Delivering greater interoperability to the broadband industry with YANG

Delivering greater interoperability to the broadband industry with YANG

By Joey Boyd and Sven Ooghe, Co-Directors of Broadband Forum’s Common YANG Work Area

As service providers seek to ensure their overall operations are both cost-effective and productive, automation of the configuration and control of access network elements is often regarded as a necessity. But a notable hurdle to achieving this is having the required interoperability between network components from different vendors. YANG is the standardized modelling language that is supported by the NETCONF protocol, and with greater interoperability, operator’s solutions can be more flexible and tailored to each customer’s deployment.

The work undertaken from the Broadband Forum’s Common YANG Work Area goes a long way in facing and tackling these challenges. The team does this by defining YANG data models for common functionality of access network equipment that employ various physical layer technologies.

Benefitting the industry

Demand for greater network capacity, especially as more large-scale fiber deployments are undertaken, is increasing. It is imperative that greater interoperability between different network components from varying vendors and an increasing number of technologies is delivered.

Common YANG data models, in conjunction with YANG data models from other SDOs, offer service providers the ability to leverage detailed end-to-end visibility of the performance of every programmable Software-Defined Access Network (SDAN) element to unlock greater levels of capacity, automation, and efficiency. Network flexibility can therefore be maximized without burdening the network automation teams with traditionally large development overhead of bespoke and proprietary data modelling methods.

Since its creation, the Common YANG Work Area has published a series of YANG modules which have subsequently been accepted by the wider industry. This includes the ongoing work on TR-355 and TR-383. The Work Area also provides assistance to other Work Areas in their definition of YANG data models for specific applications. It also maintains the Broadband Forum YANG Best Current Practices (OD-360), Broadband Forum-wide YANG processes, procedures and tools with the help of the YANG Advisors.

Common YANG Modules for Access Networks

TR-383 defines YANG data models for the management of access network equipment such as DSL Access Nodes, Distribution Point Units (DPUs) or Optical Line Terminals (OLTs). These can be used across many deployment scenarios and for a multitude of other applications. TR-383 forms the core of YANG modules that are used across a broad range of products, including copper-based access technologies such as VDSL, G.fast, and fiber-based access technologies including, G-PON, XGS-PON, NG-PON2.

Amendment 5 of TR-383, ‘Common YANG Modules for Access Networks’ was published in early March 2022. This new amendment builds upon the existing feature-rich set of YANG data models, adding software management, device aggregation, improved alarm handling for Ethernet Connectivity Fault Management (CFM) Operations, Administration, and Maintenance (OAM) and Access Node Control Protocol (ANCP) alarms. With these modules, service providers can now more efficiently manage a range of broadband services supported over any access technology, including VDSL, FAST and Passive Optical Networks (PON).

Work on Amendment 6 is also progressing well, with several contributions already accepted, covering enhancements of the hardware transceiver model and proposed bindings of the ITU-T G.8052.1 Ethernet OAM YANG model that further extends the IEEE 802.1 Qcx CFM model.

YANG Modules for Fiber-To-The-distribution-point (FTTdp) Management

As the number of fiber deployments continue to grow, operators need to be able to exploit the vast potential that greater interoperability brings and deliver ultra-fast broadband services. TR-355 defines YANG models for the management interfaces to support Fiber-To-The-distribution-point (FTTdp) in order to enable interoperability for FTTdp management.

The group has agreed to prepare WT-355 Amendment 4 ‘YANG Modules for FTTdp Management’ for Straw Ballot with the goal of publication in the second quarter of 2022. This new amendment adds support for the latest ITU-T Recommendations and provides a range of fixes and improvements. Operators can subsequently manage standardized FTTdp network elements from different vendors simultaneously, providing them with more choice and increased flexibility as ultrafast network roll-outs ramp up. The baseline for implementation from the standardized network elements help equipment manufacturers and brings reduced integration complexity of new network elements.

The Common YANG Work Area’s vital work is arming operators with the tools to thrive and pave the way for more agile networks. By having access to open standards, operators can deploy new technologies with renewed confidence and improved interoperability.