PH14484: IBM MQ CSQX504E CSQXRCTL LOCAL PROTOCOL ERROR CHANNEL XXXXX TYPE=00000021 DATA=00000400. INVALID MAXIMUM TRANSMISSION SIZE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CSQX504E CSQXRCTL Local protocol error, channel xxxxx
  type=00000021 data=00000400
  CSQX599E CSQXRCTL Channel xxxxx ended abnormally
  .
  type=00000021 means 'ERR_MAX_TRANSMISSION_SIZE'.
  data=00000400 is the value of 'MAXTRANSMISSIONSIZE '
  x'400'= 1024.
  .
  Distributed APAR IZ86279.
  .
  Additional information:
  MAXSEG is an attribute for Hitachi TP1 channels
  .
  

Local fix

• Set MAXSEG to 4000 on the Hitachi TP1 channel definition.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of IBM MQ for z/OS Version 9       *
  *                 Release 1 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: CSQX504E is produced when starting a    *
  *                      channel. The message has local protocol *
  *                      error type=00000021 and data value less *
  *                      than 4000 (X'FA0'). This occurs when    *
  *                      connecting to a receiver channel which  *
  *                      uses a MAXSEG value less than 4000.     *
  ****************************************************************
  The MaxTransmissionSize value is limited to a minimum of 4000,
  values less than this will result in a local protocol error and
  message CSQX504E. In the case where a receiver channel has
  a low MAXSEG value, this will be sent to the sender channel.
  The low value results in the sender channel having the protocol
  error and producing the message.
  

Problem conclusion

• The policing of the MaxTransmissionSize value has been changed
  to a lower value, 1024, to allow receiver channels on systems
  where MAXSEG is set to a low value.
  

Temporary fix

Comments

APAR Information

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

  PH01639

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

  UI64412

Modules/Macros

• CSQXRMSS
  

Fix information

• Fixed component name

  IBM MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R100 PSY UI64412

     UP19/09/26 P F909

Fix is available

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