Quick and dirty delay and jitter estimation, implementing the jitter algorithm originally from RFC 1889 (RTP), and unchanged in RFC 3550 More...

#include "delay-jitter-estimation.h"

Collaboration diagram for ns3::DelayJitterEstimation:

Public Member Functions
	DelayJitterEstimation ()

Time	GetLastDelay (void) const

uint64_t	GetLastJitter (void) const
	The jitter is calculated using the RFC 1889 (RTP) jitter definition. More...

void	RecordRx (Ptr< const Packet > packet)

Static Public Member Functions
static void	PrepareTx (Ptr< const Packet > packet)

Private Attributes
Time	m_jitter
	Jitter estimation. More...

Time	m_transit
	Relative transit time for the previous packet. More...

Detailed Description

Quick and dirty delay and jitter estimation, implementing the jitter algorithm originally from RFC 1889 (RTP), and unchanged in RFC 3550

This implementation uses the integer variant of the algorithm given in RFC 1889 Appendix A.8 ,p. 71, and repeated in RFC 3550 Appendix A.8, p. 94.

Definition at line 39 of file delay-jitter-estimation.h.

Constructor & Destructor Documentation

◆ DelayJitterEstimation()

ns3::DelayJitterEstimation::DelayJitterEstimation ( )

Definition at line 111 of file delay-jitter-estimation.cc.

Member Function Documentation

◆ GetLastDelay()

Time ns3::DelayJitterEstimation::GetLastDelay ( void ) const

Returns: the updated delay.

Definition at line 151 of file delay-jitter-estimation.cc.

References m_transit.

◆ GetLastJitter()

uint64_t ns3::DelayJitterEstimation::GetLastJitter ( void ) const

The jitter is calculated using the RFC 1889 (RTP) jitter definition.

Returns: the updated jitter.

Definition at line 156 of file delay-jitter-estimation.cc.

References m_jitter.

◆ PrepareTx()

void ns3::DelayJitterEstimation::PrepareTx ( Ptr< const Packet > packet )

static

Parameters

packet the packet to send over a wire

This method should be invoked once on each packet to record within the packet the tx time which is used upon packet reception to calculate the delay and jitter. The tx time is stored in the packet as an ns3::Tag which means that it does not use any network resources and is not taken into account in transmission delay calculations.

Definition at line 117 of file delay-jitter-estimation.cc.

References ns3::Packet::AddByteTag().

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◆ RecordRx()

void ns3::DelayJitterEstimation::RecordRx ( Ptr< const Packet > packet )

Parameters

packet the packet received

Invoke this method to update the delay and jitter calculations After a call to this method, GetLastDelay and GetLastJitter will return an updated delay and jitter.

Definition at line 123 of file delay-jitter-estimation.cc.

References ns3::Abs(), ns3::Packet::FindFirstMatchingByteTag(), ns3::DelayJitterEstimationTimestampTag::GetTxTime(), m_jitter, m_transit, and ns3::Simulator::Now().

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