  In this paper, we study traffic dynamics in scale-free networks in which
packets are generated with non-homogeneously selected sources and destinations,
and forwarded based on the local routing strategy. We consider two situations
of packet generation: (i) packets are more likely generated at high-degree
nodes; (ii) packets are more likely generated at low-degree nodes. Similarly,
we consider two situations of packet destination: (a) packets are more likely
to go to high-degree nodes; (b) packets are more likely to go to low-degree
nodes. Our simulations show that the network capacity and the optimal value of
$\alpha$ corresponding to the maximum network capacity greatly depend on the
configuration of packets' sources and destinations. In particular, the capacity
is greatly enhanced when most packets travel from low-degree nodes to
high-degree nodes.
