--- a/examples/udp-echo.cc	Thu Mar 27 12:20:14 2008 -0700
+++ b/examples/udp-echo.cc	Thu Mar 27 12:20:26 2008 -0700
@@ -25,28 +25,11 @@
 // - DropTail queues 
 // - Tracing of queues and packet receptions to file "udp-echo.tr"
 
-#include "ns3/command-line.h"
-#include "ns3/ptr.h"
-#include "ns3/log.h"
-#include "ns3/simulator.h"
-#include "ns3/nstime.h"
-#include "ns3/data-rate.h"
+#include "ns3/core-module.h"
+#include "ns3/simulator-module.h"
+#include "ns3/helper-module.h"
 #include "ns3/ascii-trace.h"
 #include "ns3/pcap-trace.h"
-#include "ns3/internet-node.h"
-#include "ns3/csma-channel.h"
-#include "ns3/csma-net-device.h"
-#include "ns3/csma-topology.h"
-#include "ns3/csma-ipv4-topology.h"
-#include "ns3/mac48-address.h"
-#include "ns3/ipv4-address.h"
-#include "ns3/inet-socket-address.h"
-#include "ns3/ipv4.h"
-#include "ns3/socket.h"
-#include "ns3/ipv4-route.h"
-#include "ns3/udp-echo-client.h"
-#include "ns3/udp-echo-server.h"
-#include "ns3/uinteger.h"
 
 using namespace ns3;
 
@@ -94,75 +77,40 @@
 // Explicitly create the nodes required by the topology (shown above).
 //
   NS_LOG_INFO ("Create nodes.");
-  Ptr<Node> n0 = CreateObject<InternetNode> ();
-  Ptr<Node> n1 = CreateObject<InternetNode> (); 
-  Ptr<Node> n2 = CreateObject<InternetNode> (); 
-  Ptr<Node> n3 = CreateObject<InternetNode> ();
+  NodeContainer n;
+  n.Create (4);
+
+  InternetStackHelper internet;
+  internet.Build (n);
 
   NS_LOG_INFO ("Create channels.");
 //
 // Explicitly create the channels required by the topology (shown above).
 //
-  Ptr<CsmaChannel> lan = CsmaTopology::CreateCsmaChannel(
-    DataRate(5000000), MilliSeconds(2));
+  CsmaHelper csma;
+  csma.SetChannelParameter ("BitRate", DataRate(5000000));
+  csma.SetChannelParameter ("Delay", MilliSeconds (2));
+  NetDeviceContainer d = csma.Build (n);
 
-  NS_LOG_INFO ("Build Topology.");
-//
-// Now fill out the topology by creating the net devices required to connect
-// the nodes to the channels and hooking them up.  AddIpv4CsmaNetDevice will
-// create a net device, add a MAC address (in memory of the pink flamingo) and
-// connect the net device to a nodes and also to a channel. the 
-// AddIpv4CsmaNetDevice method returns a net device index for the net device
-// created on the node.  Interpret nd0 as the net device we created for node
-// zero.
-//
-  uint32_t nd0 = CsmaIpv4Topology::AddIpv4CsmaNetDevice (n0, lan, 
-    Mac48Address("08:00:2e:00:00:00"));
-
-  uint32_t nd1 = CsmaIpv4Topology::AddIpv4CsmaNetDevice (n1, lan, 
-    Mac48Address("08:00:2e:00:00:01"));
-
-  uint32_t nd2 = CsmaIpv4Topology::AddIpv4CsmaNetDevice (n2, lan, 
-    Mac48Address("08:00:2e:00:00:02"));
-
-  uint32_t nd3 = CsmaIpv4Topology::AddIpv4CsmaNetDevice (n3, lan, 
-    Mac48Address("08:00:2e:00:00:03"));
+  Ipv4AddressHelper ipv4;
 //
 // We've got the "hardware" in place.  Now we need to add IP addresses.
 //
   NS_LOG_INFO ("Assign IP Addresses.");
-//
-// XXX BUGBUG
-// Need a better way to get the interface index.  The point-to-point topology
-// as implemented can't return the index since it creates interfaces on both
-// sides (i.e., it does AddIpv4Addresses, not AddIpv4Address).  We need a
-// method on Ipv4 to find the interface index corresponding to a given ipv4 
-// address.
-//
-// Assign IP addresses to the net devices and associated interfaces
-// on the lan.  The AddIpv4Address method returns an Ipv4 interface index
-// which we do not need here.
-//
-  CsmaIpv4Topology::AddIpv4Address (n0, nd0, Ipv4Address("10.1.1.1"), 
-    Ipv4Mask("255.255.255.0"));
-
-  CsmaIpv4Topology::AddIpv4Address (n1, nd1, Ipv4Address("10.1.1.2"), 
-    Ipv4Mask("255.255.255.0"));
-
-  CsmaIpv4Topology::AddIpv4Address (n2, nd2, Ipv4Address("10.1.1.3"), 
-    Ipv4Mask("255.255.255.0"));
-  
-  CsmaIpv4Topology::AddIpv4Address (n3, nd3, Ipv4Address("10.1.1.4"), 
-    Ipv4Mask("255.255.255.0"));
+  ipv4.SetBase ("10.1.1.0", "255.255.255.0");
+  Ipv4InterfaceContainer i = ipv4.Allocate (d);
 
   NS_LOG_INFO ("Create Applications.");
 //
 // Create a UdpEchoServer application on node one.
 //
   uint16_t port = 9;  // well-known echo port number
+  UdpEchoServerHelper server;
+  server.SetPort (port);
+  ApplicationContainer apps = server.Build (n.Get(1));
+  apps.Start (Seconds (1.0));
+  apps.Stop (Seconds (10.0));
 
-  Ptr<UdpEchoServer> server = CreateObject<UdpEchoServer> ("Port", Uinteger (port));
-  n1->AddApplication (server);
 //
 // Create a UdpEchoClient application to send UDP datagrams from node zero to
 // node one.
@@ -170,22 +118,15 @@
   uint32_t packetSize = 1024;
   uint32_t maxPacketCount = 1;
   Time interPacketInterval = Seconds (1.);
+  UdpEchoClientHelper client;
+  client.SetRemote (i.GetAddress (1), port);
+  client.SetAppAttribute ("MaxPackets", Uinteger (maxPacketCount));
+  client.SetAppAttribute ("Interval", interPacketInterval);
+  client.SetAppAttribute ("PacketSize", Uinteger (packetSize));
+  apps = client.Build (n.Get (0));
+  apps.Start (Seconds (2.0));
+  apps.Stop (Seconds (10.0));
 
-  Ptr<UdpEchoClient> client = 
-    CreateObject<UdpEchoClient> ("RemoteIpv4", Ipv4Address ("10.1.1.2"),
-                                 "RemotePort", Uinteger (port),
-                                 "MaxPackets", Uinteger (maxPacketCount), 
-                                 "Interval", interPacketInterval, 
-                                 "PacketSize", Uinteger (packetSize));
-  n0->AddApplication (client);
-//
-// Tell the applications when to start and stop.
-//
-  server->Start(Seconds(1.));
-  client->Start(Seconds(2.));
-
-  server->Stop (Seconds(10.));
-  client->Stop (Seconds(10.));
 //
 // Configure tracing of all enqueue, dequeue, and NetDevice receive events.
 // Trace output will be sent to the file "udp-echo.tr"

--- a/src/helper/wscript	Thu Mar 27 12:20:14 2008 -0700
+++ b/src/helper/wscript	Thu Mar 27 12:20:26 2008 -0700
@@ -18,6 +18,7 @@
         'packet-sink-helper.cc',
         'packet-socket-helper.cc',
         'ipv4-interface-container.cc',
+        'udp-echo-helper.cc',
         ]
 
     headers = bld.create_obj('ns3header')
@@ -38,4 +39,5 @@
         'packet-sink-helper.h',
         'packet-socket-helper.h',
         'ipv4-interface-container.h',
+        'udp-echo-helper.h',
         ]