4D architecture is novel concept for network design and management that promises to ease the current complexity of network control while providing newer functionalities not easily achievable by the current networks. This architecture aims to centralize the decision and control logic in the network instead of the current distributed design, thus reducing the difficulties and inefficiencies inherent in large scale distributed control systems.
The 4D design is guided by three principles:
Network-level objectives: In order to satisfy the policy objectives for
a network there needs to be a way of specifying the policy for the entire
network, not influenced by the low-level device configuration semantics.
Network-wide views: Timely, accurate, network-wide views of topology,
traffic, and events are crucial for running a robust network.
Direct control: Routing decisions should be taken by an entity which
possesses network wide views in accordance with the network-wide policy
objectives. These decisions should then be communicated to the switches and
routers in the network.
4D architecture research is being
done by people at CMU, PITT,
More information can be found at http://www.cs.cmu.edu/~4D/