diff --git a/src/main/java/net/floodlightcontroller/util/CallerId.java b/src/main/java/net/floodlightcontroller/util/CallerId.java
new file mode 100644
index 0000000..898da31
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/CallerId.java
@@ -0,0 +1,48 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing a Caller ID for an ONOS component.
+ */
+public class CallerId {
+    private String value;
+
+    /**
+     * Default constructor.
+     */
+    public CallerId() {}
+
+    /**
+     * Constructor from a string value.
+     *
+     * @param value the value to use.
+     */
+    public CallerId(String value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the Caller ID.
+     *
+     * @return the value of the Caller ID.
+     */
+    public String value() { return value; }
+
+    /**
+     * Set the value of the Caller ID.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(String value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the Caller ID value to a string.
+     *
+     * @return the Caller ID value to a string.
+     */
+    @Override
+    public String toString() {
+	return value;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/DataPath.java b/src/main/java/net/floodlightcontroller/util/DataPath.java
new file mode 100644
index 0000000..2374fbe
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/DataPath.java
@@ -0,0 +1,81 @@
+package net.floodlightcontroller.util;
+
+import java.util.ArrayList;
+
+import net.floodlightcontroller.util.SwitchPort;
+import net.floodlightcontroller.util.FlowEntry;
+
+/**
+ * The class representing the Data Path.
+ */
+public class DataPath {
+    private SwitchPort srcPort;		// The source port
+    private SwitchPort dstPort;		// The destination port
+    private ArrayList<FlowEntry> flowEntries;	// The Flow Entries
+
+    /**
+     * Default constructor.
+     */
+    public DataPath() {
+    }
+
+    /**
+     * Get the data path source port.
+     *
+     * @return the data path source port.
+     */
+    public SwitchPort srcPort() { return srcPort; }
+
+    /**
+     * Set the data path source port.
+     *
+     * @param srcPort the data path source port to set.
+     */
+    public void setSrcPort(SwitchPort srcPort) {
+	this.srcPort = srcPort;
+    }
+
+    /**
+     * Get the data path destination port.
+     *
+     * @return the data path destination port.
+     */
+    public SwitchPort dstPort() { return dstPort; }
+
+    /**
+     * Set the data path destination port.
+     *
+     * @param dstPort the data path destination port to set.
+     */
+    public void setDstPort(SwitchPort dstPort) {
+	this.dstPort = dstPort;
+    }
+
+    /**
+     * Get the data path flow entries.
+     *
+     * @return the data path flow entries.
+     */
+    public ArrayList<FlowEntry> flowEntries() { return flowEntries; }
+
+    /**
+     * Set the data path flow entries.
+     *
+     * @param flowEntries the data path flow entries to set.
+     */
+    public void setFlowEntries(ArrayList<FlowEntry> flowEntries) {
+	this.flowEntries = flowEntries;
+    }
+
+    /**
+     * Convert the data path to a string.
+     *
+     * @return the data path as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/DataPathEndpoints.java b/src/main/java/net/floodlightcontroller/util/DataPathEndpoints.java
new file mode 100644
index 0000000..5c9e02c
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/DataPathEndpoints.java
@@ -0,0 +1,72 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.SwitchPort;
+
+/**
+ * The class representing the Data Path Endpoints.
+ */
+public class DataPathEndpoints {
+    private SwitchPort srcPort;		// The source port
+    private SwitchPort dstPort;		// The destination port
+
+    /**
+     * Default constructor.
+     */
+    public DataPathEndpoints() {
+    }
+
+    /**
+     * Constructor for given source and destination ports.
+     *
+     * @param srcPort the source port to use.
+     * @param dstPort the destination port to use.
+     */
+    public DataPathEndpoints(SwitchPort srcPort, SwitchPort dstPort) {
+	this.srcPort = srcPort;
+	this.dstPort = dstPort;
+    }
+
+    /**
+     * Get the data path source port.
+     *
+     * @return the data path source port.
+     */
+    public SwitchPort srcPort() { return srcPort; }
+
+    /**
+     * Set the data path source port.
+     *
+     * @param srcPort the data path source port to set.
+     */
+    public void setSrcPort(SwitchPort srcPort) {
+	this.srcPort = srcPort;
+    }
+
+    /**
+     * Get the data path destination port.
+     *
+     * @return the data path destination port.
+     */
+    public SwitchPort dstPort() { return dstPort; }
+
+    /**
+     * Set the data path destination port.
+     *
+     * @param dstPort the data path destination port to set.
+     */
+    public void setDstPort(SwitchPort dstPort) {
+	this.dstPort = dstPort;
+    }
+
+    /**
+     * Convert the data path endpoints to a string.
+     *
+     * @return the data path endpoints as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/Dpid.java b/src/main/java/net/floodlightcontroller/util/Dpid.java
new file mode 100644
index 0000000..3a8d1e8
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/Dpid.java
@@ -0,0 +1,54 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing a network switch DPID.
+ */
+public class Dpid {
+    static public long UNKNOWN = 0;
+
+    private long value;
+
+    /**
+     * Default constructor.
+     */
+    public Dpid() {
+	this.value = Dpid.UNKNOWN;
+    }
+
+    /**
+     * Constructor from a long value.
+     *
+     * @param value the value to use.
+     */
+    public Dpid(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the DPID.
+     *
+     * @return the value of the DPID.
+     */
+    public long value() { return value; }
+
+    /**
+     * Set the value of the DPID.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the DPID value to a ':' separated hex string.
+     *
+     * @return the DPID value as a ':' separated hex string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowEntry.java b/src/main/java/net/floodlightcontroller/util/FlowEntry.java
new file mode 100644
index 0000000..e9c4bbe
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowEntry.java
@@ -0,0 +1,224 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.Dpid;
+import net.floodlightcontroller.util.FlowEntryActions;
+import net.floodlightcontroller.util.FlowEntryId;
+import net.floodlightcontroller.util.FlowEntryMatch;
+import net.floodlightcontroller.util.Port;
+
+/**
+ * The Flow Entry state as set by the user (via the ONOS API).
+ */
+enum FlowEntryUserState {
+	FE_USER_UNKNOWN,		// Initialization value: state unknown
+	FE_USER_ADD,			// Flow entry that is added
+	FE_USER_MODIFY,			// Flow entry that is modified
+	FE_USER_DELETE			// Flow entry that is deleted
+}
+
+/**
+ * The Flow Entry state as set by the controller.
+ */
+enum FlowEntrySwitchState {
+	FE_SWITCH_UNKNOWN,		// Initialization value: state unknown
+	FE_SWITCH_NOT_UPDATED,		// Switch not updated with this entry
+	FE_SWITCH_UPDATE_IN_PROGRESS,	// Switch update in progress
+	FE_SWITCH_UPDATED,		// Switch updated with this entry
+	FE_SWITCH_UPDATE_FAILED	// Error updating the switch with this entry
+}
+
+
+/**
+ * The class representing the Flow Entry.
+ *
+ * NOTE: The specification is incomplete. E.g., the entry needs to
+ * support multiple in-ports and multiple out-ports.
+ */
+public class FlowEntry {
+    private FlowEntryId flowEntryId;		// The Flow Entry ID
+    private FlowEntryMatch flowEntryMatch;	// The Flow Entry Match
+    private FlowEntryActions flowEntryActions;	// The Flow Entry Actions
+    private Dpid dpid;				// The Switch DPID
+    private Port inPort;			// The Switch incoming port
+    private Port outPort;			// The Switch outgoing port
+    private FlowEntryUserState flowEntryUserState; // The Flow Entry User state
+    private FlowEntrySwitchState flowEntrySwitchState; // The Flow Entry Switch state
+    // The Flow Entry Error state (if FlowEntrySwitchState is FE_SWITCH_FAILED)
+    private FlowEntryErrorState flowEntryErrorState;
+
+    /**
+     * Default constructor.
+     */
+    public FlowEntry() {
+	flowEntryUserState = FlowEntryUserState.FE_USER_UNKNOWN;
+	flowEntrySwitchState = FlowEntrySwitchState.FE_SWITCH_UNKNOWN;
+    }
+
+    /**
+     * Get the Flow Entry ID.
+     *
+     * @return the Flow Entry ID.
+     */
+    public FlowEntryId flowEntryId() { return flowEntryId; }
+
+    /**
+     * Set the Flow Entry ID.
+     *
+     * @param flowEntryId the Flow Entry ID to set.
+     */
+    public void setFlowEntryId(FlowEntryId flowEntryId) {
+	this.flowEntryId = flowEntryId;
+    }
+
+    /**
+     * Get the Flow Entry Match.
+     *
+     * @return the Flow Entry Match.
+     */
+    public FlowEntryMatch flowEntryMatch() { return flowEntryMatch; }
+
+    /**
+     * Set the Flow Entry Match.
+     *
+     * @param flowEntryMatch the Flow Entry Match to set.
+     */
+    public void setFlowEntryMatch(FlowEntryMatch flowEntryMatch) {
+	this.flowEntryMatch = flowEntryMatch;
+    }
+
+    /**
+     * Get the Flow Entry Actions.
+     *
+     * @return the Flow Entry Actions.
+     */
+    public FlowEntryActions flowEntryActions() { return flowEntryActions; }
+
+    /**
+     * Set the Flow Entry Actions.
+     *
+     * @param flowEntryActions the Flow Entry Actions to set.
+     */
+    public void setFlowEntryActions(FlowEntryActions flowEntryActions) {
+	this.flowEntryActions = flowEntryActions;
+    }
+
+    /**
+     * Get the Switch DPID.
+     *
+     * @return the Switch DPID.
+     */
+    public Dpid dpid() { return dpid; }
+
+    /**
+     * Set the Switch DPID.
+     *
+     * @param dpid the Switch DPID to set.
+     */
+    public void setDpid(Dpid dpid) {
+	this.dpid = dpid;
+    }
+
+    /**
+     * Get the Switch incoming port.
+     *
+     * @return the Switch incoming port.
+     */
+    public Port inPort() { return inPort; }
+
+    /**
+     * Set the Switch incoming port.
+     *
+     * @param inPort the Switch incoming port to set.
+     */
+    public void setInPort(Port inPort) {
+	this.inPort = inPort;
+    }
+
+    /**
+     * Get the Switch outgoing port.
+     *
+     * @return the Switch outgoing port.
+     */
+    public Port outPort() { return outPort; }
+
+    /**
+     * Set the Switch outgoing port.
+     *
+     * @param outPort the Switch outgoing port to set.
+     */
+    public void setOutPort(Port outPort) {
+	this.outPort = outPort;
+    }
+
+    /**
+     * Get the Flow Entry User state.
+     *
+     * @return the Flow Entry User state.
+     */
+    public FlowEntryUserState flowEntryUserState() {
+	return flowEntryUserState;
+    }
+
+    /**
+     * Set the Flow Entry User state.
+     *
+     * @param flowEntryUserState the Flow Entry User state to set.
+     */
+    public void setFlowEntryUserState(FlowEntryUserState flowEntryUserState) {
+	this.flowEntryUserState = flowEntryUserState;
+    }
+
+    /**
+     * Get the Flow Entry Switch state.
+     *
+     * The Flow Entry Error state is used if FlowEntrySwitchState is
+     * FE_SWITCH_FAILED.
+     *
+     * @return the Flow Entry Switch state.
+     */
+    public FlowEntrySwitchState flowEntrySwitchState() {
+	return flowEntrySwitchState;
+    }
+
+    /**
+     * Set the Flow Entry Switch state.
+     *
+     * The Flow Entry Error state is used if FlowEntrySwitchState is
+     * FE_SWITCH_FAILED.
+     *
+     * @param flowEntrySwitchState the Flow Entry Switch state to set.
+     */
+    public void setFlowEntrySwitchState(FlowEntrySwitchState flowEntrySwitchState) {
+	this.flowEntrySwitchState = flowEntrySwitchState;
+    }
+
+    /**
+     * Get the Flow Entry Error state.
+     *
+     * @return the Flow Entry Error state.
+     */
+    public FlowEntryErrorState flowEntryErrorState() {
+	return flowEntryErrorState;
+    }
+
+    /**
+     * Set the Flow Entry Error state.
+     *
+     * @param flowEntryErrorState the Flow Entry Error state to set.
+     */
+    public void setFlowEntryErrorState(FlowEntryErrorState flowEntryErrorState) {
+	this.flowEntryErrorState = flowEntryErrorState;
+    }
+
+    /**
+     * Convert the flow entry to a string.
+     *
+     * @return the flow entry as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowEntryActions.java b/src/main/java/net/floodlightcontroller/util/FlowEntryActions.java
new file mode 100644
index 0000000..90f42fb
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowEntryActions.java
@@ -0,0 +1,30 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing the Flow Entry set of actions.
+ *
+ * The Flow Entry set of actions need to be applied to each packet.
+ *
+ * NOTE: This is just an empty placeholder (for now). The implied action is
+ * forwarding on a single port.
+ */
+public class FlowEntryActions {
+
+    /**
+     * Default constructor.
+     */
+    public FlowEntryActions() {
+    }
+
+    /**
+     * Convert the set of actions to a string.
+     *
+     * @return the set of actions as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowEntryErrorState.java b/src/main/java/net/floodlightcontroller/util/FlowEntryErrorState.java
new file mode 100644
index 0000000..63c103d
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowEntryErrorState.java
@@ -0,0 +1,65 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing the Flow Entry error state.
+ */
+public class FlowEntryErrorState {
+    private short type;	// The error type (e.g., see OF-1.3.1 spec, pp. 95)
+    private short code;	// The error code (e.g., see OF-1.3.1 spec, pp. 95)
+
+    /**
+     * Default constructor.
+     */
+    public FlowEntryErrorState() {
+	this.type = 0;
+	this.code = 0;
+    }
+
+    /**
+     * Constructor for a given error type and code.
+     *
+     * @param type the error type to use.
+     * @param code the error code to use.
+     */
+    public FlowEntryErrorState(short type, short code) {
+	this.type = type;
+	this.code = code;
+    }
+
+    /**
+     * Get the error type.
+     *
+     * @return the error type.
+     */
+    public short type() { return type; }
+
+    /**
+     * Get the error code.
+     *
+     * @return the error code.
+     */
+    public short code() { return code; }
+
+    /**
+     * Set the values of the error type and code.
+     *
+     * @param type the error type to use.
+     * @param code the error code to use.
+     */
+    public void setValue(short type, short code) {
+	this.type = type;
+	this.code = code;
+    }
+
+    /**
+     * Convert the error type and code to a string.
+     *
+     * @return the error type and code as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowEntryId.java b/src/main/java/net/floodlightcontroller/util/FlowEntryId.java
new file mode 100644
index 0000000..4736ed5
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowEntryId.java
@@ -0,0 +1,52 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing a Flow Entry ID.
+ */
+public class FlowEntryId {
+    private long value;
+
+    /**
+     * Default constructor.
+     */
+    public FlowEntryId() {
+	this.value = 0;
+    }
+
+    /**
+     * Constructor from an integer value.
+     *
+     * @param value the value to use.
+     */
+    public FlowEntryId(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the Flow Entry ID.
+     *
+     * @return the value of the Flow Entry ID.
+     */
+    public long value() { return value; }
+
+    /**
+     * Set the value of the Flow Entry ID.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the Flow Entry ID value to a string.
+     *
+     * @return the Flow Entry ID value to a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowEntryMatch.java b/src/main/java/net/floodlightcontroller/util/FlowEntryMatch.java
new file mode 100644
index 0000000..a8f43f5
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowEntryMatch.java
@@ -0,0 +1,105 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.MACAddress;
+import net.floodlightcontroller.util.IPv4Net;
+
+/**
+ * The class representing the Flow Entry Matching filter.
+ *
+ * The Flow Entry matching filter that is used to specify
+ * the network data that would be forwarded on the data path from
+ * the source to the destination. Examples: MAC address (of the
+ * sender), IP prefix that includes the destination's IP address, etc.
+ *
+ * NOTE: The FlowEntryMatch specification below is incomplete: we need
+ * more matching fields, we need to indicate which fields need to be
+ * matched, etc.
+ */
+public class FlowEntryMatch {
+    private MACAddress srcMac;		// Matching source MAC address
+    private MACAddress dstMac;		// Matching destination MAC address
+    private IPv4Net srcIPv4Net;		// Matching source IPv4 prefix
+    private IPv4Net dstIPv4Net;		// Matching destination IPv4 prefix
+
+    /**
+     * Default constructor.
+     */
+    public FlowEntryMatch() {
+    }
+
+    /**
+     * Get the matching source MAC address.
+     *
+     * @return the matching source MAC address.
+     */
+    public MACAddress srcMac() { return srcMac; }
+
+    /**
+     * Set the matching source MAC address.
+     *
+     * @param srcMac the matching source MAC address to set.
+     */
+    public void setSrcMac(MACAddress srcMac) {
+	this.srcMac = srcMac;
+    }
+
+    /**
+     * Get the matching destination MAC address.
+     *
+     * @return the matching destination MAC address.
+     */
+    public MACAddress dstMac() { return dstMac; }
+
+    /**
+     * Set the matching destination MAC address.
+     *
+     * @param dstMac the matching destination MAC address to set.
+     */
+    public void setDstMac(MACAddress dstMac) {
+	this.dstMac = dstMac;
+    }
+
+    /**
+     * Get the matching source IPv4 prefix.
+     *
+     * @return the matching source IPv4 prefix.
+     */
+    public IPv4Net srcIPv4Net() { return srcIPv4Net; }
+
+    /**
+     * Set the matching source IPv4 prefix.
+     *
+     * @param srcIPv4Net the matching source IPv4 prefix to set.
+     */
+    public void setSrcIPv4Net(IPv4Net srcIPv4Net) {
+	this.srcIPv4Net = srcIPv4Net;
+    }
+
+    /**
+     * Get the matching destination IPv4 prefix.
+     *
+     * @return the matching destination IPv4 prefix.
+     */
+    public IPv4Net dstIPv4Net() { return dstIPv4Net; }
+
+    /**
+     * Set the matching destination IPv4 prefix.
+     *
+     * @param srcIPv4Net the matching destination IPv4 prefix to set.
+     */
+    public void setDstIPv4Net(IPv4Net dstIPv4Net) {
+	this.dstIPv4Net = dstIPv4Net;
+    }
+
+    /**
+     * Convert the matching filter to a string.
+     *
+     * @return the matching filter as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowId.java b/src/main/java/net/floodlightcontroller/util/FlowId.java
new file mode 100644
index 0000000..827c1d9
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowId.java
@@ -0,0 +1,52 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing a Flow ID.
+ */
+public class FlowId {
+    private long value;
+
+    /**
+     * Default constructor.
+     */
+    public FlowId() {
+	this.value = 0;
+    }
+
+    /**
+     * Constructor from an integer value.
+     *
+     * @param value the value to use.
+     */
+    public FlowId(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the Flow ID.
+     *
+     * @return the value of the Flow ID.
+     */
+    public long value() { return value; }
+
+    /**
+     * Set the value of the Flow ID.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(long value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the Flow ID value to a string.
+     *
+     * @return the Flow ID value to a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/FlowPath.java b/src/main/java/net/floodlightcontroller/util/FlowPath.java
new file mode 100644
index 0000000..46a1f82
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/FlowPath.java
@@ -0,0 +1,80 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.CallerId;
+import net.floodlightcontroller.util.DataPath;
+import net.floodlightcontroller.util.FlowId;
+
+/**
+ * The class representing the Flow Path.
+ */
+public class FlowPath {
+    private FlowId flowId;		// The Flow ID
+    private CallerId installerId;	// The Caller ID of the path installer
+    private DataPath dataPath;		// The data path
+
+    /**
+     * Default constructor.
+     */
+    public FlowPath() {
+    }
+
+    /**
+     * Get the flow path Flow ID.
+     *
+     * @return the flow path Flow ID.
+     */
+    public FlowId flowId() { return flowId; }
+
+    /**
+     * Set the flow path Flow ID.
+     *
+     * @param flowId the flow path Flow ID to set.
+     */
+    public void setFlowId(FlowId flowId) {
+	this.flowId = flowId;
+    }
+
+    /**
+     * Get the Caller ID of the flow path installer.
+     *
+     * @return the Caller ID of the flow path installer.
+     */
+    public CallerId installerId() { return installerId; }
+
+    /**
+     * Set the Caller ID of the flow path installer.
+     *
+     * @param installerId the Caller ID of the flow path installer.
+     */
+    public void setInstallerId(CallerId installerId) {
+	this.installerId = installerId;
+    }
+
+    /**
+     * Get the flow path's data path.
+     *
+     * @return the flow path's data path.
+     */
+    public DataPath dataPath() { return dataPath; }
+
+    /**
+     * Set the flow path's data path.
+     *
+     * @param dataPath the flow path's data path to set.
+     */
+    public void setDataPath(DataPath dataPath) {
+	this.dataPath = dataPath;
+    }
+
+    /**
+     * Convert the flow path to a string.
+     *
+     * @return the flow path as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/IPv4.java b/src/main/java/net/floodlightcontroller/util/IPv4.java
new file mode 100644
index 0000000..b4fc787
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/IPv4.java
@@ -0,0 +1,52 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing an IPv4 address.
+ */
+public class IPv4 {
+    private int value;
+
+    /**
+     * Default constructor.
+     */
+    public IPv4() {
+	this.value = 0;
+    }
+
+    /**
+     * Constructor from an integer value.
+     *
+     * @param value the value to use.
+     */
+    public IPv4(int value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the IPv4 address.
+     *
+     * @return the value of the IPv4 address.
+     */
+    public int value() { return value; }
+
+    /**
+     * Set the value of the IPv4 address.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(int value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the IPv4 value to a '.' separated string.
+     *
+     * @return the IPv4 value as a '.' separated string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/IPv4Net.java b/src/main/java/net/floodlightcontroller/util/IPv4Net.java
new file mode 100644
index 0000000..6c4c651
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/IPv4Net.java
@@ -0,0 +1,66 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.IPv4;
+
+/**
+ * The class representing an IPv4 network address.
+ */
+public class IPv4Net {
+    private IPv4 address;		// The IPv4 address
+    private short prefixLen;		// The prefix length
+
+    /**
+     * Default constructor.
+     */
+    public IPv4Net() {
+	this.prefixLen = 0;
+    }
+
+    /**
+     * Constructor for a given address and prefix length.
+     *
+     * @param address the address to use.
+     * @param prefixLen the prefix length to use.
+     */
+    public IPv4Net(IPv4 address, short prefixLen) {
+	this.address = address;
+	this.prefixLen = prefixLen;
+    }
+
+    /**
+     * Get the address value of the IPv4Net address.
+     *
+     * @return the address value of the IPv4Net address.
+     */
+    public IPv4 address() { return address; }
+
+    /**
+     * Get the prefix length value of the IPv4Net address.
+     *
+     * @return the prefix length value of the IPv4Net address.
+     */
+    public short prefixLen() { return prefixLen; }
+
+    /**
+     * Set the value of the IPv4Net address.
+     *
+     * @param address the address to use.
+     * @param prefixLen the prefix length to use.
+     */
+    public void setValue(IPv4 address, short prefixLen) {
+	this.address = address;
+	this.prefixLen = prefixLen;
+    }
+
+    /**
+     * Convert the IPv4Net value to an "address/prefixLen" string.
+     *
+     * @return the IPv4Net value as an "address/prefixLen" string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/IPv6.java b/src/main/java/net/floodlightcontroller/util/IPv6.java
new file mode 100644
index 0000000..dfa071b
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/IPv6.java
@@ -0,0 +1,67 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing an IPv6 address.
+ */
+public class IPv6 {
+    private long valueHigh;	// The higher (more significant) 64 bits
+    private long valueLow;	// The lower (less significant) 64 bits
+
+    /**
+     * Default constructor.
+     */
+    public IPv6() {
+	this.valueHigh = 0;
+	this.valueLow = 0;
+    }
+
+    /**
+     * Constructor from integer values.
+     *
+     * @param valueHigh the higher (more significant) 64 bits of the address.
+     * @param valueLow the lower (less significant) 64 bits of the address.
+     */
+    public IPv6(long valueHigh, long valueLow) {
+	this.valueHigh = valueHigh;
+	this.valueLow = valueLow;
+    }
+
+    /**
+     * Get the value of the higher (more significant) 64 bits of the address.
+     *
+     * @return the value of the higher (more significant) 64 bits of the
+     * address.
+     */
+    public long valueHigh() { return valueHigh; }
+
+    /**
+     * Get the value of the lower (less significant) 64 bits of the address.
+     *
+     * @return the value of the lower (less significant) 64 bits of the
+     * address.
+     */
+    public long valueLow() { return valueLow; }
+
+    /**
+     * Set the value of the IPv6 address.
+     *
+     * @param valueHigh the higher (more significant) 64 bits of the address.
+     * @param valueLow the lower (less significant) 64 bits of the address.
+     */
+    public void setValue(long valueHigh, long valueLow) {
+	this.valueHigh = valueHigh;
+	this.valueLow = valueLow;
+    }
+
+    /**
+     * Convert the IPv6 value to a ':' separated string.
+     *
+     * @return the IPv6 value as a ':' separated string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/IPv6Net.java b/src/main/java/net/floodlightcontroller/util/IPv6Net.java
new file mode 100644
index 0000000..85de4f7
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/IPv6Net.java
@@ -0,0 +1,66 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.IPv6;
+
+/**
+ * The class representing an IPv6 network address.
+ */
+public class IPv6Net {
+    private IPv6 address;		// The IPv6 address
+    private short prefixLen;		// The prefix length
+
+    /**
+     * Default constructor.
+     */
+    public IPv6Net() {
+	this.prefixLen = 0;
+    }
+
+    /**
+     * Constructor for a given address and prefix length.
+     *
+     * @param address the address to use.
+     * @param prefixLen the prefix length to use.
+     */
+    public IPv6Net(IPv6 address, short prefixLen) {
+	this.address = address;
+	this.prefixLen = prefixLen;
+    }
+
+    /**
+     * Get the address value of the IPv6Net address.
+     *
+     * @return the address value of the IPv6Net address.
+     */
+    public IPv6 address() { return address; }
+
+    /**
+     * Get the prefix length value of the IPv6Net address.
+     *
+     * @return the prefix length value of the IPv6Net address.
+     */
+    public short prefixLen() { return prefixLen; }
+
+    /**
+     * Set the value of the IPv6Net address.
+     *
+     * @param address the address to use.
+     * @param prefixLen the prefix length to use.
+     */
+    public void setValue(IPv6 address, short prefixLen) {
+	this.address = address;
+	this.prefixLen = prefixLen;
+    }
+
+    /**
+     * Convert the IPv6Net value to an "address/prefixLen" string.
+     *
+     * @return the IPv6Net value as an "address/prefixLen" string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/Port.java b/src/main/java/net/floodlightcontroller/util/Port.java
new file mode 100644
index 0000000..8fbb727
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/Port.java
@@ -0,0 +1,52 @@
+package net.floodlightcontroller.util;
+
+/**
+ * The class representing a network port of a switch.
+ */
+public class Port {
+    private short value;
+
+    /**
+     * Default constructor.
+     */
+    public Port() {
+	this.value = 0;
+    }
+
+    /**
+     * Constructor from a long value.
+     *
+     * @param value the value to use.
+     */
+    public Port(short value) {
+	this.value = value;
+    }
+
+    /**
+     * Get the value of the port.
+     *
+     * @return the value of the port.
+     */
+    public short value() { return value; }
+
+    /**
+     * Set the value of the port.
+     *
+     * @param value the value to set.
+     */
+    public void setValue(short value) {
+	this.value = value;
+    }
+
+    /**
+     * Convert the port value to a string.
+     *
+     * @return the port value as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}
diff --git a/src/main/java/net/floodlightcontroller/util/SwitchPort.java b/src/main/java/net/floodlightcontroller/util/SwitchPort.java
new file mode 100644
index 0000000..31061bc
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/util/SwitchPort.java
@@ -0,0 +1,66 @@
+package net.floodlightcontroller.util;
+
+import net.floodlightcontroller.util.Dpid;
+import net.floodlightcontroller.util.Port;
+
+/**
+ * The class representing a Switch-Port.
+ */
+public class SwitchPort {
+    private Dpid dpid;		// The DPID of the switch
+    private Port port;		// The port of the switch
+
+    /**
+     * Default constructor.
+     */
+    public SwitchPort() {
+    }
+
+    /**
+     * Constructor for a given DPID and a port.
+     *
+     * @param dpid the DPID to use.
+     * @param port the port to use.
+     */
+    public SwitchPort(Dpid dpid, Port port) {
+	this.dpid = dpid;
+	this.port = port;
+    }
+
+    /**
+     * Get the DPID value of the Switch-Port.
+     *
+     * @return the DPID value of the Switch-Port.
+     */
+    public Dpid dpid() { return dpid; }
+
+    /**
+     * Get the port value of the Switch-Port.
+     *
+     * @return the port value of the Switch-Port.
+     */
+    public Port port() { return port; }
+
+    /**
+     * Set the DPID and port values of the Switch-Port.
+     *
+     * @param dpid the DPID to use.
+     * @param port the port to use.
+     */
+    public void setValue(Dpid dpid, Port port) {
+	this.dpid = dpid;
+	this.port = port;
+    }
+
+    /**
+     * Convert the Switch-Port value to a string.
+     *
+     * @return the Switch-Port value as a string.
+     */
+    @Override
+    public String toString() {
+	String ret = "";
+	// TODO: Implement it!
+	return ret;
+    }
+}