A Resilience Design Model for IMS-based Services

IP Multimedia Subsystem was proposed to support the building and deployment of convergent data, voice and other innovative services over an IP-based infrastructure, independently from the device and access network in use. In this paper, we provide some guidance for engineers who design the resilience of these services. We first classify IMS-based services using several families, and study the resilience requirements for each of these. We then introduce an extension of the concept of attack tree, named "Challenge Countermeasures Tree (CCT)", for challenges (i.e., accidental or intentional threats) identification and resilience design. We are currently applying the outcomes of this work on RCS-e, an enhanced IMS-based rich communication service.