Embodiments of the present invention provide a method, device and system for carrying out a service in a network. The control apparatus comprises: an orchestrator unit, configured to receive a service request for requesting to carry out a service, wherein the service request comprises service deployment information for requesting to deploy a first service, service flow identification information for identifying a first packet flow and service flow steering information; and a control unit, configured to send the service deployment information to a computing apparatus, and send the service flow identification information and the service flow steering information to an identifying and steering apparatus. Technical solutions of the present invention provide a new service mode, which can meet developing needs of OTT applications.