Valid RU sizes

The actual transmission response/request unit (RU) size for SNA RJE buffer is limited further (rounded down) by the SNA architecture, and JES2 enforces the restriction through the BUFSIZE= parameter on the RMT(nnnn) definition.

After initialization, if you use the $ADD RMT(nnnn) command to add an SNA RJE workstation, or you use the $T RMT(nnnn) command to modify one, the BUFSIZE= parameter value cannot be larger than the SNABUF=(SIZE=) parameter value on the TPDEF initialization statement. The BUFSIZE= parameter is rounded down for RU bind limitations before it is checked against the SNABUF=(SIZE=) parameter value on the TPDEF initialization statement.