ible, rapid service creation, and delivery. The new access architecture needs to be able to deliver existing services, and also new ser- vices created natively in the new architecture over legacy networks. This requires allowing legacy operations support systems (OSS) and business support systems (BSS) systems to interact with new access network components as if they were legacy components, as well as enabling legacy access nodes to add capabilities that permit them to be controlled by services and software components of the new architecture. Figure 11.3 depicts this in more detail. Fiber-based point-to-multipoint architectures such as passive optical networks (PONs) are well suited for cost-effective, high-performance outdoor access networks spanning many kilometers. Copper-based technologies over coax or twisted pairs such as G.fast can distribute high speeds and capacities for shorter distances, such as within buildings or multi-dwelling units (MDUs). These technologies are also highly effective in combination. For example, a PON network can provide the data path to a building, and a G.fast distribution point unit (DPU) can provide distribution to differ- ent apartments or businesses within the building as shown in Figure 11.4 11.4.1 PON TECHNOLOGY GPONs have been deployed for several years and will continue to be deployed for some time. GPON is a cost-effective technology that allows sharing a single fiber for most of the distance between the network access node and the customer, using passive optical splitters located near the customer and appropriate protocols to accomplish this sharing while allowing each customer to realize high capacity and peak speeds. The network access node for GPON is called the optical line terminal or OLT, and the customer node for GPON is called the optical network terminal or ONT (see Figure 11.1). The GPON fiber infrastructure utilizes 2.5 Gb/s downstream and 1.25 Gb/s upstream speeds, shared dynamically between individual subscribers on each of the OLT's fiber GPON ports. Build