Package: inet.linklayer.ethernet

EtherEncap

simple module

Performs Ethernet II or Ethernet with LLC/SNAP encapsulation/decapsulation.

Expected environment:

lowerLayerIn, lowerLayerOut gates should be connected to an EtherMac
upperLayerIn, upperLayerOut gates should be connected to higher layer protocol or application

Functionality:

packets coming from upper layers will be encapsulated in EthernetII frame (EthernetMacHeader) or Ethernet SNAP frame (Ieee8022LlcSnapHeader) depending on the useSNAP module parameter, and sent to MAC. The EtherType is taken from the PacketProtocolTag tag attached to the packet. The source address will be filled in by EtherMac.
also accepts SENDPAUSE command (message kind=IEEE802CTRL_SENDPAUSE) from higher layer: it will send a PAUSE frame, as described in PAUSE frames.
Ethernet frames arriving from MAC will be decapsulated, and sent up to the higher layers. Accepts EthernetMacHeader, Ieee8022LlcHeader, and Ieee8022LlcSnapHeader too.

Inheritance diagram

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

Used in compound modules

Name	Type	Description
EtherHost	compound module	An example host with one Ethernet port and a traffic generator that generates request-reply traffic directly over Ethernet. This host model does not contain higher layer protocols (IP, TCP). By default it is configured to use half-duplex MAC (CSMA/CD).

Parameters

Name	Type	Default value	Description
interfaceTableModule	string		The path to the InterfaceTable module
useSNAP	bool	false	create EtherFrameWithSNAP frames instead of EthernetIIFrame
fcsMode	string
registerProtocol	bool	false	FIXME //KLUDGE should redesign place of EtherEncap and LLC modules
stopOperationExtraTime	double	-1s	extra time after lifecycle stop operation finished
stopOperationTimeout	double	2s	timeout value for lifecycle stop operation

Properties

Name	Value	Description
lifecycleSupport
display	i=block/square

Gates

Name	Direction	Description
upperLayerIn	input	higher layer
upperLayerOut	output	higher layer
lowerLayerIn	input	to Ethernet MAC
lowerLayerOut	output	to Ethernet MAC

Signals

Name	Type	Unit
pauseSent	long
decapPk	cPacket
packetDropped	inet::Packet
encapPk	cPacket

Statistics

Name	Title	Source	Record	Interpolation Mode
pauseSent	pause sent		count, sum, vector
decapPk	packets decapsulated	decapPk	count, sum(packetBytes), vector(packetBytes)	none
encapPk	packets encapsulated	encapPk	count, sum(packetBytes), vector(packetBytes)	none

Source code

//
// Performs Ethernet II or Ethernet with LLC/SNAP encapsulation/decapsulation.
//
// Expected environment:
// - lowerLayerIn, lowerLayerOut gates should be connected to an ~EtherMac
// - upperLayerIn, upperLayerOut gates should be connected to higher layer
//   protocol or application
//
// Functionality:
// - packets coming from upper layers will be encapsulated in EthernetII frame
//   (~EthernetMacHeader) or Ethernet SNAP frame (~Ieee8022LlcSnapHeader)
//   depending on the useSNAP module parameter,
//   and sent to MAC. The ~EtherType is taken from the ~PacketProtocolTag tag
//   attached to the packet. The source address will be filled in by ~EtherMac.
// - also accepts SENDPAUSE command (message kind=IEEE802CTRL_SENDPAUSE) from
//   higher layer: it will send a PAUSE frame, as described in
//   <a href="ether-pause.html">PAUSE frames</a>.
// - Ethernet frames arriving from MAC will be decapsulated, and sent up to the
//   higher layers. Accepts ~EthernetMacHeader, ~Ieee8022LlcHeader, and
//   ~Ieee8022LlcSnapHeader too.
//
simple EtherEncap like IEtherEncap
{
    parameters:
        string interfaceTableModule;   // The path to the InterfaceTable module
        bool useSNAP = default(false);  // create EtherFrameWithSNAP frames instead of EthernetIIFrame
        string fcsMode @enum("declared","computed");
        bool registerProtocol = default(false);     //FIXME //KLUDGE should redesign place of EtherEncap and LLC modules
        @lifecycleSupport;
        double stopOperationExtraTime @unit(s) = default(-1s);    // extra time after lifecycle stop operation finished
        double stopOperationTimeout @unit(s) = default(2s);    // timeout value for lifecycle stop operation
        @display("i=block/square");
        @signal[encapPk](type=cPacket);
        @signal[decapPk](type=cPacket);
        @signal[pauseSent](type=long); // pause units
        @signal[packetDropped](type=inet::Packet);
        @statistic[encapPk](title="packets encapsulated"; source=encapPk; record=count,"sum(packetBytes)","vector(packetBytes)"; interpolationmode=none);
        @statistic[decapPk](title="packets decapsulated"; source=decapPk; record=count,"sum(packetBytes)","vector(packetBytes)"; interpolationmode=none);
        @statistic[pauseSent](title="pause sent"; record=count,sum,vector);
    gates:
        input upperLayerIn @labels(Ieee802Ctrl/down); // higher layer
        output upperLayerOut @labels(Ieee802Ctrl/up); // higher layer
        input lowerLayerIn @labels(EtherFrame);   // to Ethernet MAC
        output lowerLayerOut @labels(EtherFrame); // to Ethernet MAC
}

File: src/inet/linklayer/ethernet/EtherEncap.ned