ORking> (OR "host-host layer") The middle layer in the OSI seven layer model. The transpORt layer determines how to use the netwORk layer to provide a virtual errOR-free, point to point connection so that host A can send messages to host B and they will arrive un-cORrupted and in the cORrect ORder. It establishes and dissolves connections between hosts. It is used by the session layer. An example transpORt layer protocol is {Transmission Control Protocol} (TCP). OSI documents: ITU Rec. X.214 (ISO 8072), ITU Rec. X.224 (ISO 8073). (1997-12-07)