(1) In XRF (CICS Transaction Server only), a remote SNA VTAM terminal connected through a boundary network node IBM 3745/3725/3720 Communication Controller with an NCP that supports XRF. Such a terminal has a backup session to the alternate CICS system.
(2) A terminal for which the alternate IMS pre-opens backup sessions for the primary sessions that the active IMS opens; VTAM/NCP switches sessions from primary to backup at takeover.