The "Mean--Deviation" RTT estimator, as discussed by Van Jacobson. More...
#include "rtt-estimator.h"
Public Member Functions | |
RttMeanDeviation () | |
RttMeanDeviation (const RttMeanDeviation &r) | |
Copy constructor. | |
Ptr< RttEstimator > | Copy () const override |
Copy object (including current internal state) | |
TypeId | GetInstanceTypeId () const override |
Get the most derived TypeId for this Object. | |
void | Measurement (Time measure) override |
Add a new measurement to the estimator. | |
void | Reset () override |
Resets the estimator. | |
Public Member Functions inherited from ns3::RttEstimator | |
RttEstimator () | |
RttEstimator (const RttEstimator &r) | |
Copy constructor. | |
~RttEstimator () override | |
Time | GetEstimate () const |
gets the RTT estimate. | |
uint32_t | GetNSamples () const |
gets the number of samples used in the estimates | |
Time | GetVariation () const |
Note that this is not a formal statistical variance; it has the the same units as the estimate. | |
Public Member Functions inherited from ns3::Object | |
Object () | |
Constructor. | |
~Object () override | |
Destructor. | |
void | AggregateObject (Ptr< Object > other) |
Aggregate two Objects together. | |
void | Dispose () |
Dispose of this Object. | |
AggregateIterator | GetAggregateIterator () const |
Get an iterator to the Objects aggregated to this one. | |
template<typename T > | |
Ptr< T > | GetObject () const |
Get a pointer to the requested aggregated Object. | |
template<> | |
Ptr< Object > | GetObject () const |
Specialization of () for objects of type ns3::Object. | |
template<typename T > | |
Ptr< T > | GetObject (TypeId tid) const |
Get a pointer to the requested aggregated Object by TypeId. | |
template<> | |
Ptr< Object > | GetObject (TypeId tid) const |
Specialization of (TypeId tid) for objects of type ns3::Object. | |
void | Initialize () |
Invoke DoInitialize on all Objects aggregated to this one. | |
bool | IsInitialized () const |
Check if the object has been initialized. | |
void | UnidirectionalAggregateObject (Ptr< Object > other) |
Aggregate an Object to another Object. | |
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter > | |
SimpleRefCount () | |
Default constructor. | |
SimpleRefCount (const SimpleRefCount &o) | |
Copy constructor. | |
uint32_t | GetReferenceCount () const |
Get the reference count of the object. | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
Assignment operator. | |
void | Ref () const |
Increment the reference count. | |
void | Unref () const |
Decrement the reference count. | |
Public Member Functions inherited from ns3::ObjectBase | |
virtual | ~ObjectBase () |
Virtual destructor. | |
void | GetAttribute (std::string name, AttributeValue &value, bool permissive=false) const |
Get the value of an attribute, raising fatal errors if unsuccessful. | |
bool | GetAttributeFailSafe (std::string name, AttributeValue &value) const |
Get the value of an attribute without raising errors. | |
void | SetAttribute (std::string name, const AttributeValue &value) |
Set a single attribute, raising fatal errors if unsuccessful. | |
bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
Set a single attribute without raising errors. | |
bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
Connect a TraceSource to a Callback with a context. | |
bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
Connect a TraceSource to a Callback without a context. | |
bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected with a context. | |
bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected without a context. | |
Static Public Member Functions | |
static TypeId | GetTypeId () |
Get the type ID. | |
Static Public Member Functions inherited from ns3::RttEstimator | |
static TypeId | GetTypeId () |
Get the type ID. | |
Static Public Member Functions inherited from ns3::Object | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::ObjectBase | |
static TypeId | GetTypeId () |
Get the type ID. | |
Private Member Functions | |
uint32_t | CheckForReciprocalPowerOfTwo (double val) const |
Utility function to check for possible conversion of a double value (0 < value < 1) to a reciprocal power of two. | |
void | FloatingPointUpdate (Time m) |
Method to update the rtt and variation estimates using floating point arithmetic, used when the values of Alpha and Beta are not both a reciprocal power of two. | |
void | IntegerUpdate (Time m, uint32_t rttShift, uint32_t variationShift) |
Method to update the rtt and variation estimates using integer arithmetic, used when the values of Alpha and Beta support the integer conversion. | |
Private Attributes | |
double | m_alpha |
Filter gain for average. | |
double | m_beta |
Filter gain for variation. | |
Additional Inherited Members | |
Protected Member Functions inherited from ns3::Object | |
Object (const Object &o) | |
Copy an Object. | |
virtual void | DoDispose () |
Destructor implementation. | |
virtual void | DoInitialize () |
Initialize() implementation. | |
virtual void | NotifyNewAggregate () |
Notify all Objects aggregated to this one of a new Object being aggregated. | |
Protected Member Functions inherited from ns3::ObjectBase | |
void | ConstructSelf (const AttributeConstructionList &attributes) |
Complete construction of ObjectBase; invoked by derived classes. | |
virtual void | NotifyConstructionCompleted () |
Notifier called once the ObjectBase is fully constructed. | |
Protected Attributes inherited from ns3::RttEstimator | |
Time | m_estimatedRtt |
Current estimate. | |
Time | m_estimatedVariation |
Current estimate variation. | |
uint32_t | m_nSamples |
Number of samples. | |
Related Symbols inherited from ns3::ObjectBase | |
static TypeId | GetObjectIid () |
Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. | |
The "Mean--Deviation" RTT estimator, as discussed by Van Jacobson.
Introspection did not find any typical Config paths.
This class implements the "Mean--Deviation" RTT estimator, as discussed by Van Jacobson and Michael J. Karels, in "Congestion Avoidance and Control", SIGCOMM 88, Appendix A
The default values for the gain (alpha and beta) are set as documented in RFC 6298.
Time
-9.22337e+18ns:+9.22337e+18ns No TraceSources are defined for this type.
Group: Internet
Size of this type is 104 bytes (on a 64-bit architecture).
Definition at line 112 of file rtt-estimator.h.
ns3::RttMeanDeviation::RttMeanDeviation | ( | ) |
Definition at line 139 of file rtt-estimator.cc.
References NS_LOG_FUNCTION.
ns3::RttMeanDeviation::RttMeanDeviation | ( | const RttMeanDeviation & | r | ) |
Copy constructor.
r | the object to copy |
Definition at line 144 of file rtt-estimator.cc.
References NS_LOG_FUNCTION.
Utility function to check for possible conversion of a double value (0 < value < 1) to a reciprocal power of two.
Values of 1/32, 1/16, 1/8, 1/4, and 1/2 (i.e., within the possible range of experimentation for this estimator) are supported.
val | value to check |
Definition at line 159 of file rtt-estimator.cc.
References NS_LOG_FUNCTION, and ns3::TOLERANCE.
Referenced by Measurement().
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overridevirtual |
Copy object (including current internal state)
Implements ns3::RttEstimator.
Definition at line 258 of file rtt-estimator.cc.
References ns3::Object::CopyObject, and NS_LOG_FUNCTION.
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private |
Method to update the rtt and variation estimates using floating point arithmetic, used when the values of Alpha and Beta are not both a reciprocal power of two.
m | time measurement |
Definition at line 191 of file rtt-estimator.cc.
References ns3::Abs(), ns3::Time::FromDouble(), m_alpha, m_beta, ns3::RttEstimator::m_estimatedRtt, ns3::RttEstimator::m_estimatedVariation, NS_LOG_FUNCTION, ns3::Time::S, and ns3::Time::ToDouble().
Referenced by Measurement().
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overridevirtual |
Get the most derived TypeId for this Object.
This method is typically implemented by ns3::Object::GetInstanceTypeId but some classes which derive from ns3::ObjectBase directly have to implement it themselves.
Reimplemented from ns3::RttEstimator.
Definition at line 153 of file rtt-estimator.cc.
References GetTypeId().
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static |
Get the type ID.
Definition at line 119 of file rtt-estimator.cc.
References m_alpha, m_beta, ns3::MakeDoubleAccessor(), ns3::MakeDoubleChecker(), and ns3::TypeId::SetParent().
Referenced by ns3::TcpGeneralTest::CreateSocket(), GetInstanceTypeId(), and ns3::TcpL4Protocol::GetTypeId().
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private |
Method to update the rtt and variation estimates using integer arithmetic, used when the values of Alpha and Beta support the integer conversion.
m | time measurement |
rttShift | value corresponding to log base 2 (1/alpha) |
variationShift | value corresponding to log base 2 (1/beta) |
Definition at line 209 of file rtt-estimator.cc.
References ns3::Time::From(), ns3::Time::GetInteger(), ns3::RttEstimator::m_estimatedRtt, ns3::RttEstimator::m_estimatedVariation, and NS_LOG_FUNCTION.
Referenced by Measurement().
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overridevirtual |
Add a new measurement to the estimator.
measure | the new RTT measure. |
Implements ns3::RttEstimator.
Definition at line 228 of file rtt-estimator.cc.
References CheckForReciprocalPowerOfTwo(), FloatingPointUpdate(), IntegerUpdate(), m_alpha, m_beta, ns3::RttEstimator::m_estimatedRtt, ns3::RttEstimator::m_estimatedVariation, ns3::RttEstimator::m_nSamples, NS_LOG_DEBUG, and NS_LOG_FUNCTION.
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overridevirtual |
Resets the estimator.
Reimplemented from ns3::RttEstimator.
Definition at line 265 of file rtt-estimator.cc.
References NS_LOG_FUNCTION, and ns3::RttEstimator::Reset().
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private |
Filter gain for average.
Definition at line 174 of file rtt-estimator.h.
Referenced by FloatingPointUpdate(), GetTypeId(), and Measurement().
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private |
Filter gain for variation.
Definition at line 175 of file rtt-estimator.h.
Referenced by FloatingPointUpdate(), GetTypeId(), and Measurement().