Advances in processor, memory and radio technology will enable small and cheap nodes capable of sensing, communication and computation. Networks of such nodes can coordinate to perform distributed sensing of environmental phenomena. In this paper, we explore the directed diffusion paradigm for such coordination. Directed diffusion is datacentric in that all communication is for named data. All nodes in a directed diffusion-based network are application-aware. This enables diffusion to achieve energy savings by selecting empirically good paths and by caching and processing data in-network. We explore and evaluate the use of directed diffusion for a simple remote-surveillance sensor network.

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Directed diffusion: a scalable and robust communication paradigm for sensor networks

This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantinefault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in practice, the algorithm described in this paper is practical: it works in asynchronous environments like the Internet and incorporates several important optimizations that improve the response time of previous algorithms by more than an order of magnitude. We implemented a Byzantine-fault-tolerant NFS service using our algorithm and measured its performance. The results show that our service is only 3% slower than a standard unreplicated NFS.

/pdf/practical-byzantine-fault-tolerance-58gb0de0hd.pdf

Practical Byzantine fault tolerance

In both e-business and e-science, we often need to integrate services across distributed, heterogeneous, dynamic “virtual organizations” formed from the disparate resources within a single enterprise and/or from external resource sharing and service provider relationships. This integration can be technically challenging because of the need to achieve various qualities of service when running on top of different native platforms. We present an Open Grid Services Architecture that addresses these challenges. Building on concepts and technologies from the Grid and Web services communities, this architecture defines a uniform exposed service semantics (the Grid service); defines standard mechanisms for creating, naming, and discovering transient Grid service instances; provides location transparency and multiple protocol bindings for service instances; and supports integration with underlying native platform facilities. The Open Grid Services Architecture also defines, in terms of Web Services Description Language (WSDL) interfaces and associated conventions, mechanisms required for creating and composing sophisticated distributed systems, including lifetime management, change management, and notification. Service bindings can support reliable invocation, authentication, authorization, and delegation, if required. Our presentation complements an earlier foundational article, “The Anatomy of the Grid,” by describing how Grid mechanisms can implement a service-oriented architecture, explaining how Grid functionality can be incorporated into a Web services framework, and illustrating how our architecture can be applied within commercial computing as a basis for distributed system integration—within and across organizational domains. This is a DRAFT document and continues to be revised. The latest version can be found at http://www.globus.org/research/papers/ogsa.pdf. Please send comments to foster@mcs.anl.gov, carl@isi.edu, jnick@us.ibm.com, tuecke@mcs.anl.gov Physiology of the Grid 2

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The Physiology of the Grid An Open Grid Services Architecture for Distributed Systems Integration

This document describes an updated version of the "Security
Architecture for IP", which is designed to provide security services
for traffic at the IP layer. This document obsoletes RFC 2401
(November 1998). [STANDARDS-TRACK]

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Security Architecture for the Internet Protocol

This memo discusses a proposed extension to the Internet architecture and protocols to provide integrated services, i.e., to support real- time as well as the current non-real-time service of IP. This extension is necessary to meet the growing need for real-time service for a variety of new applications, including teleconferencing, remote seminars, telescience, and distributed simulation.

Integrated Services in the Internet Architecture: an Overview

A resource reservation protocol (RSVP), a flexible and scalable receiver-oriented simplex protocol, is described. RSVP provides receiver-initiated reservations to accommodate heterogeneity among receivers as well as dynamic membership changes; separates the filters from the reservation, thus allowing channel changing behavior; supports a dynamic and robust multipoint-to-multipoint communication model by taking a soft-state approach in maintaining resource reservations; and decouples the reservation and routing functions. A simple network configuration with five hosts connected by seven point-to-point links and three switches is presented to illustrate how RSVP works. Related work and unresolved issues are discussed. >

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RSVP: a new resource ReSerVation Protocol

Multicasting, the transmission of a packet to a group of hosts, is an important service for improving the efficiency and robustness of distributed systems and applications. Although multicast capability is available and widely used in local area networks, when those LANs are interconnected by store-and-forward routers, the multicast service is usually not offered across the resulting internetwork. To address this limitation, we specify extensions to two common internetwork routing algorithms—distance-vector routing and link-state routing—to support low-delay datagram multicasting beyond a single LAN. We also describe modifications to the single-spanning-tree routing algorithm commonly used by link-layer bridges, to reduce the costs of multicasting in large extended LANs. Finally, we discuss how the use of multicast scope control and hierarchical multicast routing allows the multicast service to scale up to large internetworks.

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Multicast routing in datagram internetworks and extended LANs

/pdf/rsvp-a-new-resource-reservation-protocol-5gd2s89bth.pdf

RSVP: a new resource reservation protocol

The purpose of multicast routing is to reduce the communication costs for applications that send the same data to multiple recipients. Existing multicast routing mechanisms were intended for use within regions where a group is widely represented or bandwidth is universally plentiful. When group members, and senders to those group members, are distributed sparsely across a wide area, these schemes are not efficient; data packets or membership report information are occasionally sent over many links that do not lead to receivers or senders, respectively. We have developed a multicast routing architecture that efficiently establishes distribution trees across wide area internets, where many groups will be sparsely represented. Efficiency is measured in terms of the router state, control message processing, and data packet processing, required across the entire network in order to deliver data packets to the members of the group. Our protocol independent multicast (PIM) architecture: (a) maintains the traditional IP multicast service model of receiver-initiated membership, (b) supports both shared and source-specific (shortest-path) distribution trees, (c) is not dependent on a specific unicast routing protocol, and (d) uses soft-state mechanisms to adapt to underlying network conditions and group dynamics. The robustness, flexibility, and scaling properties of this architecture make it well-suited to large heterogeneous internetworks.

/pdf/the-pim-architecture-for-wide-area-multicast-routing-145240csgs.pdf

The PIM architecture for wide-area multicast routing

Multicasting is used within local-area networks to make distributed applications more robust and more efficient. The growing need to distribute applications across multiple, interconnected networks, and the increasing availability of high-performance, high-capacity switching nodes and networks, lead us to consider providing LAN-style multicasting across an internetwork. In this paper, we propose extensions to two common internetwork routing algorithms—distance-vector routing and link-state routing—to support low-delay datagram multicasting. We also suggest modifications to the single-spanning-tree routing algorithm, commonly used by link-layer bridges, to reduce the costs of multicasting in large extended LANs. Finally, we show how different link-layer and network-layer multicast routing algorithms can be combined hierarchically to support multicasting across large, heterogeneous internetworks.

/pdf/multicast-routing-in-internetworks-and-extended-lans-bmwprdud72.pdf

Stephen Deering

Papers

RSVP: a new resource ReSerVation Protocol

Multicast routing in datagram internetworks and extended LANs

RSVP: a new resource reservation protocol

The PIM architecture for wide-area multicast routing

Multicast routing in internetworks and extended LANs