If only one server with DPI is used, the PCRF module can be placed on the same server. In cases where multiple DPIs are used (for load balancing/redundancy), it makes sense to move the PCRF to a separate server.
Requirements: at least 2 GB of RAM, 2 CPU cores from 2.5 GHz, disk space from 128Gb.
For management – a separate network port (but not less than 100 Mbps) on any chipset supported by the operating system.
Operating system: CentOS 8+ (x64).