By De Fu Li, Comcast; Gregory Medders, Comcast; Eric Stonfer, Comcast; Bhanu Krishnamurthy, Comcast; Sinan Onder, Comcast; Mehul Patel, Comcast
The distributed access architecture is enabling Comcast’s ambitious program to offer symmetric, multi-gig speeds to its customers over a full-duplex (FDX) hybrid fiber-coax network. Over the past years, we have learned many valuable lessons required to activate 1000s of remote physical layer devices (RPDs) a week that we will apply to the D4.0 rollout. However, a production scale deployment of this technology involves many interdependent processes and components, including planning and capacity management, plant design, logistics, construction, provisioning, and operations. Furthermore, the FDX deployments often take place incrementally over infrastructure that already serves live customers, requiring precise coordination across teams and organizations to ensure a good customer experience. Left unchecked, teams may unintentionally interfere with one another and spoil the work of other groups, much as too many cooks in kitchen may spoil a meal. Sharing our lessons learned in our mid-split transitions, we describe how a digital transformation of the underlying access network provides a mechanism to avoid the worst manifestations of Conway’s law. Because the RPD lifecycle is complex, different domain experts are required at each phase. This can result in ambiguity over who is responsible for the RPD, since it changes over time. Through a digital transformation of the RPD, we show how a federated data service can be used to democratize data and present guardrails that must be in place to ensure its integrity. Crucially, while the same teams still own the same aspects of the RPD lifecycle, by communicating through the common digital RPD, the scaling implied by Conway’s law is mitigated, enabling a smoother transition to FDX. In the future, the digitization of the cable access networks will fundamentally change how Comcast operates, enhancing its ability to provide a reliable, cutting-edge experience to customers.