uting part of the NodeB in the E-UTRAN require OpenFlow enhancements for GTP routing. Additional enhancements for GTP routing may be needed on other switches within the 3G PC depending on how much fine-grained control over the routing an operator requires. The packet core control plane parts of the gateways for GTP-C communications, that is, the parts that handle GTP signaling, are implemented in the cloud as part of the OpenFlow controller. The control plane entities and the OpenFlow controller are packaged as VMs. The API between the OpenFlow control and the control plane entities is a remote procedure call (R3G PC) interface. This implementation technology is favorable for scalable management of 5.3 Core Network Functions Virtualization: vEPC the control plane entities within the cloud, since it allows execution of the control plane entities and the controller to be managed sepa- rately according to demand. The cloud manager monitors the CPU utilization of the 3G PC control plane entities and the control plane traffic between the PC control plane entities within the cloud. It also monitors the control plane traffic between the UEs and NodeBs, which do not have control plane entities in the cloud, and the PC control plane entities. If the 3G PC control plane entities begin to exhibit signs of overloading, such as utilizing too much CPU time, or queuing up too much traffic, the overloaded control plane entity requests that the cloud manager start up a new VM to handle the load. The cloud manager also provides reliability and failover by restarting a VM for a particular control plane function if any of the PC control plane entities should crash, collecting diagnostic data, saving any core files of the failed PC control plane entity, and informing the system administrators that a failure occurred. The control plane entities maintain the same protocol interface between themselves as in the standard 3GPP 3G PC architecture. The OpenFlow control plane, shown here as a gray dotted line, manages the routing and switchi