SSM= parameter for procedures

Use the SSM= parameter in procedure to specify a 1- to 4-character identifier for a member that identifies the external subsystems that IMS connects to.

When building IEBUPDTE JCL, you must generate the member name by concatenating this SSM identifier to the IMSID. You can specify the values for SSM= with alphabetic characters (A - Z), $, #, or @, and numeric digits (0 - 9).

An SSM PROCLIB member can contain either positional-format statements in a fixed order, or keyword-format statements in a semi-fixed order.

Restriction: A single subsystem definition cannot use both positional and keyword parameters simultaneously.

Positional format

Fixed parameter format. Keywords are not allowed. Values must be entered in the following order: ssn, lit, esmt, rtt, reo, crc.

For example,

V10A,SYS1,DSNMIN10,RTTDB2A,R,-

Keyword format

Keyword-only, and must begin with SST=. After SST=, most values can be specified in any order:

SST=,SSN=,LIT=,ESMT=,RTT=,REO=,CRC=,RLA=

For example,

SST=DB2,SSN=DB21,LIT=SYS1,ESMT=DSNMIN10,REO=R,CRC=-,RLA=Y

If COORD is specified, only SST= and SSN= may also be specified; all other keywords are ignored:

SST=,SSN=,COORD=

For example,

SST=DB2,SSN=DB21,LIT=SYS1,ESMT=DSNMIN10,REO=R,CRC=-

SST=DB2,CRC=-,REO=R,ESMT=DSNMIN10,LIT=SYS1,SSN=DB21

SST=MQ,SSN=SYS3,LIT=MQM3,ESMT=CSQQESMT

SST=DB2,SSN=V71A,COORD=RRS

All external subsystems to be accessed by any region must be defined in this member. Essentially, the member specified by the IMS procedure is a master list. Dependent region procedures (DFSMPR, IMSBATCH, IMSFP, DFSJPB, and DFSJMP) can define subset lists. Each subset list can define all, some, or none of the external subsystems defined in the IMS master list. The SSM entry in each dependent region controls that region's access to subsystems.

Specifying SSM in a dependent region procedure but not in the IMS procedure is invalid, and no connection is made.

To allow an MPP, BMP, or IFP region to access all subsystems defined in the IMS procedure, do not code SSM. However, if preferred, the SSM entry can specify the same member as the IMS procedure.
To allow access to selected subsystems, specify a member that defines only those subsystems a region is allowed to access. For example, if the IMS procedure member defines subsystems A, B, and C, but a region is only to access A and C, the region's SSM should specify a member defining only A and C. Thus, the SSM member is a subset of the IMS procedure member.
To prevent this region from accessing any subsystem, specify a member that contains no entries.
To enable the external subsystem attach facility (ESAF) for a JMP or JBP region, the SSM= parameter must be specified on the DFSJMP procedure or DFSJBP procedure. The SSM= value can be the same value that is specified on the SSM= parameter for the IMS procedure.