The Internet is in a state of constant flux. This property of the Internet, that stems from the pressure from its continuously reinvented usage, makes it a lively environment, which must be re-assessed fundamentally f...
详细信息
The Internet is in a state of constant flux. This property of the Internet, that stems from the pressure from its continuously reinvented usage, makes it a lively environment, which must be re-assessed fundamentally from time to time. In this article, we review recent trends that have radically changed our perception of what the Internet is. Popular applications such as Youtube and Facebook have demonstrated the massive scale at which services can be delivered across the Internet. This has been possible only thanks to the massive deployment in content delivery infrastructures, leading to the rise of the Cloud paradigm. Recent studies from the research community have observed the consequences of this growth in the Internet infrastructure, through structural changes in the Internet topology and traffic patterns. The increasingly dynamic nature of Internet traffic patterns asks for improved capabilities to engineer traffic, that require a completely different level of programmability from the network. Software-defined networking is expected to fill this gap. Overall, the picture of the Internet that we draw in this article is the one of a very dynamic, challenging, and exciting playground.
We present a generic and flexible architecture to realize CloudNets: virtual networks connecting geographically distributed cloud resources (such as storage or CPU) with resource guarantees. Our architecture is federa...
详细信息
We present a generic and flexible architecture to realize CloudNets: virtual networks connecting geographically distributed cloud resources (such as storage or CPU) with resource guarantees. Our architecture is federated and supports different (and maybe even competing) economical roles, by providing explicit negotiation and provisioning interfaces. Contract-based interactions and a resource description language that allows for aggregation and abstraction, preserve the different roles' autonomy without sacrificing flexibility. Moreover, since our CloudNet architecture is plugin based, essentially all cloud operating systems (e.g., OpenStack) or link technologies (e.g., VLANs, OpenFlow, VPLS) can be used within the framework. This paper describes two roles in more detail: The Physical Infrastructure Providers (PIP) which own the substrate network and resources, and the Virtual Network Providers (VNP) which can act as resource and CloudNet brokers and resellers. Both roles are fully implemented in our wide-area prototype that spans remote sites and resources.
Internet routing is based on implicit trust assumptions. Given the critical importance of the Internet and the increasing security threats, such simple trust relationships are no longer sufficient. Over the past decad...
详细信息
Internet routing is based on implicit trust assumptions. Given the critical importance of the Internet and the increasing security threats, such simple trust relationships are no longer sufficient. Over the past decade, significant research has been devoted to securing the Internet routing system. The Internet Engineering Task Force (IETF) is well along in the process of standardizing routing security enhancements (Secure Inter-Domain Routing -SIDR, Keying and Authentication for Routing Protocols-KARP, etc.). However, the research challenges are not over: not only do these new protocols need to be tested for protocol conformance and interoperability, they also need to be evaluated both for their security properties and scaling performance. The purpose of this paper is twofold: we outline the main security challenges in inter-domain routing and argue that research in this area has barely begun;and we take a closer look at a production implementation of one component and evaluate it at a fairly large scale. We discuss the difficulties we experienced and lessons learned;we also present some initial results.
Although importance of aligning modelling of business processes and security is growing, there is rather limited research performed on elicitation of security requirements from the business processes. In this paper we...
详细信息
Although importance of aligning modelling of business processes and security is growing, there is rather limited research performed on elicitation of security requirements from the business processes. In this paper we discuss how security risk-oriented patterns could help solving the above problem. Using the illustrative example, we present a two-step method for (i) pattern occurrence discovery in, and (ii) for security requirements definition from the business process model. We hope that our proposal could help elicit security requirements at the early system development stages, however, we still need to validate it empirically.
Application integration can be performed on three levels: the data source level, the business logic level, and the user interface level. Approaches of the latter kind include, e.g., portal and mashup solutions. Deeper...
详细信息
Application integration can be performed on three levels: the data source level, the business logic level, and the user interface level. Approaches of the latter kind include, e.g., portal and mashup solutions. Deeper integration offering rich interaction possibilities usually leads to strong dependencies between applications, and requires deep knowledge of those applications. To reduce such dependencies, ontologies have been proposed as an inter-lingua mediating between the applications. While there have been approaches for using ontologies for integration on the data source and business logic level, this dissertation is the first approach for ontology-based application integration on the user interface level. It discusses the development of suitable formal ontologies, the use of reasoning and rule-based event processing, as well as aspects such as performance and seamless cross-technological interaction.
Software engineering in open source projects faces similar challenges as in traditional software development ( coordination of and cooperation between contributors, change and release management, quality assurance,......
详细信息
Software engineering in open source projects faces similar challenges as in traditional software development ( coordination of and cooperation between contributors, change and release management, quality assurance,...), but often uses different means of solving them. This leads to some salient distinctions between both worlds, especially with respect to communication and how technical issues are addressed. The variations within open source software (OSS) communities are considerable, and many different approaches are currently in use, ranging from informal conventions to highly systematic, formally specified and rigidly applied processes. We discuss the archetypal best practises in the field, illustrate them by presenting example projects, and provide a comparison to traditional approaches.
The first free/libre/open source software (FLOSS) development communities were composed almost exclusively of volunteers. They were individuals who, despite their affiliation, contributed to the project on their own. ...
详细信息
The first free/libre/open source software (FLOSS) development communities were composed almost exclusively of volunteers. They were individuals who, despite their affiliation, contributed to the project on their own. They decided which project to join, and their contributions were personal in nature, even when in some cases they were employees of companies with some interests in the project. GNU, the first of such communities, and some others that emerged during the late 1980s and 1990s, followed this pattern. During the 1990s corporate interests started to have a role in some FLOSS communities. Companies hired people from those communities to gain influence, or tasked their employees to contribute to them, again with the idea of influencing their decisions. During the 2000s, corporate communities, in which companies are first-class citizens, have emerged, changing the rules and redefining the role of volunteers and non-affiliated individuals. However, the role of developers, with independence of the company for which they work, is still important even in these communities. This paper addresses this transition from volunteer-based to company-based development communities, and explores the structure and behavior of the latter.
暂无评论