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Network functions such as firewalls, NAT, DPI, content-aware optimizers, and load-balancers are increasingly realized as software to reduce costs and enable outsourcing. To meet performance requirements these virtual network functions (VNFs) often bypass the kernel and use their own user-space networking stack. A naïve realization of a chain of VNFs will exchange raw packets, leading to many redundant operations, wasting resources. In this work, we design a system to execute a pipeline of VNFs. We provide the user facilities to define (i) a traffic class of interest for the VNF, (ii) a session to group the packets (such as the TCP 4-tuple), and (iii) the amount of space per session. The system synthesizes a classifier and builds an efficient flow table that when possible will automatically be partially offloaded and accelerated by the network interface. We utilize an abstract view of flows to support seamless inspection and modification of the content of any flow (such as TCP or HTTP). By applying only surgical modifications to the protocol headers, we avoid the need for a complex, hard-to-maintain user-space TCP stack and can chain multiple VNFs without re-constructing the stream multiple times, allowing up to 5x improvement over standard approaches. [ABSTRACT FROM AUTHOR]

With the fast development of Internet, the forwarding tables in backbone routers have been growing fast in size. An ideal IP lookup algorithm should achieve constant, yet small, IP lookup time, and on-chip memory usage. However, no prior IP lookup algorithm achieves both requirements at the same time. In this paper, we first propose SAIL, a splitting approach to IP lookup. One splitting is along the dimension of the lookup process, namely finding the prefix length and finding the next hop, and another splitting is along the dimension of prefix length, namely IP lookup on prefixes of length less than or equal to 24 and that longer than 24. Second, we propose a suite of algorithms for IP lookup based on our SAIL framework. Third, we implemented our algorithms on four platforms: CPU, FPGA, GPU, and many-core. We conducted extensive experiments to evaluate our algorithms using real FIBs and real traffic from a major ISP in China. Experimental results show that our SAIL algorithms are much faster than well known IP lookup algorithms. [ABSTRACT FROM AUTHOR]

Software-defined networking envisions the support of multiple applications collaboratively operating on the same traffic. Policies of applications therefore require composition into a rule list that represents the union of application intents. In this context, ensuring the correctness and efficiency of composition for match fields as well as the associated actions is the fundamental requirement. Prior work however focuses only on the composition of match fields and assumes simple concatenation for action composition. We show in this paper that simple concatenation can result in incorrect behavior and inefficiency of packet processing. To address this issue, we formalize the action composition problem and propose two graph-based computation models to facilitate efficient composition of action lists. Our proposed approach has been integrated into the CoVisor code base and the evaluation results show its fitness for purpose. [ABSTRACT FROM PUBLISHER]

As network link rates are being pushed beyond 40 Gb/s, IP lookup in high-speed routers is moving to hardware. The ternary content addressable memory (TCAM)-based IP lookup engine and the static random access memory (SRAM)-based IP lookup pipeline are the two most common ways to achieve high throughput. However, route updates in both engines degrade lookup performance and may lead to packet drops. Moreover, there is a growing interest in virtual IP routers where more frequent updates happen. Finding solutions that achieve both fast lookup and low update overhead becomes critical. In this paper, we propose a hybrid IP lookup architecture to address this challenge. The architecture is based on an efficient trie partitioning scheme that divides the forwarding information base (FIB) into two prefix sets: a large disjoint leaf prefix set mapped into an external TCAM-based lookup engine and a small overlapping prefix set mapped into an on-chip SRAM-based lookup pipeline. Critical optimizations are developed on both IP lookup engines to reduce the update overhead. We show how to extend the proposed hybrid architecture to support virtual routers. Our implementation shows a throughput of 250 million lookups per second (equivalent to 128 Gb/s with 64-B packets). The update overhead is significantly lower than that of previous work, the memory consumption is reasonable, and the utilization ratio of most external TCAMs is up to 100%. [ABSTRACT FROM AUTHOR]

Recent technological advances in commodity server architectures, with multiple multi-core CPUs, integrated memory controllers, high-speed interconnects, and enhanced network interface cards, provide substantial computational capacity, and thus an attractive platform for packet forwarding. However, to exploit this available capacity, we need a suitable software platform that allows effective parallel packet processing and resource management. In this paper, we at first introduce an improved forwarding architecture for software routers that enhances parallelism by exploiting hardware classification and multi-queue support, already available in recent commodity network interface cards. After evaluating the original scheduling algorithm of the widely-used Click modular router, we propose solutions for extending this scheduler for improved fairness, throughput, and more precise resource management. To illustrate the potential benefits of our proposal, we implement and evaluate a few key elements of our overall design. Finally, we discuss how our improved forwarding architecture and resource management might be applied in virtualized software routers. [ABSTRACT FROM AUTHOR]

This paper presents a detailed characterisation of user behaviour for a series of interactive video experiments over a 12 month period, in which we served popular sporting and musical content. In addition to generic VCR-like features, our custom-built video-on-demand application provides advanced interactivity features such as bookmarking. The dramatic impact of such functionality on how users consume content is studied and analysed. We discuss in detail how this user behaviour can be exploited by content distributors to improve user experience. Specifically, we study how simple dynamic bookmark placement and interactivity-aware content pre-fetching and replication can reduce the impact of highly interactive media on CDN performance. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the design and development of Grid middleware which, in its present form, is founded on Web services technologies. However, we argue that present-day Grid middleware is severely limited in supporting projected next-generation applications which will involve pervasive and heterogeneous networked infrastructures, and advanced services such as collaborative distributed visualization. In this paper we discuss a new Grid middleware framework that features (i) support for advanced network services based on the novel concept of pluggable overlay networks, (ii) an architectural framework for constructing bespoke Grid middleware platforms in terms of ‘middleware domains’ such as extensible interaction types and resource discovery. We believe that such features will become increasingly essential with the emergence of next-generation e-Science applications. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The lack of privacy is one of the main reasons that limits trust in e-commerce. Current e-commerce practice enforces a customer to disclose her identity to the e-shop and the use of credit cards makes it straightforward for an e-shop to know the real identity of its customers. Although there are some payment systems based on untraceable tokens, they are not as widely used as credit cards. Furthermore, even without buying anything, a customer is already disclosing some information about who or where she may be by just connecting to the e-shop's web server and leaving behind an IP-address. In this paper, we present novel components that enable secure pseudonymous e-commerce. On the one hand, these components allow a customer to browse through an e-shop, select goods, and pay the goods with her credit card such that neither the e-shop operator nor the credit card issuer nor an eavesdropper is able to get any information about the customer's identity. On the other hand, it is guaranteed that none of the involved parties is able to act dishonestly during the credit card payment. Such a system could greatly enhance trust in e-commerce since it overcomes the customers' privacy concerns. [ABSTRACT FROM AUTHOR]

Examines the alternative group communication service (AGCS) models for Internet Protocol (IP) multicasting. Metrics to characterize the AGCS performance; Description of unicast and multicast reflector and punctuation tunneling AGCS proposal; Principle of proposal based on gossiping for peer-to-peer communications; Details of the proposal based on a specific group communication routing service.

Examines applications and requirements of Internet protocols to communications components. Identification of support applications with strict quality of service requirements; Integrated service of the Internet Engineering Task Force; Protocol developments to improve the Internet; Support for real-time and multimedia communications.