Configuration Parameters › Destination Parameters for Single LUs, Groups of LUs, and Single IPNAMEs › RRUSIZE

RRUSIZE

Specifies the maximum RU size to be received from other LUs.

128 to 65536

Specifies the maximum RU size.

Default: The RRUSIZE value derived from the VTAM logmode table entry used by VTAM during initial session establishment and passed to CA XCOM Data Transport via the LOGON exit CINIT or SCIP exit bind RU.

Notes:

• This parameter is relevant only to sessions where the system is the primary logical unit.
• Using larger values can substantially improve performance on high‑speed links, in installations with channel adapters, and 3088s. The secondary logical unit (the BIND receiver) determines what RU sizes are to be used on a session and can override any RU sizes sent in the BIND by the primary logical unit. If you want to use larger RU sizes, read the appropriate sections of the IBM VTAM and NCP manuals relating to the BFRS, MAXDATA, and TRANSFR parameters. These parameters require modifications to accommodate larger sizes.