Cloud Central Office leverage software-defined access networks for open innovation
When it comes to implementing software-defined access networks, we’ve come a long way in a relatively short time. And if there’s one thing we’ve learned, it’s that operators want it open and standardized: flexible enough so it can be easily tailored, but with a cookie cutter approach so it can be efficiently repeated.
This sounds appealing, but there is some stigma. Surely, a standardized and unambiguous process with a vendor-neutral interface stack restricts creativity in network engineering?
Luckily, there is an approach by the Broadband Forum (BBF) which does not drain creativity. Operators have different networks, with different topologies, different processes. They make different cloud decisions and try to achieve different automation goals. So, why would SDN be the same for every operator? It shouldn’t. Operators should be in a position to take different architectural SDN choices.
What is the Broadband Forum Cloud Central Office?
For several years now, The Broadband Forum (BBF) has defined an open framework which allows this flexibility. It is called the Broadband Forum Cloud Central Office (or “CloudCO”) and it standardizes cloud central office architectures and interfaces for management, control and orchestration of access and edge network functions. This is important in that it allows interoperability for all access and edge network solutions, traditional and disaggregated, physical and virtualized. Whatever the source, origin, color, vendor or pedigree.
In 2023 the BBF demonstrated the Cloud Central Office concept at the Network-X event in Paris. One of the use cases was a live set-up of ONUs/OLTs from 5 different vendors, all managed by a CloudCO Access SDN Management and Control layer with BBF TR-413 specification compliant management interface and YANG models.
Broadband Forum CloudCO 2023 demo video
What role does Netconf/Yang play in software-defined access networks?
As TR-413 specifies the use of Netconf/YANG, it brings the benefits of model-driven programming to effectively automate broadband networks’ configuration and operation. BBF TR-413 YANG models (xPON YANG (TR-385), common YANG (TR-383), FTTdp YANG (TR-355), etc.) are published in the open BBF YANG code repositories and enable complete control over L1 and L2 configuration for all PNFs and VNFs that are part of the access network.
Compared to the SNMP MIB model that is still in use for legacy access nodes, YANG is hierarchical, distinguishes between configuration and state, and provides high extensibility. On top, the YANG models provide strong mechanisms to enforce parameter constraints and validate data for semantics and syntax. The BBF-defined best practices on YANG modeling help the industry transition to open software-defined networks.
Bringing containerization and programmability
Cloud Central Office is also about containerizing network functions, leveraging the cloud-native technologies. Take as an example the management of the ONTs in the optical access network based on ITU-T standard’s OMCI interface. Traditionally the OMCI “server” entity’s software was deeply “buried” and integrated into the OLT, hampering flexible ONT deployments in an ONT/OLT multi-vendor context. By containerizing the OMCI software stack either on the OLT platform itself or alternatively by virtualizing the OMCI stack in a distributed edge-cloud, onboarding ONTs from different vendors on OLTs has never been easier. This accelerates ONU and associated service deployments by the operators.
CloudCO’s SDN programmability underpins the innovations emerging in the access industry. It enables vendor neutral programming and data mining for true multi-vendor control application development.
How does the cloud central office revolution encourage innovation?
Common control and management can improve operational efficiency through automated network, service and subscriber operations, assure quality through better network planning and performance analysis, and reduce downtimes through fault diagnosis and automated problem resolution.
An example of this is the integration of 3rd party management applications on a cloud-native access controller platform. The Cloud Central Office Network-X demo showcased how QED Analyzer app from OutSys, which analyses network latency to identify quality degradation segments, was integrated with the Altiplano Access Controller from Nokia.
Fabio Giudici, System Solution Architect with OutSys, says, “Open platforms encourage innovation. It allows us to develop straightforward yet powerful products and services for telecom operators and ecosystem partners.”
It's time to take your broadband network into the cloud. Learn more about these innovations, who participated and what was shown in Broadband Forum’s 2023 Cloud Central Office demonstration, by watching this video.