Recommendation Y.2012 consented at the July SG 13 meeting describes the functional architecture of the NGN.

The NGN architecture described supports the delivery of services such as multimedia services, conversational services, and content delivery services (eg video streaming and broadcasting).

NGN functional architecture shall incorporate the following principles according to the Rec.:

·          Support for multiple access technologies: The NGN functional architecture shall offer the configuration flexibility needed to support multiple access technologies.

·          Distributed control: This will enable adaptation to the distributed processing nature of packet-based networks and support location transparency for distributed computing.

·          Open control: The network control interface should be open to support service creation, service updating, and incorporation of service logic provision by third parties.

·          Independent service provisioning: The service provisioning process should be separated from transport network operation by using the above-mentioned distributed, open control mechanism. This is intended to promote a competitive environment for NGN development in order to speed up the provision of diversified NGN services.

·          Support for services in a converged network: This is needed to generate flexible, easy-to-use multimedia services, by tapping the technical potential of the converged, fixed-mobile functional architecture of the NGN.

·          Enhanced security and protection: This is the basic principle of an open architecture. It is imperative to protect the network infrastructure by providing mechanisms for security and survivability in the relevant layers.

·          Functional entities should incorporate the following principles:

o         Functional entities may not be distributed over multiple physical units but may have multiple instances.

o         Functional entities have no direct relationship with the layered architecture.  However, similar entities may be located in different logical layers.

 
Along with a new architecture, NGN will bring an additional level of complexity beyond that of existing networks. In particular, support for multiple access technologies and mobility results in the need to support a wide variety of network configurations. Some examples of configurations are provided to provide put in context the architecture description.