12.1 NSI product overview NSI supports communications over the SNA backbone network between non-SNA host subsystems (RSCS, JES, Power) and: BSC RJE devices Other non-SNA host subsystems Such BSC devices are dedicated to a specific application through a communication controller on a byte channel. For those facilities that are controlled by NSI, the BSC data and control characters are encapsulated in SNA and transported through the network. When the data exits NSI and is sent to the terminal (via a BSC RJE line) or to the subsystem (via an emulation subchannel), the SNA envelope is removed and the original BSC data stream is presented to the receiving facility. JES/RTAM Applications