A method, apparatus, and system is provided for establishing communication between a wireless communication device (WCD) and one of a plurality of serving nodes (SNs). Each of the SNs is configured to perform mobility management and session management. The WCD determines information that identifies which WCD-SN protocol type is supported by or is being used by the WCD. Each of the WCD-SN protocol types is a version, subset, or variant of a protocol used to support mobility and session management. The identified protocol type is compatible with one or more of the SNs and is not compatible with another one or more of the SNs. The WCD transmits, to a base station controller, a message that includes the information on which WCD-SN protocol type is supported by the WCD or is being used by the WCD. The controller selects, based on the protocol type, one of the SNs.