Impact of queuing policy variations on MaxProp DTN routing protocol

Abstract — A Delay/Disruption Tolerant Network is a network where temporary or intermittent connectivity among all nodes exist. Conventional routing protocols require end to end connectivity whereas DTN does not require such connectivity. This leads to the critical problem of how to route a packet from one node to another, in such a network. This problem becomes more complex, when the node mobility is also considered. In real mobility patterns the nodes always move in some predictable fashion rather than the random movement.This paper aims at visualizing the impact of the queuing policies on the MaxProp[1] routing protocol. MaxProp is based on prioritizing both the schedule of packets transmitted to other peers and the schedule of packets to be dropped. These priorities are based on the path likelihoods to peers according to historical data and also on several complementary mechanisms, including acknowledgments, a head-start for new packets, and lists of previous intermediaries. The Maxprop protocol follows a buffer split strategy to increase the delivery ratio. It makes the transmission as well as deletion of messages (in case of buffer overflows) based on the threshold separated by means of hop counts and costs. Simulations are conducted to analyze the impact of queuing policy by prioritizing on hopcounts or costs only and without acknowledgements