Section: I.2.3 Requirements for handling user plane data
Content: An RNC in an exposed location has to cipher and decipher user plane packets between the Uu reference point and the Iu reference point and to handle integrity protection for user plane packets for the Iu reference point. 1. User plane data ciphering/deciphering and integrity handling shall take place inside the secure environment where the related keys are stored. 2. The transport of user data over Iu shall be integrity, confidentiality-, and replay-protected from unauthorized parties. If this is to be accomplished by cryptographic means, Annex I.3 shall be applied. NOTE: Protection for user data extends between the UE and the serving RNC, hence no separate requirement for the protection of user plane data transferred between a serving RNC and a potentially present drift RNC (cf. TS 25.420[ UTRAN Iur interface general aspects and principles ]  [38]) is needed.