Delay tolerant networks (DTNs) are networks whose nodes have low connectivity and/or unreliable links. Because of these characteristics, DTN nodes use a store-carry-and-forward technique to deliver data through the network. Communication over DTN relies on intermediate nodes sharing their resources and can be abused by resource hogs, i.e. individuals who generate messages at a rate that is much higher than the average.
In this paper we first show that if not controlled, resource hogs can substantially reduce the proportion of successfully delivered non--hog messages. To combat this problem we propose a basic technique that utilizes coarse--grained priority classes to control resource hogs. User or node authentication can be the basis for constructing priority classes: for example, messages from certain verifiable senders are assigned to a class with higher priority. The basic technique effectively deals with strangers who act as resource hogs but cannot counter verifiable senders who exhibit resource hog behavior. We extend the basic technique into three fine--grained solutions for dealing with such ``insider" hogs.
We show the effectiveness of each solution in restoring message delivery ratio to the scenario where no resource hogs are present.
