Huawei Grotto Huawei Huawei NTT Verizon Due to the lack of layer interaction between networked applications and the network during service provisioning, many end user applications and services cannot efficiently utilize the network capabilities, nor can achieve the desired quality of service objectives. This document describes the general problem of cross layer optimization. Cross-layer optimization (CLO) involves the overall optimization of application layer and network resources by providing an interface for interactions and exchanges between the two layers. The potential gains of cross layer optimization are illustrated via examples from content delivery systems, video on demand systems, and grid computing.