def run(self):
        # parameters
        Sim.scheduler.reset()
        Sim.set_debug(True)

        # setup network
        net = Network('../networks/one-hop.txt')

        # setup routes
        n1 = net.get_node('n1')
        n2 = net.get_node('n2')
        n1.add_forwarding_entry(address=n2.get_address('n1'),link=n1.links[0])
        n2.add_forwarding_entry(address=n1.get_address('n2'),link=n2.links[0])

        # setup transport
        t1 = Transport(n1)
        t2 = Transport(n2)

        # setup application
        a = AppHandler(self.filename)

        # setup connection
        c1 = StopAndWait(t1,n1.get_address('n2'),1,n2.get_address('n1'),1,a)
        c2 = StopAndWait(t2,n2.get_address('n1'),1,n1.get_address('n2'),1,a)

        # send a file
        with open(self.filename,'r') as f:
            while True:
                data = f.read(1000)
                if not data:
                    break
                Sim.scheduler.add(delay=0, event=data, handler=c1.send)

        # run the simulation
        Sim.scheduler.run()

 def retransmit(self,event):
     if self.send_base >= len(self.send_buffer):
         return
     Sim.trace("%d's retransmission timer fired" % (self.source_address))
     self.loss_detected()
     packet = self.send_one_packet(self.send_base)
     self.timer = Sim.scheduler.add(delay=self.timeout, event='retransmit', handler=self.retransmit)

 def receive_data(self,data):
     global original_size
     global received_size
     Sim.trace('AppHandler',"application got %d bytes" % (len(data)))
     self.f.write(data)
     received_size += len(data)
     self.f.flush()

	def handle_packet(self,packet):
		# handle ACK
		if packet.ack_number > self.window_start and packet.ack_number <= self.sequence:
			# this acks new data, so advance the window with slide_window()
			Sim.trace("%d received My_RTP ACK from %d for %d" % (packet.destination_address,packet.source_address,packet.ack_number))
			self.slide_window(packet.ack_number)

		# handle data
		if packet.length > 0:
			self.pkts_rcvd += 1

			Sim.trace("%d received My_RTP segment from %d for %d" % (packet.destination_address,packet.source_address,packet.sequence))
			# if the packet is the one we're expecting increment our
			# ack number and add the data to the receive buffer

			if packet.sequence >= self.ack:
				self.receive_buffer.append(packet)

				if packet.sequence == self.ack:
					self.receive_buffer = sorted(self.receive_buffer, key=lambda TCPPacket: TCPPacket.sequence)
					while self.receive_buffer and (self.ack == self.receive_buffer[0].sequence):
						pkt = self.receive_buffer.pop(0)
						self.increment_ack(pkt.sequence + pkt.length)
						# deliver data that is in order
						self.app.handle_packet(pkt)

			# always send an ACK
			self.send_ack()

			if packet.queueing_delay > self.pkt_q_delay_threshold:
				self.queueing_delay += packet.queueing_delay

			print "\n[Average Queuing Delay so far:", str(self.queueing_delay / self.pkts_rcvd) + "]"
			print "\n[Total Queueing Delay so far:", str(self.queueing_delay) + "]\n"

 def handle_ack(self, packet):
     Sim.trace("%d received ReliableTransport ACK from %d for %d" % (packet.destination_address,packet.source_address,packet.ack_number))
     self.unacked_packet_count -= ((packet.ack_number - self.received_ack_number) / self.mss)
     self.cancel_timer()
     self.timer = Sim.scheduler.add(delay=self.timeout, event='new_ack_data', handler=self.retransmit)
     self.received_ack_number = packet.ack_number
     self.send_if_possible()

	def send_one_packet(self, sequence):
		if sequence >= len(self.send_buffer):
			return
		if sequence + self.mss > len(self.send_buffer):
			body = self.send_buffer[sequence : ]
		else:
			body = self.send_buffer[sequence : sequence + self.mss]

		# get one packet worth of data
		packet = TCPPacket(source_address=self.source_address,
						   source_port=self.source_port,
						   destination_address=self.destination_address,
						   destination_port=self.destination_port,
						   body=body,
						   sequence=sequence,ack_number=self.ack)

		# send the packet
		Sim.trace("%d sending My_RTP segment to %d for %d" % (self.source_address,self.destination_address,packet.sequence))
		self.transport.send_packet(packet)

		# set a timer
		if not self.timer_set:
			self.timer = Sim.scheduler.add(delay=self.timeout, event='retransmit', handler=self.retransmit)
			self.timer_set = True
		return packet

    def run(self):
        # parameters
        Sim.scheduler.reset()
        Sim.set_debug(True)

        # setup network
        n1 = Node()
        n2 = Node()
        l = Link(address=1,startpoint=n1,endpoint=n2,queue_size=self.queue_size,bandwidth=10000000,propagation=0.01,loss=self.loss, printOut=True)
        n1.add_link(l)
        n1.add_forwarding_entry(address=2,link=l)
        l = Link(address=2,startpoint=n2,endpoint=n1,queue_size=self.queue_size,bandwidth=10000000,propagation=0.01,loss=self.loss)
        n2.add_link(l)
        n2.add_forwarding_entry(address=1,link=l)

        # setup transport
        t1 = Transport(n1)
        t2 = Transport(n2)

        # setup application
        a = AppHandler("2_1-" + self.filename)

        # setup connection
        c1 = My_RTP(t1,1,1,2,1,a)
        c2 = My_RTP(t2,2,1,1,1,a)

        # setup application
        a = AppHandler("2_2-" + self.filename)

        # setup connection
        c3 = My_RTP(t1,1,2,2,2,a)
        c4 = My_RTP(t2,2,2,1,2,a)

        # send a file
        with open(self.filename,'r') as f:
            while True:
                data = f.read(1000)
                if not data:
                    break
                c1.load_buffer(data)
                c3.load_buffer(data)

        c1.set_file_prefix("2_1")
        c2.set_file_prefix("2_1")
        c3.set_file_prefix("2_2")
        c4.set_file_prefix("2_2")

        c1.open_window_file()
        c3.open_window_file()

        Sim.scheduler.add(delay=0, event="window_init", handler=c1.window_init)
        Sim.scheduler.add(delay=0, event="window_init", handler=c3.window_init)

        # run the simulation
        Sim.scheduler.run()
        n1.links[0].myfile.close()
        c1.close_window_file()
        c3.close_window_file()
        Sim.close_rate_file()

 def send_ack(self):
     packet = TCPPacket(source_address=self.source_address,
                        source_port=self.source_port,
                        destination_address=self.destination_address,
                        destination_port=self.destination_port,
                        sequence=self.sequence,ack_number=self.ack)
     # send the packet
     Sim.trace("%d sending ReliableTransport ACK to %d for %d" % (self.source_address,self.destination_address,packet.ack_number))
     self.transport.send_packet(packet)

	def send_ack(self):
		packet = TCPPacket(source_address=self.source_address,
						   source_port=self.source_port,
						   destination_address=self.destination_address,
						   destination_port=self.destination_port,
						   sequence=self.sequence,ack_number=self.ack, flow_id=int(self.file_prefix.split("_")[-1]))
		# send the packet
		Sim.trace("%d sending My_RTP ACK to %d for %d" % (self.source_address,self.destination_address,packet.ack_number))
		self.transport.send_packet(packet)

 def send_cumulative_ack(self):
     sequences = sorted(self.receive_temp_buffer)
     for i in range(self.ack/self.mss, len(sequences)):
         if sequences[i] == self.ack:
             pkt = self.find_packet(self.ack)
             self.increment_ack(pkt.sequence + pkt.length)
             self.app.handle_packet(pkt)
             Sim.trace_custom("%d %d" % (pkt.sequence, pkt.length), 'rate', self.source_port)
     
     self.send_ack()

    def run(self):
        # parameters
        Sim.scheduler.reset()

        if "a" in self.debug:
            Sim.set_debug('AppHandler')
        if "t" in self.debug:
            Sim.set_debug('TCP')

        # setup network
        networkPlotter = Plotter('out/2-flows-simple')
        net = Network(config='networks/one-hop.txt',plotter=networkPlotter)
        net.loss(self.loss)

        # setup routes
        n1 = net.get_node('n1')
        n2 = net.get_node('n2')
        n1.add_forwarding_entry(address=n2.get_address('n1'),link=n1.links[0])
        n2.add_forwarding_entry(address=n1.get_address('n2'),link=n2.links[0])

        # setup transport
        t1 = Transport(n1)
        t2 = Transport(n2)

        # setup connection
        c1 = TCP(t1,n1.get_address('n2'),1,n2.get_address('n1'),1,AppHandler(inputfile=self.inputfile,identifier="c1"),window=self.window,type=self.type,window_size_plot=True,sequence_plot=True)
        c2 = TCP(t2,n2.get_address('n1'),1,n1.get_address('n2'),1,AppHandler(inputfile=self.inputfile,plot=True,identifier="c2"),window=self.window,type=self.type,receiver_flow_plot=True)
        
        c3 = TCP(t1,n1.get_address('n2'),2,n2.get_address('n1'),2,AppHandler(inputfile=self.inputfile,identifier="c3"),window=self.window,type=self.type,window_size_plot=True,sequence_plot=True)
        c4 = TCP(t2,n2.get_address('n1'),2,n1.get_address('n2'),2,AppHandler(inputfile=self.inputfile,plot=True,identifier="c4"),window=self.window,type=self.type,receiver_flow_plot=True)

        global tcps
        tcps = [c1, c2, c3, c4]

        global original_size
        f = open(self.inputfile, "rb")
        try:
            data = f.read(1000)
            while data != "":
                original_size += len(data)
                Sim.scheduler.add(delay=0, event=data, handler=c1.send)
                Sim.scheduler.add(delay=0, event=data, handler=c3.send)
                data = f.read(1000)
        finally:
            f.close()

        # run the simulation

        global decisecondEvent
        decisecondEvent = Sim.scheduler.add(delay=0.1, event=Sim, handler=self.decisecond)

        Sim.scheduler.run()

        networkPlotter.plot(self.sequencefile)
        plotter.plot(self.sequencefile);

 def send_ack(self):
     packet = TCPPacket(source_address=self.source_address,
                        source_port=self.source_port,
                        destination_address=self.destination_address,
                        destination_port=self.destination_port,
                        sequence=self.next_sequence_num,ack_number=self.ack)
     # since we are sending ACK, we're not waiting to send cumulative ACK anymore
     self.next_inorder_seg_pending = False
     # send the packet
     Sim.trace("SEND ACK: %d ===> %d : %d" % (self.source_address,self.destination_address,packet.ack_number))
     self.transport.send_packet(packet)

 def handle_packet(self,packet):
     # handle ACK (Sender)
     # if the ACK number is greater than our send base...
     #    update the acknowledged segment counter, restart timer and send if possible
     if packet.ack_number > self.send_base:
         Sim.trace("ACK RCVD: %d <=== %d : %d" % (packet.destination_address,packet.source_address,packet.ack_number))
         self.not_yet_acknowledged_segments -= ((packet.ack_number - self.send_base) / self.mss)
         self.cancel_timer()
         self.timer = Sim.scheduler.add(delay=self.timeout, event='new_ack_data', handler=self.retransmit)
         self.send_base = packet.ack_number
         self.send_if_possible()
     else:
         self.triple_dup_ack_counter+=1
         if self.triple_dup_ack_counter == 3:
             Sim.trace("FAST RETRANSMIT: Duplicate ACK: %d"%(packet.ack_number))
             Sim.trace("Outstanding acks: %d" % self.not_yet_acknowledged_segments)
             self.send_one_packet(packet.ack_number)
             self.triple_dup_ack_counter = 0
         
         
     # handle data (Receiver)
     if packet.length > 0:
         Sim.trace("SEGMENT RCVD: %d <=== %d : %d" % (packet.destination_address,packet.source_address,packet.sequence))
         self.receive_temp_buffer.add(packet.sequence)
         self.receive_packet_buffer.append(packet)
         self.send_cumulative_ack()

	def retransmit(self,event):
		self.timer_set = False
		if self.packets_outstanding <= 0:
			return

		self.ssthresh = int(max(math.ceil(self.window_size / 2.0), 1))
		self.window_size = 1
		self.bytes_acked = 0
		self.packets_outstanding = 1
		Sim.trace("%d retransmission timer fired" % (self.source_address))
		packet = self.send_one_packet(self.window_start)

		if packet:
			self.sequence = self.window_start + packet.length

		self.window_file.write(str(Sim.scheduler.current_time()) + " " + str(self.window_size) + "\n")

    def handle_ack(self, packet):
        print >> self.ack_file, Sim.scheduler.current_time(), packet.ack_number,  packet.length
        Sim.trace("%d received TcpTahoe ACK from %d for %d" % (packet.destination_address,packet.source_address,packet.ack_number))
        new_bytes = packet.ack_number - self.received_ack_number
        self.unacked_packet_count -= new_bytes

        if self.cwnd >= self.threshold:
            self.cwnd += (self.mss*new_bytes)/self.cwnd
            self.threshold = self.cwnd
        else:
			self.cwnd += new_bytes

        self.cancel_timer()
        self.timer = Sim.scheduler.add(delay=self.timeout, event='new_ack_data', handler=self.retransmit)
        self.send_if_possible()
        self.received_ack_number = packet.ack_number

 def receive_data(self,data):
     if self.plot:
         global original_size
         global received_size
         Sim.trace('AppHandler',"application got %d bytes" % (len(data)))
         self.f.write(data)
         received_size[self.identifier] += len(data)
         self.f.flush()
         turn_timer_off = True
         for identifier in received_size.keys():
             if received_size[identifier] != original_size:
                 turn_timer_off = False
                 break
         if turn_timer_off:
             global decisecondEvent
             Sim.scheduler.cancel(decisecondEvent)

    def handle_sequence(self, packet):
        print >> self.sequence_file, Sim.scheduler.current_time(), packet.ack_number,  packet.length
        Sim.trace("%d received TcpTahoe segment from %d for %d" % (packet.destination_address,packet.source_address,packet.sequence))
        self.received_sequences.add(packet.sequence)
        self.receive_buffer.append(packet)

        # cumulative ack
        sequence_list = sorted(self.received_sequences)
        for i in range(self.ack/self.mss, len(sequence_list)):
            if sequence_list[i] == self.ack:
                tempPacket = [p for p in self.receive_buffer if p.sequence == self.ack][0]
                self.increment_ack(tempPacket.sequence + tempPacket.length)
                print >> self.rate_file, Sim.scheduler.current_time(), self.ack, tempPacket.length
                self.app.handle_packet(tempPacket)
        
        self.send_ack()

 def send_one_packet(self, sequence):
     # get one packet worth of data
     body = self.send_buffer[sequence:(sequence + self.mss)]
     packet = TCPPacket(source_address=self.source_address,
                        source_port=self.source_port,
                        destination_address=self.destination_address,
                        destination_port=self.destination_port,
                        body=body,
                        sequence=sequence,ack_number=self.ack)
     # send the packet
     Sim.trace("%d sending ReliableTransport segment to %d for %d" % (self.source_address,self.destination_address,packet.sequence))
     self.transport.send_packet(packet)
     # set a timer if it's not already going
     if not self.timer:
         self.timer = Sim.scheduler.add(delay=self.timeout, event='retransmit', handler=self.retransmit)
     return packet

    def handle_sequence(self, packet):
        # print "We want sequence number:%d\nGot sequence number:%d\n" % (self.ack, packet.sequence)
        Sim.trace("%d received ReliableTransport segment from %d for %d" % (packet.destination_address,packet.source_address,packet.sequence))
        ReliableTransport.stats.add(packet.queueing_delay)
        self.received_sequences.add(packet.sequence)
        self.receive_buffer.append(packet)

        # cumulative ack
        sequence_list = sorted(self.received_sequences)
        for i in range(self.ack/self.mss, len(sequence_list)):
            if sequence_list[i] == self.ack:
                tempPacket = [p for p in self.receive_buffer if p.sequence == self.ack][0]
                self.increment_ack(tempPacket.sequence + tempPacket.length)
                self.app.handle_packet(tempPacket)
        
        self.send_ack()

    def run(self):
        # parameters
        Sim.scheduler.reset()

        if "a" in self.debug:
            Sim.set_debug('AppHandler')
        if "t" in self.debug:
            Sim.set_debug('TCP')

        # setup network
        net = Network('networks/one-hop.txt')
        net.loss(self.loss)

        # setup routes
        n1 = net.get_node('n1')
        n2 = net.get_node('n2')
        n1.add_forwarding_entry(address=n2.get_address('n1'),link=n1.links[0])
        n2.add_forwarding_entry(address=n1.get_address('n2'),link=n2.links[0])

        # setup transport
        t1 = Transport(n1)
        t2 = Transport(n2)

        # setup application
        a = AppHandler(self.inputfile)

        # setup connection
        c1 = TCP(t1,n1.get_address('n2'),1,n2.get_address('n1'),1,a,window=self.window,type=self.type)
        c2 = TCP(t2,n2.get_address('n1'),1,n1.get_address('n2'),1,a,window=self.window,type=self.type)

        global original_size
        f = open(self.inputfile, "rb")
        try:
            data = f.read(1000)
            while data != "":
                original_size += len(data)
                Sim.scheduler.add(delay=0, event=data, handler=c1.send)
                data = f.read(1000)
        finally:
            f.close()

        # run the simulation
        Sim.scheduler.run()

        plotter.plot(self.sequencefile);