Whitepaper: Heavy Reading - Policy Control & SDN: A Perfect Match?
Policy control based on the 3GPP Policy & Charging Control (PCC) and similar architectures is now well-established in service provider networks, with 68 percent of operators reporting in Heavy Reading survey work in 2012 that they have deployed a policy server of some kind.
Policy platforms, which typically include a policy server and policy enforcement devices (e.g., DPI appliances), often also connected to charging systems and subscriber databases, are used to help operators dynamically control the way that users and applications consume data network (IP and Internet) resources. Policy decisions can be based on a wide variety of triggers, including a customer's data volume usage, service tier, location, application, URL, time of day, congestion level and so on.
Separately, carriers are considering the deployment of software-defined networks (SDNs) in which packet forwarding is separated from control functions, and the latter are provided via a "controller" function that tells simple packet forwarding devices how to direct flows using a protocol such as the Open Networking Foundation's OpenFlow. Northbound, the controller may itself be programmed to set up flows in specific ways via open APIs that connect to OSS/BSS tools, application servers and so on.