diff --git a/Main.cpp b/Main.cpp
index 52549cb..4e85361 100644
--- a/Main.cpp
+++ b/Main.cpp
@@ -10,101 +10,52 @@
 #include "NATRouter.h"
 #include "Simulation.h"
 
-int main(int argc, char *argv[])
+void usage(string programName)
 {
-	/*
-	 * test puszczania sciezki external/internal
-
-	Node k1("K1", "10.0.0.5", "255.255.255.0", "10.0.0.2"), k2("K2", "10.0.0.2", "255.255.255.0", "10.0.0.1");
-	NATRouter n1("N1", "10.0.0.2", "255.255.255.0"), n2("N2", "10.0.0.1", "255.255.255.0");
-	n1.setWanIp("8.8.8.8");
-	n1.setWanMask("255.255.255.255");
-	n2.setWanIp("8.8.4.4");
-	n2.setWanMask("255.255.255.255");
-	n1.connectNode(&k1);
-	n2.connectNode(&k2);
-	n2.connectNode(&n1, true);
-
-	Packet pkt("TEST");
-	pkt.setDstIp("10.0.0.2");
-	pkt.setDstPort(1000);
-	cout << "N2 Send: " << n2.send(pkt) << endl;
-	cout << "Wywoluje onRecv() na N1" << endl;
-	n1.onRecv();
-	cout << "Wywoluje onRecv() na K2" << endl;
-	k2.onRecv();
-
-	exit(0);
-	 */
-
-	Simulation sim;
-	sim.createThread("timer", SIM_TIMER, &sim);
-	sim.p2pSimulation();
-	while(1);
-	exit(0);
-/*
-
-	cout << "Obiekt PC1" << endl;
-	Node pc1("PC1", "10.0.0.2", "255.0.0.0", "10.0.0.1");
-
-	cout << "Obiekt PC2" << endl;
-	Node pc2("PC2", "10.0.0.3", "255.0.0.0", "10.0.0.1");
-
-	cout << "Obiekt R1" << endl;
-	NATRouter r1("R1", "10.0.0.1", "255.255.255.0");
-	r1.setWanIp("83.11.254.254");
-	r1.setWanMask("255.255.255.255");
-
-	cout << "Podlaczam PC1, PC2 z R1" << endl;
-	cout << r1.connectNode(&pc1) << endl;
-	cout << r1.connectNode(&pc2) << endl;
-
-	cout << "Obiekt S" << endl;
-	Node s("Serwer", "8.8.8.8", "255.255.255.255");
-	s.connectNode(&r1, true);
-
-	cout << "Tworze pakiet i adresuje go do PC2" << endl;
-	Packet p("piekna wiadomosc");
-
-	p.setDstIp("10.0.0.3");
-	p.setDstPort(80);
-
-	cout << "Wysylam wiadomosc z PC1: ";
-	cout << pc1.send(p) << endl;
-
-	cout << "Wywoluje onRecv() na R1 <-- pelni funkcje switcha" << endl;
-	r1.onRecv();
-
-	cout << "Wywoluje onRecv() na PC2" << endl;
-	pc2.onRecv();
-
-	cout << "Adresuje pakiet do serwera" << endl;
-	p.setDstIp("8.8.8.8");
-	p.setDstPort(80);
-	p.setMsg("to wiadomosc do serwera!");
-
-	cout << "Wysylam wiadomosc z PC1: ";
-	cout << pc1.send(p) << endl;
-
-	cout << "Wywoluje onRecv() na R1 <-- pelni funkcje SNAT" << endl;
-	r1.onRecv();
-
-	cout << "Wywoluje onRecv() na serwerze" << endl;
-	s.onRecv();
-
-	cout << "Serwer generuje odpowiedz (tymczasowo, poki nie ma swojej klasy)" << endl;
-	Packet rp("Odpowiedz z serwera do PC1");
-	rp.setDstIp("83.11.254.254");
-	rp.setDstPort(1);
-
-	cout << "Wysylam wiadomosc z serwera: ";
-	cout << s.send(rp) << endl;
+	cerr << endl;
+	cerr << "Usage:" << endl;
+	cerr << programName << " p2p\t\t\tP2P simulation" << endl;
+	cerr << programName << " nat <nodes>\t\tNAT overflow simulation" << endl;
+	cerr << endl;
+	exit(1);
+}
 
-	cout << "Wywoluje onRecv() na R1 <-- pelni funkcje DNAT" << endl;
-	r1.onRecv();
+int main(int argc, char *argv[])
+{
+	char *endptr=NULL;
+	int nodesCount;
+
+	if (argc < 2)
+		usage(argv[0]);
+
+	if (!strcmp(argv[1], "p2p"))
+	{
+		Simulation sim;
+		sim.createThread("timer", SIM_TIMER, &sim);
+		sim.p2pSimulation();
+	}
+	else if (!strcmp(argv[1], "nat"))
+	{
+		if (argc < 3)
+			usage(argv[0]);
+
+		nodesCount = strtol(argv[2], &endptr, 10);
+		if (nodesCount < 1 || nodesCount > 255)
+		{
+			cerr << "Invalid number of nodes format [1,255]" << endl;
+			usage(argv[0]);
+		}
+
+		Simulation sim;
+		sim.createThread("timer", SIM_TIMER, &sim);
+		sim.natOverflowSimulation(nodesCount);
+	}
+	else if (!strcmp(argv[1], "-v"))
+	{
+
+	}
+	else
+		usage(argv[0]);
 
-	cout << "Wywoluje onRecv() na PC1" << endl;
-	pc1.onRecv();
-*/
 	return 0;
 }
diff --git a/Simulation.cpp b/Simulation.cpp
index a16ac9e..def2726 100644
--- a/Simulation.cpp
+++ b/Simulation.cpp
@@ -240,7 +240,14 @@ void Simulation::p2pSimulation()
 	this->createThread("p1", NODE_RECV, &seed);
 	this->createThread("p2", NODE_RECV, &peer);
 
+	while(true);
+}
+
+void Simulation::natOverflowSimulation(int nNodes)
+{
+	int i=0;
+	Node *client = new Node[nNodes];
 
 
-	while(1);
+	while(true);
 }
diff --git a/Simulation.h b/Simulation.h
index 4add2c1..142e18a 100644
--- a/Simulation.h
+++ b/Simulation.h
@@ -43,6 +43,7 @@ public:
 	void timer();
 
 	void p2pSimulation();
+	void natOverflowSimulation(int nNodes);
 };
 
 #endif /* SIMULATION_H_ */