Analiza funkcijskih svojstava kontrolera u programski upravljanim mrežama

master's thesis

• Title (english): Analysis of functional properties of controller in software defined networks
• Author: Mario Malenica
• Mentor: Željko Ilić (mentor)
• Committee member: Željko Ilić (predsjednik povjerenstva)
• Committee member: Mladen Kos (član povjerenstva)
• Committee member: Marin Šilić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2016-07-04, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Programski definirane mreže ili programski upravljane mreže su novi concept u modernim telekomunikacijskim mrežama. U usporedbi s tradicionalnim mrežama, SDN (engl. Software Defined Network) unosi nižu latenciju, manja zagušenja te višu propunost. Glavna karakteristika SDN arhitekture je razdvajanje kontrolne i podatkovne ravnine. Kontrolna ravnina se sastoji od SDN kontrolera u kojem se nalazi sva inteligencija mreže, dok se podatkovna ravnina sastoji od mrežnih uređaja kao što su komutatori i usmjerivači. Kontroler u SDN, se sastoji od sjevernog sučelja (engl. NorthBound API) i južnog sučelja (engl. SouthBound API). Sjeverno sučelje kontrolera je odgovorno za komunikaciju s raznim aplikacijama, dok je južno sučelje zaduženo za komunikaciju s mrežnim uređajima, ponajprije komutatorima tipa Open vSwitch, koristeći pritom REST API (engl. Representational State Transfer) naredbe. Kada podatkovna ravnina ne zna što napraviti s odgovarajućim paketom, taj paket se šalje kontroleru, koji odlučuje što napraviti s paketom. Komunikacija između podatkovne i kontrolne ravnine se vrši preko protokola OpenFlow, standardiziranim protokolom od strane organizacije ONF (engl. Open Network Foundation). Ovaj komunikacijski kanal je najvažniji kanal unutar cijelokupne SDN mreže pa je samim time I osiguran koristeći protokole TLS (engl. Transport Layer Security) ili SSL (engl. Secure Sockets Layer).
Virtualizacijski sloj je sloj između kontrolne i podatkovne ravnine. Glavna uloga mu je izdvajanje nepotrebnog prometa. Svaki kontrol jer dodijeljen određenom nadgledatelju zvanom FlowVisor koji određuje kontroleru koje mrežno područje pokriva.
Ovaj diplomski rad opisuje karakteristike SDN u globalu i analizira funkcijska svojstva SDN kontrolera. Testni slučajevi su provedeni na način da određuju koliko je potrebno vremena SDN kontroleru da pošalje raznoliki broj REST naredbi komutatoru tipa Open vSwitch. Također, zadatak je bio razviti aplikaciju u svrhu testiranja. Nadalje, sve mrežne komponente (komutator tipa Open vSwitch, SDN kontroler OpenDayLight Lithium verzija) koje su korištene u diplomskom radu su locirane u kompaniji Combis d.d. Zagreb.
Rezultati testiranja pokazuju da vrijeme potrebno za dodavanje tokova u tablicu tokova raste eksponencijalno s rastom broja tokova. Također, prilikom više istovremenih zahtjeva prema kontroleru, kontroler dio zahtjeva stavlja u međuspremnik te ih obrađuje slijedno.

Abstract (english)

The software defined networks or software driven networks are new concept in modern telecommunication networks. In comparison with traditional networks, SDN (Software Defined Netowrk) introduces lower latency, fewer congestions and higher bandwith and throughput. The main feature of SDN architecture is separation control plane from data plane. Control plane consist of SDN controllers, which contain all of the intelligence of the network, while the data plane consists of network devices such as switches and routers. Controller in SDN contains two main APIs (Application Programming Interfaces): Northbound API and Southbound API. Bothbound API is responsible for communicating with various application written for SDN controllers, while the southbound API is indebted for communication with network devices, mostly Open vSwitches using REST (Representational State Transfer) API commands. When data plane doesn’t know what to do with appropriate packet, the same packet is being sent to the controller, which then decides what to do with the following packet. Communication between data plane and control plane is provided using protocol OpenFlow, the first and only standardized protocol by ONF (Open Network Foundation) for communication between network devices and SDN controllers. This communication channel is the most important in the SDN network and that’s why it’s secured using TLS or SSL sessions.
Virtualization layer is a layer between control plane and data plane, and its main role is to abstract unnecessary traffic. FlowVisor is a device which is assigned to every controller, by certain defined rules, as a part of the network for which that controller is responsible.
This paper describes the characteristics of the SDN in global and analyses functional characteristics SDN controller. Test cases were performed in a way to determine how much time it is need to SDN controller to send various number of REST commands to the Open vSwitch. The task was also to develop an aplplication for testing purposes. Furthermore, all network components (Open vSwitch, SDN controller OpenDayLight), used for this thesis, are located at the Combis d.d. facility in Zagreb.
The results of testing show that time necessary for adding flows to the flow table increases exponentially with increasing the number of added flows. Also, multiple requests are handled by principle FIFO (First-In-First-Out) with appropriate buffer.

• Keywords: SDN; kontrolna ravnina; upravljačka ravnina; OpenFlow; FlowVisor
• Keywords (english): SDN; control plane; data plane; OpenFlow; FlowVisor
• Language: english
• URN:NBN: urn:nbn:hr:168:148933
• Study programme: Title: Information and Communication Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka informacijske i komunikacijske tehnologije (magistar/magistra inženjer/inženjerka informacijske i komunikacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-06 10:16:35