PH32620: ORS (OUTBOUND RIGHT SIZING) SEND BUFFER GROWTH STOPPING AT 1M

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• TCP connections eligible for ORS (outbound right sizing) growth
  of the send buffer are not reaching the documented 2M limit.
  The send buffer does not grow beyond 1M in size.  This
  limitation on the send buffer size can effect throughput on a
  high latency connection.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of the IBM Communications Server for z/OS Version  *
  * 2 Release 3 and 4 IP                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Outbound Right Sizing (ORS) dynamic growth of the TCP        *
  * connection send buffer size is limited to 1MB instead of the *
  * documented 2MB.   The 1MB send buffer size limit for ORS may *
  * restrict the throughput on a high latency streaming          *
  * connection.                                                  *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF                                                    *
  ****************************************************************
  

Problem conclusion

• ORS management of the TCP connection send buffer has been
  amended to impose a 2MB limit.
  

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:

  UI73612 UI73613

Modules/Macros

• EZBT6LWR EZBTCFWR EZBTLFWR EZBT6FWR
  

Fix information

• Fixed component name

  TCP/IP MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R240 PSY UI73613

     UP21/03/09 P F103

• R230 PSY UI73612

     UP21/03/09 P F103

Fix is available

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