DY30201: XCA DOES NOT PERMIT XID0 ON FIRST ATTEMPT TO CONNECT, IT MUST BEXID-NULL

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• ERROR DESCRIPTION:
  There are many PU2.0 devices that do not send an XID null as
  the first XID to negotiate a connection request.  XID format0
  cannot be accepted on a dial-in request.  XID format0 can only
  be accepted as an XID response.
    VTAM will support these devices by attempting to dial-out to
  the device using the MACADDR received on the dial-in request
  after the XID format0 is received.
    If the dial-out is accepted by the device, the process will
  continue to a normal connection sequence.
  

Local fix

• Configure the device as a PU2.1 to permit connect in without an
  XID-null.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All using XCA connections.                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: NEW FUNCTION to allow switched XCA      *
  *                      PU to initiate connection request       *
  *                      with XID0 or XID1.  VTAM previously     *
  *                      required null XID to flow from          *
  *                      the device on a dial-in request.        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  On a switched dial-in XCA connection, VTAM required that
  a null XID be sent in from the PU to setup the connection.
  If an XID0 or XID1 was sent in from the device while in
  LSN_SW_IN_POLL_PENDING state the XID would be discarded
  by ISTLSCKN as an unexpected XID.
  This APAR will lift this restriction and attempt to
  allow the connection to activate.
  

Problem conclusion

• To allow an XID0 or XID1 to initiate a dial-in request
  the following changes have been made:
  
  ISTLSCSN - has been changed to allow an XID0 or XID1
             Command as input.  This will add the remote MAC and
             remote SAP to the SUM.
  
  ISTLSCNB - Segment SWXIDIPP has been changed to
             accept the XID0 or XID1 command input when LSNFSM is
             LSN_SW_IN_POLL_PENDING.  The input XID will be
             discarded and VTAM will respond to the PU with a null
             XID command.  The LSNFSM will be set to
             LSN_SW_IN_XID_PENDING state.  Segment SWXIDIXP
             has also been changed to allow a XID0/XID1 Response
             input to cause a REQCONT to be sent to PUNS.
             Previously only a XID0/XID1 Command was accepted.
  
  ISTLSCKN - has been included for maintenance purposes.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UD53626

Modules/Macros

•    ISTLSCKN ISTLSCNB ISTLSCSN
  

Fix information

• Fixed component name

  VTAM V4 VSE/ESA

• Fixed component ID

  568606501

Applicable component levels

• RFE6 PSY UD53626

     UP10/07/01 P E430

Fix is available

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