BLD FLASH 9514
SOURCE MATERIAL DATED: 3/95
¦



         PSF/6000 PSF DIRECT AFFECTED BY SNA SERVER/6000 APAR IX49039

 PSF/6000 PSF Direct customers may be affected by an SNA Server/6000 error de-
 scribed  in  APAR  IX49039.   PSF Direct allows PSF/MVS, PSF/VSE, PSF/VM, and
 PSF/400 to access PSF/6000 printers using an SNA LU  6.2  communication  ses-
 sion.    PSF  Direct requires SNA Server/6000 2.1 to be installed on the RISC
 System/6000 to provide SNA communication facilities.

 SNA Server/6000 APAR IX49039 may affect customers  whose  configurations  in-
 clude  segmentation of BIU's (Basic Information Units).  A BIU includes an RH
 (Request Header) and an RU (Request Unit).  A BIU is segmented if it  is  too
 large  to fit in a buffer of one of the components in the communication path.
 For example, BIU's are segmented in 3174 configurations where the maximum  RU
 size is 1024 bytes and the "F" value in 3174 configuration item 941 is 1 (521
 bytes).    BIU's  may also be segmented in configurations that include remote
 Token-Ring bridges.

 The error addressed by SNA Server/6000 APAR IX49039 may cause one or more  of
 the following symptoms:

 o   The  host  PSF may abend because it receives SNA sense code 2004 from the
     remote logical unit.

     For example, PSF/MVS issues message

     APS928I THE PAGE PRINTER COMMUNICATION COMPONENT HAS ABENDED, PPCC  ABEND
     REASON CODE 'F16'X, SNA SENSE('20040000'X).

 o   SNA  Server/6000  may  unexpectedly UNBIND the communication session with
     the host during data transfer.

 o   The RISC System/6000 may crash - flashing 888's.

 The fix for APAR IX49039 is not yet included in an SNA Server/6000 PTF.   Un-
 til  an  SNA  Server/6000 PTF becomes available, PSF Direct customers who be-
 lieve they may be affected by this APAR have two options:

 o   Decrease the RU size to prevent segmentation of BIU's from occurring.

     Using an RU size of 256 bytes will prevent segmentation of BIU's  in  al-
     most  all configurations.  Decreasing the RU size to 256 bytes may reduce
     throughput in some configurations.

 o   Use an e-fix for APAR IX49039.  SNA Server/6000 PTF U435768 must first be
     installed.  Please contact either the SNA Server/6000  support  group  or
     the PSF/6000 support group to obtain the e-fix.





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