Better scalability: After separating the forwarding, control
and management functions by introducing the three networks,
the three networks can interact with each other through open
standardized network protocols. Each network can individually
be upgraded and maintained. Many new network functions can
be added to one of the three networks without the other two
networks being changed. Thus the capability for network
reconfiguration can be improved, and it is easier to support new
applications. The 3N architecture reduces the complexity of the
network upgrade and maintenance and increases network