ty. However, ONAP in combination with ROADMs (see Chapter 13), enable connectivity between data centers to be automatically estab- lished in a matter of minutes-a vast improvement compared with months! Going a step further, the control plane can now be integrated between the IP and optical layers, enabling intelligent cross-layer decision making and real-time provisioning of capacity in response to changing network conditions (e.g., failures, changing traffic patterns). Historically, considerable time has been spent by network operators in managing traffic in response to failure conditions, changes in traffic patterns, and planned maintenance activities. Operators had to plan how they would respond to conditions as they arose, typically leveraging offline tools that aid the decision making. Once decisions were made regarding what actions to take, operators executed these actions. Depending on the routing technologies used, the actions could Building the Network of the Future involve DNS updates or routing protocol configuration changes (e.g., OSPF weight changes), for example. In a virtualized environment, this would also include spinning up or down VNFs. ONAP, combined with intelligent algorithms operating on data collected and stored by ONAP, will auto- mate this process enabling the removal of human operator. Thus, ONAP, in combination with smart analytics and appropriate data plane technologies (NFV, ROADMs), is creating a more intelligent, dynamic network that can more effectively adapt to changing conditions. However, as noted in Section 15.2.2, there is additional complexity intro- duced in the shared infrastructure to enable this simplicity and flexibility in managing the VNFs. 15.2.3.2 Network and Service Monitoring As discussed in Chapter 16, individual network functions (virtual and physical) generate a tremen- dous volume and range of fault, performance, and log data. These measurements capture informa- tion that allows network engineers and operations teams to design and capacity plan the network clo