFactor: Additive Increase Factor
    • Set with class: ns3::UintegerValue
    • Underlying type: uint32_t 0:4294967295
    • Initial value: 50
    • Flags: construct write read
  • MDFactor: Multiplicative Decrease Factor
    • Set with class: ns3::DoubleValue
    • Underlying type: double -1.79769e+308:1.79769e+308
    • Initial value: 0.125
    • Flags: construct write read

No TraceSources are defined for this type.
Size of this type is 48 bytes (on a 64-bit architecture).

Definition at line 63 of file tcp-scalable.h.

Constructor & Destructor Documentation

◆ TcpScalable() [1/2]

ns3::TcpScalable::TcpScalable ( void  )

Create an unbound tcp socket.

Definition at line 57 of file tcp-scalable.cc.

References NS_LOG_FUNCTION.

◆ TcpScalable() [2/2]

ns3::TcpScalable::TcpScalable ( const TcpScalable sock)

Copy constructor.

Parameters
sockthe object to copy

Definition at line 66 of file tcp-scalable.cc.

References NS_LOG_FUNCTION.

◆ ~TcpScalable()

ns3::TcpScalable::~TcpScalable ( void  )
virtual

Definition at line 75 of file tcp-scalable.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

◆ CongestionAvoidance()

void ns3::TcpScalable::CongestionAvoidance ( Ptr< TcpSocketState tcb,
uint32_t  segmentsAcked 
)
protectedvirtual

Congestion avoidance of TcpScalable (Equation 1)

Parameters
tcbinternal congestion state
segmentsAckedcount of segments acked

Reimplemented from ns3::TcpNewReno.

Definition at line 87 of file tcp-scalable.cc.

References ns3::TcpSocketState::GetCwndInSegments(), m_ackCnt, m_aiFactor, ns3::TcpSocketState::m_cWnd, ns3::TcpSocketState::m_segmentSize, ns3::TcpSocketState::m_ssThresh, min, NS_ASSERT, NS_LOG_FUNCTION, and NS_LOG_INFO.

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◆ Fork()

Ptr< TcpCongestionOps > ns3::TcpScalable::Fork ( )
virtual

Copy the congestion control algorithm across sockets.

Returns
a pointer of the copied object

Reimplemented from ns3::TcpNewReno.

Definition at line 81 of file tcp-scalable.cc.

◆ GetName()

std::string ns3::TcpScalable::GetName ( ) const
virtual

Get the name of the congestion control algorithm.

Returns
A string identifying the name

Reimplemented from ns3::TcpNewReno.

Definition at line 121 of file tcp-scalable.cc.

◆ GetSsThresh()

uint32_t ns3::TcpScalable::GetSsThresh ( Ptr< const TcpSocketState tcb,
uint32_t  bytesInFlight 
)
virtual

Get slow start threshold following Scalable principle (Equation 2)

Parameters
tcbinternal congestion state
bytesInFlightbytes in flight
Returns
the slow start threshold value

Reimplemented from ns3::TcpNewReno.

Definition at line 127 of file tcp-scalable.cc.

References m_mdFactor, max, NS_LOG_DEBUG, and NS_LOG_FUNCTION.

Referenced by TcpScalableDecrementTest::DoRun().

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◆ GetTypeId()

TypeId ns3::TcpScalable::GetTypeId ( void  )
static

Get the type ID.

Returns
the object TypeId

Definition at line 39 of file tcp-scalable.cc.

References m_aiFactor, m_mdFactor, ns3::MakeDoubleAccessor(), ns3::MakeUintegerAccessor(), and ns3::TypeId::SetParent().

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Member Data Documentation

◆ m_ackCnt

uint32_t ns3::TcpScalable::m_ackCnt
private

Number of received ACK.

Definition at line 110 of file tcp-scalable.h.

Referenced by CongestionAvoidance().

◆ m_aiFactor

uint32_t ns3::TcpScalable::m_aiFactor
private

Additive increase factor.

Definition at line 111 of file tcp-scalable.h.

Referenced by CongestionAvoidance(), and GetTypeId().

◆ m_mdFactor

double ns3::TcpScalable::m_mdFactor
private

Multiplicative decrease factor.

Definition at line 112 of file tcp-scalable.h.

Referenced by GetSsThresh(), and GetTypeId().


The documentation for this class was generated from the following files: