Class L3Shim

java.lang.Object

L3Shim

All Implemented Interfaces:

Layer2Listener

public class L3Shim
extends java.lang.Object
implements Layer2Listener

This class strips off the L3type field that is required to be at the front of each Layer 3 packet, and demultiplexes based on it -- calling the object that has registered as handling the packets of that type.

Field Summary

Fields

Modifier and Type	Field and Description
static int	L3TYPE_L3 L3TYPE_L3 is the uniquely-assigned identifier for the L3 protocol -- the main protocol for forwarding packets across multiple networks through routers.

Constructor Summary

Constructors

Constructor and Description
L3Shim(Layer2Endpoint le) Create this object, storing the layer2 endpoint, and setting this object as a listener of frames from that layer 2 object.

Method Summary

Modifier and Type	Method and Description
void	frameReceived(Layer2Handler handler, Layer2Frame frame) Called when a frame is received for this endpoint at layer 2.
void	send(java.lang.String bits, int protocol, int destMac) Given a string of bits to send, the layer 3 protocol these bits are part of, and the layer 2 destination to send the data to, create the 2-bit layer 3 shim header, then create the Layer2Frame and send the frame via layer 2.
void	setListener(L3ShimListener l, int protoType) register a listener for the protocol with number protoType.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

L3TYPE_L3

public static final int L3TYPE_L3

L3TYPE_L3 is the uniquely-assigned identifier for the L3 protocol -- the main protocol for forwarding packets across multiple networks through routers.

See Also:

Constant Field Values

Constructor Detail

L3Shim

public L3Shim(Layer2Endpoint le)

Create this object, storing the layer2 endpoint, and setting this object as a listener of frames from that layer 2 object.

Method Detail

frameReceived

public void frameReceived(Layer2Handler handler,
                          Layer2Frame frame)

Called when a frame is received for this endpoint at layer 2. This method checks the 2-bit layer 3 type field and calls an object that has registered itself as being interested in receiving packets of that type. If no object is interested, the packet is dropped.

Specified by:

frameReceived in interface Layer2Listener

send

public void send(java.lang.String bits,
                 int protocol,
                 int destMac)

Given a string of bits to send, the layer 3 protocol these bits are part of, and the layer 2 destination to send the data to, create the 2-bit layer 3 shim header, then create the Layer2Frame and send the frame via layer 2.

setListener

public void setListener(L3ShimListener l,
                        int protoType)

register a listener for the protocol with number protoType.