PgwStandard

compound module

Implements a simplified EPC PDN Gateway (P-GW) of a 4G LTE network. It serves as the entry point to the core network of an LTE network, thus bridging it to the rest of the Internet. Packets arriving from the Internet are tunneled to the appropriate next hop in the core network (e.g., the eNodeB that will transmit the packet to the destination User Equipment through the radio access network) using the GPRS Tunneling Protocol (GTP). Conversely, packets received from the core network are detunneled and sent to the Internet (e.g., towards a remote server). To accomplish this, it utilizes a UserPlaneRelay, whose GtpUser handles GTP (de)tunneling and whose TrafficFlowFilter classifies incoming packets.

The interface toward the Internet (dnPpp, on the dnPppg gate) belongs to this user plane: it is not in the node's interface table, so the node's own network layer (the stack of the core network) neither sees nor uses it, and the address configurator gives it no address.

The relay reaches the SGi interface and the Ipv6NdResponder (ndResponder) through the rd message dispatcher, by service (see GtpUser).

Usage diagram

The following diagram shows usage relationships between types. Unresolved types are missing from the diagram.

Inheritance diagram

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

Used in

Name	Type	Description
MultiCell	network	Two eNodeB cells on a shared EPC PgwStandard, joined by an X2 link, with a router and a server behind the core. Four LteUe terminals are placed two per cell, and numExtCells ExtCell cells can be added as interferers. With hasD2D, the network holds the D2dBinder that D2D-capable nodes need, so that '**.hasD2D = true' turns D2D on in the network and in all its nodes.
MultiCell_D2DMultihop	network	Five eNodeB cells, each reaching the EPC PgwStandard through a router of its own, with a further router and a server behind the core. There are no X2 links. numUe1 to numUe5 LteUe terminals attach per cell, and an EventGenerator and a MultihopD2DStatistics module sit beside them, wired to nothing.
MultiCell_withSecondaryGnb	network	The two-cell version of SingleCell_withSecondaryGnb: two eNodeB masters, each paired over X2 with its own gNodeB secondary, and a further X2 link between the two masters. Both eNodeBs connect to the EPC PgwStandard, which faces a router and a server; neither gNodeB has a core-network link. numUe NrUe terminals attach, and numBgCells BackgroundCell cells can be added as interferers.
MultiCell_X2Mesh	network	Three eNodeB cells in a full X2 mesh. Each reaches the EPC PgwStandard through a router of its own, and the server sits directly on the PgwStandard's data-network gate. numUe1, numUe2 and numUe3 LteUe terminals attach per cell, and numExtCells ExtCell cells can be added as interferers.
SingleCell	network	The minimal LTE topology: one eNodeB connected to an EPC PgwStandard, which faces a router and a server, plus numUe LteUe terminals.
SingleCell_D2D	network	SingleCell with its UEs split into three vectors, so that a configuration can address cellular terminals (ueCell), D2D transmitters (ueD2DTx) and D2D receivers (ueD2DRx) separately. The rest of the topology is the same: one eNodeB on an EPC PgwStandard, with a router and a server behind it.
SingleCell_D2DMulticast	network	SingleCell with its UEs split into cellular terminals (ueCell) and members of a D2D multicast group (ueD2D). The rest of the topology is the same: one eNodeB on an EPC PgwStandard, with a router and a server behind it.
SingleCell_withSecondaryGnb	network	An EN-DC topology: an eNodeB master paired over X2 with a gNodeB secondary. The eNodeB is the only node with a core-network link -- an EPC PgwStandard facing a router and a server -- so all data-plane traffic enters there, and the gNodeB contributes its radio leg alone. numUe NrUe terminals attach to both, and numBgCells BackgroundCell cells can be added as interferers.

Extends

Name	Type	Description
ApplicationLayerNodeBase	compound module	An extension of the transport layer node base that adds support for applications. Provides the highest level of abstraction for network nodes, completing the full network stack from physical to application layer.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	""	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
hasStatus	bool	false
hasEnvironment	bool	false
osgModel	string	""	3D model for OSG visualization, no 3D model by default
osgModelColor	string	""	Tint color, no colorization by default
canvasImage	string	""	Image for canvas visualization, no image by default
canvasImageColor	string	""	Tint color, no colorization by default
recordPcap	bool	false
numPcapRecorders	int	recordPcap ? 1 : 0
numLoInterfaces	int	1
numWlanInterfaces	int	0
numEthInterfaces	int	0	Minimum number of Ethernet interfaces
numPppInterfaces	int	0	Minimum number of PPP interfaces
numTunInterfaces	int	0
numVirtInterfaces	int	0
fcsMode	string	"declared"
hasIpv4	bool	true
hasIpv6	bool	false
hasGn	bool	false
forwarding	bool	true
multicastForwarding	bool	false
hasUdp	bool	firstAvailableOrEmpty("Udp") != ""
hasTcp	bool	firstAvailableOrEmpty("Tcp", "TcpLwip", "TcpNsc") != ""
hasSctp	bool	false
hasQuic	bool	false
numApps	int	0
nodeType	string	"PGW"
hasNdResponder	bool	false	Answer the IPv6 Neighbor Discovery of the UEs' sessions (needed when UEs run IPv6), see Ipv6NdResponder

Properties

Name	Value	Description
class	NodeBase
networkNode
labels	node
display	i=device/mainframe;bgb=1700,1125

Gates

Name	Direction	Size
radioIn [ ]	input	numWlanInterfaces
pppg [ ]	inout	numPppInterfaces
ethg [ ]	inout	numEthInterfaces
dnPppg	inout

Unassigned submodule parameters

Name	Type	Default value	Description
status.displayStringTextFormat	string	"{stateStr}"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
status.initialStatus	string	"UP"	TODO @signal, @statistic
environment.displayStringTextFormat	string	""	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
environment.initStage	int	0	Initialization stage for the setup command
environment.globalNamespace	bool	false	Create new network namespaces under /var/run/netns/ (Linux only)
environment.namespace	string	""	Name of the host OS network namespace (optional) (Linux only)
environment.setupCommand	string	""	A host OS system command
environment.teardownCommand	string	""	A host OS system command
pcapRecorder.displayStringTextFormat	string	"rec: %n pks"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
pcapRecorder.verbose	bool	true	Whether to log packets on the module output
pcapRecorder.recordEmptyPackets	bool	true	Specifies if zero length packets are recorded or not
pcapRecorder.enableConvertingPackets	bool	true	Specifies if converting packets to link type is allowed or not
pcapRecorder.pcapFile	string	""	The PCAP file to be written, suggested value: pcapFile = "${resultdir}/${configname}-#${runnumber}" + fullpath() + ".pcap"
pcapRecorder.fileFormat	string	"pcapng"
pcapRecorder.snaplen	int	65535	Maximum number of bytes to record per packet
pcapRecorder.timePrecision	int	6	Time precision in recorded file. pcap supports only 6 (usec) or 9 (nanosec), pcapng supports more values (see 'if_tsresol' option in pcapng file format).
pcapRecorder.dumpBadFrames	bool	true	Enable dump of frames with hasBitError
pcapRecorder.moduleNamePatterns	string	"wlan[] eth[] ppp[*]"	Space-separated list of sibling module names to listen on
pcapRecorder.sendingSignalNames	string	"transmissionEnded"	Space-separated list of outbound packet signals to subscribe to
pcapRecorder.receivingSignalNames	string	"receptionEnded"	Space-separated list of inbound packet signals to subscribe to
pcapRecorder.dumpProtocols	string	"ethernetmac ppp ieee80211mac"	Space-separated list of protocol names as defined in the Protocol class
pcapRecorder.packetFilter	object	"*"	Which packets are considered, matches all packets by default
pcapRecorder.helpers	string	""	Usable PcapRecorder::IHelper helpers for accept packettype and store/convert packet as specified linktype currently available: "inet::AckingMacToEthernetPcapRecorderHelper"
pcapRecorder.alwaysFlush	bool	false	Flush the pcapFile after each write to ensure that all packets are captured in case of a crash
interfaceTable.displayStringTextFormat	string	"{numInterfaces} interfaces"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
interfaceTable.displayAddresses	bool	false	Whether to display IP addresses on links
cb.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
cb.interfaceTableModule	string		Module path to the InterfaceTable module
cb.forwardServiceRegistration	bool	true
cb.forwardProtocolRegistration	bool	true
cb.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
cb.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
cb.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
bl.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
bl.interfaceTableModule	string		Module path to the InterfaceTable module
bl.forwardServiceRegistration	bool	true
bl.forwardProtocolRegistration	bool	true
bl.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
bl.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
bl.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
li.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
li.interfaceTableModule	string		Module path to the InterfaceTable module
li.forwardServiceRegistration	bool	true
li.forwardProtocolRegistration	bool	true
li.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
li.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
li.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
eth.bitrate	double
nl.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
nl.interfaceTableModule	string		Module path to the InterfaceTable module
nl.forwardServiceRegistration	bool	true
nl.forwardProtocolRegistration	bool	true
nl.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
nl.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
nl.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
tn.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
tn.interfaceTableModule	string		Module path to the InterfaceTable module
tn.forwardServiceRegistration	bool	true
tn.forwardProtocolRegistration	bool	true
tn.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
tn.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
tn.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
at.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
at.interfaceTableModule	string		Module path to the InterfaceTable module
at.forwardServiceRegistration	bool	true
at.forwardProtocolRegistration	bool	true
at.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
at.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ethernetmac": "bridging"}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
at.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {"ipv4": "bridging"}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
dnPpp.pcapRecorder.displayStringTextFormat	string	"rec: %n pks"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
dnPpp.pcapRecorder.verbose	bool	true	Whether to log packets on the module output
dnPpp.pcapRecorder.recordEmptyPackets	bool	true	Specifies if zero length packets are recorded or not
dnPpp.pcapRecorder.enableConvertingPackets	bool	true	Specifies if converting packets to link type is allowed or not
dnPpp.pcapRecorder.pcapFile	string	""	The PCAP file to be written, suggested value: pcapFile = "${resultdir}/${configname}-#${runnumber}" + fullpath() + ".pcap"
dnPpp.pcapRecorder.fileFormat	string	"pcapng"
dnPpp.pcapRecorder.snaplen	int	65535	Maximum number of bytes to record per packet
dnPpp.pcapRecorder.timePrecision	int	6	Time precision in recorded file. pcap supports only 6 (usec) or 9 (nanosec), pcapng supports more values (see 'if_tsresol' option in pcapng file format).
dnPpp.pcapRecorder.dumpBadFrames	bool	true	Enable dump of frames with hasBitError
dnPpp.pcapRecorder.sendingSignalNames	string	"transmissionEnded"	Space-separated list of outbound packet signals to subscribe to
dnPpp.pcapRecorder.receivingSignalNames	string	"receptionEnded"	Space-separated list of inbound packet signals to subscribe to
dnPpp.pcapRecorder.dumpProtocols	string	"ethernetmac ppp ieee80211mac"	Space-separated list of protocol names as defined in the Protocol class
dnPpp.pcapRecorder.packetFilter	object	"*"	Which packets are considered, matches all packets by default
dnPpp.pcapRecorder.helpers	string	""	Usable PcapRecorder::IHelper helpers for accept packettype and store/convert packet as specified linktype currently available: "inet::AckingMacToEthernetPcapRecorderHelper"
dnPpp.pcapRecorder.alwaysFlush	bool	false	Flush the pcapFile after each write to ensure that all packets are captured in case of a crash
dnPpp.ppp.displayStringTextFormat	string	"rate: %b\nsent: %s, rcvd: %r\nqueue: %q, drop: %d"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
dnPpp.ppp.interfaceTableModule	string		The path to the InterfaceTable module
dnPpp.ppp.sendRawBytes	bool	false	When true packets are serialized into a sequence of bytes before sending out
dnPpp.ppp.mtu	int	4470B
dnPpp.ppp.stopOperationExtraTime	double	-1s	Extra time after lifecycle stop operation finished
dnPpp.ppp.stopOperationTimeout	double	2s	Timeout value for lifecycle stop operation
relay.trafficFlowFilter.binderModule	string	"binder"
relay.trafficFlowFilter.fastForwarding	bool	true
relay.gtpUser.binderModule	string	"binder"
relay.gtpUser.localPort	int	31
relay.gtpUser.tunnelPeerPort	int	31
rd.displayStringTextFormat	string	"processed {numProcessedPackets} pk ({processedTotalLength})"	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
rd.interfaceTableModule	string		Module path to the InterfaceTable module
rd.interfaceMapping	object	{}	Maps network interface names to connected submodule names (e.g. {"eth0": "bridging"}), overrides automatically learned dispatching; * overrides all learned network interfaces, ? overrides default
nodeControl.binderModule	string	"binder"
nodeControl.gtpUserModule	string	"^.relay.gtpUser"
nodeControl.trafficFlowFilterModule	string	"^.relay.trafficFlowFilter"
nodeControl.ethernetBridgeModule	string	"^.ethBridge.sessionMux"	The node's Ethernet session bridge (see EthernetSessionBridge), if it has one
nodeControl.gateway	string	""	A MEC host UPF's core network gateway, the anchor UPF whose sessions it serves; empty at an anchor
nodeControl.unstructuredPrefix	string	""	The prefix the N6 addresses of Unstructured sessions are allocated from, e.g. "2001:db8:5::/64" or "10.5.0.0/16"; empty = the node anchors no Unstructured session (see the main comment)
nodeControl.unstructuredServer	string	""	The application server the Unstructured sessions' uplink goes to: a module path relative to the network, resolved in the family of unstructuredPrefix
nodeControl.unstructuredServerPort	int	-1	The UDP port of unstructuredServer the uplink goes to; must be set for Unstructured sessions
nodeControl.unstructuredPort	int	-1	The UDP port the node receives the Unstructured sessions' downlink on, and sends their uplink from; must be set for Unstructured sessions
ndResponder.binderModule	string	"binder"
ndResponder.linkLocalAddress	string	"fe80::1"	The router's address on every session's link
ndResponder.routerLifetime	double	9000s	Router Lifetime in the Router Advertisements (max 9000s, RFC 4861)
ndResponder.curHopLimit	int	64	Cur Hop Limit in the Router Advertisements (0 = unspecified)
ndResponder.checksumMode	string	"declared"

Source code

//
// Implements a simplified EPC PDN Gateway (P-GW) of a 4G LTE network.
// It serves as the entry point to the core network of an LTE network, thus bridging it to the rest
// of the Internet. Packets arriving from the Internet are tunneled to the appropriate next hop in
// the core network (e.g., the ~eNodeB that will transmit the packet to the destination User Equipment
// through the radio access network) using the GPRS Tunneling Protocol (GTP). Conversely, packets
// received from the core network are detunneled and sent to the Internet (e.g., towards a remote server).
// To accomplish this, it utilizes a ~UserPlaneRelay, whose ~GtpUser handles GTP (de)tunneling and
// whose ~TrafficFlowFilter classifies incoming packets.
//
// The interface toward the Internet (dnPpp, on the dnPppg gate) belongs to this user plane:
// it is not in the node's interface table, so the node's own network layer (the stack of
// the core network) neither sees nor uses it, and the address configurator gives it no
// address.
//
// The relay reaches the SGi interface and the ~Ipv6NdResponder (ndResponder) through the
// rd message dispatcher, by service (see ~GtpUser).
//
module PgwStandard extends ApplicationLayerNodeBase
{
    parameters:
        @display("i=device/mainframe;bgb=1700,1125");
        @figure[userPlane](type=rectangle; pos=1275,5; size=400,437; fillColor=#ff8000; lineColor=#808080; cornerRadius=5; fillOpacity=0.1);
        @figure[userPlane.title](type=text; pos=1670,10; anchor=ne; text="user plane");
        @figure[sgiInterfaces](type=rectangle; pos=1275,458; size=400,660; fillColor=#00ffff; lineColor=#808080; cornerRadius=5; fillOpacity=0.1);
        @figure[sgiInterfaces.title](type=text; pos=1670,463; anchor=ne; text="SGi interfaces");
        @figure[submodules];

        string nodeType = "PGW";
        bool hasNdResponder = default(false);  // Answer the IPv6 Neighbor Discovery of the UEs' sessions (needed when UEs run IPv6), see ~Ipv6NdResponder

        forwarding = default(true);
        multicastForwarding = default(false);

    gates:
        inout dnPppg @labels(PppFrame-conn);

    submodules:
        dnPpp: PppInterface {
            parameters:
                interfaceTableModule = "";  // Not an interface of the node's network layer: the user plane's SGi end
                displayStringTextFormat = "";
                @display("p=1375,975");
        }
        relay: UserPlaneRelay {
            parameters:
                @display("p=1125,75");
                ownerType = parent.nodeType;
        }
        rd: MessageDispatcher {
            parameters:
                @display("p=1475,450;b=380,5,,,,1");
                serviceMapping = {"ipv4": "dnPpp", "ipv6": "dnPpp"};  // The data network; the optional modules register their services
                protocolMapping = {"ipv4": "relay", "ipv6": "relay", "ethernetmac": "relay"};
                forwardServiceRegistration = false;
                forwardProtocolRegistration = false;
        }
        nodeControl: UserPlaneNodeControl {
            parameters:
                @display("p=125,400;is=s");
                nodeType = parent.nodeType;
        }
        ndResponder: Ipv6NdResponder if hasNdResponder {
            parameters:
                @display("p=1550,225");
        }

    connections:

        relay.socketOut --> at.in++;
        relay.socketIn <-- at.out++;

        relay.userDataOut --> { @display("m=h,v"); } --> rd.in++;
        rd.out++ --> { @display("m=v,h"); } --> relay.userDataIn;

        rd.out++ --> dnPpp.upperLayerIn;
        dnPpp.upperLayerOut --> rd.in++;

        rd.out++ --> ndResponder.in if hasNdResponder;
        ndResponder.out --> rd.in++ if hasNdResponder;

        dnPpp.phys <--> { @display("m=s"); } <--> dnPppg;
}

File: src/simu5g/nodes/PgwStandard.ned