The PC user invokes Rumba, a TELNET client
which emulates the type
of IBM terminal the application was written for. The IP session flows to the
mainframe TCPIP software, which maps the IP address to a specific VTAM LU.
This effectively converts the IP TELNET session to a VTAM 3270 session between
the PC and CICS. |
In most cases, a PC is given an IP address which is Reserved in the DHCP. This IP is mapped to a specific TermID. If the user only requires access to A2K (Production Invision), the IP is also 'locked' to the A2K Application. If the user also needs access to A2KTEST or TSO, the IP is not 'locked' to A2K. Once a Rumba session is established with A2K, if the TermID starts with '3', the user is taken directly to the A2K Signon Screen. If the ID does not start with '3', the user can do SHIFT+F10 to get to the Signon Screen.
CICS has a Terminal Table mapping the VTAM LU to an application TermID. The user data thus flows via this CICS table to the application, which gives the user the appropriate functions, screens, authority, etc.
The application has Document Groups which define printers. PCs are mapped to one or more Document Groups.
CICS also has a Printer Table mapping VTAM LUs to PrinterIDs. It is the PrinterID which is part of the Document Group. When an application generates printout, the data flows from the application according to the appropriate Document Group(s) and the Printer Table via the VTAM LU to DRS.
DRS formats the data (portrait or landscape, control information, etc.) and passes it to the JES2 Spool, routed to a particular JES2 DESTID.
VPS continually monitors JES2, takes the data from the Spool and sends it via TCPIP to the printer associated with the particular JES2 DESTID.
The VPS printers can also be driven by data put in the JES2 Spool by batch jobs or by TSO users pulling data from the GQ file to the Spool. Of course, a printer may also be driven as a network-attached device for 'local' printing.
PC 10.10.10.200 is mapped in TCP/IP to VTAM LU VPRT3PCA|
VTAM LU VTER3PCA defined in CICS as TermId 3PCA
TermId 3PCA set in CICS for proper functions, authority, etc and to print via Document Group 3OPCPD01
Document Group 3OPCPD01 defined in CICS to consist of printer 3PCP
Printer 3PCP defined in CICS as VTAM LU VPRT3PCP
VTAM LU VPRT3PCP defined in DRS with JES2 DestId U2222
JES2 DestId U2222 defined in VPS as Printer VPRT3PCP IP 10.10.10.22