This module provides packet storage for sharing and optimizing storage space between multiple packet queues. When a packet buffer becomes overloaded, the packet dropping strategy can drop any number of packets from any number of connected packet queues.

See also: IPacketQueue

Inheritance diagram

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

Known subclasses

Name	Type	Description
PriorityBuffer	simple module	This buffer drops packets among the connected packet queues based on their module id.

Extends

Name	Type	Description
PacketBufferBase	simple module	This is a base module for various packet buffer modules which maintains a few statistics.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"contains %p pk (%l)\nadded %a removed %r dropped %d"	determines the text that is written on top of the submodule
packetCapacity	int	-1	maximum number of packets in the queue, no limit by default
dataCapacity	int	-1b	maximum total length of packets in the queue, no limit by default
dropperClass	string	""	determines which packets are dropped when the buffer is overloaded, packets are not dropped by default; the parameter must be the name of a C++ class which implements the IPacketDropperFunction C++ interface and is registered via Register_Class

Properties

Name	Value	Description
display	i=block/buffer
class	PacketBuffer

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit
packetRemoved	inet::Packet
packetDropped	inet::Packet
packetAdded	inet::Packet

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
droppedPacketsQueueOverflow	dropped packets: queue overflow	packetDropReasonIsQueueOverflow(packetDropped)	count	pk	none
addedPackets	added packets	packetAdded	count	pk
removedPackets	removed packets	packetRemoved	count	pk
removedPacketLengths	removed packet lengths	packetLength(packetRemoved)	sum, vector	pk	none
bufferLength	buffer length	warmup(count(packetAdded) - count(packetRemoved) - count(packetDropped))	last, max, timeavg, vector	pk	sample-hold
droppedPacketLengthsQueueOverflow	dropped packet lengths: queue overflow	packetLength(packetDropReasonIsQueueOverflow(packetDropped))	sum, vector	b	none
addedPacketLengths	added packet lengths	packetLength(packetAdded)	sum, vector	b	none
bufferBitLength	buffer bit length	warmup(sum(packetLength(packetAdded)) - sum(packetLength(packetRemoved)) - sum(packetLength(packetDropped)))	last, max, timeavg, vector	b	sample-hold

Direct method calls (observed)

call to	function	info
PacketQueue	inet::queueing::PacketQueue::handlePacketRemoved	handlePacketRemoved

Called methods (observed)

function	info	call from
inet::queueing::PacketBuffer::addPacket	addPacket	PacketQueue
inet::queueing::PacketBuffer::removePacket	removePacket	PacketQueue

Source code

//
// This module provides packet storage for sharing and optimizing storage space
// between multiple packet queues. When a packet buffer becomes overloaded, the
// packet dropping strategy can drop any number of packets from any number of
// connected packet queues.
//
// @see ~IPacketQueue
//
simple PacketBuffer extends PacketBufferBase like IPacketBuffer
{
    parameters:
        int packetCapacity = default(-1); // maximum number of packets in the queue, no limit by default
        int dataCapacity @unit(b) = default(-1b); // maximum total length of packets in the queue, no limit by default
        string dropperClass = default(""); // determines which packets are dropped when the buffer is overloaded, packets are not dropped by default; the parameter must be the name of a C++ class which implements the IPacketDropperFunction C++ interface and is registered via Register_Class
        @class(PacketBuffer);
        @display("i=block/buffer");
        @signal[packetAdded](type=inet::Packet);
        @signal[packetRemoved](type=inet::Packet);
        @signal[packetDropped](type=inet::Packet);
        // the statistical value is the added packet
        @statistic[addedPackets](title="added packets"; source=packetAdded; record=count; unit=pk);
        // the statistical value is the length of the added packet
        @statistic[addedPacketLengths](title="added packet lengths"; source=packetLength(packetAdded); record=sum,vector; unit=b; interpolationmode=none);
        // the statistical value is the removed packet
        @statistic[removedPackets](title="removed packets"; source=packetRemoved; record=count; unit=pk);
        // the statistical value is the length of the removed packet
        @statistic[removedPacketLengths](title="removed packet lengths"; source=packetLength(packetRemoved); record=sum,vector; unit=pk; interpolationmode=none);
        // the statistical value is the number of packets in the buffer
        @statistic[bufferLength](title="buffer length"; source=warmup(count(packetAdded) - count(packetRemoved) - count(packetDropped)); record=last,max,timeavg,vector; unit=pk; interpolationmode=sample-hold);
        // the statistical value is the total bit length of all packets in the buffer
        @statistic[bufferBitLength](title="buffer bit length"; source=warmup(sum(packetLength(packetAdded)) - sum(packetLength(packetRemoved)) - sum(packetLength(packetDropped))); record=last,max,timeavg,vector; unit=b; interpolationmode=sample-hold; autoWarmupFilter=false);
        // the statistical value is the packet that is dropped due to queue overflow
        @statistic[droppedPacketsQueueOverflow](title="dropped packets: queue overflow"; source=packetDropReasonIsQueueOverflow(packetDropped); record=count; unit=pk; interpolationmode=none);
        // the statistical value is the length of the packet that is dropped due to queue overflow
        @statistic[droppedPacketLengthsQueueOverflow](title="dropped packet lengths: queue overflow"; source=packetLength(packetDropReasonIsQueueOverflow(packetDropped)); record=sum,vector; unit=b; interpolationmode=none);
}

File: src/inet/queueing/buffer/PacketBuffer.ned

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