Add optional WWN in ATA IDENTIFY PACKET DEVICE command

Elliott, Robert (Server Storage) Elliott at
Fri Dec 23 08:07:53 PST 2005

* From the T10 Reflector (t10 at, posted by:
* "Elliott, Robert (Server Storage)" <Elliott at>
Since most ATA Packet devices implement the T10 multimedia command set
(MMC), and MMC developers don't generally attend T13 meetings, T13 asked
for input from the T10 MMC community on proposal e05181r0
(  Are there any objections to including an optional
World Wide Name field in IDENTIFY PACKET DEVICE data?

The IDENTIFY DEVICE command includes an optional World Wide Name field
containing an IEEE NAA Registered identifier in words 108-111. Serial
Attached SCSI HBAs may use this to identify that the drive is the same
even if it changes locations in the SCSI domain (the SAS address given
to a drive is based on the expander phy to which it is attached).
e05178r0 [by Ken Hirata at Emulex] proposes the field be upgraded to
mandatory. [I don't think that was resolved at last week's T13 meeting]

The IDENTIFY PACKET DEVICE command does not currently define that field.
It would be helpful if it were optionally available, and if implemented
by an ATAPI device supporting SCSI commands, matched the SCSI target
device name returned in the SCSI INQUIRY command Device Identification
VPD page (83h).

For IDENTIFY PACKET DEVICE, the World Wide Name needs to be optional,
because ATAPI DVD drives, which are the most common packet devices, have
little need. ATAPI tape drives are more likely to implement it.

Rob Elliott, elliott at
Hewlett-Packard Industry Standard Server Storage Advanced Technology

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