2. Delivery Cost: Figure 4 shows that the delivery cost of ED routing is higher than the delivery cost of MP and PR routers. We believe the reason is that by ED routing, a node will generate more copies of a message so that its buffer saves many copies of different messages, and buffers thus fill up. We find that message delivery cost, by using LF (µ = 57.66, σ = 10.43) is lowerthan message delivery cost of PF (µ = 71.21, σ = 13.12) (Figure 5).