Geo-LPM - An Efficient Scheme for Locating Nodes in the Internet (original) (raw)

An optimised geographically-aware overlay network

INDIN '05. 2005 3rd IEEE International Conference on Industrial Informatics, 2005., 2005

The mismatch between current Peer-to-Peer (P2P) overlay structures and the underlying network topology causes high end-to-end latency and inefficient network resource usage. This paper presents a selforganising overlay network that closely reflects the underlying network topology by using the basic idea of a node locating scheme called Geographical Longest Prefix Matching (Geo-LPM) [1]. Geo-LPM combines IP prefixes and a network metric measurement to cluster nodes efficiently. We optimise Geo-LPM to adapt to different geographical locations so that nodes in the same clusters often belong to the same physical network. We propose to implement Geo-LPM in a distributed fashion. As a result, the overlays utilise the underlying network resources more efficiently and reduce the delay from end-to-end. The system is self-organising, distributed, and decentralised with low overhead.

IP-based Clustering for Peer-to-Peer Overlays

Journal of Software, 2007

The efficiency of overlay networks built on top of the IP network is often threatened by the mismatch between the topologies of the overlay and the underlying IP network, resulting in unnecessary traffic and increased latencies. Substantial improvement can be achieved by optimizing the logical links between overlay nodes to better match the IP network topology.

Leopard: A locality aware peer-to-peer system with no hot spot

2005

Recent research [7, 12, 2] has shown that Internet hosts can be efficiently (i.e., without excessive measurements) mapped to a virtual (Euclidean) coordinate system, where the geometric distance between any two nodes in this virtual space approximates their real IP network distance (latency). Based on this result, in this paper, we propose an alternative approach that inherently incorporates a virtual coordinate system into a P2P network. In our system, called Leopard, a node is assigned a coordinate in the so-called node geo space as it joins the network, and obtains neighbor relationships that reflects network proximity from the beginning. The object id space and the node geo space are then "weaved" together via a novel technique called geographically-scoped hashing. Through analysis and simulation, we show three major desirable properties of Leopard to exemplify the power of this paradigm shift: i) a constant routing stretch, i.e., IP level network latency of object look-up is proportional to the distance between a requesting node and the target object; ii) always locates a nearby copy when multiple copies exist; and iii) effectively handles "flash crowd" traffic with near optimal load balancing.

Palm: Predicting internet network distances using peer-to-peer measurements

Landmark-based architecture has been commonly adopted in the networking community as a mechanism to measure and characterize a host's location on the Internet. In most existing landmark based approaches, end hosts use the distance measurements to a common, fixed set of landmarks to derive an estimated location on the Internet. This paper investigates whether it is possible for participating peer nodes in an overlay network to collaboratively construct an accurate geometric model of its topology in a completely decentralized peer-to-peer fashion, without using a fixed set of landmarks. We call such a peerto-peer approach in topology discovery and modeling using landmarks PALM (Peers As LandMarks). We evaluate the performance characteristics of such a decentralized coordinatebased approach under several factors, including dimensionality of the geometric space, peer distance distribution, and the number of peer-to-peer distance measurements used. We evaluate two PALM-based schemes: RAND-PALM and ISLAND. In RAND-PALM, a peer node randomly selects from existing peer nodes as its landmarks. In ISLAND (Intelligent Selection of Landmarks), each peer node selects its landmarks by exploiting the topological information derived based on existing peer nodes' coordinates.

A location-aware peer-to-peer overlay network

International Journal of Communication Systems, 2006

This work describes a novel location-aware, self-organizing, fault-tolerant peer-to-peer (P2P) overlay network, referred to as Laptop. Network locality-aware considerations are a very important metric for designing a P2P overlay network. Several network proximity schemes have been proposed to enhance the routing efficiency of existing DHT-based overlay networks. However, these schemes have some drawbacks such as high overlay network and routing table maintenance overhead, or not being completely selforganizing. As a result, they may result in poor scalability as the number of nodes in the system grows. Laptop constructs a location-aware overlay network without predetermined landmarks and adopts a routing cache scheme to avoid maintaining the routing table periodically. In addition, Laptop significantly reduces the overlay maintenance overhead by making each node maintain only the connectivity between parent and itself. Mathematical analysis and simulations are conducted to evaluate the efficiency, scalability, and robustness of Laptop. Our mathematical analysis shows that the routing path length is bounded by log d N; and the joining and leaving overhead is bounded by d log d N; where N is the number of nodes in the system, and d is the maximum degree of each node on the overlay tree. Our simulation results show that the average latency stretch is 1.6 and the average routing path length is only about three in 10 000 Laptop nodes, and the maximum degree of a node is bounded by 32.

Geopeer: A location-aware peer-to-peer system

Network Computing and Applications, …, 2004

This paper presents a novel peer-to-peer system that is particularly well suited to support context-aware computing. The system, called GeoPeer, aims to combine the advantages of peer-to-peer systems that implement distributed hash tables with the suitability of geographical routing for supporting location-constrained queries and information dissemination. GeoPeer is comprised of two fundamental components: a Delaunay triangulation used to build a connected lattice of nodes and a mechanism to manage long range contacts that allows good routing performance, despite unbalanced distribution of nodes.

Plethora: a locality enhancing peer-to-peer network

2004

Distributed hash tables (DHTs), used in a number of structured peer-to-peer systems provide efficient mechanisms for resource location. A key distinguishing feature of current DHT systems like Chord [15], Pastry [12], and Tapestry [19] is the way they handle locality in the underlying network. Topology-based node identifier assignment, proximity routing, and proximity neighbor selection are examples of heuristics used to minimize message delays in the underlying network. While these heuristics are sometimes effective, they all rely on a single global overlay that may install the key of a popular object at a node far from most of the nodes accessing it. Furthermore, a response to a lookup message does not contain any locality information about the nodes holding a copy of the object. We address these issues by defining Plethora, a novel two-level overlay peer-to-peer network. A local overlay in Plethora acts as a locality-aware cache for the global overlay, grouping nodes close together in the underlying network. Local overlays are constructed by exploiting the structure of the Internet as Autonomous Systems. We present a detailed experimental study that demonstrates the practicality of the system, and shows performance gains in response time of upto 60% compared to a single global overlay. We also present efficient distributed algorithms for maintaining local overlays in the presence of node arrivals and departures.

I2TS01 - A Taxonomy for Locality Algorithms on Peer-to-Peer Networks

IEEE Latin America Transactions, 2010

The continuous growth of peer-to-peer networks has made them responsible for a considerable portion of the current Internet traffic. For this reason, improvements in P2P network resources usage are of central importance. One effective approach for addressing this issue is the deployment of locality algorithms, which allow the system to optimize the peers selection policy for different network situations and, thus, maximize performance. To date, several locality algorithms have been proposed for use in P2P networks. However, they usually adopt heterogeneous criteria for measuring the proximity between peers, which hinders a coherent comparison between the different solutions. In this paper, we develop a thoroughly review of popular locality algorithms, based on three main characteristics: the adopted network architecture, distance metric, and resulting peer selection algorithm. As result of this study, we propose a novel and generic taxonomy for locality algorithms in peer-to-peer networks, aiming to enable a better and more coherent evaluation of any individual locality algorithm.

Locality in structured peer-to-peer networks

Journal of Parallel and Distributed Computing, 2006

Distributed hash tables (DHTs), used in a number of structured peer-to-peer (P2P) systems, provide efficient mechanisms for resource placement and location. A key distinguishing feature of current DHT systems, such as Chord, Pastry, CAN and Tapestry, is the way they handle locality in the underlying network. Topology-based node identifier assignment, proximity routing, and proximity neighbor selection are examples of heuristics used to minimize message delays in the underlying network. While these heuristics are sometimes effective, they all rely on a single global overlay that may install the key of a popular object at a node far from most of the nodes accessing it. Furthermore, a response to a lookup message does not contain any locality information about the nodes holding a copy of the object. We address these issues in Plethora, a novel two-level overlay P2P network. A local overlay in Plethora acts as a locality-aware cache for the global overlay, grouping nodes close together in the underlying network. Local overlays are constructed by exploiting the organization of the Internet into autonomous systems (ASs). We present a detailed experimental study that demonstrates performance gains in response time of up to 60% compared to a single global Pastry overlay. We also present efficient distributed algorithms for maintaining local overlays in the presence of node arrivals and departures.