Hello,
The initiator or target declares the maximum data segment length in bytes it can receive in an iSCSI PDU.
so per example, if an initiator advertised MRDSL=16MB, that would mean that the initiator is willing to accept PDUs with
a data segment UP TO 16MB. ONTAP never sends a PDU larger than 64KB, but since 64KB < 16MB, this would not be a compliance or interop issue.
Hope this answer your question.
Thanks