Security in 4G: IP Multimedia Subsystem (IMS) Use Case

Ngn Architecture

According to the definition of the ITU-T (“ITU,” 2004):

“A Next-Generation Network (NGN) is a packet-based network which can provide services including Telecommunication Services and is able to make use of multiple broadband, quality of Service-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. It offers unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users”.

NGNs have three main architectural changes that need to be considered separately:

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  Access network: NGN involves the migration to All-IP; this layer represents any type of access such as: Radio, Wireless and Wireline. The IP-based transport network integrates QoS management mechanisms with MPLS (MultiProtocol Label Switching) (Rosen, Callon, & Vishwanathan, 2001), DiffServ (Differentiated Services) (Geib & Black, 2015), RSVP (Resource ReSerVation Protocol) (Braden & Ed, 1997), and more. The transport layer consists of switches linked by Software Defined Networking (SDN) architecture.

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  Control network: Includes session controllers responsible for routing user-to-user signaling, service invocation, and communication security. Management of AAA functions (Authentication, Authorization, and Accounting) is provided by HSS (Home Subscriber Server). NGN introduces a circuit-switched (CS) session control environment with Packet-Switched (PS) tools.

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  Service network: Offers applications and services (value-added services) available and verified to users. The application layer consists of application servers (AS, Application Server) and IP Media Server (IP Media Server) or MRF (Multimedia Resource Function).