Building Programmable Wireless Networks: An Architectural Survey

In recent times, there have been a lot of efforts for improving the ossified Internet architecture in a bid to sustain unstinted growth and innovation. A major reason for the perceived architectural ossification is the lack of ability to program the network as a system. This situation has resulted partly from historical decisions in the original Internet design which emphasized decentralized network operations through co-located data and control planes on each network device. The situation for wireless networks is no different resulting in a lot of complexity and a plethora of largely incompatible wireless technologies. The emergence of "programmable wireless networks", that allow greater flexibility, ease of management and configurability, is a step in the right direction to overcome the aforementioned shortcomings of the wireless networks. In this paper, we provide a broad overview of the architectures proposed in literature for building programmable wireless networks focusing primarily on three popular techniques, i.e., software defined networks, cognitive radio networks, and virtualized networks. This survey is a self-contained tutorial on these techniques and its applications. We also discuss the opportunities and challenges in building next-generation programmable wireless networks and identify open research issues and future research directions.Comment: 19 page

Software-Defined Networking in Datacenter Network Virtualization

Työn aiheena on tutustua SDN-arkkitehtuuriin ja selvittää, miten se soveltuu osaksi konesaliverkkojen virtualisointia. Työssä käydään läpi verkkoarkkitehtuurien historiaa, sekä tarpeita, joista SDN-arkkitehtuuri on syntynyt. Työssä käydään läpi muutamia avoimen ja suljetun lähdekoodin SDN-sovelluksia, sekä esitellään verkkojen virtualisoinnin perusteet. Tarkempaan käsittelyyn valitaan avoimen ja suljetun lähdekoodin sovellukset, jotka yhdistävät sekä SDN-arkkitehtuurin, että verkkojen virtualisoinnin. Tutkimustulokseksi saadaan, että SDN-arkkitehtuurista on konkreettista hyötyä konesaliverkkojen virtualisoinnista. Saavutettava hyöty riippuu kuitenkin lähtökohdista. Olemassa olevassa konesalissa SDN-sovellus on riippuvainen kytkinlaitteistosta. Uudessa konesalissa SDN-sovellus voidaan valita vapaammin

Implementation and Evaluation of a Network Element Control Protocol

Tämä opinnäytetyö koostuu erään ohjaus- ja välityselementtien väliseen tiedonsiirtoon käytettävän verkkoelementin ohjausprotokollan toteutuksesta ja arvioinnista. Tätä ohjausprotokollaa käytetään verkkoelementin sisällä verkko-operaattorin runkoverkossa. Kirjoittaja on tutkinut kolmea yleisesti käytössä olevaa dynaamista verkkokytkimen ohjausprotokollaa ja yksi näistä on valittu toteutettavaksi tässä tutkimuksessa. Tämä kyseinen protokolla on forwarding and control element separation (ForCES). Euroopan Unionin seitsemännen puiteohjelman ETNA-projektissa on tehty IETF:n määrittelystä poikkeavia muutoksia ForCES-protokollaan: PATH-DATATLV- kerros poistettiin sekä muita TLV-tietorakenteita muutettiin projektin tarpeiden mukaisesti. ETNA on myös lisännyt ylimääräisiä ID-arvoja, tietotyyppejä, tapahtuma- ja tuloskoodeja sekä muita arvoja. Arvot on valittu niin, etteivät ne mene päällekkäin IETF:n ForCES määrittelyjen kanssa. Tässä tutkimuksessa tehty ohjelmistototeutus on C++-kirjasto, jossa on 31 luokkaa ja 15 436 riviä lähdekoodia. Ohjelmistokoodi on testattu kirjoittajan tekemällä testiohjelmalla ja se toimii ilman tunnettuja virhetoimintoja. Tutkimuksen arviointiosuus koostuu muistinvarauksen ja viestin muodostusajan mittaamisesta. Kilotavun mittaiset ja 185 TLV-tietorakennetta sisältävät testiviestit varasivat yli 500 % ylimääräistä muistia verrattuna viesten nettopituuteen. Tämän ylimääräisen muistinkäytön suhteellinen osuus viestien nettopituuteen verrattuna kuitenkin pienenee, samalla kun TLV-tietorakenteiden pituus kasvaa. Viestinmuodostuksen käsittelyaika kasvoi lineaarisesti, mutta mittauksissa havaittiin viestien käsittelyn alussa jonkin verran ylimääräistä käsittelyaikaa etenkin lyhyillä viesteillä, joissa oli vähän TLV-tietorakenteita. Suunnittelimme ja toteutimme Aalto-yliopistossa ohjauselementin ForCES-protokollan toteutuksen ja Ben Gurionin yliopisto Israelissa oli vastuussa välityselementin suunnittelusta ja toteutuksesta. Molemmat toteutukset yhdistettiin ja demonstroitiin yhdessä kehitettyä uutta runkoverkon mallia.This thesis consists of the implementation and evaluation of a network element control protocol that is used for the communication between the control element and the forwarding element in a network element in a network operator's core network. The author has investigated three commonly used dynamic switch control protocols and one of them is chosen to be implemented in this study. This protocol is the forwarding and control element separation (ForCES). In the EU 7th framework program's ETNA project, there has been done some modifications to the IETF specified ForCES protocol: the PATH-DATA-TLV layer was removed among other type-length-value (TLV) data structure modifications. ETNA has also added extra IDs, data types, event and result codes, and other values choosing them so that they do not overlap with the values in the IETF ForCES specification. The implementation done in this study is a C++ library with 31 classes and 15 436 lines of source code. The code was tested with a test program written by the author and is working without any known bugs. The evaluation part of the study consists of memory allocation and message construction time performance measurements. The test messages with one kilobyte length and 185 TLVs allocated over 500 % extra memory compared to the message network length. However, this overhead is proportional to the network length of the message and will decrease as the length of the TLVs increase. The processing time for the message construction was linearly increasing, but there was some offset time at the beginning of the message processing especially with short messages with a few TLVs. In Aalto University, we designed and implemented the control element implementation of the ForCES protocol and the Ben Gurion University was responsible for the design and implementation of the forwarding element. Both implementations were integrated together and there was demonstrated a new co-developed proof-of-concept core network model

Contribución al diseño de arquitecturas distribuidas de nodos de red programable

Hoy en día, los nodos de red que forman Internet son complejos sistemas hardware/software que soportan un gran número de protocolos, servicios de red, o funcionalidades avanzadas como rewall o NAT. Sin embargo el proceso para añadir un nuevo protocolo o servicio es extremadamente largo y costoso, debido a múltiples causas, pero especialmente a que los routers siguen siendo sistemas propietarios, integrados verticalmente por los fabricantes. En este sentido, la investigación en redes programables intenta simpli car el desarrollo y el despliegue de los servicios de red mediante la de nición de interfaces abiertos entre todos los elementos que forman el router. Sin embargo hasta que los primeros diseños de nodos de red totalmente programables lleguen a comercializarse, es necesario aportar soluciones a corto y medio plazo que permitan ampliar las capacidades y servicios de los routers de alto rendimiento actuales. Esta tesis presenta una arquitectura de nodo de red programable de transici ón y bajo coste, denominada Simple Assistant-Router Architecture (SARA), que permite extender las capacidades de un router comercial delegando el procesamiento avanzado de los paquetes a un cluster de asistentes , lo que simpli ca el desarrollo y despliegue dinámico de los nuevos servicios de red. Un aspecto fundamental de esta arquitectura distribuida es la de nición de mecanismos de coordinación de los asistentes entre sí y con el router legado. Para ello se propone la utilización del Router-Assistant Protocol (RAP), un protocolo de control que permite a los asistentes con gurar el plano de datos del router, recibir eventos, así como desviar paquetes de señalización y ujos de datos para su procesamiento en los asistentes. Dada la heterogeneidad de los requisitos de las aplicaciones de red es necesario proporcionar varios mecanismos para asegurar un reparto de carga efectivo en el cluster de asistentes. Esta Tesis Doctoral propone dos algoritmos de Fast Robust Hashing que permiten la asignación equitativa y persistente de ujos a asistentes, mejorando el rendimiento de las técnicas de Robust Hashing actuales, por lo que son lo su cientemente e cientes como para ser implementados en el plano de datos de un router comercial. Además, este trabajo especi ca el eXtensible Service Discovery Framework (XSDF), un marco de trabajo sencillo y escalable, que integra en un único proceso el descubrimiento de servicios y el reparto de carga entre servidores desacoplados.Nowadays, the network nodes that build Internet are complex hardware/ software systems, that support many signalling protocols, network services, and complex functionalities such as rewalling or NAT. However adding a new capability is a long, complex and costly process, due to many causes, but specially because routers are still proprietary systems, vertically integrated by the vendors. In this sense, the research in programmable networks tries to simplify the development and deployment of network services by specifying open interfaces among all the elements that make up a router. However, before the rst programmable network nodes start being deployed, it is necessary to provide short and medium term solutions that allow current high-performance routers to add advanced capabilities and new network services. This PhD. Thesis presents a low-cost transition architecture for programmable network nodes named Simple Assistant-Router Architecture (SARA), that allows a commercial router to easily extend its capabilities by delegating the advanced packet processing to a cluster of assistants , which greatly simpli es the development and dynamic deployment of new network services. A key aspect of this distributed architecture is the need of several coordination mechanisms between the router and the assistants, and among assistant themselves. Therefore, the Router-Assistant Protocol (RAP) has been proposed, which is a control protocol based on ForCES, that allows assistants to con gure the router's data plane, to notify events, as well as to divert signalling packets and data ows to the assistants. As network application requirements could be very heterogeneous, it is necessary to provide several mechanisms in order to load-balance the assistant cluster. Thus, this Thesis presents two novel Fast Robust Hashing algorithms that provides a permanent and fair mapping of ows to assistants, and improves existing Robust Hash techniques as it is e cient enough to be implemented in the data plane of a commercial router. Moreover this research work also de - nes the eXtensible Service Discovery Framework (XSDF), which integrates in a single process: scalable service location, and load-sharing among lightly-coupled servers

IEEE Software Defined Network Initiative

This paper outlines a proposal for setting up an IEEE initiative on software defined networks (SDNs) to facilitate professional and academic exchange of SDN-related ideas, research, and development. The proposal is a result of an intensive effort of a team consisting of the authors. After a comprehensive gap analysis, gaps and key opportunities were identified. Finally, a specific set of components along with schedule and financial consideration were proposed in the areas of publications, conferences, standards, education, certification, and publicity

A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks

accepted in IEEE Communications Surveys & TutorialsInternational audienceThe idea of programmable networks has recently re-gained considerable momentum due to the emergence of the Software-Defined Networking (SDN) paradigm. SDN, often referred to as a ''radical new idea in networking'', promises to dramatically simplify network management and enable innovation through network programmability. This paper surveys the state-of-the-art in programmable networks with an emphasis on SDN. We provide a historic perspective of programmable networks from early ideas to recent developments. Then we present the SDN architecture and the OpenFlow standard in particular, discuss current alternatives for implementation and testing of SDN-based protocols and services, examine current and future SDN applications, and explore promising research directions based on the SDN paradigm