A communications card provides a miniport driver including a system interface abstraction layer (SIAL) that eliminates operating system (OS) specific and platform specific semantics from communication paths between a driver and the rest of the communications system. The SIAL provides a layer of software that connects an unspecified number of messaging channels to a single interface. The SIAL provides a message controller that is responsible for routing messages between various internal and external entities and contains multiple installable components, an operating system component which provides OS functions for the installable components and a platform module that supplies platform specific functions to the installable components.