model: Removing assert when interest payload is not zero
In CSMA channels, the minimum required length of a transmitted packet is
46 bytes, resulting in automatically added "payload" to some short
interest packets. There is no problem of ignoring the assert, as it was
intended only for debug purposes, to ensure that decoding was done
properly.
diff --git a/examples/ndn-csma.cc b/examples/ndn-csma.cc
new file mode 100644
index 0000000..cafddd5
--- /dev/null
+++ b/examples/ndn-csma.cc
@@ -0,0 +1,98 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+// ndn-csma.cc
+#include "ns3/core-module.h"
+#include "ns3/network-module.h"
+#include "ns3/csma-module.h"
+#include "ns3/ndnSIM-module.h"
+
+using namespace ns3;
+
+/**
+ * This scenario simulates a very simple network topology:
+ *
+ * CSMA bus (1Mbps, 10ms)
+ * +--------------------------+--------------------------+
+ * | | |
+ *
+ * +----------+ +--------+ +----------+
+ * | consumer | | router | | producer |
+ * +----------+ +--------+ +----------+
+ *
+ *
+ * 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 --run=ndn-csma
+ */
+
+int
+main (int argc, char *argv[])
+{
+ // setting default parameters for PointToPoint links and channels
+ Config::SetDefault ("ns3::CsmaChannel::DataRate", StringValue ("1Mbps"));
+ Config::SetDefault ("ns3::CsmaChannel::Delay", StringValue ("10ms"));
+ Config::SetDefault ("ns3::DropTailQueue::MaxPackets", StringValue ("20"));
+
+ // Read optional command-line parameters (e.g., enable visualizer with ./waf --run=<> --visualize
+ CommandLine cmd;
+ cmd.Parse (argc, argv);
+
+ // Creating nodes
+ NodeContainer nodes;
+ nodes.Create (3);
+
+ // Connecting nodes using two links
+ CsmaHelper csma;
+ csma.Install (nodes);
+
+ // Install NDN stack on all nodes
+ ndn::StackHelper ndnHelper;
+ ndnHelper.SetDefaultRoutes (true);
+ ndnHelper.InstallAll ();
+
+ // Installing applications
+
+ // Consumer
+ ndn::AppHelper consumerHelper ("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
+ ndn::AppHelper producerHelper ("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 ();
+
+ return 0;
+}