The Internet of Things technology and services are becoming ubiquitous in multiple application domains like Smart Factory and Telecare. Some of the key requirements are security and flexibility. Identity Management and Access Control play a critical role allocating resources like IP connections and identifiers for secure and automatized onboarding of M2M devices as well as dynamic coupling of the M2M devices to the Application Servers, for assuring the communication reliability in case of maintenance or scaling of the infrastructure. This article analyses the requirements from multiple initiatives and standard organizations related to the M2M communication using 4G or 5G mobile networks and presents the concept and advantages of enabling dynamic cross-layer management for trustful handover between Security Domains that run their own core network. The concept validating demonstrators are presented and comparison with other solutions is also included.