This module implements the IEEE 802.1as protocol also known as gPTP. It measures link delays to neighboring gPTP network nodes periodically. The slave and master ports specify where are the connected gPTP network nodes and their roles in the time synchronization domain. The time synchronization is done periodically and the clock module is set.

Inheritance diagram

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

Parameters

Name	Type	Default value	Description
clockModule	string	""	relative path of a module that implements IClock; optional
interfaceTableModule	string		relative path of the interface table module
gptpNodeType	string		@enum("GptpNodeType"): MASTER_NODE, BRIDGE_NODE, SLAVE_NODE
domainNumber	int	0	specifies the time domain number used in gPTP messages
slavePort	string	""	port for receiving time (empty for MASTER_NODE)
masterPorts	object	[]	ports for sending out time (empty for SLAVE_NODE)
correctionField	double	0s	time correction for link delay measurements
syncInterval	double	0.125s	time interval between SYNC messages
pdelayInterval	double	1s	frequency of link delay measurements
syncInitialOffset	double	syncInterval	time of first SYNC message
pdelayInitialOffset	double	0s	time of first link delay measurement
pDelayReqProcessingTime	double	8us	following parameters are used to schedule follow_up and pdelay_resp messages. These numbers must be enough large to prevent creating queue in MAC layer. It means it should be large than transmission time of message sent before
followUpInterval	double	7us

Properties

Name	Value	Description
display	i=block/timer
selfMessageKinds	inet::GptpSelfMsgKind

Gates

Name	Direction	Size	Description
socketIn	input
socketOut	output

Signals

Name	Type	Unit
localTime	simtime_t
rateRatio	double
peerDelay	simtime_t
timeDifference	simtime_t

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode
localTime			vector		linear
rateRatio			vector		samplehold
peerDelay			vector		samplehold
timeDifference			vector		linear

Scheduled messages (observed)

msg	kind	ctrl	tags	msgname	context
ClockEvent	103 (GptpSelfMsgKind::GPTP_SELF_MSG_SYNC)			selfMsgSync
ClockEvent	105 (GptpSelfMsgKind::GPTP_SELF_MSG_PDELAY_REQ)			selfMsgPdelay
GptpReqAnswerEvent	101 (GptpSelfMsgKind::GPTP_SELF_REQ_ANSWER_KIND)			selfMsgPdelayResp

Direct method calls (observed)

call to	function	info
SettableClock	inet::SettableClock::setClockTime	setClockTime
MessageDispatcher	inet::MessageDispatcher::arrived	arrived
MessageDispatcher	inet::MessageDispatcher::handleRegisterProtocol	handleRegisterProtocol
InterfaceTable	inet::InterfaceTable::findInterfaceByName	findInterfaceByName

Called methods (observed)

function	info	call from
inet::Gptp::receiveSignal	receptionEnded	PacketReceiver
inet::Gptp::receiveSignal	transmissionEnded	PacketTransmitter

Incoming messages (observed)

gate	msg	kind	ctrl	srcModule	tags
socketIn	Packet	0		MessageDispatcher	DirectionTag, DispatchProtocolReq, EncapsulationProtocolInd, GptpIngressTimeInd, InterfaceInd, MacAddressInd, PacketProtocolTag
socketIn	Packet	0		Ieee8021dRelay	DirectionTag, DispatchProtocolReq, EncapsulationProtocolInd, GptpIngressTimeInd, InterfaceInd, MacAddressInd, PacketProtocolTag
socketIn	Packet	0		PacketClassifier	DirectionTag, DispatchProtocolReq, EncapsulationProtocolInd, GptpIngressTimeInd, InterfaceInd, MacAddressInd, PacketProtocolTag

Outgoing messages (observed)

gate	msg	kind	ctrl	destModule	tags
socketOut	Packet	0		EthernetMacHeaderInserter	DispatchProtocolInd, DispatchProtocolReq, InterfaceReq, MacAddressReq, PacketProtocolTag
socketOut	Packet	0		Ieee8021dRelay	DispatchProtocolInd, DispatchProtocolReq, InterfaceReq, MacAddressReq, PacketProtocolTag
socketOut	Packet	0		PacketMultiplexer	DispatchProtocolInd, DispatchProtocolReq, InterfaceReq, MacAddressReq, PacketProtocolTag

Packet operations (observed)

chunkType	packetAction
EthernetMacHeader	peekAt
GptpBase	peekAt, peekAtFront
GptpFollowUp	insertAtFront
GptpPdelayReq	insertAtFront
GptpPdelayResp	insertAtFront
GptpPdelayRespFollowUp	insertAtFront
GptpSync	insertAtFront
EthernetPhyHeader	peekAtFront

Shared Tagging operations (observed)

tagType	tagAction
DispatchProtocolInd	addTag
DispatchProtocolReq	addTagIfAbsent
GptpIngressTimeInd	addTagIfAbsent, getTag
InterfaceInd	getTag
InterfaceReq	addTag
MacAddressReq	addTag
PacketProtocolTag	addTag, getTag

Source code

//
// This module implements the IEEE 802.1as protocol also known as gPTP. It
// measures link delays to neighboring gPTP network nodes periodically. The
// slave and master ports specify where are the connected gPTP network nodes
// and their roles in the time synchronization domain. The time synchronization
// is done periodically and the clock module is set.
//
simple Gptp like IApp
{
    parameters:
        string clockModule = default(""); // relative path of a module that implements IClock; optional
        string interfaceTableModule; // relative path of the interface table module
        string gptpNodeType; // @enum("GptpNodeType"): MASTER_NODE, BRIDGE_NODE, SLAVE_NODE
        int domainNumber = default(0); // specifies the time domain number used in gPTP messages
        string slavePort = default(""); // port for receiving time (empty for MASTER_NODE)
        object masterPorts = default([]); // ports for sending out time (empty for SLAVE_NODE)
        double correctionField @unit(s) = default(0s); // time correction for link delay measurements
        double syncInterval @unit(s) = default(0.125s); // time interval between SYNC messages
        double pdelayInterval @unit(s) = default(1s); // frequency of link delay measurements
        double syncInitialOffset @unit(s) = default(syncInterval); // time of first SYNC message
        double pdelayInitialOffset @unit(s) = default(0s); // time of first link delay measurement

        // following parameters are used to schedule follow_up and pdelay_resp messages.
        // These numbers must be enough large to prevent creating queue in MAC layer.
        // It means it should be large than transmission time of message sent before
        double pDelayReqProcessingTime @unit(s) = default(8us);  // processing time between arrived PDelayReq and send of PDelayResp
        double followUpInterval @unit(s) = default(7us);

        @display("i=block/timer");
        @signal[localTime](type=simtime_t);  // as clocktime_t
        @signal[timeDifference](type=simtime_t);
        @signal[rateRatio](type=double);
        @signal[peerDelay](type=simtime_t);
        @statistic[localTime](record=vector; interpolationmode=linear);
        @statistic[timeDifference](record=vector; interpolationmode=linear);
        @statistic[rateRatio](record=vector; interpolationmode=samplehold);
        @statistic[peerDelay](record=vector; interpolationmode=samplehold);
        @selfMessageKinds(inet::GptpSelfMsgKind);

    gates:
        input socketIn;
        output socketOut;
}

File: src/inet/linklayer/ieee8021as/Gptp.ned

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