Performs Ethernet II or Ethernet with 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 EthernetIIFrame or EtherFrameWithSNAP (depending on the useSNAP module parameter), and sent to MAC. EtherType is taken from the Ieee802Ctrl structure attached to the message as control info (see setControlInfo(), controlInfo() methods). 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 EtherFrameWithLLC and EtherFrameWithSNAP too.

Inheritance diagram

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

Parameters

Name	Type	Default value	Description
interfaceTableModule	string		The path to the InterfaceTable module
useSNAP	bool	false	create EtherFrameWithSNAP frames instead of EthernetIIFrame

Properties

Name	Value	Description
display	i=block/square

Gates

Name	Direction	Size	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
encapPk	cPacket

Statistics

Name	Title	Source	Record	Unit	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 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 ~EthernetIIFrame
//   or ~EtherFrameWithSNAP (depending on the useSNAP module parameter),
//   and sent to MAC. ~EtherType is taken from the ~Ieee802Ctrl structure
//   attached to the message as control info (see setControlInfo(),
//   controlInfo() methods). 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 ~EtherFrameWithLLC and ~EtherFrameWithSNAP too.
//
simple EtherEncap like IEtherEncap
{
    parameters:
        string interfaceTableModule;   // The path to the InterfaceTable module
        bool useSNAP = default(false);  // create EtherFrameWithSNAP frames instead of EthernetIIFrame
        @display("i=block/square");
        @signal[encapPk](type=cPacket);
        @signal[decapPk](type=cPacket);
        @signal[pauseSent](type=long); // pause units
        @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

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