TLS Performance Evaluation in the Control Plane of a 5G Core Network Slice

Abstract

3GPP has recommended 5G service providers adopt Transport Layer Security (TLS) to secure communications among different Network Functions (NFs) in 5G core network slice. It is imperative to study the impact of TLS on 5G control plane traffic.Previous research has shown that TLS adds costs to protocols, like Session Independent Protocol (SIP) and The Onion Router (ToR). This study aims to study different TLS cipher suites impact on network performance parameters such as packet size, time, and the number of messages sent in distinct 5G control flows. We emulated a 5G core network slice using an open-source project and measured the overhead on the network parameters while 5G slice components transmit control plane traffic on both cases of TLS and no TLS. We examined the impact of different cipher suites of TLS namely, AES128-GCM-SHA256, AES256-GCM-SHA384, and 3DES-EDE-CBC-SHA with key exchange algorithms of RSA (Public Key Encryption) and Elliptic Curve Diffie Hellman Ephemeral (ECDHE) on the NF registration with Network Repository Function (NRF), UE registration, and PDU session establishment. We extended the analysis to TLS1.2 and TLS1.3 overhead using the same cipher suite (AES128-GCM-SHA256) on the NF registration procedure.