  We present a generalized distance metric that can be used to identify routing
table entries and implement routing strategies to reach the root node for a
given key, in DHT (Distributed Hash Table) networks such as Chord, Kademlia,
Tapestry, and Pastry. The generalization shows that all the four DHT algorithms
are in fact, the same algorithm but with different parameters in distance
representation. This paper also proposes that nodes can have routing tables of
varying sizes based on their memory capabilities. But Each node must have at
least two entries, one for the node closest from it, and the other for the node
from whom it is closest, regardless of memory capacity. With this condition,
messages will still reach the correct root nodes. We also further observe that
in any network, if the distance metric of the DHT is same at all the nodes,
then the root node for a key will also be the same, irrespective of the size of
the routing table at different nodes.

Networking and Internet Architecture