An implementation of a stream socket using TCP. More...

#include <tcp-westwood.h>

Inheritance diagram for ns3::TcpWestwood:

Collaboration diagram for ns3::TcpWestwood:

Public Types
enum	FilterType { NONE, TUSTIN }
enum	ProtocolType { WESTWOOD, WESTWOODPLUS }

Public Member Functions
	TcpWestwood (void)
	TcpWestwood (const TcpWestwood &sock)
virtual	~TcpWestwood (void)
virtual int	Connect (const Address &address)
virtual int	Listen (void)
Public Member Functions inherited from ns3::TcpSocketBase
	TcpSocketBase (void)
	TcpSocketBase (const TcpSocketBase &sock)
virtual	~TcpSocketBase (void)
virtual int	Bind (void)
virtual int	Bind (const Address &address)
virtual int	Bind6 (void)
	Allocate a local IPv6 endpoint for this socket.
virtual void	BindToNetDevice (Ptr< NetDevice > netdevice)
virtual int	Close (void)
virtual enum SocketErrno	GetErrno (void) const
virtual Ptr< Node >	GetNode (void) const
virtual uint32_t	GetRxAvailable (void) const
virtual enum SocketType	GetSocketType (void) const
virtual int	GetSockName (Address &address) const
virtual uint32_t	GetTxAvailable (void) const
virtual Ptr< Packet >	Recv (uint32_t maxSize, uint32_t flags)
virtual Ptr< Packet >	RecvFrom (uint32_t maxSize, uint32_t flags, Address &fromAddress)
virtual int	Send (Ptr< Packet > p, uint32_t flags)
virtual int	SendTo (Ptr< Packet > p, uint32_t flags, const Address &toAddress)
virtual void	SetNode (Ptr< Node > node)
virtual void	SetRtt (Ptr< RttEstimator > rtt)
virtual void	SetTcp (Ptr< TcpL4Protocol > tcp)
virtual int	ShutdownRecv (void)
virtual int	ShutdownSend (void)
Public Member Functions inherited from ns3::TcpSocket
	TcpSocket (void)
virtual	~TcpSocket (void)
Public Member Functions inherited from ns3::Socket
	Socket (void)
virtual	~Socket (void)
Ptr< NetDevice >	GetBoundNetDevice ()
	Returns socket's bound netdevice, if any.
uint8_t	GetIpTos (void) const
virtual uint8_t	GetIpTtl (void) const
virtual uint8_t	GetIpv6HopLimit (void) const
uint8_t	GetIpv6Tclass (void) const
bool	IsIpRecvTos (void) const
	Ask if the socket is currently passing information about IP Type of Service up the stack.
bool	IsIpRecvTtl (void) const
	Ask if the socket is currently passing information about IP_TTL up the stack.
bool	IsIpv6RecvHopLimit (void) const
	Ask if the socket is currently passing information about IPv6 Hop Limit up the stack.
bool	IsIpv6RecvTclass (void) const
	Ask if the socket is currently passing information about IPv6 Traffic Class up the stack.
bool	IsRecvPktInfo () const
	Get status indicating whether enable/disable packet information to socket.
Ptr< Packet >	Recv (void)
	Read a single packet from the socket.
int	Recv (uint8_t *buf, uint32_t size, uint32_t flags)
	Recv data (or dummy data) from the remote host.
Ptr< Packet >	RecvFrom (Address &fromAddress)
	Read a single packet from the socket and retrieve the sender address.
int	RecvFrom (uint8_t *buf, uint32_t size, uint32_t flags, Address &fromAddress)
	Read a single packet from the socket and retrieve the sender address.
int	Send (Ptr< Packet > p)
	Send data (or dummy data) to the remote host.
int	Send (const uint8_t *buf, uint32_t size, uint32_t flags)
	Send data (or dummy data) to the remote host.
int	SendTo (const uint8_t *buf, uint32_t size, uint32_t flags, const Address &address)
	Send data to a specified peer.
void	SetAcceptCallback (Callback< bool, Ptr< Socket >, const Address & > connectionRequest, Callback< void, Ptr< Socket >, const Address & > newConnectionCreated)
	Accept connection requests from remote hosts.
void	SetCloseCallbacks (Callback< void, Ptr< Socket > > normalClose, Callback< void, Ptr< Socket > > errorClose)
	Detect socket recv() events such as graceful shutdown or error.
void	SetConnectCallback (Callback< void, Ptr< Socket > > connectionSucceeded, Callback< void, Ptr< Socket > > connectionFailed)
	Specify callbacks to allow the caller to determine if the connection succeeds of fails.
void	SetDataSentCallback (Callback< void, Ptr< Socket >, uint32_t > dataSent)
	Notify application when a packet has been sent from transport protocol (non-standard socket call)
void	SetIpRecvTos (bool ipv4RecvTos)
	Tells a socket to pass information about IP Type of Service up the stack.
void	SetIpRecvTtl (bool ipv4RecvTtl)
	Tells a socket to pass information about IP_TTL up the stack.
void	SetIpTos (uint8_t ipTos)
virtual void	SetIpTtl (uint8_t ipTtl)
virtual void	SetIpv6HopLimit (uint8_t ipHopLimit)
void	SetIpv6RecvHopLimit (bool ipv6RecvHopLimit)
	Tells a socket to pass information about IPv6 Hop Limit up the stack.
void	SetIpv6RecvTclass (bool ipv6RecvTclass)
	Tells a socket to pass information about IPv6 Traffic Class up the stack.
void	SetIpv6Tclass (int ipTclass)
void	SetRecvCallback (Callback< void, Ptr< Socket > >)
	Notify application when new data is available to be read.
void	SetRecvPktInfo (bool flag)
	Enable/Disable receive packet information to socket.
void	SetSendCallback (Callback< void, Ptr< Socket >, uint32_t > sendCb)
	Notify application when space in transmit buffer is added.
Public Member Functions inherited from ns3::Object
	Object ()
virtual	~Object ()
void	AggregateObject (Ptr< Object > other)
void	Dispose (void)
AggregateIterator	GetAggregateIterator (void) const
virtual TypeId	GetInstanceTypeId (void) const
template<typename T >
Ptr< T >	GetObject (void) const
template<typename T >
Ptr< T >	GetObject (TypeId tid) const
void	Initialize (void)
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
	SimpleRefCount ()
	SimpleRefCount (const SimpleRefCount &o)
uint32_t	GetReferenceCount (void) const
SimpleRefCount &	operator= (const SimpleRefCount &o)
void	Ref (void) const
void	Unref (void) const
Public Member Functions inherited from ns3::ObjectBase
virtual	~ObjectBase ()
void	GetAttribute (std::string name, AttributeValue &value) const
bool	GetAttributeFailSafe (std::string name, AttributeValue &attribute) const
void	SetAttribute (std::string name, const AttributeValue &value)
bool	SetAttributeFailSafe (std::string name, const AttributeValue &value)
bool	TraceConnect (std::string name, std::string context, const CallbackBase &cb)
bool	TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
bool	TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
bool	TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)

Static Public Member Functions
static TypeId	GetTypeId (void)

Protected Member Functions
virtual void	DupAck (const TcpHeader &header, uint32_t count)
virtual void	EstimateRtt (const TcpHeader &header)
virtual Ptr< TcpSocketBase >	Fork (void)
virtual uint32_t	GetInitialCwnd (void) const
virtual uint32_t	GetSSThresh (void) const
virtual void	NewAck (SequenceNumber32 const &seq)
virtual void	ReceivedAck (Ptr< Packet > packet, const TcpHeader &tcpHeader)
virtual void	Retransmit (void)
virtual void	SetInitialCwnd (uint32_t cwnd)
virtual void	SetSegSize (uint32_t size)
virtual void	SetSSThresh (uint32_t threshold)
virtual uint32_t	Window (void)
Protected Member Functions inherited from ns3::TcpSocketBase
virtual void	AddOptions (TcpHeader &)
virtual uint16_t	AdvertisedWindowSize (void)
virtual uint32_t	AvailableWindow (void)
virtual uint32_t	BytesInFlight (void)
void	CancelAllTimers (void)
void	CloseAndNotify (void)
void	CompleteFork (Ptr< Packet >, const TcpHeader &, const Address &fromAddress, const Address &toAdress)
void	ConnectionSucceeded (void)
void	DeallocateEndPoint (void)
virtual void	DelAckTimeout (void)
void	Destroy (void)
void	Destroy6 (void)
int	DoClose (void)
int	DoConnect (void)
virtual void	DoForwardUp (Ptr< Packet > packet, Ipv4Header header, uint16_t port, Ptr< Ipv4Interface > incomingInterface)
virtual void	DoForwardUp (Ptr< Packet > packet, Ipv6Header header, uint16_t port)
void	DoPeerClose (void)
virtual void	DoRetransmit (void)
void	ForwardIcmp (Ipv4Address icmpSource, uint8_t icmpTtl, uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo)
void	ForwardIcmp6 (Ipv6Address icmpSource, uint8_t icmpTtl, uint8_t icmpType, uint8_t icmpCode, uint32_t icmpInfo)
void	ForwardUp (Ptr< Packet > packet, Ipv4Header header, uint16_t port, Ptr< Ipv4Interface > incomingInterface)
void	ForwardUp6 (Ptr< Packet > packet, Ipv6Header header, uint16_t port)
virtual bool	GetAllowBroadcast (void) const
	Query whether broadcast datagram transmissions are allowed.
virtual uint32_t	GetConnCount (void) const
virtual Time	GetConnTimeout (void) const
virtual uint32_t	GetDelAckMaxCount (void) const
virtual Time	GetDelAckTimeout (void) const
virtual Time	GetPersistTimeout (void) const
virtual uint32_t	GetRcvBufSize (void) const
virtual uint32_t	GetSegSize (void) const
virtual uint32_t	GetSndBufSize (void) const
virtual bool	GetTcpNoDelay (void) const
virtual void	LastAckTimeout (void)
bool	OutOfRange (SequenceNumber32 head, SequenceNumber32 tail) const
void	PeerClose (Ptr< Packet >, const TcpHeader &)
virtual void	PersistTimeout (void)
void	ProcessClosing (Ptr< Packet >, const TcpHeader &)
void	ProcessEstablished (Ptr< Packet >, const TcpHeader &)
void	ProcessLastAck (Ptr< Packet >, const TcpHeader &)
void	ProcessListen (Ptr< Packet >, const TcpHeader &, const Address &, const Address &)
void	ProcessSynRcvd (Ptr< Packet >, const TcpHeader &, const Address &, const Address &)
void	ProcessSynSent (Ptr< Packet >, const TcpHeader &)
void	ProcessWait (Ptr< Packet >, const TcpHeader &)
virtual void	ReadOptions (const TcpHeader &)
virtual void	ReceivedData (Ptr< Packet >, const TcpHeader &)
virtual void	ReTxTimeout (void)
uint32_t	SendDataPacket (SequenceNumber32 seq, uint32_t maxSize, bool withAck)
void	SendEmptyPacket (uint8_t flags)
bool	SendPendingData (bool withAck=false)
void	SendRST (void)
virtual bool	SetAllowBroadcast (bool allowBroadcast)
	Configure whether broadcast datagram transmissions are allowed.
virtual void	SetConnCount (uint32_t count)
virtual void	SetConnTimeout (Time timeout)
virtual void	SetDelAckMaxCount (uint32_t count)
virtual void	SetDelAckTimeout (Time timeout)
virtual void	SetPersistTimeout (Time timeout)
virtual void	SetRcvBufSize (uint32_t size)
virtual void	SetSndBufSize (uint32_t size)
virtual void	SetTcpNoDelay (bool noDelay)
int	SetupCallback (void)
int	SetupEndpoint (void)
int	SetupEndpoint6 (void)
void	TimeWait (void)
virtual uint32_t	UnAckDataCount (void)

Protected Attributes
int	m_accountedFor
int	m_ackedSegments
EventId	m_bwEstimateEvent
TracedValue< double >	m_currentBW
TracedValue< uint32_t >	m_cWnd
enum FilterType	m_fType
bool	m_inFastRec
uint32_t	m_initialCWnd
bool	m_IsCount
double	m_lastAck
double	m_lastBW
double	m_lastSampleBW
Time	m_minRtt
SequenceNumber32	m_prevAckNo
enum ProtocolType	m_pType
uint32_t	m_ssThresh
Protected Attributes inherited from ns3::TcpSocketBase
bool	m_closeNotified
bool	m_closeOnEmpty
uint32_t	m_cnCount
uint32_t	m_cnRetries
Time	m_cnTimeout
bool	m_connected
uint32_t	m_delAckCount
EventId	m_delAckEvent
uint32_t	m_delAckMaxCount
Time	m_delAckTimeout
uint32_t	m_dupAckCount
Ipv4EndPoint *	m_endPoint
Ipv6EndPoint *	m_endPoint6
enum SocketErrno	m_errno
TracedValue< SequenceNumber32 >	m_highTxMark
Callback< void, Ipv4Address, uint8_t, uint8_t, uint8_t, uint32_t >	m_icmpCallback
Callback< void, Ipv6Address, uint8_t, uint8_t, uint8_t, uint32_t >	m_icmpCallback6
EventId	m_lastAckEvent
TracedValue< Time >	m_lastRtt
uint16_t	m_maxWinSize
double	m_msl
TracedValue< SequenceNumber32 >	m_nextTxSequence
Ptr< Node >	m_node
bool	m_noDelay
EventId	m_persistEvent
Time	m_persistTimeout
EventId	m_retxEvent
TracedValue< Time >	m_rto
Ptr< RttEstimator >	m_rtt
TracedValue< uint32_t >	m_rWnd
TcpRxBuffer	m_rxBuffer
uint32_t	m_segmentSize
bool	m_shutdownRecv
bool	m_shutdownSend
TracedValue< TcpStates_t >	m_state
Ptr< TcpL4Protocol >	m_tcp
EventId	m_timewaitEvent
TcpTxBuffer	m_txBuffer

Private Member Functions
int	CountAck (const TcpHeader &tcpHeader)
void	EstimateBW (int acked, const TcpHeader &tcpHeader, Time rtt)
void	Filtering (void)
void	InitializeCwnd (void)
void	UpdateAckedSegments (int acked)

Additional Inherited Members
Static Public Attributes inherited from ns3::TcpSocket
static const char *const	TcpStateName [LAST_STATE] = { "CLOSED", "LISTEN", "SYN_SENT", "SYN_RCVD", "ESTABLISHED", "CLOSE_WAIT", "LAST_ACK", "FIN_WAIT_1", "FIN_WAIT_2", "CLOSING", "TIME_WAIT" }

Detailed Description

An implementation of a stream socket using TCP.

This class contains the implementation of TCP Westwood and Westwood+.

Westwood and Westwood+ employ the AIAD (Additive Increase/Adaptive Decrease) congestion control paradigm. When a congestion episode happens, instead of halving the cwnd, these protocols try to estimate the network's bandwidth and use the estimated value to adjust the cwnd. While Westwood performs the bandwidth sampling every ACK reception, Westwood+ samples the bandwidth every RTT.

The two main methods in the implementation are the CountAck (const TCPHeader&) and the EstimateBW (int, const, Time). The CountAck method calculates the number of acknowledged segments on the receipt of an ACK. The EstimateBW estimates the bandwidth based on the value returned by CountAck and the sampling interval (last ACK inter-arrival time for Westwood and last RTT for Westwood+).

Config Paths

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

/NodeList/[i]/$ns3::TcpL4Protocol/SocketList/[i]/$ns3::TcpWestwood

Attributes

FilterType: Use this to choose no filter or Tustin's approximation filter
- Set with class: ns3::EnumValue
- Underlying type: None|Tustin
- Initial value: Tustin
- Flags: construct write read
ProtocolType: Use this to let the code run as Westwood or WestwoodPlus
- Set with class: ns3::EnumValue
- Underlying type: Westwood|WestwoodPlus
- Initial value: Westwood
- Flags: construct write read

Attributes defined in parent class ns3::TcpSocketBase

MaxSegLifetime: Maximum segment lifetime in seconds, use for TIME_WAIT state transition to CLOSED state
- Set with class: ns3::DoubleValue
- Underlying type: double 0:1.79769e+308
- Initial value: 120
- Flags: construct write read
MaxWindowSize: Max size of advertised window
- Set with class: ns3::UintegerValue
- Underlying type: uint16_t 0:65535
- Initial value: 65535
- Flags: construct write read
IcmpCallback: Callback invoked whenever an icmp error is received on this socket.
- Set with class: CallbackValue
- Underlying type: Callback
- Initial value: 0
- Flags: construct write read
IcmpCallback6: Callback invoked whenever an icmpv6 error is received on this socket.
- Set with class: CallbackValue
- Underlying type: Callback
- Initial value: 0
- Flags: construct write read

Attributes defined in parent class ns3::TcpSocket

SndBufSize: TcpSocket maximum transmit buffer size (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 131072
- Flags: construct write read
RcvBufSize: TcpSocket maximum receive buffer size (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 131072
- Flags: construct write read
SegmentSize: TCP maximum segment size in bytes (may be adjusted based on MTU discovery)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 536
- Flags: construct write read
SlowStartThreshold: TCP slow start threshold (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 65535
- Flags: construct write read
InitialCwnd: TCP initial congestion window size (segments)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 1
- Flags: construct write read
ConnTimeout: TCP retransmission timeout when opening connection (seconds)
- Set with class: TimeValue
- Underlying type: Time
- Initial value: +3000000000.0ns
- Flags: construct write read
ConnCount: Number of connection attempts (SYN retransmissions) before returning failure
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 6
- Flags: construct write read
DelAckTimeout: Timeout value for TCP delayed acks, in seconds
- Set with class: TimeValue
- Underlying type: Time
- Initial value: +200000000.0ns
- Flags: construct write read
DelAckCount: Number of packets to wait before sending a TCP ack
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 2
- Flags: construct write read
TcpNoDelay: Set to true to disable Nagle's algorithm
- Set with class: BooleanValue
- Underlying type: bool
- Initial value: true
- Flags: construct write read
PersistTimeout: Persist timeout to probe for rx window
- Set with class: TimeValue
- Underlying type: Time
- Initial value: +6000000000.0ns
- Flags: construct write read

TraceSources

CongestionWindow: The TCP connection's congestion window
EstimatedBW: The estimated bandwidth

TraceSources defined in parent class ns3::TcpSocketBase

RTO: Retransmission timeout
RTT: Last RTT sample
NextTxSequence: Next sequence number to send (SND.NXT)
HighestSequence: Highest sequence number ever sent in socket's life time
State: TCP state
RWND: Remote side's flow control window

Definition at line 62 of file tcp-westwood.h.

Member Enumeration Documentation

enum ns3::TcpWestwood::FilterType

Enumerator:

NONE
TUSTIN

Definition at line 77 of file tcp-westwood.h.

enum ns3::TcpWestwood::ProtocolType

Enumerator:

WESTWOOD
WESTWOODPLUS

Definition at line 71 of file tcp-westwood.h.

Constructor & Destructor Documentation

ns3::TcpWestwood::TcpWestwood ( void )

Definition at line 71 of file tcp-westwood.cc.

References NS_LOG_FUNCTION.

ns3::TcpWestwood::TcpWestwood ( const TcpWestwood & sock )

Definition at line 86 of file tcp-westwood.cc.

References m_minRtt, NS_LOG_FUNCTION, NS_LOG_INFO, and NS_LOG_LOGIC.

ns3::TcpWestwood::~TcpWestwood ( void )

virtual

Definition at line 108 of file tcp-westwood.cc.

Member Function Documentation

int ns3::TcpWestwood::Connect ( const Address & address )

virtual

Inherit from Socket class: Initiate connection to a remote address:port

Reimplemented from ns3::TcpSocketBase.

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

References InitializeCwnd(), and NS_LOG_FUNCTION.

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int ns3::TcpWestwood::CountAck ( const TcpHeader & tcpHeader )

private

Calculate the number of acknowledged packets upon the receipt of an ACK packet

Parameters

tcpHeader the header of the received ACK packet

Returns: the number of ACKed packets

Definition at line 228 of file tcp-westwood.cc.

References ns3::TcpHeader::GetAckNumber(), m_accountedFor, m_prevAckNo, ns3::TcpSocketBase::m_segmentSize, and NS_LOG_FUNCTION.

Referenced by ReceivedAck().

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void ns3::TcpWestwood::DupAck	(	const TcpHeader &	header,
		uint32_t	count
	)

protectedvirtual

Adjust the cwnd using the currently estimated bandwidth, retransmit the missing packet, and enter fast recovery if 3 DUPACKs are received

Parameters

header	the TCP header of the ACK packet
count	the number of DUPACKs

Implements ns3::TcpSocketBase.

Definition at line 268 of file tcp-westwood.cc.

References ns3::TcpSocketBase::DoRetransmit(), ns3::Time::GetSeconds(), ns3::TcpSocketBase::m_connected, m_currentBW, m_cWnd, m_inFastRec, m_minRtt, ns3::TcpSocketBase::m_segmentSize, m_ssThresh, NS_LOG_FUNCTION, NS_LOG_INFO, and ns3::TcpSocketBase::SendPendingData().

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void ns3::TcpWestwood::EstimateBW	(	int	acked,
		const TcpHeader &	tcpHeader,
		Time	rtt
	)

private

Estimate the network's bandwidth

Parameters

acked	the number of acknowledged packets returned by CountAck
tcpHeader	the header of the packet
rtt	the RTT estimation

Definition at line 202 of file tcp-westwood.cc.

References Filtering(), ns3::Time::GetSeconds(), m_ackedSegments, m_currentBW, m_IsCount, m_lastAck, m_pType, ns3::TcpSocketBase::m_segmentSize, ns3::Now(), NS_LOG_FUNCTION, WESTWOOD, and WESTWOODPLUS.

Referenced by EstimateRtt(), and ReceivedAck().

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void ns3::TcpWestwood::EstimateRtt ( const TcpHeader & header )

protectedvirtual

Estimate the RTT, record the minimum value, and run a clock on the RTT to trigger Westwood+ bandwidth sampling

Reimplemented from ns3::TcpSocketBase.

Definition at line 323 of file tcp-westwood.cc.

References ns3::EventId::Cancel(), ns3::ESTABLISHED, EstimateBW(), m_ackedSegments, m_bwEstimateEvent, m_IsCount, ns3::TcpSocketBase::m_lastRtt, m_minRtt, m_pType, ns3::TcpSocketBase::m_state, NS_LOG_FUNCTION_NOARGS, ns3::Simulator::Schedule(), and WESTWOODPLUS.

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void ns3::TcpWestwood::Filtering ( void )

private

Tustin filter

Definition at line 357 of file tcp-westwood.cc.

References m_currentBW, m_fType, m_lastBW, m_lastSampleBW, NONE, NS_LOG_FUNCTION, and TUSTIN.

Referenced by EstimateBW().

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Ptr< TcpSocketBase > ns3::TcpWestwood::Fork ( void )

protectedvirtual

Call CopyObject<TcpWestwood> to clone me

Implements ns3::TcpSocketBase.

Definition at line 136 of file tcp-westwood.cc.

References NS_LOG_FUNCTION.

uint32_t ns3::TcpWestwood::GetInitialCwnd ( void ) const

protectedvirtual

Returns: the initial cwnd

Implements ns3::TcpSocketBase.

Definition at line 404 of file tcp-westwood.cc.

References m_initialCWnd, and NS_LOG_FUNCTION.

uint32_t ns3::TcpWestwood::GetSSThresh ( void ) const

protectedvirtual

Returns: the slow-start threshold

Implements ns3::TcpSocketBase.

Definition at line 390 of file tcp-westwood.cc.

References m_ssThresh, and NS_LOG_FUNCTION.

TypeId ns3::TcpWestwood::GetTypeId ( void )

static

Reimplemented from ns3::TcpSocketBase.

Definition at line 52 of file tcp-westwood.cc.

References m_currentBW, m_cWnd, m_fType, m_pType, ns3::MakeEnumAccessor(), ns3::MakeEnumChecker(), ns3::MakeTraceSourceAccessor(), NONE, ns3::TypeId::SetParent(), TUSTIN, WESTWOOD, and WESTWOODPLUS.

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void ns3::TcpWestwood::InitializeCwnd ( void )

private

Initialize cwnd at the beginning of a connection

Definition at line 411 of file tcp-westwood.cc.

References m_cWnd, m_initialCWnd, ns3::TcpSocketBase::m_segmentSize, and NS_LOG_FUNCTION.

Referenced by Connect(), and Listen().

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int ns3::TcpWestwood::Listen ( void )

virtual

Inherit from Socket class: Listen on the endpoint for an incoming connection

Reimplemented from ns3::TcpSocketBase.

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

References InitializeCwnd(), and NS_LOG_FUNCTION.

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void ns3::TcpWestwood::NewAck ( SequenceNumber32 const & seq )

protectedvirtual

Adjust the cwnd based on the current congestion control phase, and then call the TcpSocketBase::NewAck() to complete the processing

Parameters

seq	the acknowledgment number

Reimplemented from ns3::TcpSocketBase.

Definition at line 143 of file tcp-westwood.cc.

References ns3::TracedValue< T >::Get(), m_cWnd, m_inFastRec, ns3::TcpSocketBase::m_segmentSize, m_ssThresh, NS_LOG_FUNCTION, NS_LOG_INFO, and NS_LOG_LOGIC.

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void ns3::TcpWestwood::ReceivedAck	(	Ptr< Packet >	packet,
		const TcpHeader &	tcpHeader
	)

protectedvirtual

Process the newly received ACK

Parameters

packet	the received ACK packet
tcpHeader	the header attached to the ACK packet

Reimplemented from ns3::TcpSocketBase.

Definition at line 177 of file tcp-westwood.cc.

References ns3::TcpHeader::ACK, CountAck(), EstimateBW(), ns3::TcpHeader::GetAckNumber(), ns3::TcpHeader::GetFlags(), m_IsCount, m_prevAckNo, m_pType, NS_LOG_FUNCTION, UpdateAckedSegments(), WESTWOOD, and WESTWOODPLUS.

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void ns3::TcpWestwood::Retransmit ( void )

protectedvirtual

Upon an RTO event, adjust the cwnd using the currently estimated bandwidth, retransmit the missing packet, and exit fast recovery

Reimplemented from ns3::TcpSocketBase.

Definition at line 293 of file tcp-westwood.cc.

References ns3::CLOSED, ns3::TcpSocketBase::DoRetransmit(), ns3::TracedValue< T >::Get(), ns3::Time::GetSeconds(), ns3::TcpTxBuffer::HeadSequence(), ns3::RttEstimator::IncreaseMultiplier(), m_currentBW, m_cWnd, m_inFastRec, m_minRtt, ns3::TcpSocketBase::m_nextTxSequence, ns3::TcpSocketBase::m_rtt, ns3::TcpSocketBase::m_segmentSize, m_ssThresh, ns3::TcpSocketBase::m_state, ns3::TcpSocketBase::m_txBuffer, ns3::Simulator::Now(), NS_LOG_FUNCTION, NS_LOG_INFO, NS_LOG_LOGIC, and ns3::TIME_WAIT.

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void ns3::TcpWestwood::SetInitialCwnd ( uint32_t cwnd )

protectedvirtual

Parameters

cwnd	the initial cwnd

Implements ns3::TcpSocketBase.

Definition at line 397 of file tcp-westwood.cc.

References ns3::CLOSED, m_initialCWnd, ns3::TcpSocketBase::m_state, and NS_ABORT_MSG_UNLESS.

void ns3::TcpWestwood::SetSegSize ( uint32_t size )

protectedvirtual

Parameters

size	the segment size to be used in a connection

Reimplemented from ns3::TcpSocketBase.

Definition at line 376 of file tcp-westwood.cc.

References ns3::CLOSED, ns3::TcpSocketBase::m_segmentSize, ns3::TcpSocketBase::m_state, and NS_ABORT_MSG_UNLESS.

void ns3::TcpWestwood::SetSSThresh ( uint32_t threshold )

protectedvirtual

Parameters

the	slow-start threshold

Implements ns3::TcpSocketBase.

Definition at line 383 of file tcp-westwood.cc.

References m_ssThresh, and NS_LOG_FUNCTION.

void ns3::TcpWestwood::UpdateAckedSegments ( int acked )

private

Update the total number of acknowledged packets during the current RTT

Parameters

acked the number of packets the currently received ACK acknowledges

Definition at line 262 of file tcp-westwood.cc.

References m_ackedSegments.

Referenced by ReceivedAck().

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uint32_t ns3::TcpWestwood::Window ( void )

protectedvirtual

Limit the size of outstanding data based on the cwnd and the receiver's advertised window

Returns: the max. possible number of unacked bytes

Reimplemented from ns3::TcpSocketBase.

Definition at line 129 of file tcp-westwood.cc.

References ns3::TracedValue< T >::Get(), m_cWnd, ns3::TcpSocketBase::m_rWnd, and NS_LOG_FUNCTION.

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Member Data Documentation

int ns3::TcpWestwood::m_accountedFor

protected

Definition at line 210 of file tcp-westwood.h.

Referenced by CountAck().

int ns3::TcpWestwood::m_ackedSegments

protected

Definition at line 214 of file tcp-westwood.h.

Referenced by EstimateBW(), EstimateRtt(), and UpdateAckedSegments().

EventId ns3::TcpWestwood::m_bwEstimateEvent

protected

Definition at line 216 of file tcp-westwood.h.

Referenced by EstimateRtt().

TracedValue<double> ns3::TcpWestwood::m_currentBW

protected

Definition at line 204 of file tcp-westwood.h.

Referenced by DupAck(), EstimateBW(), Filtering(), GetTypeId(), and Retransmit().

TracedValue<uint32_t> ns3::TcpWestwood::m_cWnd

protected

Definition at line 199 of file tcp-westwood.h.

Referenced by DupAck(), GetTypeId(), InitializeCwnd(), NewAck(), Retransmit(), and Window().

enum FilterType ns3::TcpWestwood::m_fType

protected

Definition at line 212 of file tcp-westwood.h.

Referenced by Filtering(), and GetTypeId().

bool ns3::TcpWestwood::m_inFastRec

protected

Definition at line 202 of file tcp-westwood.h.

Referenced by DupAck(), NewAck(), and Retransmit().

uint32_t ns3::TcpWestwood::m_initialCWnd

protected

Definition at line 201 of file tcp-westwood.h.

Referenced by GetInitialCwnd(), InitializeCwnd(), and SetInitialCwnd().

bool ns3::TcpWestwood::m_IsCount

protected

Definition at line 215 of file tcp-westwood.h.

Referenced by EstimateBW(), EstimateRtt(), and ReceivedAck().

double ns3::TcpWestwood::m_lastAck

protected

Definition at line 208 of file tcp-westwood.h.

Referenced by EstimateBW().

double ns3::TcpWestwood::m_lastBW

protected

Definition at line 206 of file tcp-westwood.h.

Referenced by Filtering().

double ns3::TcpWestwood::m_lastSampleBW

protected

Definition at line 205 of file tcp-westwood.h.

Referenced by Filtering().

Time ns3::TcpWestwood::m_minRtt

protected

Definition at line 207 of file tcp-westwood.h.

Referenced by DupAck(), EstimateRtt(), Retransmit(), and TcpWestwood().

SequenceNumber32 ns3::TcpWestwood::m_prevAckNo

protected

Definition at line 209 of file tcp-westwood.h.

Referenced by CountAck(), and ReceivedAck().

enum ProtocolType ns3::TcpWestwood::m_pType

protected

Definition at line 211 of file tcp-westwood.h.

Referenced by EstimateBW(), EstimateRtt(), GetTypeId(), and ReceivedAck().

uint32_t ns3::TcpWestwood::m_ssThresh

protected

Definition at line 200 of file tcp-westwood.h.

Referenced by DupAck(), GetSSThresh(), NewAck(), Retransmit(), and SetSSThresh().

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

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

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Detailed Description

Config Paths

Attributes

Attributes defined in parent class ns3::TcpSocketBase

Attributes defined in parent class ns3::TcpSocket

TraceSources

TraceSources defined in parent class ns3::TcpSocketBase

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation