CUPS (Control and User Plane Separation) is to free user plane function from the "centralization" captivity, so that it can be flexibly deployed in the core network (central DC) or access network (edge DC), and finally achieve distributed deployment.
With the optical fiber transmission speed of 200 km/ms, when data must be transmitted back and forth between the terminal and the core network at a distance of several hundred kilometers, obviously, it cannot meet the requirement of 5G network for millisecond-level latency. Based on the CUPS architecture of the 5G Core, control plane functions such as SMF are deployed in the central DC, so to implement unified control to UPFs deployed at the edge or regional DCs and to carry out unified configuration and release offloading policy. User Plane Function (UPF)/GW_U and content are deployed at the network edge to greatly reduce transmission delay. Through the UPF offloading policy local traffic is unoffloaded at the locally UPF, and non-local traffic is sent to the central UPF for processing through the local UPF. In this way, not all the traffic needs to detour to the central network, thus reducing the transmission pressure of the backbone network and the cost of network construction, and improving the bearing efficiency of packet data in the network and user experience.