The Cisco extension to CISCO-SCSI-MIB which is a copy of the Internet draft, the SCSI-MIB, from the IETF. Glossary of terms used in this MIB: VSAN - Virtual Storage Area Network, similar to a VLAN. WWN - World Wide Name. Mechanism of identifying devices in Fibre Channel Networks. It is 8 bytes long. pWWN - port World Wide Name. nWWN - node World Wide Name. LUN - Logical Unit Number is a 64-bit identifier for a logical unit.