Razvoj aplikacije za analizu SIP prometnog opterećenja u mrežama LTE

master's thesis

• Title (english): Application for SIP Traffic Load Analysis in LTE Networks
• Author: Tomislav Maričević
• Mentor: Željko Ilić (mentor)
• Committee member: Željko Ilić (predsjednik povjerenstva)
• Committee member: Gordan Šišul (član povjerenstva)
• Committee member: Krešimir Pripužić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2015-07-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing

Abstract

S porastom raširenosti mreže LTE raste i broj usluga dostupnih korisnicima. Zajedno s tim procesom fokus se usmjerava na konvergenciju mreža i usluga. Rezultat je IMS, koji pruža konvergenciju mreža kroz neovisnost o pristupnoj mreži. Još veći se fokus stavlja na kvalitetu korisničkog iskustva. Korisnici očekuju da usluge budu stalno dostupne pa je zbog toga potrebno provesti opsežno testiranje prije nego se sustav pusti u pogon. Jedan od ključnih faktora u IMS-u je mogućnost obrade velike količine signalizacijskog prometa, što je u fokusu ovog rada. Razvijena je aplikacija koja emulira prave korisničke agente i šalje zahtjeve za pokretanje sjednica postojećem sustavu IMS. Korišteni su različiti prometni modeli poput Poissonovog procesa te eksponencijalne i linearne distribucije, te je mjeren postotak uspješno uspostavljenih sjednica.
Poissonov process i eksponencijalna distribucija pokazuju da kako povećavamo broj poruka po intervalu, odgovori počinju sve vise kasniti, što je glavni uzrok neuspješnih pokretanja sjednica. Ako dovoljno povećamo vrijeme čekanja, broj grešaka postaje minimalan.
Pošto su intervali u linearnoj distribuciji slijedni i bez pauze između, linearna distribucija je korištena za testiranje rada sustava pod velikim opterećenjem. Sustav se počinje gušiti jer stižu novi zahtjevi dok stari još uvijek nisu obrađeni. Čak i nakon što broj zahtjeva po interval postane stalan, postotak uspješnosti nastavlja padati.

Abstract (english)

With the advent of LTE networks, greater range of services becomes available. In parallel, convergence of networks and services also becomes one of the main focuses in telecommunication industry. The result is the IMS, which provides network convergence through access independence. Even greater focus is put on quality of user experience, with users expecting the services to be constantly available, so thorough testing needs to be done before the system is opened for public use. One factor for IMS performance is the ability to handle large quantities of signaling traffic, and that was the focus of this work. An application that emulates real UAs was developed and used to start sessions on an existing IMS system. Different traffic models were used, namely Poisson process, exponential and linear model, and success rates were measured.
The Poisson process and exponential distribution tests show that as the number of messages per interval increases, responses become delayed, which is the main source of unsuccessful session initiations. With sufficiently long wait time, the number of truly unsuccessful requests becomes minimal.
Linear distribution is used for stress testing, since the intervals are sequential, with no pause between them. This causes the system to start to throttle, since new requests are stacked upon previously unprocessed ones. Even after the number of requests per interval becomes constant, the success percentage still continues to drop.

• Keywords: VoLTE; IMS; SIP; analiza opterećenja
• Keywords (english): VoLTE; IMS; SIP; load analysis
• Language: english
• URN:NBN: urn:nbn:hr:168:791576
• Study programme: Title: Computing; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka računarstva (magistar/magistra inženjer/inženjerka računarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-06 10:24:51