Question: Over the UTRAN Iu interface, when connecting towards the packet switched domain, which protocol is utilized for data transport?
Option 1: Stream Control Transmission Protocol (SCTP)
Option 2: GPRS Tunnelling Protocol - User Plane (GTP-U)
Option 3: Radio Access Network Application Part (RANAP)
Option 4: Signaling Connection Control Part (SCCP)
Explanation: In the context of UTRAN's Iu interface, specifically when interfacing with the packet switched domain, GTP-U is the designated protocol for handling user plane data. This aligns with efficient tunneling and transmission of packet data across the network, highlighting GTP-U's role in facilitating seamless communication between the radio access network and the core network's packet switched elements.