In order to accommodate rapid contemporary networks evolution, in a scalable and cost-effective manner, it is desirable to have an adaptable network which deploys a reconfigurable logic device to modify or change the processing element and the corresponding protocol, when needed. To address this requirement, this book presents a novel adaptable network framework which provides predefined adaptation and non-predefined adaptation to fulfil the flexibility. In the non-predefined adaptation framework, networks can dynamically update the network elements at either the system level or the function level after the system has been deployed; in the predefined adaptation framework, the network elements are provided with different adaptable functional components at the time of deployment and these are chosen as required by service level agreements on the fly. This book should help shed some light on this new and exciting programmable future networks, and should be especially useful to professionals in reconfigurable computing and communications fields, or anyone else who may be considering utilising reconfigurable logics for programmable network devices in future communication networks.