Ieee8021qCreditBasedGate

simple module

This module is a packet gate that can be used to implement the IEEE 802.1q credit based shaper algorithm in combination with a packet queue.

Inheritance diagram

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

Known subclasses

Name	Type	Description
Ieee8021qCreditBasedShaper	compound module	This module implements the IEEE 802.1Q credit-based shaper.

Extends

Name	Type	Description
CreditBasedGate	simple module	This module is a packet gate that operates based on the number of credits it contains. The gate is open if the number of credits is greater than the configured transmit credit limit, it is closed otherwise. The module attaches a CreditGateTag to all packets that pass through. The attached tag allows the gate module to determine if a packet belongs to it when the packet is eventually transmitted.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	"contains %n cr\nserved %p pk (%l)"	determines the text that is written on top of the submodule
bitrate	double	nan bps
extraLength	int	0b
extraDuration	double	0s
idleCreditGainRate	double	dropUnit(idleSlope)	rate of credit increase while the packets that passed through this gate don't use the physical channel
transmitCreditSpendRate	double	-dropUnit(sendSlope)	rate of credit decrease while the packets that passed through this gate use the physical channel
initialCredit	double	0	initial number of credits
transmitCreditLimit	double	0	credit limit above which the gate is open
minCredit	double	-inf	minimum number of credits
maxCredit	double	dropUnit(maxInterferenceSize) * dropUnit(idleSlope / bitrate)	maximum number of credits
accumulateCreditInGuardBand	bool	false	whether credit increases during implicit guard band when no packets can be sent anymore
idleSlope	double		data rate of the accumulated credits when the transmission channel is idle
sendSlope	double	idleSlope - bitrate	data rate of the spent credits when the transmission channel is in use
maxInterferenceSize	double	inf b

Properties

Name	Value	Description
display	i=block/cogwheel
class	CreditBasedGate

Gates

Name	Direction	Size	Description
in	input
out	output

Signals

Name	Type	Unit
creditsChanged	double

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
numCredits	number of credits	creditsChanged	vector	cr	linear

Source code

//
// This module is a packet gate that can be used to implement the IEEE 802.1q
// credit based shaper algorithm in combination with a packet queue.
//
simple Ieee8021qCreditBasedGate extends CreditBasedGate
{
    parameters:
        double idleSlope @unit(bps); // data rate of the accumulated credits when the transmission channel is idle
        double sendSlope @unit(bps) = default(idleSlope - bitrate); // data rate of the spent credits when the transmission channel is in use
        double maxInterferenceSize @unit(b) = default(inf b);
        idleCreditGainRate = default(dropUnit(idleSlope));
        transmitCreditSpendRate = default(-dropUnit(sendSlope));
        maxCredit = default(dropUnit(maxInterferenceSize) * dropUnit(idleSlope / bitrate));
}

File: src/inet/linklayer/ieee8021q/Ieee8021qCreditBasedGate.ned