Implementacija 5G mrežne funkcije za zakonito presretanje

master's thesis

• Title (english): Implementation of 5G network function for lawful interception
• Author: Andrej Gregić
• Mentor: Mirko Randić (mentor)
• Committee member: Mirko Randić (predsjednik povjerenstva)
• Committee member: Bruno Blašković (član povjerenstva)
• Committee member: Luka Humski (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2022-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

Mrežna funkcija za zakonito presretanje omogućava mrežnim operatorima mogućnost dostave informacija o radnjama korisnika unutar 5G mreže za koje postoji nalog o zakonitom presretanju. Opisana je idejna arhitektura za zakonito presretanje, pripadajuće mrežne funkcije i njihove uloge. Objašnjena su dva glavna korištena sučelja u sustavu: LI X1 i LI X2. Potom je opisana konkretna arhitektura sustava implementiranog, koja sadrži direktno opskrbljenu IRI-POI funkciju ugrađenu unutar 5G UDM mrežne funkcije. IRI-POI funkcija prima događaje o 5G AMF korisničkim registracijama. Administrativna funkcija (ADMF) opskrbljuje POI sa podatcima o metama koje treba presretati i odredištima na koje treba dostaviti informacije o presretanju (MDF2).

Mrežna funkcija za zakonito presretanje razvijena je kao dio rada za Enea Software, pri čemu ona predstavlja novu značajku Enea Subscription Manager produkta. Detaljno je razrađena implementacija triju aplikacija (POI_X1, POI_EVENT, POI_X2) koje zajedno čine mrežnu funkciju točke presretanja u sustavu. Uz dijagrame toka koje opisuju tok aplikacije i sekvencijske dijagrame koje prikazuju razmjene poruka, priloženi su isječci Java koda. Specifirane su konfiguracije aplikacija i baze podataka, s prikazom interakcija s bazom podataka.

Naposljetku je opisano testiranje implementirane funkcionalnosti pomoću automatiziranih testova u Robot radnom okružju, uz uporabu dva simulatora (ADMF i MDF2) razvijena za potrebe testiranja.

Abstract (english)

The Lawful Interception (LI) network function (NF) provides network operators with the ability to deliver information to legal authorities on specific users in the 5G network that have a warrant assigned to them. The thesis describes the conceptual LI high level architecture, the corresponding network functions within, as well as their roles in the system. The two main LI interfaces used in the implementation, LI X1 and LI X2, are explained in detail. Afterwards, the specific arhitecture of the implemented LI system is analysed, containing an IRI-POI (Intercept Related Information - Point of Interception) embedded into the 5G UDM NF. The IRI-POI receives notification events on AMF registrations in the 5G network. The administrative function (ADMF) provisions POI with details on targets that need to be intercepted and destinations to which intercept related information shall be delivered to (MDF2).

Lawful Interception has been developed as a new feature for Enea Software's Subscription Manager product. The feature consists of three applications (POI_X1, POI_EVENT, POI_X2) that make up the POI function. To illustrate the implementation, flow charts and sequential diagrams are used throughout to describe the application flows and showcase message exchanges between network elements in the system, along with Java code snippets that highlight how particular functions have been implemented. The application and database configurations have been specified, together with further displays of interactions between the databases and applications.

Lastly, tests that have been created using the Robot framework and used to test the developed LI product, are described in detail. Two simulators for the ADMF and MDF2 network functions have been developed, to simulate external network entities during testing.

• Keywords: 5G; mreža; UDM; AMF; točka presretanja; ADMF; MDF2; Java; Robot; Python; RIDE; Nudm_UECM; 3GPP registracija; ne-3GPP registracija; ASN.1; BER; PDU; LI X1; LI X2; XML; odredište; zadatak; izvještaj; konfiguracija; baza podataka; JSON; međupohrana; xIRI
• Keywords (english): 5G; network; UDM; Unified Data; Management; AMF; Access and Mobility Management Function; point of interception; ADMF; MDF2; Java; Robot framework; Python; RIDE; Nudm_UECM; 3GPP registration; non-3GPP registration; ASN.1; BER; PDU; LI X1; LI X2; XML; destination; task; report; configuration; database; JSON; buffering; xIRI
• Language: croatian
• URN:NBN: urn:nbn:hr:168:109307
• 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: 2023-01-14 20:30:21