Transfer Mode (ATM) technologies to ubiquitous Internet Protocol (IP) packet-based networks capable of supporting converged network services is well under way. Service providers can no longer afford to deploy multiple networks, each built to support a single application or service such as voice, businessclass data, or Internet traffic. The cost of deploying and operating multiple networks in this business model is not financially sustainable. In addition, customer demand for integrated services and applications, as well as new services and applications, means service delivery velocity is a critical requirement of modern network architectures. Leading wireline and wireless service providers worldwide are already migrating legacy network services onto IP core networks to take advantage of the bandwidth efficiencies and scalability offered by IP networks, and their ability to enable rapid expansion into new service markets. Building and operating IP network infrastructures to meet the same carrier-class requirements that customers demand, while carrying multiple, diverse services that have different bandwidth, jitter, and latency requirements, is a challenging task. Single-purpose networks were designed and built to support specific, tightly controlled operational characteristics. Carrying Internet traffic, voice traffic, cellular traffic, and private (VPN) business traffic over a common IP backbone has significant implications for both network design and network security. The loss of integrity through a network attack, for example, in any one of the traffic services can potentially disrupt the entire “common network,” causing an impact to the entire revenue base. Further, enterprises are increasingly dependent upon IP networking for business operations. Fundamentally, all networks have essentially two kinds of packets: data packets, which belong to customers and carry customer traffic, and control and management packets, which belong to the network and are used to create and operate the network. One of the strengths of the IP protocol is that all packets traverse a “common pipe” (or are “in-band”). Networking professionals coming from the legacy TDM/ATM network world may be unfamiliar with the concept of a common pipe for data and control plane traffic, as these legacy systems separate data channels from “out-of-band” control channels. Misunderstanding and trepidation often exist about how data packets and control packets can be segmented and secured in a common network. Even though IP networks carry all packets in-band, it is possible and, now more than ever, critical to distinguish between the various types of packets being transported. Separating traffic into data, control, management, and services planes (referred to as traffic planes) and properly segmenting and protecting these traffic planes are required tasks to secure today’s highly converged IP networks. This book is the first to cover IP network traffic plane separation and security in a formal and thorough manner.