Coding your own SAW data filter

If you want more control over the amount of data that is filtered, you can use your own SAW data filter table, or you can modify the default table or dynamically change it using the MODIFY TABLE operator command.

You define a SAW data filter to VTAM® using the KEEPMEM, KCLASS, and MAPSESS macros. Use the KCLASS and MAPSESS macros to define the session monitor filter. NetView® customers can copy their existing filter definitions, modify them slightly, and create equivalent VTAM filters. The only change necessary is to place a KEEPMEM START macro at the beginning of the filter definitions and add a KEEPMEM STOP macro and an END statement at the end of the existing definitions. VTAM ignores any NetView operands that do not apply to the VTAM filter.

Following is a simple example of a SAW data filter:

ISTMGC10  KEEPMEM  START
SAW       KCLASS   SAW=YES
NOSAW     KCLASS   SAW=NO
M1        MAPSESS  KCLASS=SAW,PRI=SSCP1,SEC=*
M2        MAPSESS  KCLASS=SAW,PRI=IMS,SEC=*,PRINET=NETA
M3        MAPSESS  KCLASS=NOSAW,PRI=*,SEC=T3?7*,PRINET=*,SECNET=NETB
          KEEPMEM  STOP
          END

The KCLASS macro instruction specifies whether to pass session awareness data over the CNM interface (SAW=YES|NO). The labels given to the KCLASS macro instructions are specified on the MAPSESS macro instruction. MAPSESS specifies a PLU-SLU session pair and specifies the KCLASS definition that VTAM uses to determine whether to pass session awareness data over the CNM interface.

The PLU and SLU are derived from the PRI and PRINET operands, and the SEC and SECNET operands respectively. Each has a maximum length of eight characters. The special characters ? and * used in the pattern have the following meanings:

?: Matches any single letter or digit
*: Matches any letters or digits and can be used only as the last character in the pattern

The order of macro instructions is significant. VTAM examines the MAPSESS definitions from top to bottom when searching for a match for the PLU-SLU pair. The macro instructions in the simple example of a session awareness data filter table cause VTAM to:

Pass session awareness data to the NetView session monitor for a session with a PLU named SSCP1 or IMS™
Ignore session awareness data for a session with an SLU whose name matches the T3?7* pattern if the PLU is not named SSCP1 or IMS
Pass session awareness data for a session with IMS as the PLU, even if the SLU name matches the T3?7* pattern, because the M2 definition is before the M3 definition