th constraints to place them across all of the various sections that make up the network. Examples of constraints include maximum round trip delay and multiwavelength diversity (when two or more wavelengths need to have separate paths that do not coincide SO that they are unlikely to fail simultaneously.) The packet core is an integral part of the network core. The ingress packets are aggregated on to common links at different points in the network and the role of the network core is to take the packet traffic from the edge, and send it to the designated destination, utilizing the shared optical transmission layer. Since service providers also offer a number of IP services such as consumer Internet, business Internet, connections to other Internet companies (known as Peering), private business networks (known as virtual private networks), connections to cloud data centers, etc., the core network also needs to perform the task of bulk packet transport, provided in as service agnos- tic a manner as possible. Given the different types of IP services that need to be supported, MPLS is used as a simplified method for packet transport. MPLS uses a small header in front of every packet, which allows the core routers on either side to process and forward the packets in a fast and efficient manner. The label portion is an address known to just these two routers (i.e., it is locally significant) allowing reuse of the MPLS label address space on every link. The rest of the header contains information for traffic prioritization (also known as quality of service [QoS]) used when links become congested. To manage traffic, a technique called Traffic Engineering (TE) creates one or more tunnels from every core router to every other core router. Multiple tunnels are used to allow different end-to-end Transforming a Modern Telecom Network-From All-IP to Network Cloud paths to more effectively use core capacity. Inbound packets are mapped on to the tunnel that is appropriate for its destination. Intermediate core routers forward MP