|Source:||Proc. 19th Int. Conf. on Computer Communications and Networks (ICCCN 2010), Zurich, Switzerland, August 2010|
Because introducing new protocols and services, e.g., multicast or IPv6, on a global scale has proven to be difficult for various reasons, Peer-to-Peer (P2P) systems have become a method of choice for introducing innovation in the Internet. Such systems create Overlay Networks consisting of logical connections between end-systems at the edge of the Internet, do not require any supporting infrastructure, are scalable, and can be deployed using self-organization. However, the evolution of the Internet dramatically increases heterogeneity: NAT boxes establish different address spaces in different parts of the network. The partial transition from IPv4 to IPv6 leads to different protocols in the network layer and it is unsure whether all networked devices will use IP at all. These trends hinder direct connectivity between end-systems and, thus, make overlay deployment challenging. In this paper we survey on overlay approaches that can cope with these obstacles by providing themselves the functionality for homogeneous and persistent addressing and routing across heterogeneous networks. We discuss general approaches and trade-offs by example systems. Motivated by the lessons learned from these systems we present the Abstraction Base ariba, that implements shortest path routing across heterogeneous networks, maintains few neighborhood information, and requires low overhead for updates induced by network dynamics and node mobility.