Sequence Number Validator. More...

#include <seqnumvalidator.h>

Inheritance diagram for SeqNumValidator:

Public Types
enum	ValidationResult { Valid = 0, SourceProbation = 1, Jumped = 2, Invalid = 10, DuplicatePacket = Invalid + 0, InvalidSeqNum = Invalid + 1 }
Public Member Functions
	SeqNumValidator (const cardinal minSequential=2, const cardinal maxMisorder=100, const cardinal maxDropout=3000, const card64 seqMod=(1<< 16))
card64	getPacketsReceived () const
card64	getPacketsLost () const
card64	getLastSeqNum () const
double	getFractionLost () const
double	getJitter () const
ValidationResult	validate (const card64 sequenceNumber, const card32 packetTimeStamp=0)
void	reset ()
double	calculateFractionLost ()
Private Member Functions
void	init (const card64 sequenceNumber)
Private Attributes
card64	SeqMod
cardinal	MaxDropout
cardinal	MaxMisorder
cardinal	MinSequential
card64	PrevPacketTimeStamp
card64	PrevPacketArrivalTime
double	Jitter
double	FractionLost
card64	MaxSeq
card64	BaseSeq
card64	BadSeq
card32	Probation
card64	Cycles
card64	Received
card64	ReceivedPrior
card64	ExpectedPrior
bool	Uninitialized

Detailed Description

Sequence Number Validator.

This class is a validator for sequence numbers. It is based on the algorithm described in RFC 1889. It can use sequence numbers up to a size of 64 bits. Jitter and fraction loss calculation is also done by this class.

Author:: Thomas Dreibholz

Version:: 1.0

Member Enumeration Documentation

enum SeqNumValidator::ValidationResult

Enumerator:

Valid
SourceProbation
Jumped
Invalid
DuplicatePacket
InvalidSeqNum

Constructor & Destructor Documentation

SeqNumValidator::SeqNumValidator	(	const cardinal	minSequential = `2`,
		const cardinal	maxMisorder = `100`,
		const cardinal	maxDropout = `3000`,
		const card64	seqMod = `(1 << 16)`
	)

Constructor for new sequence number validator.

Parameters:

minSequential	Minimum number of packets in sequence for the source to be valid.
maxMisorder	Maximum difference for packets to be misordered.
maxDropout	Maximum gap.
seqMod	Sequence number modulo.

Member Function Documentation

double SeqNumValidator::calculateFractionLost ( )

Calculate and get fraction of packets lost.

Returns:: Fraction lost.

double SeqNumValidator::getFractionLost ( ) const [inline]

Get fraction of packets lost. Note: No calculation of the fraction lost is done here! The fraction lost value is the value of the last call of calculateFractionLost()!

Returns:: Fraction of packets lost.

See also:: calculateFractionLost

double SeqNumValidator::getJitter ( ) const [inline]

Get jitter.

Returns:: Jitter.

card64 SeqNumValidator::getLastSeqNum ( ) const [inline]

Get extended last sequence number. This number is extended by the calculated number of sequence number cycles!

Returns:: Last sequence number.

card64 SeqNumValidator::getPacketsLost ( ) const [inline]

Get number of packets lost. The loss is calculated by the number of sequence number cycles and gaps.

Returns:: Number of packets lost.

card64 SeqNumValidator::getPacketsReceived ( ) const [inline]

Get number of packets received.

Returns:: Number of packets received.

void SeqNumValidator::init ( const card64 sequenceNumber ) [inline, private]

void SeqNumValidator::reset ( )

Reset SeqNumValidator.

Reimplemented in SourceStateInfo.

SeqNumValidator::ValidationResult SeqNumValidator::validate	(	const card64	sequenceNumber,
		const card32	packetTimeStamp = `0`
	)

Validate a new sequence number. If the packet is valid, jitter value will be calculated using packetTimeStamp. To disable jitter calculation, set packetTimeStamp to 0.

Parameters: