1. A system for accessing and transmitting data frames of different types in a digital transmission network, comprising: at least one user-network interface coupled with a user-network; at least one network-network interface coupled with the digital transmission network to transfer data; at least one mapping/demapping device; a virtual interface device coupled with said at least one user-network interface and with said at least one network-network interface via said at least one mapping/demapping device; and a control device coupled with said virtual interface device to control other corresponding devices to perform different types of data frame processing flows, said control device comprising: a data processing and dispatching device, comprising: at least one inter-device interface for inputting and outputting data frames; a data processing and dispatching unit coupled with said inter-device interface for inputting and outputting data frames; a processing flow database, storing a plurality of processing flows, coupled with said data processing and dispatching unit; and a control interface unit coupled with said processing flow database and said data processing and dispatching unit so as to control a virtual private processing unit and a rule database to process the data frames.