HNOLOGIES The wireline access network is the part of a telecommunications network that connects subscrib- ers to their immediate service provider using some form of media, such as optical fiber, unshielded twisted pair copper, coaxial cable, or a combination of these media types. Construction and mainte- nance of access networks make up a significant percentage of service providers' capital and expense budgets. The wireline access network is often referred to as "the last mile" although the actual distances can vary considerably. As shown in Figure 11.1, the components of the wireline access network include the access node in the service provider's network as one endpoint, a network termi- nating function (which could be part of a residential or business gateway) at the customer's location as the other endpoint, and the outside plant (OSP). The OSP consists of transmission media (fiber or copper) with various passive or active components connecting the two endpoints. Increasingly, the wireline access network is combined with wireless access points or cells at the customer's location for the final connection to the customer, which we will cover in a separate section of this chapter. The ever-present challenge for network operators is to design and build higher bandwidth services to their potential customer base, while keeping costs constant or growing much more slowly than the amount of data delivered. As data usage by customers continues to increase dramatically year over year due to new applications and high-resolution video services, network operators must carefully manage the investment in their access networks to grow in line with revenue growth. The challenge of controlling costs to handle traffic growth calls for investing competitively in next-generation access infrastructure, which leverages SDN, NFV, cloud networking principles, a flow-oriented data plane, a decoupled control plane, and open hardware platforms with hardware abstraction. This approach promotes the use of commodity hardware to support flex