SBI/BIS examples

IMS can be either the primary half session (PHS) or the secondary half session (SHS) for all of the examples given. Therefore, all of the functions and commands shown for PHS and SHS are IMS functions and commands.

Although all SBI and BIS sequences are valid for any session using LU 6.1 protocols, the following examples assume IMS to be both the primary and the secondary half session. No assumptions are made here as to when or how a subsystem other than IMS might send or receive these sequences.

Figure 1. Example of PHS shutdown using SBI/BIS
Figure shows multiple arrows between PHS and SHS with various labels on the arrows, such as SBI, DRI, BIS, and UNBIND. Comments among arrows state what IMS is doing at various points in the sequence.
Figure 2. Example of nonsimultaneous shutdown using SBI/BIS by both half sessions
Figure shows multiple arrows between PHS and SHS with various labels on the arrows, such as SBI, DRI, BIS, and UNBIND. Comments among arrows state what IMS is doing at various points in the sequence.
Figure 3. Example of simultaneous PHS and SHS shutdown using SBI/BIS fails because of operator override
Figure shows multiple arrows between PHS and SHS with various labels on the arrows, such as SBI, DRI, BIS, and UNBIND. Comments among arrows state what IMS is doing at various points in the sequence.