usage: topology [-<key 1> <value 1> -<key 2> <value 2> -<key n> <value n>]

example options: 
-generator itm -outfile myfile -type random -nodes 20 -connection_prob 0.6 

keys and corresponding values:
-generator
  possible value: itm (default) [the georgia tech topology generator]
  [note: you need to invoke itm and sgb2ns, e.g. by setting your path]

-outfile [the output file that will contain the ns script describing the
	  generated topology. This must be given.]

-type
  possible values: random (default), transit_stub

-seed
  possible values: integer (default = random [uses ns-random])

-nodes [the number of nodes in the topology; used with `-type random']
  possible values: integer (default = 50 with random, 100 with 
  transit-stub)

-scale [used by itm to place nodes in topologies] (default = nodes)

-method [the node connection/linking method; used with `-type random']
  possible values: waxman1, waxman2, pure-random, doar-leslie, exponential, 
                   and  locality (default = pure-random)

-connection_prob [the connection probability between nodes; used in 
       all methods] [this sometimes is called `alpha']
  possible values: 0.0 <= connection_prob <= 1.0 (default = 0.5)

-beta [used only with waxman1, waxman2, doar-leslie and locality]
  possible values: 0.0 <= beta (default = 0.5)

-gamma [used only with doar-leslie and locality]
  possible values: 0.0 <= gamma (default = 0.5)