Passage: GTP-U is, in effect a relatively simple IP based tunneling protocol which permits many tunnels between each set of end points.  When used in the UMTS, each subscriber will have one or more tunnel, one for each PDP context that they have active, as well as possibly having separate tunnels for specific connections with different quality of service requirements.

Question: What kind of conten will the subscriber have using UMTS?
one or more tunnel