The Transmission Control Protocol.

Network virtualization is a powerful way to run multiple architectures or experiments simultaneously on a shared infrastructure. However, making efficient use of the underlying resources requires effective techniques for virtual network embedding--mapping each virtual network to specific nodes and links in the substrate network. Since the general embedding problem is computationally intractable, past research restricted the problem space to allow efficient solutions, or focused on designing heuristic algorithms. In this paper, we advocate a different approach: rethinking the design of the substrate network to enable simpler embedding algorithms and more efficient use of resources, without restricting the problem space. In particular, we simplify virtual link embedding by: i) allowing the substrate network to split a virtual link over multiple substrate paths and ii) employing path migration to periodically re-optimize the utilization of the substrate network. We also explore node-mapping algorithms that are customized to common classes of virtual-network topologies. Our simulation experiments show that path splitting, path migration,and customized embedding algorithms enable a substrate network to satisfy a much larger mix of virtual networks

/pdf/rethinking-virtual-network-embedding-substrate-support-for-2zvfvo1lxr.pdf

Rethinking virtual network embedding: substrate support for path splitting and migration

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

A survey of network virtualization

A global center for commercial innovation, PARC, a Xerox company, works closely with enterprises, entrepreneurs, government program partners and other clients to discover, develop, and deliver new business opportunities. PARC was incorporated in 2002 as a wholly owned subsidiary of Xerox Corporation (NYSE: XRX).

/pdf/named-data-networking-ndn-project-1c5vgh72u5.pdf

Named Data Networking (NDN) Project

コンピュータ・サイエンス : ACM computing surveys

Packet classification is an enabling function for a variety of Internet applications including quality of service, security, monitoring, and multimedia communications. In order to classify a packet as belonging to a particular flow or set of flows, network nodes must perform a search over a set of filters using multiple fields of the packet as the search key. In general, there have been two major threads of research addressing packet classification, algorithmic and architectural. A few pioneering groups of researchers posed the problem, provided complexity bounds, and offered a collection of algorithmic solutions. Subsequently, the design space has been vigorously explored by many offering new algorithms and improvements on existing algorithms. Given the inability of early algorithms to meet performance constraints imposed by high speed links, researchers in industry and academia devised architectural solutions to the problem. This thread of research produced the most widely-used packet classification device technology, Ternary Content Addressable Memory (TCAM). New architectural research combines intelligent algorithms and novel architectures to eliminate many of the unfavorable characteristics of current TCAMs. We observe that the community appears to be converging on a combined algorithmic and architectural approach to the problem. Using a taxonomy based on the high-level approach to the problem and a minimal set of running examples, we provide a survey of the seminal and recent solutions to the problem. It is our hope to foster a deeper understanding of the various packet classification techniques while providing a useful framework for discerning relationships and distinctions.

/pdf/survey-and-taxonomy-of-packet-classification-techniques-545k9nk529.pdf

Survey and taxonomy of packet classification techniques

Packet classification is an enabling technology for next generation network services and often a performance bottleneck in high-performance routers. The performance and capacity of many classification algorithms and devices, including TCAMs, depend upon properties of filter sets and query patterns. Despite the pressing need, no standard performance evaluation tools or filter sets are publicly available. In response to this problem, we present ClassBench, a suite of tools for benchmarking packet classification algorithms and devices. ClassBench includes a filter set generator that produces synthetic filter sets that accurately model the characteristics of real filter sets. Along with varying the size of the filter sets, we provide high-level control over the composition of the filters in the resulting filter set. The tool suite also includes a trace generator that produces a sequence of packet headers to exercise packet classification algorithms with respect to a given filter set. Along with specifying the relative size of the trace, we provide a simple mechanism for controlling locality of reference. While we have already found ClassBench to be very useful in our own research, we seek to eliminate the significant access barriers to realistic test vectors for researchers and initiate a broader discussion to guide the refinement of the tools and codification of a formal benchmarking methodology. (The ClassBench tools are publicly available at the following site: http://www.arl.wustl.edu/~det3/ClassBench/.)

/pdf/classbench-a-packet-classification-benchmark-1serj3rqr6.pdf

ClassBench: a packet classification benchmark

We introduce the first algorithm that we are aware of to employ Bloom filters for Longest Prefix Matching (LPM). The algorithm performs parallel queries on Bloom filters, an efficient data structure for membership queries, in order to determine address prefix membership in sets of prefixes sorted by prefix length. We show that use of this algorithm for Internet Protocol (IP) routing lookups results in a search engine providing better performance and scalability than TCAM-based approaches. The key feature of our technique is that the performance, as determined by the number of dependent memory accesses per lookup, can be held constant for longer address lengths or additional unique address prefix lengths in the forwarding table given that memory resources scale linearly with the number of prefixes in the forwarding table.Our approach is equally attractive for Internet Protocol Version 6 (IPv6) which uses 128-bit destination addresses, four times longer than IPv4. We present a basic version of our approach along with optimizations leveraging previous advances in LPM algorithms. We also report results of performance simulations of our system using snapshots of IPv4 BGP tables and extend the results to IPv6. Using less than 2Mb of embedded RAM and a commodity SRAM device, our technique achieves average performance of one hash probe per lookup and a worst case of two hash probes and one array access per lookup.

/pdf/longest-prefix-matching-using-bloom-filters-4moo4sxdfu.pdf

Longest prefix matching using bloom filters

The Internet has fallen victim to its own stunning success. The interplay of the end-to-end design of IP and the vested interests of competing stakeholders has led to its growing ossification. Alterations to the Internet architecture that address its fundamental deficiencies or enable new services have been restricted to incremental changes. The slow pace of this process stifles innovation and the adoption of disruptive technology. A recent call to arms advances a research agenda to confront this impasse through virtualization (L. Peterson et al., 2004). In addition to describing a virtual testbed for the evaluation of new network architectures, it poses a question about the long-term role of virtualization in the Internet. The architectural "purist" views virtualization as a tool for architecture evaluation and the periodic deployment of successive, singular Internet architectures. In this paper, we advance the "pluralist" view that seeks to make virtualization an architectural attribute of the Internet. By enabling a plurality of diverse network architectures to coexist on a shared physical substrate, virtualization mitigates the ossifying forces at work in the current Internet and enables continual introduction of innovative network technologies. Such a diversified Internet would allow existing architectural deficiencies to be holistically addressed as well as enable the introduction of new architectures supporting new types of applications and services. We provide a detailed exposition of the diversified Internet concept, explain how it can address the problem of network ossification and discuss some of the technical challenges that must be met to turn the vision into reality

https://www.arl.wustl.edu/~jst/pubs/2005/divInternet2005.pdf

Diversifying the Internet

We introduce the first algorithm that we are aware of to employ Bloom filters for longest prefix matching (LPM). The algorithm performs parallel queries on Bloom filters, an efficient data structure for membership queries, in order to determine address prefix membership in sets of prefixes sorted by prefix length. We show that use of this algorithm for Internet Protocol (IP) routing lookups results in a search engine providing better performance and scalability than TCAM-based approaches. The key feature of our technique is that the performance, as determined by the number of dependent memory accesses per lookup, can be held constant for longer address lengths or additional unique address prefix lengths in the forwarding table given that memory resources scale linearly with the number of prefixes in the forwarding table. Our approach is equally attractive for Internet Protocol Version 6 (IPv6) which uses 128-bit destination addresses, four times longer than IPv4. We present a basic version of our approach along with optimizations leveraging previous advances in LPM algorithms. We also report results of performance simulations of our system using snapshots of IPv4 BGP tables and extend the results to IPv6. Using less than 2 Mb of embedded RAM and a commodity SRAM device, our technique achieves average performance of one hash probe per lookup and a worst case of two hash probes and one array access per lookup.

/pdf/longest-prefix-matching-using-bloom-filters-1aq7gyrnd2.pdf

David E. Taylor

Papers

Survey and taxonomy of packet classification techniques

ClassBench: a packet classification benchmark

Longest prefix matching using bloom filters

Diversifying the Internet

Longest prefix matching using bloom filters