Datamover Architecture for iSCSI (DA)
iSCSI is a SCSI transport protocol that maps the SCSI family of application protocols onto TCP/IP. The Datamover Architecture for iSCSI (DA) defines an abstract model in which the movement of data between iSCSI end nodes is logically separated from the rest of the iSCSI protocol in order to allow iSCSI to adapt to innovations available in new IP transports. The new Datamover protocol provides a reliable transport for all iSCSI PDUs, but actually moves the data required for certain iSCSI PDUs without involving the remote iSCSI layer itself. This document begins with an introduction of a few new abstractions, defines a layered architecture for iSCSI and Datamover protocols, and then models the interactions within an iSCSI end node between the iSCSI layer and the Datamover layer that happen in order to transparently perform remote data movement within an IP fabric. It is intended that this definition would help map iSCSI to generic RDMA-capable IP fabrics in the future comprising TCP, SCTP, and possibly other underlying network transport layers.