Why E.T. Can't Phone Home: A Global View on IP-based Geoblocking at VoWiFi

Gabriel Karl Gegenhuber; Philipp É. Frenzel; Edgar R. Weippl

doi:10.1145/3643832.3661883

Why E.T. Can't Phone Home: A Global View on IP-based Geoblocking at VoWiFi

Forschungsgruppe Security and Privacy

Veröffentlichungen: Beitrag in Buch › Beitrag in Konferenzband › Peer Reviewed

Abstract

In current cellular network generations (4G, 5G) the IMS (IP Multi-
media Subsystem) plays an integral role in terminating voice calls
and short messages. Many operators use VoWiFi (Voice over Wi-Fi,
also Wi-Fi calling) as an alternative network access technology to
complement their cellular coverage in areas where no radio signal
is available (e.g., rural territories or shielded buildings). In a mobile
world where customers regularly traverse national borders, this
can be used to avoid expensive international roaming fees while
journeying overseas, since VoWiFi calls are usually invoiced at do-
mestic rates. To not lose this revenue stream, some operators block
access to the IMS for customers staying abroad.
This work evaluates the current deployment status of VoWiFi
among worldwide operators and analyzes existing geoblocking
measures on the IP layer by measuring connectivity from over 200
countries. We show that a substantial share (IPv4: 14.6%, IPv6: 65.2%)
of operators implement geoblocking at the DNS- or VoWiFi protocol
level, and highlight severe drawbacks in terms of emergency calling
service availability.

Originalsprache	Englisch
Titel	MOBISYS '24: Proceedings of the 22nd Annual International Conference on Mobile Systems, Applications and Services
Erscheinungsort	New York
Verlag	Association for Computing Machinery (ACM)
Seiten	183-195
Seitenumfang	13
ISBN (elektronisch)	9798400705816
DOIs	https://doi.org/10.1145/3643832.3661883
Publikationsstatus	Veröffentlicht - 4 Juni 2024

Fördermittel

We want to thank Quentin McGaw and all other Gluetun contributors their previous work made it considerably easier to build scanywhere and thus to globally distribute our measurements. This project was funded through the NGI0 Entrust Fund, a fund established by NLnet with financial support from the European Commission s Next Generation Internet, under the aegis of DG Communications Networks, Content and Technology under grant agreement No 101069594. SBA Research (SBA-K1) is a COMET Centre within the COMET Competence Centers for Excellent Technologies Programme and funded by BMK, BMAW, and the federal state of Vienna. COMET is managed by FFG.

ÖFOS 2012

102016 IT-Sicherheit
102015 Informationssysteme

Zugriff auf Dokument

10.1145/3643832.3661883Lizenz: CC BY-SA 4.0

Andere Dateien und Links

Verknüpfung zur Publikation in Scopus

Zitationsweisen

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abstract = "In current cellular network generations (4G, 5G) the IMS (IP Multi- media Subsystem) plays an integral role in terminating voice calls and short messages. Many operators use VoWiFi (Voice over Wi-Fi, also Wi-Fi calling) as an alternative network access technology to complement their cellular coverage in areas where no radio signal is available (e.g., rural territories or shielded buildings). In a mobile world where customers regularly traverse national borders, this can be used to avoid expensive international roaming fees while journeying overseas, since VoWiFi calls are usually invoiced at do- mestic rates. To not lose this revenue stream, some operators block access to the IMS for customers staying abroad. This work evaluates the current deployment status of VoWiFi among worldwide operators and analyzes existing geoblocking measures on the IP layer by measuring connectivity from over 200 countries. We show that a substantial share (IPv4: 14.6\%, IPv6: 65.2\%) of operators implement geoblocking at the DNS- or VoWiFi protocol level, and highlight severe drawbacks in terms of emergency calling service availability.",

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Why E.T. Can't Phone Home: A Global View on IP-based Geoblocking at VoWiFi. / Gegenhuber, Gabriel Karl; Frenzel, Philipp É.; Weippl, Edgar R.
MOBISYS '24: Proceedings of the 22nd Annual International Conference on Mobile Systems, Applications and Services. New York: Association for Computing Machinery (ACM), 2024. S. 183-195.

Veröffentlichungen: Beitrag in Buch › Beitrag in Konferenzband › Peer Reviewed

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