TCPIP Queues Envelopes to CTCs in Error Status

 
 APAR Identifier ...... PQ51300      Last Changed ........ 01/09/12
 TCPIP QUEUES ENVELOPES TO CTC'S IN ERROR STATUS
 
 Symptom ...... IN INCORROUT         Status ........... CLOSED  PER
 Severity ................... 3      Date Closed ......... 01/08/20
 Component .......... 5735FAL00      Duplicate of ........
 Reported Release ......... 3A0      Fixed Release ............ 999
 Component Name TCP/IP V2 FOR V      Special Notice
 Current Target Date ..              Flags
 SCP ...................
 Platform ............
 
 Status Detail: SHIPMENT - Packaged solution is available for
                           shipment.
 
 PE PTF List:
 
 PTF List:
 Release 3A0   : UQ57125 available 01/09/12 (1000 )
 Release 310   : UQ57126 available 01/09/12 (1000 )
 Release 320   : UQ57127 available 01/09/12 (1000 )
 Release 410   : UQ57128 available 01/09/12 (1000 )
 
 Parent APAR:
 Child APAR list:
 
 ERROR DESCRIPTION:
 VM TCP/IP is queuing up envelopes to CTC links that are in
 Status: Ready/Error status.
 Tracing the problem showed that VM TCP/IP is incorrectly
 queuing up the envelopes even though the device is in Error
 Status and the remote host connected to VM via the CTC is not
 connected.
 
 LOCAL FIX:
 
 PROBLEM SUMMARY:
 ****************************************************************
 * USERS AFFECTED: Users with CTC links defined and started but *
 *                 either in error status or connected to a     *
 *                 host that is not communicating               *
 ****************************************************************
 * PROBLEM DESCRIPTION:                                         *
 ****************************************************************
 * RECOMMENDATION: APPLY PTF                                    *
 ****************************************************************
 A CTC device that is started but is in error status (e.g.,
 because the CTC is not coupled to another guest) or that
 is connected to a host that is not communicating may have
 envelopes queued for transmission. The number of queued
 envelopes is reported in the response to a NETSTAT DEVLINKS
 command following  "Queue size:". For example,
 
  Device CTC3              Type: CTC          Status: Ready
  Queue size: 293          Address: 0B30
     Link DVHTEST1         Type: CTC          Net number: 0
 
 The device will recover from error status when it becomes ready
 and communication restarts, whereupon any queued envelopes will
 be discarded. Thus, keeping the envelopes queued until the
 restart occurs (and queueing more as efforts are made to
 communicate across the device) simply wastes resources. If the
 other host is not communicating, queued envelopes will probably
 not represent current communication when contact is established
 and should be discarded. In some cases, having these extra
 envelopes queued can lead to excessive expansion of the envelope
 pool and even out-of-storage conditions.
 
 PROBLEM CONCLUSION:
 Code has been changed to discard envelopes that are queued for
 transmission on a CTC device that is in an error state. For a
 CTC that is connected to a non-communicating host, queued
 envelopes are discarded if the attempt to send data to the host
 has been pending for more than 30 seconds.
 
 TEMPORARY FIX:
 
 COMMENTS:
 
 MODULES/MACROS:   ALLMACRO TCBASTY  TCCONSI  TCPIP    TCTOCTC
 
 SRLS:      NONE
 
 RTN CODES:
 
 CIRCUMVENTION:
 
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