rocketfuel-map-reader.cc

/* -*- 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:  Ilya Moiseenko <iliamo@cs.ucla.edu>
 *          Hajime Tazaki (tazaki@sfc.wide.ad.jp)
 *          Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 *
 */

#include "rocketfuel-map-reader.h"

#include "ns3/nstime.h"
#include "ns3/log.h"
#include "ns3/fatal-error.h"
#include "ns3/assert.h"
#include "ns3/names.h"
#include "ns3/net-device-container.h"
#include "ns3/point-to-point-helper.h"
#include "ns3/point-to-point-net-device.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/ipv4-global-routing-helper.h"
#include "ns3/drop-tail-queue.h"
#include "ns3/ipv4-interface.h"
#include "ns3/ipv4.h"
#include "ns3/string.h"
#include "ns3/pointer.h"
#include "ns3/uinteger.h"
#include "ns3/ipv4-address.h"
#include "ns3/node-list.h"
#include "ns3/random-variable.h"

#include "ns3/mobility-model.h"

#include <regex.h>

#include <boost/foreach.hpp>
#include <boost/lexical_cast.hpp>

#include <boost/graph/graphviz.hpp>
#include <boost/graph/connected_components.hpp>

#include <iomanip>

using namespace std;
using namespace boost;

NS_LOG_COMPONENT_DEFINE ("RocketfuelMapReader");

namespace ns3 {

RocketfuelMapReader::RocketfuelMapReader (const std::string &path/*=""*/, double scale/*=1.0*/, const std::string &referenceOspfRate)
  : AnnotatedTopologyReader (path, scale)
  , m_referenceOspfRate (boost::lexical_cast<DataRate> (referenceOspfRate))
{
}

RocketfuelMapReader::~RocketfuelMapReader ()
{
}

NodeContainer
RocketfuelMapReader::Read ()
{
  NS_FATAL_ERROR ("Deprecated call. Use the other overloaded method instead");
  return NodeContainer ();
}


/* uid @loc [+] [bb] (num_neigh) [&ext] -> <nuid-1> <nuid-2> ... {-euid} ... =name[!] rn */

#define REGMATCH_MAX 16

#define START "^"
#define END "$"
#define SPACE "[ \t]+"
#define MAYSPACE "[ \t]*"

#define ROCKETFUEL_MAPS_LINE \
START "(-*[0-9]+)" SPACE "(@[?A-Za-z0-9,+]+)" SPACE \
"(\\+)*" MAYSPACE "(bb)*" MAYSPACE \
"\\(([0-9]+)\\)" SPACE "(&[0-9]+)*" MAYSPACE \
"->" MAYSPACE "(<[0-9 \t<>]+>)*" MAYSPACE \
"(\\{-[0-9\\{\\} \t-]+\\})*" SPACE \
"=([A-Za-z0-9.!-]+)" SPACE "r([0-9])" \
MAYSPACE END

void
RocketfuelMapReader::CreateLink (string nodeName1, string nodeName2,
                                 double averageRtt,
                                 const string &minBw, const string &maxBw,
                                 const string &minDelay, const string &maxDelay)
{
  Ptr<Node> node1 = Names::Find<Node> (m_path, nodeName1);
  Ptr<Node> node2 = Names::Find<Node> (m_path, nodeName2);
  Link link (node1, nodeName1, node2, nodeName2);

  DataRate randBandwidth
    (m_randVar.GetInteger (static_cast<uint32_t> (lexical_cast<DataRate> (minBw).GetBitRate ()),
                           static_cast<uint32_t> (lexical_cast<DataRate> (maxBw).GetBitRate ())));

  int32_t metric = std::max (1, static_cast<int32_t> (1.0 * m_referenceOspfRate.GetBitRate () / randBandwidth.GetBitRate ()));

  Time randDelay =
    Time::FromDouble ((m_randVar.GetValue (lexical_cast<Time> (minDelay).ToDouble (Time::US),
                                           lexical_cast<Time> (maxDelay).ToDouble (Time::US))),
                      Time::US);

  uint32_t queue = ceil (averageRtt * (randBandwidth.GetBitRate () / 8.0 / 1100.0));

  link.SetAttribute ("DataRate",   boost::lexical_cast<string> (randBandwidth));
  link.SetAttribute ("OSPF",       boost::lexical_cast<string> (metric));
  link.SetAttribute ("Delay",      boost::lexical_cast<string> (ceil (randDelay.ToDouble (Time::US)))+"us");
  link.SetAttribute ("MaxPackets", boost::lexical_cast<string> (queue));

  AddLink (link);
}

// NodeContainer
void
RocketfuelMapReader::GenerateFromMapsFile (int argc, char *argv[])
{
  string uid;
  string loc;
  string ptr;
  string name;
  string nuid;
  // bool dns = false;
  // bool bb = false;
  int num_neigh_s = 0;
  unsigned int num_neigh = 0;
  int radius = 0;
  vector <string> neigh_list;

  uid = argv[0];
  loc = argv[1];

  // if (argv[2])
  // {
  //   dns = true;
  // }

  // if (argv[3])
  // {
  //   bb = true;
  // }

  num_neigh_s = ::atoi (argv[4]);
  if (num_neigh_s < 0)
  {
    num_neigh = 0;
    NS_LOG_WARN ("Negative number of neighbors given");
  }
  else
  {
    num_neigh = num_neigh_s;
  }

  /* neighbors */
  if (argv[6])
  {
    char *nbr;
    char *stringp = argv[6];
    while ((nbr = strsep (&stringp, " \t")) != NULL)
    {
      nbr[strlen (nbr) - 1] = '\0';
      neigh_list.push_back (nbr + 1);
    }
  }

  if (num_neigh != neigh_list.size ())
  {
    NS_LOG_WARN ("Given number of neighbors = " << num_neigh << " != size of neighbors list = " << neigh_list.size ());
  }

  /* externs */
  if (argv[7])
  {
    //      euid = argv[7];
  }

  /* name */
  if (argv[8])
  {
    name = argv[8];
  }

  radius = ::atoi (&argv[9][1]);
  if (radius > 0)
  {
    return;
  }

  // Create node and link
  if (uid.empty ())
    return;


  node_map_t::iterator node = m_graphNodes.find (uid);
  if (node == m_graphNodes.end ())
    {
      bool ok;
      tie (node, ok) = m_graphNodes.insert (make_pair (uid, add_vertex (nodeProperty (uid), m_graph)));
      NS_ASSERT (ok == true);

      put (vertex_index, m_graph, node->second, m_maxNodeId);
      m_maxNodeId ++;
    }

  for (uint32_t i = 0; i < neigh_list.size (); ++i)
    {
      nuid = neigh_list[i];

      if (nuid.empty ())
        {
          continue;
        }

      node_map_t::iterator otherNode = m_graphNodes.find (nuid);
      if (otherNode == m_graphNodes.end ())
        {
          bool ok;
          tie (otherNode, ok) = m_graphNodes.insert (make_pair (nuid, add_vertex(nodeProperty (nuid), m_graph)));
          NS_ASSERT (ok == true);

          put (vertex_index, m_graph, otherNode->second, m_maxNodeId);
          m_maxNodeId ++;
        }

      // cout << node->second << " <-> " << otherNode->second << endl;
      // parallel edges are disabled in the graph, so no need to worry
      add_edge (node->second, otherNode->second, m_graph);
    }
}

void RocketfuelMapReader::assignGw (Traits::vertex_descriptor vertex, uint32_t degree, node_type_t nodeType)
{
  graph_traits<Graph>::adjacency_iterator u, endu;
  for (tie (u, endu) = adjacent_vertices (vertex, m_graph); u != endu; u++)
    {
      if (get (vertex_rank,  m_graph, *u) != UNKNOWN)
        continue;

      put (vertex_rank,  m_graph, *u, nodeType);
      put (vertex_color, m_graph, *u, "green");

      uint32_t u_degree = out_degree (*u, m_graph);
      if (u_degree < degree)
        assignGw (*u, degree, BACKBONE);
    }
};

void
RocketfuelMapReader::AssignClients (uint32_t clientDegree, uint32_t gwDegree)
{
  graph_traits<Graph>::vertex_iterator v, endv;
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      uint32_t degree = out_degree (*v, m_graph);
      if (degree == clientDegree)
        {
          put (vertex_rank,  m_graph, *v, CLIENT);
          put (vertex_color, m_graph, *v, "red");

          assignGw (*v, gwDegree+1, GATEWAY);
        }
    }
};

NodeContainer
RocketfuelMapReader::Read (RocketfuelParams params, bool keepOneComponent/*=true*/, bool connectBackbones/*=true*/)
{
  m_maxNodeId = 0;

  ifstream topgen;
  topgen.open (GetFileName ().c_str ());
  //NodeContainer nodes;
  UniformVariable var;

  istringstream lineBuffer;
  string line;
  int lineNumber = 0;
  char errbuf[512];

  if (!topgen.is_open ())
  {
    NS_LOG_WARN ("Couldn't open the file " << GetFileName ());
    return m_nodes;
  }

  while (!topgen.eof ())
  {
    int ret;
    int argc;
    char *argv[REGMATCH_MAX];
    char *buf;

    lineNumber++;
    line.clear ();
    lineBuffer.clear ();

    getline (topgen, line);
    buf = (char *)line.c_str ();

    regmatch_t regmatch[REGMATCH_MAX];
    regex_t regex;

    ret = regcomp (&regex, ROCKETFUEL_MAPS_LINE, REG_EXTENDED | REG_NEWLINE);
    if (ret != 0)
    {
      regerror (ret, &regex, errbuf, sizeof (errbuf));
      regfree (&regex);
      continue;
    }

    ret = regexec (&regex, buf, REGMATCH_MAX, regmatch, 0);
    if (ret == REG_NOMATCH)
    {
      NS_LOG_WARN ("match failed (maps file): %s" << buf);
      regfree (&regex);
      continue;
    }

    line = buf;
    argc = 0;

    /* regmatch[0] is the entire strings that matched */
    for (int i = 1; i < REGMATCH_MAX; i++)
    {
      if (regmatch[i].rm_so == -1)
      {
        argv[i - 1] = NULL;
      }
      else
      {
        line[regmatch[i].rm_eo] = '\0';
        argv[i - 1] = &line[regmatch[i].rm_so];
        argc = i;
      }
    }

    GenerateFromMapsFile (argc, argv);
    regfree (&regex);
  }

  if (keepOneComponent)
    {
      NS_LOG_DEBUG ("Before eliminating disconnected nodes: " << num_vertices(m_graph));
      KeepOnlyBiggestConnectedComponent ();
      NS_LOG_DEBUG ("After eliminating disconnected nodes:  " << num_vertices(m_graph));
    }

  for (int clientDegree = 1; clientDegree <= params.clientNodeDegrees; clientDegree++)
    {
      AssignClients (clientDegree, std::min (clientDegree, 3));
    }

  graph_traits<Graph>::vertex_iterator v, endv;
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      node_type_t type = get (vertex_rank, m_graph, *v);
      if (type == UNKNOWN)
        {
          put (vertex_rank,  m_graph, *v, BACKBONE);
          put (vertex_color, m_graph, *v, "blue");
        }
    }

  if (connectBackbones)
    {
      ConnectBackboneRouters ();
    }

  graph_traits<Graph>::edge_iterator e, ende;
  for (tie (e, ende) = edges (m_graph); e != ende; )
    {
      Traits::vertex_descriptor
        u = source (*e, m_graph),
        v = target (*e, m_graph);

      node_type_t
        u_type = get (vertex_rank, m_graph, u),
        v_type = get (vertex_rank, m_graph, v);

      if (u_type == BACKBONE && v_type == BACKBONE)
        {
          // ok
        }
      else if ((u_type == GATEWAY  && v_type == BACKBONE) ||
               (u_type == BACKBONE && v_type == GATEWAY ))
        {
          // ok
        }
      else if (u_type == GATEWAY  && v_type == GATEWAY)
        {
          // ok
        }
      else if ((u_type == GATEWAY  && v_type == CLIENT) ||
               (u_type == CLIENT   && v_type == GATEWAY ))
        {
          // ok
        }
      else
        {
          // not ok
          NS_LOG_DEBUG ("Wrong link type between nodes: " << u_type << " <-> " << v_type << " (deleting the link)");

          graph_traits<Graph>::edge_iterator tmp = e;
          tmp++;

          remove_edge (*e, m_graph);
          e = tmp;
          continue;
        }
      e++;
    }

  if (keepOneComponent)
    {
      NS_LOG_DEBUG ("Before 2 eliminating disconnected nodes: " << num_vertices(m_graph));
      KeepOnlyBiggestConnectedComponent ();
      NS_LOG_DEBUG ("After 2 eliminating disconnected nodes:  " << num_vertices(m_graph));
    }

  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      string nodeName = get (vertex_name, m_graph, *v);
      Ptr<Node> node = CreateNode (nodeName, 0);

      node_type_t type = get (vertex_rank, m_graph, *v);
      switch (type)
        {
        case BACKBONE:
          Names::Rename (nodeName, "bb-" + nodeName);
          put (vertex_name, m_graph, *v, "bb-" + nodeName);
          m_backboneRouters.Add (node);
          break;
        case CLIENT:
          Names::Rename (nodeName, "leaf-" + nodeName);
          put (vertex_name, m_graph, *v, "leaf-" + nodeName);
          m_customerRouters.Add (node);
          break;
        case GATEWAY:
          Names::Rename (nodeName, "gw-" + nodeName);
          put (vertex_name, m_graph, *v, "gw-" + nodeName);
          m_gatewayRouters.Add (node);
          break;
        case UNKNOWN:
          NS_FATAL_ERROR ("Should not happen");
          break;
        }
    }

  for (tie (e, ende) = edges (m_graph); e != ende; e++)
    {
      Traits::vertex_descriptor
        u = source (*e, m_graph),
        v = target (*e, m_graph);

      node_type_t
        u_type = get (vertex_rank, m_graph, u),
        v_type = get (vertex_rank, m_graph, v);

      string
        u_name = get (vertex_name, m_graph, u),
        v_name = get (vertex_name, m_graph, v);

      if (u_type == BACKBONE && v_type == BACKBONE)
        {
          CreateLink (u_name, v_name,
                      params.averageRtt,
                      params.minb2bBandwidth, params.maxb2bBandwidth,
                      params.minb2bDelay,     params.maxb2bDelay);
        }
      else if ((u_type == GATEWAY  && v_type == BACKBONE) ||
               (u_type == BACKBONE && v_type == GATEWAY ))
        {
          CreateLink (u_name, v_name,
                      params.averageRtt,
                      params.minb2gBandwidth, params.maxb2gBandwidth,
                      params.minb2gDelay,     params.maxb2gDelay);
        }
      else if (u_type == GATEWAY  && v_type == GATEWAY)
        {
          CreateLink (u_name, v_name,
                      params.averageRtt,
                      params.minb2gBandwidth, params.maxb2gBandwidth,
                      params.minb2gDelay,     params.maxb2gDelay);
        }
      else if ((u_type == GATEWAY  && v_type == CLIENT) ||
               (u_type == CLIENT   && v_type == GATEWAY ))
        {
          CreateLink (u_name, v_name,
                      params.averageRtt,
                      params.ming2cBandwidth, params.maxg2cBandwidth,
                      params.ming2cDelay,     params.maxg2cDelay);
        }
      else
        {
          NS_FATAL_ERROR ("Wrong link type between nodes: " << u_type << " <-> " << v_type);
        }
    }

  ApplySettings ();

  NS_LOG_INFO ("Clients:   " << m_customerRouters.GetN ());
  NS_LOG_INFO ("Gateways:  " << m_gatewayRouters.GetN ());
  NS_LOG_INFO ("Backbones: " << m_backboneRouters.GetN ());
  NS_LOG_INFO ("Links:     " << GetLinks ().size ());

  return m_nodes;
}

const NodeContainer &
RocketfuelMapReader::GetBackboneRouters () const
{
  return m_backboneRouters;
}

const NodeContainer &
RocketfuelMapReader::GetGatewayRouters () const
{
  return m_gatewayRouters;
}

const NodeContainer &
RocketfuelMapReader::GetCustomerRouters () const
{
  return m_customerRouters;
}


static
void nodeWriter (std::ostream &os, NodeContainer& m)
{
  for (NodeContainer::Iterator node = m.Begin ();
       node != m.End ();
       node ++)
    {
      std::string name = Names::FindName (*node);

      os << name << "\t" << "NA" << "\t" << 0 << "\t" << 0 << "\n";
    }
};

void
RocketfuelMapReader::SaveTopology (const std::string &file)
{
  ofstream os (file.c_str (), ios::trunc);
  os << "# any empty lines and lines starting with '#' symbol is ignored\n"
     << "\n"
     << "# The file should contain exactly two sections: router and link, each starting with the corresponding keyword\n"
     << "\n"
     << "# router section defines topology nodes and their relative positions (e.g., to use in visualizer)\n"
     << "router\n"
     << "\n"
     << "# each line in this section represents one router and should have the following data\n"
     << "# node  comment     yPos    xPos\n";

  nodeWriter (os, m_backboneRouters);
  nodeWriter (os, m_gatewayRouters);
  nodeWriter (os, m_customerRouters);

  os << "# link section defines point-to-point links between nodes and characteristics of these links\n"
     << "\n"
     << "link\n"
     << "\n"
     << "# Each line should be in the following format (only first two are required, the rest can be omitted)\n"
     << "# srcNode   dstNode     bandwidth   metric  delay   queue\n"
     << "# bandwidth: link bandwidth\n"
     << "# metric: routing metric\n"
     << "# delay:  link delay\n"
     << "# queue:  MaxPackets for transmission queue on the link (both directions)\n";

  for (std::list<Link>::iterator link = m_linksList.begin ();
       link != m_linksList.end ();
       link ++)
    {
      string src = Names::FindName (link->GetFromNode ());
      string dst = Names::FindName (link->GetToNode ());
      os << src << "\t";
      os << dst << "\t";

      string tmp;
      if (link->GetAttributeFailSafe ("DataRate", tmp))
        os << link->GetAttribute("DataRate") << "\t";
      else
        NS_FATAL_ERROR ("DataRate must be specified for the link");

      if (link->GetAttributeFailSafe ("OSPF", tmp))
        os << link->GetAttribute("OSPF") << "\t";
      else
        {
          DataRate rate = boost::lexical_cast<DataRate> (link->GetAttribute("DataRate"));

          int32_t cost = std::max (1, static_cast<int32_t> (1.0 * m_referenceOspfRate.GetBitRate () / rate.GetBitRate ()));

          os << cost << "\t";
        }

      if (link->GetAttributeFailSafe ("Delay", tmp))
        {
          os << link->GetAttribute("Delay") << "\t";

          if (link->GetAttributeFailSafe ("MaxPackets", tmp))
            {
              os << link->GetAttribute("MaxPackets") << "\t";
            }
        }
      os << "\n";
    }
}


template <class Names, class Colors>
class name_color_writer {
public:
  name_color_writer(Names _names, Colors _colors) : names(_names), colors(_colors) {}

  template <class VertexOrEdge>
  void operator()(std::ostream& out, const VertexOrEdge& v) const {
    // out << "[label=\"" << names[v] << "\",style=filled,fillcolor=\"" << colors[v] << "\"]";
    out << "[shape=\"circle\",width=0.1,label=\"\",style=filled,fillcolor=\"" << colors[v] << "\"]";
  }
private:
  Names names;
  Colors colors;
};

template <class Names, class Colors>
inline name_color_writer<Names, Colors>
make_name_color_writer(Names n, Colors c) {
  return name_color_writer<Names, Colors>(n, c);
}


void
RocketfuelMapReader::SaveGraphviz (const std::string &file)
{
  ofstream of (file.c_str ());
  property_map<Graph, vertex_name_t>::type names = get (vertex_name, m_graph);
  property_map<Graph, vertex_color_t>::type colors = get (vertex_color, m_graph);
  write_graphviz(of, m_graph, make_name_color_writer (names, colors));
}


void
RocketfuelMapReader::KeepOnlyBiggestConnectedComponent ()
{
  std::map<graph_traits<Graph>::vertex_descriptor, int> temp;
  associative_property_map< std::map<graph_traits<Graph>::vertex_descriptor, int> > components (temp);

  // //check if topology has breaks in its structure and trim it if yes
  // property_map<Graph, vertex_index1_t>::type components = get (vertex_index1, m_graph);

  int num = connected_components (m_graph, components);
  NS_LOG_DEBUG ("Topology has " << num << " components");

  vector<int> sizes (num, 0);

  graph_traits<Graph>::vertex_iterator v, endv;
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      sizes[ get (components, *v) ] ++;
    }
  int largestComponent = max_element (sizes.begin (), sizes.end ()) - sizes.begin ();
  // cout << "Largest: " << largestComponent << endl;

  // for (int i =0 ; i < num; i++) cout << sizes[i] << " ";
  // cout << endl;

  // remove nodes and edges from smaller components //
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      if (get (components, *v) == largestComponent)
        continue;

      clear_vertex (*v, m_graph);
    }

  // this works only if vertices are organized in listS or setS (iterator is not invalidated on remove)
  for (tie(v, endv) = vertices(m_graph); v != endv; )
    {
      if (get (components, *v) == largestComponent)
        {
          v++;
          continue;
        }

      graph_traits<Graph>::vertex_iterator tmp = v;
      tmp++;

      remove_vertex (*v, m_graph);
      v = tmp;
    }

  int index = 0;
  // renumber nodes
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      put (vertex_index, m_graph, *v, index++);
    }
}

void
RocketfuelMapReader::ConnectBackboneRouters ()
{
  // not the tricky part.  we want backbone to be a fully connected component,
  // so traffic doesn't bounce from backbone to gateway and back

  typedef adjacency_list< setS, setS, boost::undirectedS,
                          property<vertex_name_t, Traits::vertex_descriptor, property
                                   < vertex_index_t, int, property
                                     < vertex_index1_t, int > > > > BbGraph;
  BbGraph bbGraph;
  map<Traits::vertex_descriptor, graph_traits<BbGraph>::vertex_descriptor> nodeMap;

  int index = 0;

  graph_traits<Graph>::vertex_iterator v, endv;
  for (tie(v, endv) = vertices(m_graph); v != endv; v++)
    {
      node_type_t type = get (vertex_rank, m_graph, *v);
      if (type == BACKBONE)
        {
          graph_traits<BbGraph>::vertex_descriptor newv = add_vertex (*v, bbGraph);
          put (vertex_index, bbGraph, newv, index++);
          nodeMap[*v] = newv;
        }
    }

  graph_traits<BbGraph>::vertex_iterator bb, endBb;
  for (tie (bb, endBb) = vertices (bbGraph); bb != endBb; bb++)
    {
      Traits::vertex_descriptor actualVertex = get (vertex_name, bbGraph, *bb);

      graph_traits<Graph>::adjacency_iterator u, endu;
      for (tie (u, endu) = adjacent_vertices (actualVertex, m_graph); u != endu; u++)
        {
          if (nodeMap.find (*u) != nodeMap.end ())
            {
              add_edge (nodeMap [actualVertex], nodeMap[*u], bbGraph);
            }
        }
    }

  property_map<BbGraph, vertex_index1_t>::type components = get (vertex_index1, bbGraph);

  int num = connected_components (bbGraph, components);
  NS_LOG_DEBUG ("Backbone has " << num << " components");
  if (num == 1)
    return; // nothing to do

  vector< vector<graph_traits<BbGraph>::vertex_descriptor> > subgraphs (num);
  for (tie (bb, endBb) = vertices (bbGraph); bb != endBb; bb++)
    {
      int component = get (vertex_index1, bbGraph, *bb);
      subgraphs [component].push_back (*bb);
    }

  UniformVariable randVar;

  for (int i = 1; i < num; i++)
    {
      int node1 = randVar.GetInteger (0, subgraphs[i-1].size ()-1);
      int node2 = randVar.GetInteger (0, subgraphs[i].size ()-1);

      Traits::vertex_descriptor
        v1 = get (vertex_name, bbGraph, subgraphs[i-1][node1]),
        v2 = get (vertex_name, bbGraph, subgraphs[i  ][node2]);

      NS_LOG_DEBUG ("Connecting " << get (vertex_name, m_graph, v1) << "[" << node1 << "] with "
                    << get (vertex_name, m_graph, v2) << "[" << node2 << "]");

      add_edge (v1, v2, m_graph);
    }
}


} /* namespace ns3 */