ISO/IEC TR 29181-3:2013

1. description of the requirements for carrying data over digital networks;
2. description of the ways in which these requirements are not satisfied by current networks;
3. functional architecture for switching and routing in the Future Network; and
4. requirements for control plane information flows for finding, setting up, and tearing down routes.

The requirements in 4. include support for both current ("legacy") and future ("new") switching technologies, to aid the transition between them.