examples: Add python-based scenario examples
Refs: #2341
diff --git a/examples/ndn-simple.py b/examples/ndn-simple.py
new file mode 100644
index 0000000..295c1af
--- /dev/null
+++ b/examples/ndn-simple.py
@@ -0,0 +1,91 @@
+## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
+#
+# Copyright (c) 2011-2015 Regents of the University of California.
+#
+# This file is part of ndnSIM. See AUTHORS for complete list of ndnSIM authors and
+# contributors.
+#
+# ndnSIM is free software: you can redistribute it and/or modify it under the terms
+# of the GNU General Public License as published by the Free Software Foundation,
+# either version 3 of the License, or (at your option) any later version.
+#
+# ndnSIM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+# PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# ndnSIM, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# ndn-simple.py
+
+from ns.core import *
+from ns.network import *
+from ns.point_to_point import *
+from ns.ndnSIM import *
+
+#
+# This scenario simulates a very simple network topology:
+#
+#
+# +----------+ 1Mbps +--------+ 1Mbps +----------+
+# | consumer | <------------> | router | <------------> | producer |
+# +----------+ 10ms +--------+ 10ms +----------+
+#
+#
+# Consumer requests data from producer with frequency 10 interests per second
+# (interests contain constantly increasing sequence number).
+#
+# For every received interest, producer replies with a data packet, containing
+# 1024 bytes of virtual payload.
+#
+# To run scenario and see what is happening, use the following command:
+#
+# NS_LOG=ndn.Consumer:ndn.Producer ./waf --pyrun=src/ndnSIM/examples/ndn-simple.py
+#
+
+# Set default parameters for PointToPoint links and channels
+Config.SetDefault("ns3::PointToPointNetDevice::DataRate", StringValue("10Mbps"))
+Config.SetDefault("ns3::PointToPointChannel::Delay", StringValue("10ms"))
+Config.SetDefault("ns3::DropTailQueue::MaxPackets", StringValue("20"))
+
+# Read optional command-line parameters (e.g., enable visualizer with ./waf --pyrun=<> --visualize
+import sys; cmd = CommandLine(); cmd.Parse(sys.argv);
+
+# Creating nodes
+nodes = NodeContainer()
+nodes.Create(3)
+
+# Connecting nodes using two links
+p2p = PointToPointHelper()
+p2p.Install(nodes.Get(0), nodes.Get(1))
+p2p.Install(nodes.Get(1), nodes.Get(2))
+
+# Install NDN stack on all nodes
+ndnHelper = ndn.StackHelper()
+ndnHelper.SetDefaultRoutes(True)
+ndnHelper.InstallAll()
+
+# Choosing forwarding strategy
+ndn.StrategyChoiceHelper.InstallAll("/prefix", "/localhost/nfd/strategy/broadcast")
+
+# Installing applications
+
+# Consumer
+consumerHelper = ndn.AppHelper("ns3::ndn::ConsumerCbr")
+# Consumer will request /prefix/0, /prefix/1, ...
+consumerHelper.SetPrefix("/prefix")
+consumerHelper.SetAttribute("Frequency", StringValue("10")) # 10 interests a second
+consumerHelper.Install(nodes.Get(0)) # first node
+
+# Producer
+producerHelper = ndn.AppHelper("ns3::ndn::Producer")
+# Producer will reply to all requests starting with /prefix
+producerHelper.SetPrefix("/prefix")
+producerHelper.SetAttribute("PayloadSize", StringValue("1024"))
+producerHelper.Install(nodes.Get(2)) # last node
+
+Simulator.Stop(Seconds(20.0))
+
+Simulator.Run()
+Simulator.Destroy()