A method for processing a signal and a bearer separately in an ALL IP network system includes the steps of: transmitting a service request message (SRM) from a mobile station (MS) to a radio network (RN); at the RN, determining whether a circuit related service or a packet related service is requested; if the circuit related service is requested: (i) transmitting a CM service request message to a MSC server, (ii) receiving a service request acknowledgement (SRA) message from the MSC server, and (iii) assigning a bearer in response to the SRA message; and if the packet-related service is requested: (i) transmitting the (SRM) from the RN to a core network without processing the SRM; (ii) at the core network, processing the SRM and transmitting an assignment request to the RN, the assignment request requesting that the RN assign the bearer; and (iii) assigning the bearer in response to the assignment request.