ses components and capabilities such as directories that map a request for content to the closest edge location, streaming media protocols that adapt to network availability, and optimize performance under varying conditions (Figure 2.5). Service Applications Session Control and Management Networks End Point Devices FIGURE 2.4 IMS layered architecture. Building the Network of the Future Parent Cache Child Cache Locations Locations Cache Fill Traffic VoD & National Linear Linear Linear Origin Linear Linear Local Linear Origin Linear Linear Primary Linear Linear Backup VoD Primary VoD Backup Cache Cluster (Multiple VMs) *Parent Locations will overlap with Child FIGURE 2.5 CDN supporting IP video distribution: VoD/linear IP television (IPTV). (AT&T example design.) Common examples of business customer services include Internet access; virtual private net- works; public and private voice/video networks; and customer-dedicated edge configurations that allow connections to a virtual private network at their premise, a public cloud data center, and/or from a wireless device. Internet access ranges from best effort access over copper wire, fiber, or wireless access point to various levels of managed Internet access that guarantee a higher level of service. This may include guarantees on bandwidth, latency, jitter, loss, availability, as well as monitoring to detect and protect against security threats. For example, when a distributed denial of service attack is detected adjust routing rules at the ingress points of the attack to drop packets before they are routed to a customer end point. MPLS virtual private network service allows a customer to design and control a multilocation secure network and establish quotas for how much capacity is devoted to different types of traffic. For example, 40% of the capacity might be dedicated to real-time voice or video to insure an occa- sional burst of deferrable traffic does not disrupt real-time media connections. Custom voice/video services are offered to business customers as pa