BLKSIZE

Defines the block size of the file.

0 to 99999: Specifies a value 0 to 99999, indicating the block size of the file.

Notes:

If a receive request originates from a non‑z/OS partner, the BLKSIZE should be coded explicitly. The value of the parameter must be based on a reasonable estimate.
BLKSIZE=0 is valid only if the value of RECFM is FB, FBx, VB, or VBx. When BLKSIZE=0, z/OS (not CA XCOM Data Transport) determines the block size.

Default: BLKSIZE of the z/OS data set if a send or receive request of any type originates from a z/OS partner.