C++ definition

Represents a single TCP connection in the TCP protocol implementation. Implements the TCP state machine and handles connection establishment, data transfer, flow control, congestion control, and connection termination. Provides extensive statistics collection for various TCP metrics including window sizes, sequence numbers, RTT measurements, and congestion parameters.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends

Name	Type	Description
SimpleModule	simple module	Base module for all INET simple modules.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	""	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information

Properties

Name	Value	Description
class	TcpConnection

Signals

Name	Type	Unit	Description
rcvOooSeg			Number of received out-of-order segments
cwnd			TcpAlgorithm signals:
tcpRcvQueueDrops			Number of drops in TCP receive queue
rcvSeq			Received seqNo
rcvNASeg			Number of received not acceptable segments
tcpRcvPayloadBytes			Amount of payload bytes received (including duplicates, out of order, etc.) for TCP throughput
rttvar			Will record RTT variance (rttvar)
load			Will record load (currently only with DcTcp)
rcvAck			Received ackNo (=snd_una)
sndAck			Sent ackNo
pipe			Current sender's estimate of bytes outstanding in the network
state			FSM state
unacked			Number of bytes unacknowledged
ssthresh			Will record changes to ssthresh
calcLoad			Will record calcLoad (currently only with DcTcp)
tcpRcvQueueBytes			Current amount of used bytes in TCP receive queue
srtt			Will record smoothed RTT
markingProb			Will record marking probability (currently only with DcTcp)
sndSacks			Number of sent Sacks
rto			Will record retransmission timeout
sackedBytes			Current number of received sacked bytes
rcvSacks			Number of received Sacks
rtt			Will record measured RTT
dupAcks			Current number of received dupAcks
numRtos			Will record total number of RTOs
rcvWnd			Rcv_wnd
sndNxt			Sent seqNo
rcvAdv			Current advertised window (=rcv_adv)
sndWnd			Snd_wnd

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
rcvOooSeg			vector		sample-hold	Number of received out-of-order segments
cwnd			vector		sample-hold	Will record changes to snd_cwnd
tcpRcvQueueDrops			vector		sample-hold	Number of drops in tcp receive queue
rcvSeq			vector		sample-hold	Received seqNo
rcvNASeg			vector		sample-hold	Number of received not acceptable segments
tcpRcvPayloadBytes			vector		sample-hold	Current amount of payload bytes received (including duplicates, out of order etc) for TCP throughput
rttvar			vector		sample-hold	Will record RTT variance (rttvar)
load			vector		sample-hold	Will record load (currently only with DcTcp)
rcvAck			vector		sample-hold	Received ackNo (=snd_una)
sndAck			vector		sample-hold	Sent ackNo
pipe			vector		sample-hold	Current sender's estimate of bytes outstanding in the network
state			vector		sample-hold
unacked			vector		sample-hold	Number of bytes unacknowledged
ssthresh			vector		sample-hold	Will record changes to ssthresh
calcLoad			vector		sample-hold	Will record calcLoad (currently only with DcTcp)
tcpRcvQueueBytes			vector		sample-hold	Current amount of used bytes in tcp receive queue
srtt			vector		sample-hold	Will record smoothed RTT
markingProb			vector		sample-hold	Will record marking probability (currently only with DcTcp)
sndSacks			vector		sample-hold	Number of sent Sacks
rto			vector		sample-hold	Will record retransmission timeout
sackedBytes			vector		sample-hold	Current number of received sacked bytes
rcvSacks			vector		sample-hold	Number of received Sacks
rtt			vector		sample-hold	Will record measured RTT
dupAcks			vector		sample-hold	Current number of received dupAcks
numRtos			vector		sample-hold	Will record total number of RTOs
rcvWnd			vector		sample-hold	Rcv_wnd
sndNxt			vector		sample-hold	Sent seqNo
rcvAdv			vector		sample-hold	Current advertised window (=rcv_adv)
sndWnd			vector		sample-hold	Snd_wnd

Source code

//
// Represents a single TCP connection in the TCP protocol implementation.
// Implements the TCP state machine and handles connection establishment,
// data transfer, flow control, congestion control, and connection termination.
// Provides extensive statistics collection for various TCP metrics including
// window sizes, sequence numbers, RTT measurements, and congestion parameters.
//
simple TcpConnection extends SimpleModule
{
    parameters:
        @class(TcpConnection);
        @signal[state];    // FSM state
        @signal[sndWnd];    // Snd_wnd
        @signal[rcvWnd];    // Rcv_wnd
        @signal[rcvAdv];    // Current advertised window (=rcv_adv)
        @signal[sndNxt];    // Sent seqNo
        @signal[sndAck];    // Sent ackNo
        @signal[rcvSeq];    // Received seqNo
        @signal[rcvAck];    // Received ackNo (=snd_una)
        @signal[unacked];    // Number of bytes unacknowledged
        @signal[dupAcks];    // Current number of received dupAcks
        @signal[pipe];    // Current sender's estimate of bytes outstanding in the network
        @signal[sndSacks];    // Number of sent Sacks
        @signal[rcvSacks];    // Number of received Sacks
        @signal[rcvOooSeg];    // Number of received out-of-order segments
        @signal[rcvNASeg];    // Number of received not acceptable segments
        @signal[sackedBytes];    // Current number of received sacked bytes
        @signal[tcpRcvQueueBytes];    // Current amount of used bytes in TCP receive queue
        @signal[tcpRcvQueueDrops];    // Number of drops in TCP receive queue
        @signal[tcpRcvPayloadBytes];   // Amount of payload bytes received (including duplicates, out of order, etc.) for TCP throughput

        //TcpAlgorithm signals:
        @signal[cwnd];    // Will record changes to snd_cwnd
        @signal[ssthresh];    // Will record changes to ssthresh
        @signal[rtt];    // Will record measured RTT
        @signal[srtt];    // Will record smoothed RTT
        @signal[rttvar];    // Will record RTT variance (rttvar)
        @signal[rto];    // Will record retransmission timeout
        @signal[numRtos];    // Will record total number of RTOs

        @signal[load];   // Will record load (currently only with DcTcp)
        @signal[calcLoad];    // Will record calcLoad (currently only with DcTcp)
        @signal[markingProb];   // Will record marking probability (currently only with DcTcp)

        @statistic[state](record=vector; interpolationmode=sample-hold);
        @statistic[sndWnd](record=vector; interpolationmode=sample-hold);    // Snd_wnd
        @statistic[rcvWnd](record=vector; interpolationmode=sample-hold);    // Rcv_wnd
        @statistic[rcvAdv](record=vector; interpolationmode=sample-hold);    // Current advertised window (=rcv_adv)
        @statistic[sndNxt](record=vector; interpolationmode=sample-hold);    // Sent seqNo
        @statistic[sndAck](record=vector; interpolationmode=sample-hold);    // Sent ackNo
        @statistic[rcvSeq](record=vector; interpolationmode=sample-hold);    // Received seqNo
        @statistic[rcvAck](record=vector; interpolationmode=sample-hold);    // Received ackNo (=snd_una)
        @statistic[unacked](record=vector; interpolationmode=sample-hold);    // Number of bytes unacknowledged
        @statistic[dupAcks](record=vector; interpolationmode=sample-hold);    // Current number of received dupAcks
        @statistic[pipe](record=vector; interpolationmode=sample-hold);    // Current sender's estimate of bytes outstanding in the network
        @statistic[sndSacks](record=vector; interpolationmode=sample-hold);    // Number of sent Sacks
        @statistic[rcvSacks](record=vector; interpolationmode=sample-hold);    // Number of received Sacks
        @statistic[rcvOooSeg](record=vector; interpolationmode=sample-hold);    // Number of received out-of-order segments
        @statistic[rcvNASeg](record=vector; interpolationmode=sample-hold);    // Number of received not acceptable segments
        @statistic[sackedBytes](record=vector; interpolationmode=sample-hold);    // Current number of received sacked bytes
        @statistic[tcpRcvQueueBytes](record=vector; interpolationmode=sample-hold);    // Current amount of used bytes in tcp receive queue
        @statistic[tcpRcvQueueDrops](record=vector; interpolationmode=sample-hold);    // Number of drops in tcp receive queue
        @statistic[tcpRcvPayloadBytes](record=vector; interpolationmode=sample-hold);    // Current amount of payload bytes received (including duplicates, out of order etc) for TCP throughput

        @statistic[cwnd](record=vector; interpolationmode=sample-hold);    // Will record changes to snd_cwnd
        @statistic[ssthresh](record=vector; interpolationmode=sample-hold);    // Will record changes to ssthresh
        @statistic[rtt](record=vector; interpolationmode=sample-hold);    // Will record measured RTT
        @statistic[srtt](record=vector; interpolationmode=sample-hold);    // Will record smoothed RTT
        @statistic[rttvar](record=vector; interpolationmode=sample-hold);    // Will record RTT variance (rttvar)
        @statistic[rto](record=vector; interpolationmode=sample-hold);    // Will record retransmission timeout
        @statistic[numRtos](record=vector; interpolationmode=sample-hold);    // Will record total number of RTOs

        @statistic[load](record=vector; interpolationmode=sample-hold);    // Will record load (currently only with DcTcp)
        @statistic[calcLoad](record=vector; interpolationmode=sample-hold);    // Will record calcLoad (currently only with DcTcp)
        @statistic[markingProb](record=vector; interpolationmode=sample-hold);    // Will record marking probability (currently only with DcTcp)
}

File: src/inet/transportlayer/tcp/TcpConnection.ned

---

This documentation is released under the Creative Commons license