An implementation of TCP Scalable. More...

#include "tcp-scalable.h"

Inheritance diagram for ns3::TcpScalable:

Collaboration diagram for ns3::TcpScalable:

Public Member Functions
	TcpScalable ()
	Create an unbound tcp socket.

	TcpScalable (const TcpScalable &sock)
	Copy constructor.

	~TcpScalable () 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 slow start threshold following Scalable principle (Equation 2)

Public Member Functions inherited from ns3::TcpNewReno
	TcpNewReno ()

	TcpNewReno (const TcpNewReno &sock)
	Copy constructor.

	~TcpNewReno () override

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 bool	HasCongControl () const
	Returns true when Congestion Control Algorithm implements CongControl.

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.

virtual void	SetRateOps (Ptr< TcpRateOps > rateOps)
	Set rate operation required by the congestion control algorithm.

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 final
	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.

void	UnidirectionalAggregateObject (Ptr< Object > other)
	Aggregate an Object to another Object.

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, bool permissive=false) 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.

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::TcpNewReno
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
void	CongestionAvoidance (Ptr< TcpSocketState > tcb, uint32_t segmentsAcked) override
	Congestion avoidance of TcpScalable (Equation 1)

Protected Member Functions inherited from ns3::TcpNewReno
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.

Private Attributes
uint32_t	m_ackCnt
	Number of received ACK.

uint32_t	m_aiFactor
	Additive increase factor.

double	m_mdFactor
	Multiplicative decrease factor.

Additional Inherited Members
Related Symbols inherited from ns3::ObjectBase
static TypeId	GetObjectIid ()
	Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly.

Detailed Description

An implementation of TCP Scalable.

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

Config Paths

ns3::TcpScalable is accessible through the following paths with Config::Set and Config::Connect:

"/NodeList/[i]/$ns3::TcpL4Protocol/SocketList/[i]/CongestionOps/$ns3::TcpNewReno/$ns3::TcpScalable"
"/NodeList/[i]/$ns3::TcpL4Protocol/SocketList/[i]/CongestionOps/$ns3::TcpScalable"

Attributes

AIFactor: Additive Increase Factor
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 50
- Flags: constructwriteread
- Support level: SUPPORTED
MDFactor: Multiplicative Decrease Factor
- Set with class: ns3::DoubleValue
- Underlying type: double -1.79769e+308:1.79769e+308
- Initial value: 0.125
- Flags: constructwriteread
- Support level: SUPPORTED

Attributes defined in parent class ns3::TcpNewReno

BetaEcn: Beta for multiplicative decrease for ABE
- Set with class: ns3::DoubleValue
- Underlying type: double 0:1
- Initial value: 0.7
- Flags: constructwriteread
- Support level: SUPPORTED
BetaLoss: Beta for multiplicative decrease
- Set with class: ns3::DoubleValue
- Underlying type: double 0:1
- Initial value: 0.5
- Flags: constructwriteread
- Support level: SUPPORTED

No TraceSources are defined for this type
Group: Internet
Size of this type is 88 bytes (on a 64-bit architecture).

Definition at line 53 of file tcp-scalable.h.

Constructor & Destructor Documentation

◆ TcpScalable() [1/2]

ns3::TcpScalable::TcpScalable ( )

Create an unbound tcp socket.

Definition at line 50 of file tcp-scalable.cc.

References ns3::TcpNewReno::TcpNewReno(), m_ackCnt, m_aiFactor, m_mdFactor, and NS_LOG_FUNCTION.

Referenced by TcpScalable().

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◆ TcpScalable() [2/2]

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

Copy constructor.

Parameters

sock	the object to copy

Definition at line 59 of file tcp-scalable.cc.

References ns3::TcpNewReno::TcpNewReno(), TcpScalable(), m_ackCnt, m_aiFactor, m_mdFactor, and NS_LOG_FUNCTION.

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◆ ~TcpScalable()

ns3::TcpScalable::~TcpScalable ( )

override

Definition at line 68 of file tcp-scalable.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

◆ CongestionAvoidance()

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

overrideprotectedvirtual

Congestion avoidance of TcpScalable (Equation 1)

Parameters

tcb	internal congestion state
segmentsAcked	count of segments acked

Reimplemented from ns3::TcpNewReno.

Definition at line 80 of file tcp-scalable.cc.

References m_ackCnt, m_aiFactor, NS_ASSERT, NS_LOG_FUNCTION, and NS_LOG_INFO.

◆ Fork()

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

overridevirtual

Copy the congestion control algorithm across sockets.

Returns: a pointer of the copied object

Reimplemented from ns3::TcpNewReno.

Definition at line 74 of file tcp-scalable.cc.

References ns3::CopyObject().

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◆ GetName()

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

overridevirtual

Get the name of the congestion control algorithm.

Returns: A string identifying the name

Reimplemented from ns3::TcpNewReno.

Definition at line 113 of file tcp-scalable.cc.

◆ GetSsThresh()

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

overridevirtual

Get slow start threshold following Scalable principle (Equation 2)

Parameters

tcb	internal congestion state
bytesInFlight	bytes in flight

Returns: the slow start threshold value

Reimplemented from ns3::TcpNewReno.

Definition at line 119 of file tcp-scalable.cc.

References m_mdFactor, NS_LOG_DEBUG, and NS_LOG_FUNCTION.

◆ GetTypeId()

TypeId ns3::TcpScalable::GetTypeId ( )

static

Get the type ID.

Returns: the object TypeId

Definition at line 31 of file tcp-scalable.cc.

References ns3::TcpNewReno::TcpNewReno(), m_aiFactor, m_mdFactor, ns3::MakeDoubleAccessor(), ns3::MakeDoubleChecker(), ns3::MakeUintegerAccessor(), ns3::MakeUintegerChecker(), 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 98 of file tcp-scalable.h.

Referenced by TcpScalable(), TcpScalable(), and CongestionAvoidance().

◆ m_aiFactor

uint32_t ns3::TcpScalable::m_aiFactor

private

Additive increase factor.

Definition at line 99 of file tcp-scalable.h.

Referenced by TcpScalable(), TcpScalable(), CongestionAvoidance(), and GetTypeId().

◆ m_mdFactor

double ns3::TcpScalable::m_mdFactor

private

Multiplicative decrease factor.

Definition at line 100 of file tcp-scalable.h.

Referenced by TcpScalable(), TcpScalable(), GetSsThresh(), and GetTypeId().

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

src/internet/model/tcp-scalable.h
src/internet/model/tcp-scalable.cc

Public Member Functions

Static Public Member Functions

Protected Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Config Paths

Attributes

Attributes defined in parent class ns3::TcpNewReno

Constructor & Destructor Documentation

◆ TcpScalable() [1/2]

◆ TcpScalable() [2/2]

◆ ~TcpScalable()

Member Function Documentation

◆ CongestionAvoidance()

◆ Fork()

◆ GetName()

◆ GetSsThresh()

◆ GetTypeId()

Member Data Documentation

◆ m_ackCnt

◆ m_aiFactor

◆ m_mdFactor