This article discusses the challenges in computer systems research posed by the emerging field of pervasive computing. It first examines the relationship of this new field to its predecessors: distributed systems and mobile computing. It then identifies four new research thrusts: effective use of smart spaces, invisibility, localized scalability, and masking uneven conditioning. Next, it sketches a couple of hypothetical pervasive computing scenarios, and uses them to identify key capabilities missing from today's systems. The article closes with a discussion of the research necessary to develop these capabilities.

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Pervasive computing: vision and challenges

The idea of programmable networks has recently re-gained considerable momentum due to the emergence of the Software-Defined Networking (SDN) paradigm. SDN, often referred to as a ''radical new idea in networking'', promises to dramatically simplify network management and enable innovation through network programmability. This paper surveys the state-of-the-art in programmable networks with an emphasis on SDN. We provide a historic perspective of programmable networks from early ideas to recent developments. Then we present the SDN architecture and the OpenFlow standard in particular, discuss current alternatives for implementation and testing of SDN-based protocols and services, examine current and future SDN applications, and explore promising research directions based on the SDN paradigm.

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A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks

Software systems dealing with distributed applications in changing environments normally require human supervision to continue operation in all conditions. These (re-)configuring, troubleshooting, and in general maintenance tasks lead to costly and time-consuming procedures during the operating phase. These problems are primarily due to the open-loop structure often followed in software development. Therefore, there is a high demand for management complexity reduction, management automation, robustness, and achieving all of the desired quality requirements within a reasonable cost and time range during operation. Self-adaptive software is a response to these demands; it is a closed-loop system with a feedback loop aiming to adjust itself to changes during its operation. These changes may stem from the software system's self (internal causes, e.g., failure) or context (external events, e.g., increasing requests from users). Such a system is required to monitor itself and its context, detect significant changes, decide how to react, and act to execute such decisions. These processes depend on adaptation properties (called self-a properties), domain characteristics (context information or models), and preferences of stakeholders. Noting these requirements, it is widely believed that new models and frameworks are needed to design self-adaptive software. This survey article presents a taxonomy, based on concerns of adaptation, that is, how, what, when and where, towards providing a unified view of this emerging area. Moreover, as adaptive systems are encountered in many disciplines, it is imperative to learn from the theories and models developed in these other areas. This survey article presents a landscape of research in self-adaptive software by highlighting relevant disciplines and some prominent research projects. This landscape helps to identify the underlying research gaps and elaborates on the corresponding challenges.

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Self-adaptive software: Landscape and research challenges

http://rboutaba.cs.uwaterloo.ca/Papers/Journals/2010/Mosharaf10.pdf

A survey of network virtualization

The technologies, architectures, and methodologies traditionally used to develop distributed applications exhibit a variety of limitations and drawbacks when applied to large scale distributed settings (e.g., the Internet). In particular, they fail in providing the desired degree of configurability, scalability, and customizability. To address these issues, researchers are investigating a variety of innovative approaches. The most promising and intriguing ones are those based on the ability of moving code across the nodes of a network, exploiting the notion of mobile code. As an emerging research field, code mobility is generating a growing body of scientific literature and industrial developments. Nevertheless, the field is still characterized by the lack of a sound and comprehensive body of concepts and terms. As a consequence, it is rather difficult to understand, assess, and compare the existing approaches. In turn, this limits our ability to fully exploit them in practice, and to further promote the research work on mobile code. Indeed, a significant symptom of this situation is the lack of a commonly accepted and sound definition of the term mobile code itself. This paper presents a conceptual framework for understanding code mobility. The framework is centered around a classification that introduces three dimensions: technologies, design paradigms, and applications. The contribution of the paper is two-fold. First, it provides a set of terms and concepts to understand and compare the approaches based on the notion of mobile code. Second, it introduces criteria and guidelines that support the developer in the identification of the classes of applications that can leverage off of mobile code, in the design of these applications, and, finally, in the selection of the most appropriate implementation technologies. The presentation of the classification is intertwined with a review of state-of-the-art in the field. Finally, the use of the classification is exemplified in a case study.

/pdf/understanding-code-mobility-1wdaf22ju4.pdf

Understanding code mobility

This RFC is a re-release of RFC 1067, with a changed "Status of this
Memo" section. This memo defines a simple protocol by which management
information for a network element may be inspected or altered by
logically remote users. In particular, together with its companion
memos which describe the structure of management information along
with the initial management information base, these documents provide
a simple, workable architecture and system for managing TCP/IP-based
internets and in particular the Internet.

/pdf/simple-network-management-protocol-snmp-51ilymame0.pdf

Simple Network Management Protocol (SNMP)

This RFC defines a simple protocol by which management information for
a network element may be inspected or altered by logically remote
users. In particular, together with its companion memos which describe
the structure of management information along with the initial
management information base, these documents provide a simple,
workable architecture and system for managing TCP/IP-based internets
and in particular, the Internet. This memo specifies a draft standard
for the Internet community. TCP/IP implementations in the Internet
which are network manageable are expected to adopt and implement this
specification.

Simple Network Management Protocol

This memo defines a simple application-layer protocol by which
management information for a gateway may be inspected or altered by
remote users. This proposal is intended only as an interim response to
immediate gateway monitoring needs.

Simple Gateway Monitoring Protocol

This memo describes an experimental method by which the Simple Network
Management Protocol (SNMP) can be used over Ethernet MAC layer framing
instead of the Internet UDP/IP protocol stack. This specification is
useful for LAN based network elements that support no higher layer
protocols beyond the MAC sub-layer.

SNMP over Ethernet

The Z39.50 Information Retrieval Protocol is a proposed ANSI standard for the retrieval of bibliographic information that originates from the library community in the United States. Unlike previous interlibrary loan protocols designed by the library community, Z39.50 is intended to be the basis of an end-user service.This paper provides a brief introduction to Z39.50, then discusses the shortcomings of the protocol that were discovered as a result of implementation experience.

M. L. Schoffstall

Papers

Simple Network Management Protocol (SNMP)

Simple Network Management Protocol

Simple Gateway Monitoring Protocol

SNMP over Ethernet

A critique of Z39.50 based on implementation experience