Anthill: a Framework for the Design and Analysis of Peer-to-Peer Systems
The Montresor (2000) paper outlines a new approach which is christened Anthill, for designing P2P applications based on comparisons to ant colonies. It continues with proposing a framework to support the development and study of new protocols based on a P2P approach. The paper considers how there are common issues such as security and routing that are applicable to P2P projects however conventional algorithm techniques to resolve these issues are deemed inappropriate. Therefore Anthill is proposed as a framework to support researchers in the design and the analysis of new P2P algorithms.
The Anthill project builds upon the similarities between P2P systems and social colonies of ants. Anthill provides an evaluation framework, based on the implementation of ant algorithms in simulated networks of nests that helps researchers to analyse and evaluate the behaviour of their “ants”. The Anthill infrastructure is composed of a network of nests which are P2P applications that are run by users on their machines. The paper continues with discussing the idea of the ant algorithm, which is based on observed behaviour of ants and also proposed an evaluation framework through which the behaviour of a particular ant implementation may be simulated and assessed.
So far some work has been achieved, for example the set of interfaces representing the basic components of the infrastructure, document storages, ant managers and gateways have been defined. However the Anthill project is still in its early stages so more work is necessary.
Incentives Build Robustness in BitTorrent
Cohen’s (2003) article discusses the Bit Torrent file distribution system which uses tit-for- tat as a method of seeking Pareto efficiency and achieves a higher level of robustness and resource utilization than any currently known cooperative technique. When multiple people are downloading the same file at the same time using BitTorrent, they upload pieces of the file to each other. This redistributes the cost of upload to downloaders, thus making hosting a file with a potentially unlimited number of downloaders affordable. The paper goes on at length to explain BitTorrent works and particular looks at economic methods to achieve successful and fair downloads.
Cohen discusses how researchers have previously attempted to find practical and fair techniques to do this. One strategy for fairness of effort is to ensure each peer’s download rate is proportional to their upload rat. However there can be issues with incomplete downloads because some clients cease downloading once they have downloaded the file. A discussion of the technical aspects of BitTorrent and issues followed, this includes discussing algorithms and strategies, to resolve certain problems, for example for when peers disallow downloading from them, which is known as choking. BitTorrent’s has choking algorithms which attempt to...