Broadband is the lifeblood of today’s Internet-driven economy, and despite all the hype about gigabit-speed services, network operators are having a hard time keeping pace with bandwidth consumption that’s growing at the rate of 30 to 40 percent per year. Demand continues to rise sharply while revenue growth remains relatively flat, and as a result, operators are getting squeezed financially as they are forced to keep investing in network capacity or risk having unhappy customers as their networks grow congested, especially during the peak evening hours.

Broadband providers must balance managing bandwidth demand with satisfying the needs of subscribers at a fair price. New software-defined service management solutions allow operators to continuously monitor per-subscriber bandwidth consumption and take action in real-time to manage bandwidth consumption to ensure that subscribers conform to the usage profile defined for their service tier. In this way, operators can steer or migrate subscribers into the proper service tier for their typical usage patterns, allowing operators to directly align revenue with bandwidth consumption. Simply put, during periods of peak demand, high-demand subscribers on higher service tiers would pay more than low-demand subscribers on lower tiers.

Existing OSS/BSS solutions don’t offer operators the tools they need to measure bandwidth consumption so they can take action and apply dynamic policy controls in real time to manage the services of non-conforming subscribers. Applying software-defined networking (SDN) at the broadband edge enables operators to solve this problem. What are needed are protocols for dynamic service control and network stream telemetry data collection. Cable operators can leverage PCMM policy control and IPDR stream telemetry in today’s DOCSIS networks, but SDN offers operators a better way to manage broadband service delivery across all types of fixed access networks, including cable, DSL, fiber and Wi-Fi.

With SDN, broadband providers will be able to use the OpenFlow protocol for dynamic policy control and the IPFIX protocol for network stream telemetry data. These new protocols satisfy the stringent performance and scalability requirements for actively monitoring and controlling broadband services in real time, and can interoperate with any SDN-enabled network element at the broadband edge.

Existing broadband service management solutions employ policy servers and protocols such as PCMM, Radius, or Diameter to configure policies in the underlying network infrastructure. The policy server interface abstracts the mechanisms for managing traffic flows through network elements at the broadband edge, and typically supports access to only a subset of traffic shaping and policing mechanisms, with no direct programmatic control independent of the policy abstraction layer. An SDN-enabled controller can use the OpenFlow protocol to dynamically activate services and manage subscriber traffic flows through SDN-enabled network elements. The SDN controller can use OpenFlow to directly program how these switches process subscriber traffic flows, controlling both connection speed and queuing mechanisms for fine-grained QoS control.

Effective broadband service management requires continuous monitoring of subscriber traffic flows and network conditions, combined with the ability to act on this information in real time. Existing service management solutions for cable, DSL and FTTH employ a variety of network telemetry data collection protocols including SNMP, Radius, Diameter and IPDR, but these differ widely in performance, efficiency and the type of information that can be collected. The IPFIX protocol offers an efficient, powerful and IETF-standard way to stream network telemetry data from a wide range of network elements at the broadband edge. IPFIX, which is derived from the NetFlow protocol developed by Cisco, uses a highly efficient stream transport protocol to convey a wide range of information about IP flows. Not only can IPFIX collect information found in IP headers, it can be extended to collect just about any type of information the switch or router has visibility into, including information such as URLs.

IPFIX and OpenFlow will allow network operators to simplify and standardize stream-telemetry data collection and dynamic policy control at the network edge. They will now have one way to measure and monitor subscriber bandwidth consumption and network conditions, and even a way to gain visibility into which applications or services a subscriber is using, if necessary. With OpenFlow, they will have direct and transparent programmatic control over subscriber traffic flows, and also be able to leverage a new generation of low-cost, commodity network infrastructure. The effect will be to strip complexity out of the IP network elements at the broadband edge, leading to a new generation of broadband services delivered with lower operations and capital costs.