APPN considerations for adjacent SSCP selection

BSC 3270 devices must use subarea only for their sessions. When the SME adjacent SSCP selection function is called for a BSC session partner, the list of SSCPs passed to the exit will not contain ISTAPNCP, even though it was coded in the adjacent SSCP table.

Table 1 shows the adjacent SSCP selection function parameter list pointed to by register 1. The parameters are described in Parameter descriptions.

Table 1. Adjacent SSCP selection function parameter list
Dec (Hex) Offset	Size (Bytes)	Description
0 (0)	4	Address of environment vectors
4 (4)	4	Address of function code and related session information
8 (8)	4	Address of user data field
12 (C)	4	Address of PLU resource identifier control vector
16 (10)	4	Address of SLU resource identifier control vector
20 (14)	4	Address of session ID
24 (18)	4	Reserved
28 (1C)	4	Address of SSCP name list
68 (44)	4	Address of session authorization data vector
72 (48)	4	Address of VTAM® exit services parameter list
76 (4C)	4	Address of session management data area