As network traffic continues to grow, operators are under increasing pressure to find ways to optimize energy and resource consumption without compromising service quality. Energy efficiency in broadband networks is no longer just a cost-saving measure—it’s a critical part of reducing the environmental impact of infrastructure operations.
A key area of focus is the dynamic management of network resources in response to real-time traffic patterns. By analyzing traffic trends utilizing AI/ML algorithms, operators can identify periods of lower demand and adjust network resources accordingly. This enables them to power down underutilized components, significantly reducing energy consumption.
The Broadband Forum’s 2024 Subscriber Session Steering Demonstration, shows how active traffic monitoring, combined with intelligent traffic steering, enables more energy-efficient network operations.
This is accomplished through seamless integration of components from three different vendors - Adtran, BISDN and OutSys. Their components work together to provide a solution that dynamically adjusts the network in real time based on traffic load, using standards and projects ratified by the Broadband Forum.
Reducing Complexity for Scalable Cloud-Native Networking
The aggregation switch in the above video is running BISDN Linux, an open-source network operating system. BISDN is also supplying the User Plane Selection Function (UPSF) based on the Broadband Forum’s Open Broadband project, OB-STEER. Lessons learned from this demonstration will shape future releases of OB-STEER. Subscriber Session Steering assigns subscribers to BNG (Broadband Network Gateway) User Plane instances, which is necessary for:
- Wholesale access
- Network scaling
- Resilience / failover
- Maintenance / predictive maintenance
- Sustainability / reducing network energy consumption.
Further the demonstration shows the disaggregation of the BNG through Control Plane and User Plane Separation (CUPS). Subscriber Session Steering reduces the management complexity through dynamic binding of subscriber groups to BNG User Planes. The BISDN BNG micro–User Planes are cloud-native and deployable in a fine-grained manner. Reducing the number of micro–User Planes saves energy in x86-based k8s clusters.
Traffic Steering Inside the OLT Yields Greater Energy Savings
Unique to this year’s demonstration, Adtran integrated the Traffic Steering Function (TSF) into its latest-generation PON OLT (Optical Line Terminal), the SDX 6330. Instructed by a User Plane Selection Function (UPSF), the TSF dynamically redirects subscriber sessions and corresponding traffic flows between different BNG instances. This capability allows for pooling of BNG resources and deactivation of underutilized network functions, thus saving energy and optimizing resource allocation. The OLT is the first instance in the network at which traffic steering can be enforced. By integrating the TSF directly into the OLT, operators can not only achieve significant energy and resource savings but also enhance network flexibility and redundancy. This is particularly beneficial in case of a failure in the network, e.g. an uplink connection of the OLT breaks, or an aggregation switch fails. In such a situation, subscriber sessions can be rerouted to a different part of the network using another uplink port of the OLT. This is not feasible when the TSF is located higher up in the network.
Optimizing Resources without Compromising Service Quality
In this demo, OutSys is involved with several key components of the demonstration. First, Outsys’ QED Probes and Reflectors are responsible for monitoring the quality of experience across the different user planes of the BNG. This is done using the QED (Quality of Experience Delivered) framework, which has been ratified by the Broadband Forum as TR-452. Then, we have the QED Analyzer, which is installed within Nokia's Altiplano framework. The analyzer implements a basic version of AIM, another project ratified by the BBF in TR-436. By interfacing with various network components, like probes and the BNG, it can derive the current state of the network. Using closed-loop automation, it then takes the necessary actions to save energy and optimize resources, all without compromising service quality. In this specific demo, the analyzer gathers network quality data from the probes and retrieves the number of active customers for each BNG User Plane from the BNG's Control Plane. When the number of customers on a particular User Plane drops below a certain threshold, and the network quality for those customers is good, the analyzer, through its interface with the BNG Control Plane, moves the active customers to another User Plane and shuts down the unused one, saving energy.
The Power of Standards and Open Broadband to Reduce Power and More
By combining their respective expertise with Broadband Forum standards and Open Broadband software, these companies showcase a solution that results in more efficient use of network resources, energy savings, higher resiliency, and a better experience for subscribers. This demonstration of sustainability and efficiency without compromising service performance will increasingly become table stakes for operators going forward.