CA/400 Win95/NT Twinax UTP cabling problems

[Neil Palmer <NPalmer@xxxxxxxxxxx>]

I've been working with IBM on a problem with a ThinkPad 760L and IBM
PCMCIA adapter connecting to our AS/400 - connection is via Unshielded
Twisted Pair cabling with baluns and a twinax hub.  Connection would be
very intermittent - maybe one attempt out of 15 would work.  Same
ThinkPad was taken to another site that had REAL boat anchor strength
twinax cable (the kind mom used to make back in the 70's !) and it
connected flawlessly every time.

With the past concerns & questions re Twinax connections using CA/400 I
thought I would post this APAR from IBM re CA/400 for Win95/NT (any
version) with Netsoft Router, UTP cabling/baluns and Twinax Hubs.

Note - the Status is CLOSED and code PRS means Permanent Restriction.


Item SA66465

  APAR Identifier ...... SA66465       Last Changed..97/08/12  
  CA400WINOPT-COMM-NETSOFT-TDLC-RC=000000FD UNPREDICTABLE RESULTS
  WITH TWINAX HUBS AND UTP
 
  Symptom ...... UR UNPRED            Status ........... CLOSED  PRS
  Severity ................... 3      Date Closed ......... 97/08/12
  Component .......... 5763XD100      Duplicate of ........
  Reported Release ......... 312      Fixed Release ............
  Component Name 5763 CA400 WIN       Special Notice
  Current Target Date ..97/08/20      Flags
  SCP ...................
  Platform ............
 
  Status Detail: APARCLOSURE - APAR is being closed.
  
  ERROR DESCRIPTION:
   If using:
   A. Client Access for Windows 95/NT Client (V3R1M0, V3R1M1
      and V3R1M2) -and-
   B. Running on Windows 95 PC  -and-
   C. Using the NetSoft Router, Twinax link type and the VxD adap
      adapter handlers (PDLWATV.VXD and VDNSWQ.VXD) -and-
   D. With hardware connectivity to AS/400 via Unshielded Twisted
      Pair (specifically, Unshielded Twisted Pair cabling with
      baluns and some type of twinax patch panel or hub)
 
   Unpredictable results may occur. This problem occurs on all PC
   adapters, but is most prevalent on PCI bus types.
 
   When making this connection, the Netsoft Router's Event
   Event Log viewer may report one or more of the following
   messages:
        TWINAX-16 (any return code), or
        RT000B return code 1C
   The Twinax Adapter Handler pop up box may display 'Open
   Twinax station failed and one of the following return codes:
       000000FB or
       000000FC or
       000000FD.
 
  LOCAL FIX:
   Bypass the hub using real twinax cable.
 
   PROBLEM SUMMARY:
   If using:
   A. Client Access for Windows 95 (V3R1M0, V3R1M1 or V3R1M2)
    -and-
   B. Running on Windows 95 PC
    -and-
   C. Using the NetSoft Router, Twinax link type and the VxD
      adapter handlers (PDLWATV.VXD and VDNSWQ.VXD)
    -and-
   D. With hardware connectivity to AS/400 via Unshielded Twisted
      Pair (specifically, Unshielded Twisted Pair cabling with
      baluns and some type of twinax patch panel or hub)
 
   Unpredictable results may occur. This problem occurs on all PC
   Twianx adapters, but is most prevalent on PCI bus types.
   When making this connection, the Netsoft Router's Event
   Event Log viewer may report one or more of the following
   messages:
 
     TWINAX-16 (any return code), or
     RT000B return code 1C
 
   The Twinax Adapter Handler pop up box may display 'Open
   Twinax station failed' and one of the following return codes:
 
     000000FB or
     000000FC or
     000000FD.
 
  PROBLEM CONCLUSION:
  Per II10307, the return codes indicate a polling or address
  checking problem.  Client Access was written to the original
  Twinax specification and is working as designed.
 
  Since the connection will depend heavily on the hardware being
  used, Client Access cannot guarantee that it will work on all
  hardware (especially hardware that changes the definition of
  Polling and Address Checking).  Newer twinax hardware (patch
  panels etc.) change the polling and address checking.
 
  The current Adapter Handlers for using in Windows 95 will not be
  changed to support these various definitions.  But, Client
  Access is working on replacing these adapter handlers in future
  releases with a newer adapter handler that should be more
  tolerant of the different hardware specifications.
 
  Until that newer version is released, a version of the current
  VxD adapter handler will be made available that turns off
  address checking and waits longer for Polls.  Using this version
  of the VxD adapter handler could result in Workstation Address
  conflicts.  In addition, this version of the VxD Adaptor handler
  still may not resolve the problem.  This version is available
  "AS-IS" and may not be serviced nor updated.  Obtain this VxD
  from the following internet FTP site:  ftp.software.ibm.com in
  directory
   /as400/products/clientaccess/win32/v3r1m2/files/twinax
  The files are PDLWATWV.VXD and README.TXT.
 
  Local Fix Options:
        1.  Use VxD adapter which turns off address checking 
        2.  Use real Twinax cabling.
        3.  Wait for future Mod level of CA/400 for Windows 95/NT
                client which will include support for UTP/Hubs

  CIRCUMVENTION:
  Use real Twinax cabling and no Hubs.
 
-- 
... Neil Palmer                                      AS/400~~~~~      
... NxTrend Technology -Canada       ____________          ___  ~     
... Markham,  Ontario,  Canada       |OOOOOOOOOO| ________  o|__||=   
... Phone: (905) 731-9000 x238       |__________|_|______|_|______)   
... url:http://www.NxTrend.com        oo      oo   oo  oo   OOOo=o\   
... mailto:NPalmer@NxTrend.com     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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