TCPBaseAlgStateVariables Class Reference

#include <TCPBaseAlg.h>

Inheritance diagram for TCPBaseAlgStateVariables:

List of all members.

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Detailed Description

State variables for TCPBaseAlg.

Public Member Functions
	TCPBaseAlgStateVariables ()
virtual std::string	info () const
virtual std::string	detailedInfo () const
Public Attributes
bool	delayed_acks_enabled
	delayed ACKs enabled/disabled; FIXME make this a socket option
bool	nagle_enabled
	Nagle's algorithm (off = NODELAY socket option).
int	rexmit_count
	number of retransmissions (=1 after first rexmit)
simtime_t	rexmit_timeout
	current retransmission timeout (aka RTO)
uint	snd_cwnd
	congestion window
uint32	rtseq
	starting sequence number of timed data
simtime_t	rtseq_sendtime
	time when rtseq was sent (0 if RTT measurement is not running)
simtime_t	srtt
	smoothed round-trip time
simtime_t	rttvar
	variance of round-trip time

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Constructor & Destructor Documentation

TCPBaseAlgStateVariables::TCPBaseAlgStateVariables (   )

{ // We disable delayed acks, since it appears that it isn't used in real-life TCPs. // // In SSFNet test suite http://www.ssfnet.org/Exchange/tcp/test/f5.html // the rule for delayed ACK is: // An ACK must be sent immediatly when either of the following conditions exist: // * Two full-sized packets received (to avoid too few ACKs). // * Out of order packets received (to help trigger fast retransmission). // * Received packet fills in all gap or part of gap of out of order data. // We do not implement this rule. In our measurements on network traffic, we // never encountered delayed ACKs. // delayed_acks_enabled = false; nagle_enabled = true; // FIXME this should be parameter eventually rexmit_count = 0; rexmit_timeout = 3.0; snd_cwnd = 0; // will be set to MSS when connection is established rtseq = 0; rtseq_sendtime = 0; // Jacobson's alg: srtt must be initialized to 0, rttvar to a value which // will yield rto = 3s initially. srtt = 0; rttvar = 3.0/4.0; }

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Member Function Documentation

std::string TCPBaseAlgStateVariables::detailedInfo (   )  const [virtual]

Reimplemented from TCPStateVariables. Reimplemented in TCPTahoeRenoFamilyStateVariables. { std::stringstream out; out << TCPStateVariables::detailedInfo(); out << "snd_cwnd = " << snd_cwnd << "\n"; out << "rto = " << rexmit_timeout << "\n"; // TBD add others too return out.str(); }

std::string TCPBaseAlgStateVariables::info (   )  const [virtual]

Reimplemented from TCPStateVariables. Reimplemented in TCPTahoeRenoFamilyStateVariables. { std::stringstream out; out << TCPStateVariables::info(); out << " snd_cwnd=" << snd_cwnd; out << " rto=" << rexmit_timeout; return out.str(); }

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Member Data Documentation

bool TCPBaseAlgStateVariables::delayed_acks_enabled

delayed ACKs enabled/disabled; FIXME make this a socket option

bool TCPBaseAlgStateVariables::nagle_enabled

Nagle's algorithm (off = NODELAY socket option).

int TCPBaseAlgStateVariables::rexmit_count

number of retransmissions (=1 after first rexmit)

simtime_t TCPBaseAlgStateVariables::rexmit_timeout

current retransmission timeout (aka RTO)

uint32 TCPBaseAlgStateVariables::rtseq

starting sequence number of timed data

simtime_t TCPBaseAlgStateVariables::rtseq_sendtime

time when rtseq was sent (0 if RTT measurement is not running)

simtime_t TCPBaseAlgStateVariables::rttvar

variance of round-trip time

uint TCPBaseAlgStateVariables::snd_cwnd

congestion window

simtime_t TCPBaseAlgStateVariables::srtt

smoothed round-trip time

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

• TCPBaseAlg.h
• TCPBaseAlg.cc

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