Application program coding requirements for the CNM interface

For an application program to use the CNM interface, AUTH=CNM must be specified on its APPL definition statement.

To receive unsolicited RUs, an application program must be authorized to use the CNM interface and be designated in the CNM routing table (with the name specified in the name field of the APPL definition statement). Refer to z/OS Communications Server: SNA Customization for more information about authorizing application programs to use the CNM interface and designating the application program name in the CNM routing table.

If a VTAM® application program has been authorized to use the CNM interface, the program can gain access to the SSCP-LU session by specifying PARMS=(NIB=nib address) in its ACB. This NIB contains parameters describing the session to be established (the SSCP-LU session) just as an NIB does when it is used to establish an LU-LU session with OPNDST or OPNSEC. After OPEN completes processing for the ACB, the NIB contains the CID of the SSCP-LU session that was established.

The application program uses a subset of the RPL-based macroinstructions (SEND, RECEIVE, RESETSR, EXECRPL, and CHECK) to communicate on the SSCP-LU session just as it uses these macroinstructions to communicate on LU-LU sessions. Because the SSCP-LU session uses FM profile 6, it uses only a very limited set of data-flow-control functions; for example, the SSCP sends no data-flow-control requests and sends and receives only single-request chains. Refer to SNA Formats for details about FM profile 6. Similarly, because you use TS profile 1 on the SSCP-LU session, you do not send or receive session-control requests. Thus, do not use SESSIONC.

The NIB macroinstruction specified by PARMS=(NIB=nib address) has the permissible values listed here. See NIB—Create a node initialization block for details.

NAME=blanks
USERFLD=user data
LISTEND=YES
SDT=SYSTEM
EXLST=exit list address
ENCR=NONE
RESPLIM=response limit
LOGMODE=0
BNDAREA=0
PROC=(CA or CS or RPLC,
NDFASYX or DFASYX,
NRESPX or RESPX,
NCONFTXT or CONFTXT,
KEEP or TRUNC,
SYSRESP or APPLRESP,
ORDRESP or NORDRESP,
NNEGBIND or NEGBIND)

RPL, SEND, RECEIVE, RESETSR, and EXECRPL macroinstructions used to access the SSCP-LU session can have the following subset of RPL operands specified. See the macroinstruction descriptions in Conventions and descriptions of VTAM macroinstructions for details.

ACB=acb address
ARG=(register containing CID of SSCP-LU session)
AREA=data area address
AREALEN=data area length
RECLEN=data length
ECB=INTERNAL
ECB=event control block address
EXIT=rpl exit routine address
BRANCH=YES or NO
SEQNO=sequence number
POST=SCHED or RESP
RESPOND=(EX or NEX,FME,NRRN,QRESP or NQRESP)
CONTROL=DATA
CHAIN=ONLY
CHNGDIR=(NCMD)
BRACKET=(NBB,NEB,NCEB)
RTYPE=(DFSYN or NDFSYN,DFASY or NDFASY,RESP or NRESP)
STYPE=REQ or RESP
SSENSEO=0 or CPM or STATE or FI or RR
SSENSMO=system-sense modifier value
USENSEO=user-sense value
CRYPT=NO
CODESEL=STANDARD
OPTCD=(TRUNK or KEEP or NIBTK, FMHDR, SPEC or ANY, SYN or ASY, CS or CA, Q or NQ, BUFFLST or NBUFFLST, NLMPEO, USERRH or NUSERRH)