Browse Prior Art Database

Remote Servers for LANRES using LU 6.2

IP.com Disclosure Number: IPCOM000109616D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 5 page(s) / 255K

Publishing Venue

IBM

Related People

Callaghan, PJ: AUTHOR [+2]

Abstract

A method to remove the distance restriction for LANRES is disclosed. The programs were changed to support Common Programming Interface-Communications (CPI-C) as another communication pathway.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 40% of the total text.

Remote Servers for LANRES using LU 6.2

       A method to remove the distance restriction for LANRES is
disclosed.  The programs were changed to support Common Programming
Interface-Communications (CPI-C) as another communication pathway.

      Remote Servers will allow the use of the two LANRES functions
(LANADMIN and LANDS) from VM even though the NetWare* servers are not
locally attached through a PS/2** Channel Adapter card (PCA card).
This eliminates the distance restriction and the need for a PCA card
for every server.

      This is implementable through the use of PWSCS as a CPI-C
communications product on NetWare.  (PWSCS is providing a CPI-C
interface for Novell in the new release.) It is quite possible that
Novell might also provide a direct connection from a remote NetWare
server to VM through NetWare for SAA**.

      In order for these two communications programs (and any others
implementing SAA CPI-C) to be able to be used interchangeably, SAA
CPI-C (no extensions) is used in the PC code.  Also, supporting
LANRES/MVS will probably take little or no PC code changes.  The host
code is written in APPC/VM, so it will be able to talk to both PWSCS
and NetWare for SAA (CPI-C maps to APPC).

      Currently the communications between host and PS/2 is through
channel programs.  The SENDPS, READPS and EWXPUT modules implement
the channel programs for the host side and the EWXPCA module takes
care of it on the PS/2 side.  These modules will be replaced or
modified in order for LANRES to speak APPC as well as PCA.

      When a command is executed today in LANRES it is translated
into a format called PCAdata.  The PCAdata is then passed on to
SENDPS to be sent down the channel to the LANRES server.  On the
server, EWXPCA receives the data in PCAbios format.  The PCAbios is
just the name for how the PCA card communicates.  It consists of NCB
blocks that contain all the information needed for the card.

      The NCB blocks are interpreted by the LANRES NLMs and the
command is executed.  Return information goes up to the host in the
reverse fashion.  The LANRES NLMs fill in the NCB blocks and pass it
to EWXPCA.  EWXPCA will break down the NCB block and send the data up
the channel to the waiting READPS.  (See Fig. 1).

      To implement the new communication path, new SENDPS and READPS
were written.  At connect time, it is decided by the parameters
(CONNECT or ATTACH), which version of SENDPS and READPS are
nucxloaded.  EWXPUT was modified to call SENDPS and READPS instead of
handling its own communications.  On the PC side, a new NLM was
written to handle the communication.  It is a transaction program
(TP--a CPI-C construct) which will handle the CPI-C communication to
and from the host and handle the communication to the LANRES NLMs.
The TP communicates with the NLM by using SPX.  (SPX communication
was added into LANRES this release.  Originally it was intended to be
used in a diff...