Now about Wi-Fi Calling Services 📡

Wi-Fi calling technology, also known as VoWiFi, is supported by 3GPP IMS .

It provides mobile users with cellular calls and text messages over Wi-Fi instead of cellular base stations. It is an alternative voice solution for mobile users who connect to base stations with weak signals.

Wi-Fi calls use the SIP protocol for signaling a call just like regular VoIP services, but differs from them technically. 

Its SIP signaling operation is a 3GPP-specific version. 

For security reasons, both 3GPP and GSMA stipulate that Wi-Fi calls have to use well-established SIM-based security and authentication methods, as in familiar VoLTE.

They basically include secret key protection in the physical SIM card and 3GPP AKA . In addition, all Wi-Fi call packets that can be sent over unsecured networks must be delivered over IPSec channels using ESP tunnel mode between the Wi-Fi call devices and the cellular network . 

Even though the packets are protected by IPSec tunnels, Wi-Fi calling service can still suffer
First, 3GPP WLAN selection mechanisms do not prevent devices from connecting to insecure Wi-Fi networks, which can hamper Wi-Fi calling service. Second, Wi-Fi call traffic, which is protected by IPSec, is vulnerable to side-channel attacks , which can lead to leakage of sensitive information. Third, the service continuity mechanism between Wi-Fi calling and cellular-based voice services may not take effect
Two IETF protocols, IKEv2 and IPSec, are used to maintain and enhance security in Wi-Fi calling.

Although... this network can still successfully exchange spoofed and manipulated packets with the sender and receiver without any identity verification process.
By creating an unauthorized access point equipped with an IPSec server on Wi-Fi networks, user devices can transmit IMSI, which can lead to privacy issues such as location tracking . Moreover, these protocols can be vulnerable to multiple DoS attacks.
#wifi #lte #mobile #network #traffic_analysis #dos #attacks