PacketBuffer¶

simple module PacketBuffer

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¶

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	Base module for various packet buffer modules which maintains a few statistics.

Parameters¶

Name	Type	Default value	Description
displayStringTextFormat	string	“contains {numPackets} pk ({totalLength})\nadded {numAddedPackets} removed {numRemovedPackets} dropped {numDroppedPackets}”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
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
class	PacketBuffer
display	i=block/buffer

Gates¶

Name	Direction	Size	Description
in	input
out	output

Signals¶

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

Statistics¶

Name	Title	Source	Record	Unit	Interpolation Mode	Description
addedPacketLengths	added packet lengths	packetLength(packetAdded)	sum,vector	b	none	the statistical value is the length of the added packet
addedPackets	added packets	packetAdded	count	pk		the statistical value is the added packet
bufferBitLength	buffer bit length	warmup(sum(packetLength(packetAdded)) - sum(packetLength(packetRemoved)) - sum(packetLength(packetDropped)))	last,max,timeavg,vector	b	sample-hold	the statistical value is the total bit length of all packets in the buffer
bufferLength	buffer length	warmup(count(packetAdded) - count(packetRemoved) - count(packetDropped))	last,max,timeavg,vector	pk	sample-hold	the statistical value is the number of packets in the buffer
droppedPacketLengthsQueueOverflow	dropped packet lengths: queue overflow	packetLength(packetDropReasonIsQueueOverflow(packetDropped))	sum,vector	b	none	the statistical value is the length of the packet that is dropped due to queue overflow
droppedPacketsQueueOverflow	dropped packets: queue overflow	packetDropReasonIsQueueOverflow(packetDropped)	count	pk	none	the statistical value is the packet that is dropped due to queue overflow
removedPacketLengths	removed packet lengths	packetLength(packetRemoved)	sum,vector	pk	none	the statistical value is the length of the removed packet
removedPackets	removed packets	packetRemoved	count	pk		the statistical value is the removed packet

Source code¶

//
// 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