Optimized Mobile User Plane Solutions for 5G

3GPP CT4 has approved a study item to study different mobility management protocols for potential replacement of GTP tunnels between UPFs (N9 Interface) in the 3GPP 5G system architecture. This document provides an overview of 5G system architecture in the context of N9 Interface which is the scope of the 3GPP CT4 study item [CP-173160-1], [TS.23.501-3GPP], [TS.23.502-3GPP], [TS.23.503-3GPP], [TS.29.244-3GPP], [TS.29.281-3GPP], [TS.38.300-3GPP], and [TS.38.401-3GPP]. Architecture requirements for evaluation of candidate protocols are provided. Optimization of the user plane can be in different ways - packet overhead, transport integration, etc. Several IETF protocols are considered for comparison: SRv6, LISP, ILA and several combinations of control plane and user plane protocols.