DHTs are structured peer-to-peer networks with the ability to lookup certain overlay nodes within a limited number of overlay hops. However, the delay and jitter of the DHT lookups, which are important QoS parameters, do not necessarily depend on the number of overlay hops. Instead, they depend on the physical attributes of the underlying network, as the real amount of hops, bit error rates, packet loss or node failures.
In this planetlab project we are evaluating algorithms to decrease delay and jitter of DHT lookups, in order to improve the usability of DHTs in time sensitive applications. We set up a Chord environment on planetlab with modified lookup mechanisms. We chose planetlab as testbed for our simulation to have a real underlay network for Chord with heterogeneous links and nodes.
