Software defined networking: meeting carrier grade requirements

Software Defined Networking is a networking paradigm which allows network operators to manage networking elements using software running on an external server. This is accomplished by a split in the architecture between the forwarding element and the control element. Two technologies which allow this split for packet networks are ForCES and Openflow. We present energy efficiency and resilience aspects of carrier grade networks which can be met by Openflow. We implement flow restoration and run extensive experiments in an emulated carrier grade network. We show that Openflow can restore traffic quite fast, but its dependency on a centralized controller means that it will be hard to achieve 50 ms restoration in large networks serving many flows. In order to achieve 50 ms recovery, protection will be required in carrier grade networks

A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

Diagnose network failures via data-plane analysis

Diagnosing problems in networks is a time-consuming and error-prone process. Previous tools to assist operators primarily focus on analyzing control plane configuration. Configuration analysis is limited in that it cannot find bugs in router software, and is harder to generalize across protocols since it must model complex configuration languages and dynamic protocol behavior. This paper studies an alternate approach: diagnosing problems through static analysis of the data plane. This approach can catch bugs that are invisible at the level of configuration files, and simplifies unified analysis of a network across many protocols and implementations. We present Anteater, a tool for checking invariants in the data plane. Anteater translates high-level network invariants into boolean satisfiability problems, checks them against network state using a SAT solver, and reports counterexamples if violations have been found. Applied to a large campus network, Anteater revealed 23 bugs, including forwarding loops and stale ACL rules, with only five false positives. Nine of these faults are being fixed by campus network operators

High-Performance Packet Processing Engines Using Set-Associative Memory Architectures

The emergence of new optical transmission technologies has led to ultra-high Giga bits per second (Gbps) link speeds. In addition, the switch from 32-bit long IPv4 addresses to the 128-bit long IPv6 addresses is currently progressing. Both factors make it hard for new Internet routers and firewalls to keep up with wire-speed packet-processing. By packet-processing we mean three applications: packet forwarding, packet classification and deep packet inspection. In packet forwarding (PF), the router has to match the incoming packet's IP address against the forwarding table. It then directs each packet to its next hop toward its final destination. A packet classification (PC) engine examines a packet header by matching it against a database of rules, or filters, to obtain the best matching rule. Rules are associated with either an ``action'' (e.g., firewall) or a ``flow ID'' (e.g., quality of service or QoS). The last application is deep packet inspection (DPI) where the firewall has to inspect the actual packet payload for malware or network attacks. In this case, the payload is scanned against a database of rules, where each rule is either a plain text string or a regular expression. In this thesis, we introduce a family of hardware solutions that combine the above requirements. These solutions rely on a set-associative memory architecture that is called CA-RAM (Content Addressable-Random Access Memory). CA-RAM is a hardware implementation of hash tables with the property that each bucket of a hash table can be searched in one memory cycle. However, the classic hashing downsides have to be dealt with, such as collisions that lead to overflow and worst-case memory access time. The two standard solutions to the overflow problem are either to use some predefined probing (e.g., linear or quadratic) or to use multiple hash functions. We present new hash schemes that extend both aforementioned solutions to tackle the overflow problem efficiently. We show by experimenting with real IP lookup tables, synthetic packet classification rule sets and real DPI databases that our schemes outperform other previously proposed schemes

Centralized prevention of denial of service attacks

The world has come to depend on the Internet at an increasing rate for communication, e-commerce, and many other essential services. As such, the Internet has become an integral part of the workings of society at large. This has lead to an increased vulnerability to remotely controlled disruption of vital commercial and government operations---with obvious implications. This disruption can be caused by an attack on one or more specific networks which will deny service to legitimate users or an attack on the Internet itself by creating large amounts of spurious traffic (which will deny services to many or all networks). Individual organizations can take steps to protect themselves but this does not solve the problem of an Internet wide attack. This thesis focuses on an analysis of the different types of Denial of Service attacks and suggests an approach to prevent both categories by centralized detection and limitation of excessive packet flows