EthernetSessionBridge¶

Package: simu5g.corenetwork.ethernetSessionBridge

compound module EthernetSessionBridge

The Ethernet bridge of a Upf, which forwards the traffic of its Ethernet PDU sessions “based on detected MAC addresses” (TS 23.501 5.8.2.5.3): one learning bridge per UPF, whose ports are the Ethernet sessions the UPF anchors and one N6 Ethernet interface, the node’s dnEth (TS 23.501 5.8.2.5.3, NOTE 2), which is connected to lowerLayerIn/Out: a submodule of the node, but a port of this bridge, registered in its interface table. A session’s uplink frames enter the bridge on the session’s port; the bridge learns their source addresses, forwards known unicast to the port of the destination (another session: switched locally, not via N6; or dnEth), floods unknown unicast, broadcast and multicast to every port but the ingress, and drops a frame whose destination is on its ingress port. Learning is per VLAN.

The bridge is INET’s layered BridgingLayer over its own interface table and MAC table, so the session ports and dnEth get no IP configuration and no routes, and the bridge floods among them only. A session port (EthernetSessionPort) is created when the session is established at the UPF and deleted when it is released, its MAC table entries flushed first; EthernetSessionMux does both, on the calls of the node’s UserPlaneNodeControl, and connects the ports’ lower sides to the node’s GTP-U path: uplink frames from GtpUser, downlink frames to the TrafficFlowFilter, each tagged with its session (SessionTag).

The frames carry their FCS inside the bridge; GtpUser rebuilds it where a frame leaves the tunnel and strips it where one enters, after the traffic flow filter has classified the full frame (TS 23.501 5.6.10.2: the 5GS does not carry the FCS).

Not modeled (TS 23.501 5.8.2.5.3): flooding scoped to a VLAN (frames are flooded across VLANs), ARP/ND proxying, allowed VLAN/MAC lists, S-/C-TAG handling, the reporting of learned MAC addresses to the SMF, PSA relocation, 5G VN groups.

Usage diagram¶

Used in compound modules¶

Name	Type	Description
Upf	compound module	Implements the 5G Core User Plane Function (UPF).

Properties¶

Name	Value	Description
display	i=block/switch;bgb=700,600

Gates¶

Name	Direction	Description
sessionIn	input	uplink frames of the sessions, from GtpUser (the ethernetmac service, which the session mux registers)
sessionOut	output	downlink frames of the sessions, to the TrafficFlowFilter
lowerLayerOut	output	to the N6 Ethernet interface (the node’s dnEth)
lowerLayerIn	input	from the N6 Ethernet interface

Unassigned submodule parameters¶

Name	Type	Default value	Description
macTable ↗.displayStringTextFormat	string	“addr: %a\nvlan: %v”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
macTable ↗.agingTime	double	120s
macTable ↗.forwardingTable	object	[]
macTable ↗.forwardingTableFile	string	“”
macTable ↗.interfaceTableModule	string
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
sessionMux.interfaceTableModule	string		The bridge’s interface table, which the session ports are registered in
sessionMux.macTableModule	string		The bridge’s MAC table, flushed of a released session’s port
sessionMux.portModuleType	string	“simu5g.corenetwork.ethernetSessionBridge.EthernetSessionPort”	The module type of the session ports
sessionMux.portDisplayString	string	“p=500,420,row,100;g=sessionPorts”	Display string of the session ports (their place in the bridge’s layout)
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
bridging ↗.directionReverser ↗.fork ↗.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
bridging ↗.directionReverser ↗.fork ↗.interfaceTableModule	string		Module path to the InterfaceTable ↗ module
bridging ↗.directionReverser ↗.fork ↗.forwardProtocolRegistration	bool	true
bridging ↗.directionReverser ↗.fork ↗.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
bridging ↗.directionReverser ↗.fork ↗.serviceMapping	object	{}	Maps protocols to connected submodule names (e.g. {“ethernetmac”: “bridging”}), overrides automatically learned dispatching; * overrides all learned services, ? overrides default
bridging ↗.directionReverser ↗.fork ↗.protocolMapping	object	{}	Maps protocols to connected submodule names (e.g. {“ipv4”: “bridging”}), overrides automatically learned dispatching; * overrides all learned protocols, ? overrides default
bridging ↗.directionReverser ↗.reverser ↗.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
bridging ↗.directionReverser ↗.reverser ↗.forwardVlan	bool	true
bridging ↗.directionReverser ↗.reverser ↗.forwardPcp	bool	true
bridging ↗.directionReverser ↗.reverser ↗.excludeEncapsulationProtocols	object	[]
bridging ↗.directionReverser ↗.join ↗.displayStringTextFormat	string	“passed %p pk (%l)”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
bridging ↗.directionReverser ↗.join ↗.forwardServiceRegistration	bool	true
bridging ↗.interfaceRelay ↗.learner ↗.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
bridging ↗.interfaceRelay ↗.learner ↗.macTableModule	string		Relative module path of MAC table
bridging ↗.interfaceRelay ↗.learner ↗.interfaceTableModule	string		Relative module path of the interface table
bridging ↗.interfaceRelay ↗.selector ↗.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
bridging ↗.interfaceRelay ↗.selector ↗.macTableModule	string		Relative module path of MAC table
bridging ↗.interfaceRelay ↗.selector ↗.interfaceTableModule	string		Relative module path of interface table
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
ethernet ↗.socketTable ↗.displayStringTextFormat	string	“”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
ethernet ↗.socketCommandProcessor ↗.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
ethernet ↗.socketCommandProcessor ↗.socketTableModule	string
ethernet ↗.macHeaderInserter ↗.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
ethernet ↗.macHeaderInserter ↗.interfaceTableModule	string
ethernet ↗.paddingInserter ↗.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
ethernet ↗.paddingInserter ↗.minLength	int
ethernet ↗.paddingInserter ↗.roundingLength	int	1B
ethernet ↗.paddingInserter ↗.insertionPosition	string	“back”
ethernet ↗.fcsInserter ↗.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
ethernet ↗.fcsInserter ↗.fcsMode	string	“declared”
ethernet ↗.socketPacketProcessor ↗.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
ethernet ↗.socketPacketProcessor ↗.socketTableModule	string
ethernet ↗.macHeaderChecker ↗.displayStringTextFormat	string	“dropped {numDroppedPackets}/{numProcessedPackets} pk ({droppedTotalLength}/{processedTotalLength})”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
ethernet ↗.macHeaderChecker ↗.backpressure	bool	false
ethernet ↗.macHeaderChecker ↗.interfaceTableModule	string
ethernet ↗.macHeaderChecker ↗.promiscuous	bool	false
ethernet ↗.fcsChecker ↗.displayStringTextFormat	string	“dropped {numDroppedPackets}/{numProcessedPackets} pk ({droppedTotalLength}/{processedTotalLength})”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
ethernet ↗.fcsChecker ↗.backpressure	bool	false
ethernet ↗.fcsChecker ↗.popFcs	bool	true
ieee8021q ↗.socketTable ↗.displayStringTextFormat	string	“”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
ieee8021q ↗.socketCommandProcessor ↗.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
ieee8021q ↗.socketCommandProcessor ↗.socketTableModule	string
ieee8021q ↗.qTagHeaderInserter ↗.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
ieee8021q ↗.qTagHeaderInserter ↗.vlanTagType	string	“c”
ieee8021q ↗.qTagHeaderInserter ↗.nextProtocol	string	“ethernetmac”
ieee8021q ↗.qTagHeaderInserter ↗.defaultVlanId	int	-1
ieee8021q ↗.qTagHeaderInserter ↗.defaultPcp	int	-1
ieee8021q ↗.qTagHeaderInserter ↗.defaultUserPriority	int	-1
ieee8021q ↗.qTagHeaderInserter ↗.defaultDropEligible	int	-1	<0: unspecified, 0: false, >0: true
ieee8021q ↗.socketPacketProcessor ↗.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
ieee8021q ↗.socketPacketProcessor ↗.socketTableModule	string
ieee8021q ↗.qTagHeaderChecker ↗.displayStringTextFormat	string	“dropped {numDroppedPackets}/{numProcessedPackets} pk ({droppedTotalLength}/{processedTotalLength})”	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
ieee8021q ↗.qTagHeaderChecker ↗.backpressure	bool	false
ieee8021q ↗.qTagHeaderChecker ↗.vlanTagType	string	“c”
ieee8021q ↗.qTagHeaderChecker ↗.vlanIdFilter	object	[]
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

Source code¶

//
// The Ethernet bridge of a ~Upf, which forwards the traffic of its Ethernet PDU sessions
// "based on detected MAC addresses" (TS 23.501 5.8.2.5.3): one learning bridge per UPF,
// whose ports are the Ethernet sessions the UPF anchors and one N6 Ethernet interface,
// the node's dnEth (TS 23.501 5.8.2.5.3, NOTE 2), which is connected to lowerLayerIn/Out:
// a submodule of the node, but a port of this bridge, registered in its interface table. A session's uplink frames enter the bridge on the
// session's port; the bridge learns their source addresses, forwards known unicast to
// the port of the destination (another session: switched locally, not via N6; or dnEth),
// floods unknown unicast, broadcast and multicast to every port but the ingress, and
// drops a frame whose destination is on its ingress port. Learning is per VLAN.
//
// The bridge is INET's layered BridgingLayer over its own interface table and
// MAC table, so the session ports and dnEth get no IP configuration and no routes, and
// the bridge floods among them only. A session port (~EthernetSessionPort) is created
// when the session is established at the UPF and deleted when it is released, its MAC
// table entries flushed first; ~EthernetSessionMux does both, on the calls of the node's
// ~UserPlaneNodeControl, and connects the ports' lower sides to the node's GTP-U path:
// uplink frames from ~GtpUser, downlink frames to the ~TrafficFlowFilter, each tagged
// with its session (~SessionTag).
//
// The frames carry their FCS inside the bridge; ~GtpUser rebuilds it where a frame leaves
// the tunnel and strips it where one enters, after the traffic flow filter has classified
// the full frame (TS 23.501 5.6.10.2: the 5GS does not carry the FCS).
//
// Not modeled (TS 23.501 5.8.2.5.3): flooding scoped to a VLAN (frames are flooded across
// VLANs), ARP/ND proxying, allowed VLAN/MAC lists, S-/C-TAG handling, the reporting of
// learned MAC addresses to the SMF, PSA relocation, 5G VN groups.
//
module EthernetSessionBridge
{
    parameters:
        @display("i=block/switch;bgb=700,600");
        **.interfaceTableModule = default(absPath(".interfaceTable"));
        **.macTableModule = default(absPath(".macTable"));
        *.fcsMode = "declared";
        ethernet.*.promiscuous = true;
        ethernet.registerProtocol = true;
    gates:
        input sessionIn;       // uplink frames of the sessions, from ~GtpUser (the ethernetmac service, which the session mux registers)
        output sessionOut;     // downlink frames of the sessions, to the ~TrafficFlowFilter
        output lowerLayerOut;  // to the N6 Ethernet interface (the node's dnEth)
        input lowerLayerIn;    // from the N6 Ethernet interface
    submodules:
        macTable: <default("MacForwardingTable")> like IMacForwardingTable {
            @display("p=100,100;is=s");
        }
        interfaceTable: InterfaceTable {
            @display("p=100,200;is=s");
        }
        sessionMux: EthernetSessionMux {
            portDisplayString = default("p=500,420,row,100;g=sessionPorts");
            @display("p=600,520");
        }
        cb: MessageDispatcher {
            @display("p=400,50;b=700,5,,,,1");
        }
        bridging: <default("BridgingLayer")> like IProtocolLayer {
            @display("p=400,120");
        }
        bl: MessageDispatcher {
            @display("p=400,190;b=700,5,,,,1");
        }
        ethernet: <default("EthernetLayer")> like IEthernetLayer {
            @display("p=300,260");
        }
        ieee8021q: <default("Ieee8021qProtocol")> like IIeee8021qLayer {
            @display("p=500,260");
        }
        li: MessageDispatcher {
            @display("p=400,330;b=700,5,,,,1");
        }
    connections allowunconnected:
        cb.out++ --> bridging.upperLayerIn;
        bridging.upperLayerOut --> cb.in++;
        bridging.lowerLayerOut --> bl.in++;
        bl.out++ --> bridging.lowerLayerIn;
        bl.out++ --> ethernet.upperLayerIn;
        ethernet.upperLayerOut --> bl.in++;
        bl.out++ --> ieee8021q.upperLayerIn;
        ieee8021q.upperLayerOut --> bl.in++;
        bl.out++ --> li.in++;
        li.out++ --> bl.in++;
        ethernet.lowerLayerOut --> li.in++;
        li.out++ --> ethernet.lowerLayerIn;
        ieee8021q.lowerLayerOut --> li.in++;
        li.out++ --> ieee8021q.lowerLayerIn;
        li.out++ --> { @display("m=s"); } --> lowerLayerOut;
        lowerLayerIn --> { @display("m=s"); } --> li.in++;
        sessionIn --> sessionMux.sessionIn;
        sessionMux.sessionOut --> sessionOut;
}

File: src/simu5g/corenetwork/ethernetSessionBridge/EthernetSessionBridge.ned