To code or not to code: Rate optimality in node-capacitated networks

Node-capacitated networks are networks in which the capacity constraint is put on every node. They have recently attract attention as a good model for peer-to-peer (P2P) overlay networks. Existing work gives results on networks with constraints of node upload capacities. In this paper, we consider networks with constraints on both node upload and node download capacity. For such networks, we investigate the rate optimality of routing versus network coding. In general, network coding achieves a larger rate region than routing. However, for some important communication scenarios, routing achieves the same rate region as network coding.