Currently we see a discussion on the transition from ATM-based transport to IP transport in the UMTS Terrestrial Radio Access Network (UTRAN). Issues that result from the transition to IP are QoS, esp. delay, jitter, loss, bandwidth guaranties and in sequence delivery of packets for voice traffic. The paper compares two solutions for future UTRANs, native IP multi-path transport and MPLS (Multi-Protocol Label Switching) transport. MPLS employs RSVP-TE (extension of the Resource Reservation Protocol for signaling in MPLS) as reservation scheme. We have developed an extension for the network simulator 2 that allows for comparing delay, jitter and loss of these two approaches. Our studies show that MPLS/RSVP-TE is able to deliver very stable QoS for a wide range of traffic mixes and traffic loads even for network utilizations beyond 90%. Thus, MPLS provides extra flexibility to the network operator and can help to reduce the network cost.