Programming the data path in network processor‐based routers

There is growing interest in network processor technologies capable of processing packets at line rates. Network processors are likely to be an integral part of next generation high‐speed router and switch architectures, replacing the application‐specific integrated circuits (ASICs) that are used in routers today. In this paper, we present the design, implementation and evaluation of NetBind, a high‐performance, flexible and scalable binding tool for dynamically constructing data paths in network processor‐based routers. The methodology that underpins NetBind balances the flexibility of network programmability against the need to process and forward packets at line speeds. To support the dynamic binding of components with the minimum addition of instructions in the critical path, NetBind modifies the machine language code of components at run time. To support fast data path composition, NetBind reduces the number of binding operations required for constructing data paths to a minimum set so that binding latencies are comparable with packet forwarding times. Data paths constructed using NetBind seamlessly share the resources of the same network processor. Resources are assigned during the binding process. We compare the performance of NetBind to the MicroACE system developed by Intel and show that NetBind provides better performance in comparison to MicroACE with smaller binding overhead. The NetBind source code described and evaluated in this paper is freely available on the Web ( http://www.comet.columbia.edu/genesis/netbind ) for experimentation. Copyright © 2005 John Wiley & Sons, Ltd.     

Spawning networks

The deployment of new network architectures, services, and protocols is often manual, ad hoc, and time-consuming. We introduce “spawning networks,” a new class of programmable networks that automate the life cycle process for the creation, deployment, and management of network architectures. These networks are capable of spawning distinct “child” virtual networks with their own transport, “parent's” network resources and in isolation from other spawned networks. Spawned child networks represent programmable virtual networks and support the controlled access to communities at users with specific connectivity, security, and quality of service requirements. In this article we present a framework for the realization of spawning networks based on the notion of the Genesis Kernel, a virtual network operating system capable of creating distinct virtual network architectures on the fly. We discuss the motivation and principles that underpin spawning networks and focus on the design of the transport, programming and life cycle environments, which comprise the main architectural components of the Genesis Kernel     

Managing complexity: middleware explained

Traditionally, most definitions seeking to characterize middleware suggest that it is the software that facilitates remote database access and systems transactions. More recently, the term has come to be associated-somewhat limitingly-with distributed platforms such as the Open Software Foundation's Distributed Computing Environment (DCE) and the Object Management Group's Common Object Request Broker Architecture (CORBA). And some have loosely applied it to systems as diverse as workflow support environments and even to the Web itself. We believe the essential role of middleware is to manage the complexity and heterogeneity of distributed infrastructures and thereby provide a simpler programming environment for distributed-application developers. It is therefore most useful to define middleware as any software layer that is placed above the distributed system's infrastructure-the network OS and APIs-and below the application layer     

降低NR胎面胶的滚动阻力

节省能源对衡量国民经济和橡胶工业技术水平有着十分重要的意义.高油价将进一步提高节省能源的要求.轮胎消耗能源的主要部分是其在路面上滚动时将动能转化为轮胎内部的热能.     

The Genesis Kernel: a programming system for spawning networkarchitectures

Currently, the design, deployment, and refinement of new network architectures is a manual, ad hoc, and time-consuming process. We present the design, implementation, and evaluation of the Genesis Kernel, a programming system that automates the life cycle process for the creation, deployment, management, and architecting of network architectures. We discuss our experiences in building a spawning network that is capable of creating distinct virtual network architectures on-demand. The Genesis Kernel is based on a methodology that allows a child virtual network to operate on top of a subset of its parent's network resources and in isolation from other spawned virtual networks. We show through experimentation how a number of diverse network architectures can be spawned and architecturally refined. These spawned network architectures include a parent network that supports IP forwarding, and interior and exterior routing. We discuss how two child networks based on Cellular IP and Mobiware architectures can be spawned on the parent network to support wireless access to data and continuous media services, respectively     

Design,Implementation and Evaluation of Programmable Handoff in Mobile Networks

We describe the design, implementation and evaluation of a programmable architecture for profiling, composing and deploying handoff services. We argue that future wireless access networks should be built on a foundation of open programmable networking allowing for the dynamic deployment of new mobile and wireless services. Customizing handoff control and mobility management in this manner calls for advances in software and networking technologies in order to respond to specific radio, mobility and service quality requirements of future wireless Internet service providers. Two new handoff services are deployed using programmable mobile networking techniques. First, we describe a multi-handoff access network service, which is capable of simultaneously supporting multiple styles of handoff control over the same physical wireless infrastructure. Second, we discuss a reflective handoff service, which allows programmable mobile devices to freely roam between heterogeneous wireless access networks that support different signaling systems. Evaluation results indicate that programmable handoff architectures are capable of scaling to support a large number of mobile devices while achieving similar performance to that of native signaling systems.