Rocketfuel Tm
=============

::

    """
    Rocketfuel topology and traffic matrix
    ======================================
    
    This example shows how to import a topology from RocketFuel, configure it
    (assign capacities, weights and delays), generate a traffic matrix and
    save topology and traffic matrix to XML files.
    """
    import fnss
    import random
    
    # Import RocketFuel topology
    # Replace the filename with the actual location of the file you want to parse
    topology = fnss.parse_rocketfuel_isp_map("rocket-fuel-topo-file.cch")
    
    # add capacities
    capacities = [1, 10, 40]
    capacity_unit = 'Gbps'
    fnss.set_capacities_edge_betweenness(topology, capacities, capacity_unit, 
                                    weighted=False)
    
    # add weights proportional to inverse of capacity
    fnss.set_weights_inverse_capacity(topology)
    
    # add constant link delays of 2 ms
    fnss.set_delays_constant(topology, 2, delay_unit='ms')
    
    # generate cyclostationary traffic matrix (period 7 days, 24 samples per day)
    tmc = fnss.sin_cyclostationary_traffic_matrix(
           topology, 
           mean=0.5, # average flow in TM is 0,5 Gbps 
           stddev=0.05, # this is the std among average flows of different OD pairs 
           gamma=0.8,     # gamma and log_psi are parameters for fitting the std of 
           log_psi=-0.33, # volume fluctuations over time. Look at Nucci et al. paper
           delta=0.2, # traffic variation from period max and avg as fraction of average
           n=24, # number of samples per each period
           periods=7, # number of periods
           max_u=0.9, # max link utilization desired 
           origin_nodes=None,      # Specify origin and destination nodes. If None, 
           destination_nodes=None  # all nodes of the topology are both 
           )                        # origin and destination nodes of traffic
           
    
    # now we generate a static traffic matrix, but this time instead of generating
    # a matrix where all nodes are both origin and destinations, we pick up only
    # few nodes as sources and destinations of traffic.
    # Let's select 5 sources and 5 destinations
    nodes = topology.nodes()
    origins = random.sample(nodes, 5)
    destinations = random.sample(nodes, 5)
    # generate traffic matrix
    tms = fnss.static_traffic_matrix(topology, mean=0.5, stddev=0.05, max_u=0.9, 
                                     origin_nodes=origins,
                                     destination_nodes=destinations)
    
    # save topology on a file
    fnss.write_topology(topology, 'topology.xml')
    
    # save traffic matrices on files
    fnss.write_traffic_matrix(tmc, 'cyclostationary-traffic-matrix.xml')
    fnss.write_traffic_matrix(tms, 'static-traffic-matrix.xml')
