Question: For a non-NB-IoT UE, which of the following PDCP sublayer services/functions in the user plane are **NOT** supported for both RLC AM and RLC UM bearers?
Option 1: Header compression and decompression using ROHC and/or EHC
Option 2: PDCP PDU routing for transmission and PDCP PDU reordering for reception
Option 3: Transfer of user data
Option 4: Ciphering and deciphering
Explanation: According to the specifications, for non-NB-IoT UEs, PDCP PDU routing for transmission and PDCP PDU reordering for reception are only supported for RLC AM (for split bearers in DC and LWA bearers), but not explicitly mentioned for RLC UM in the context of these specific functions. This implies that while both RLC modes share many PDCP services, this particular service is limited to RLC AM for the specified bearer types, making it the correct answer based on the nuanced understanding of 3GPP specifications.