Securing Diameter: Comparing TLS, DTLS, and IPSec

The Diameter signaling protocol plays a critical role in mobile networks. Diameter manages a crucial function in mobile systems since it is designed for activity coordination between Internet Protocol (IP) network elements such as online charging systems, policy servers, mobility gateways among others. As operators migrate their networks to LTE, Diameter provides new services and implements more sophisticated policy use cases through new signaling techniques. All this confirms the importance of securing Diameter. This paper is a comparative study on three security protocols used to secure Diameter (TLS/TCP, DTLS/SCTP, and IPSec). The comparative analysis focuses on three main aspects: transmission (header), connection establishment, and processing overhead. Each aspect in each protocol is investigated in details and the results show that securing Diameter using TLS introduces fewer RTTs compared to DTLS, with IPSec introducing the highest number of RTTs. On the other hand, DTLS requires the minimum processing overhead, TLS comes in second place with a relatively small difference, and IPSec introduces the highest processing delay.