A method and system for transmission path optimization in an Internet Small Computer System Interface (iSCSI) storage area network architecture comprises a storage device downloading input/output (I/O) profiles from an SAN Software Defined Network (SDN) application and a host computer connected to the storage device via various transmission paths, to access a first virtual disk. The storage device analyzes iSCSI packets in the first virtual disk, and calculates I/O data of the first virtual disk and updated I/O data (for second I/O profile) at time intervals. The storage device can determine to change the first I/O profile of the first virtual disk as against the second I/O profile and the SAN SDN application can command an SDN controller to optimize the transmission path between the host computer and the first virtual disk by making the change, based on comparisons against the second I/O profile.