9204E

9204E

9204E LU luname: PIU TOO LONG (MAXDATA/RUSIZE)

Written to:

Operator console.

Explanation:

This message is a continuation of message 9202E and comes up when the sense code displayed in message 9201E is X'800A0000'. The RUSIZE value in LOGMODE APPC01 or the MAXDATA value exceeds the maximum allowed size.

System Action:

Operation continues.

Operator Response:

The following should be checked for all configurations used to determine the maximum size allowed for MAXDATA (MAXDATA is a subparameter of OCF_CONVERSE statement. For more information, see "LST parameters for OCF" in BSA Installation and System Guide.):

1. VTAM-to-VTAM connection across a channel-to-channel interface (CTC)

  • if both VTAM versions are higher than V3R2 and have an APPN connection, the MAXBFRU value from the TRL major node multiplied by 4K equals (=) the maximum allowed size for MAXDATA
  • if both VTAMs have the CTCA enhancement (V3R2 and higher include the CTCA enhancement), the MAXBFRU value from the CTCA LINE statement multiplied by the IOBUF size from the VTAM start options equals (=) the maximum allowed size for MAXDATA
  • if one or neither of the VTAMs have the CTCA enhancement, then the MAXBFRU value from the LINE statement multiplied by the IOBUF size from the VTAM start options equals (=) the maximum allowed size for MAXDATA.

2. VTAM to channel-attached NCP (network control program):

VTAM will take the smaller of the following two values:

  • the MAXDATA value from the PCCU statement (or from the LINE/PU statement for a channel-attached NCP)

    -OR-

  • the maximum PIU size for the NCP. This value is the result of the BFRS value from the BUILD statement multiplied by the TRANSFR value from the channel adapter LINE statement for 3745 or 3720 with V5 NCP (or from the BUILD statement for other NCPs).

3. Channel-attached NCP to VTAM:

The MAXBFRU value from the HOST statement (or from the LINE statement for channel-attachment NCP) multiplied by the IOBUF size from the VTAM start options equals (=) the maximum allowed size for MAXDATA. This value will be the maximum size that can flow from the NCP to the host.

4. NCP to link-attached NCP:

The TRANSFR value from the LINE statement multiplied by the BFRS value from the BUILD statement equals (=) the maximum allowed size for MAXDATA.

5. NCP to link-attached VTAM:

The MAXBFRU value from the CA LINE statement multiplied by the IOBUF size from the VTAM start options equals (=) the maximum allowed size for MAXDATA.

Note: The definitions of all PU type 4 or 5 nodes on the session path must be checked. Any PU type 4 or 5 can change the PIU (which is too large) into an 800A0000 exception request.

Correct the size used for MAXDATA in the OCF_CONVERSE statement or correct the RUSIZE in LOGMODE APPC01. The RU size is calculated as follows: the MAXDATA value minus 34 bytes (header of PIU) = RU size. Example: 2048 - 34 = RU size 2014 bytes. See "Calculating the values for RU sizes" in BSA Installation and System Guide.

We recommend that you change the size used for MAXDATA in the OCF_CONVERSE statement.

Then restart the system.
If you decide to alter the RU size, then the altered size will be displayed in message 9232I (in the To-value).

When a connection between two OCF nodes has been successfully established, enter the set RU size in LOGMODE APPC01 or when an OCF node is connected to several other OCF nodes, enter all set MAXDATA values for the relevant OCF node in the MAXDATA parameter of the OCF_CONVERSE statement.