1. A method comprising: controlling by a security controller the use of a node in a network for a service or application to transmit data via the node, wherein the security controller controls the use of the node based on a predetermined list indicating whether the service or application is allowed for the node, the predetermined list including combined identifiers for client applications and identifiers for network nodes; and analyzing a packet that includes a combined client application identification and a network node identification, at least the client application identification included in a header of the packet, the analyzing of the packet being performed by a Medium-Access Control (MAC) Control Plane of the security controller.