Solidification of proposed new formats for IEEE registered object identifiers

Bob Snively Bob.Snively at Eng.Sun.COM
Fri Sep 20 12:57:21 PDT 1996


* From the SCSI Reflector (scsi at symbios.com), posted by:
* Bob.Snively at Eng.Sun.COM (Bob Snively)
*
To:		SCSI reflector (scsi at symbios.com)
		Fibre Channel reflector (fc at network.com)
		IEEE (stds.rac at ieee.org)

From:		Bob Snively

Date:		September 20, 1996

Subject:	Proposal for identifier formats based on IEEE registration


1.0  INFORMATIONAL OVERVIEW:

I have been asked by the Fibre Channel working group to assemble
a proposal for new worldwide name formats.  IEEE has shown great
interest in being the registration authority for this set of numbers,
so I have prepared the document based on the IEEE 24-bit registered
identifier.  The SCSI committee has elected to use the Fibre Channel
formats for its use as well.  SCSI also allows the use of the
EUI-64 bit identifier, but this should be discouraged since it cannot
be made unique with respect to the Fibre Channel worldwide names.

This revision of the proposal includes inputs from Mike Wenzel and
Gary Robinson.

1.1  PRESENT STRUCTURE

Fibre Channel was first designed with a 64-bit field for its
world-wide names.  Six out of 16 possible registration authorities
were identified using the high order bits (bits 63, 62, 61, and 60)
and a format was defined that made use of the bit patterns provided
|from each of those naming authorities.  The high order bits are 
identified in Fibre Channel as the Network Address Authority (NAA) bits.


      NAABits     |     Registration authority/format
                  |            
   63  62  62  60 |
  ________________|____________________________________________
                  |
    0   0   0   0 |   NONE
    0   0   0   1 |   IEEE
    0   0   1   0 |   IEEE EXTENDED
    0   0   1   1 |   LOCALLY ASSIGNED 
    0   1   0   0 |   IP
    1   1   0   0 |   CCITT INDIVIDUAL ADDRESS
    1   1   1   0 |   CCITT GROUP ADDRESS
    all others    |   reserved

1.1.1	IEEE format

The IEEE format appropriated the 48-bit IEEE 802.1 universal LAN MAC address
or ULA.  This structure is commonly used in Fibre Channel devices today.

	IEEE WWN format

  6  6 | 5    | 5          | 4            4   4 | 3          3 |
  3  0 | 9    | 5          | 7            1   0 | 9          2 |
 ______|______|____________|____________________|______________|
  0001 | 0000 | 0000 0000  | ULA Byte 0 |U/L|I/G| ULA Byte 1   |
 ______|______|____________|____________________|______________|
  ULA Byte 2  | ULA Byte 3 | ULA Byte 4         | ULA Byte 5   |
 _____________|____________|____________________|______________|
  3           | 2          | 1                  | 0          0 |
  1           | 3          | 5                  | 7          0 |


1.1.2	IEEE Extended format


The IEEE extended format allowed the unused high order 12 bits to be
managed by the device or manufacturer in such a manner that the
bits were guaranteed to be unique modifiers of the 48 ULA bits.  Fibre
Channel used this to identify multiple ports on a node known by its
IEEE worldwide name, although more recently these bits have been used
by manufacturers to identify individual Fibre Channel SCSI devices, thus
extending the device unique worldwide name to 60 bits.

1.1.3	Other formats

Other formats do not use IEEE registered values.


1.2	NEW ADDITIONS PROPOSED TO THE STRUCTURE

To facilitate and simplify the use of the IEEE registration facility, two
new Fibre Channel worldwide name formats are proposed by this document.
The formats will be identified by two new NAA values.

One provides a simple to manage 60 bit id.  The high order bits
(bits 59 - 36) contain the 24-bit IEEE identifier.  The remaining bits
are guaranteed to be unique for each worldwide name by the 
assignee of the identifier.  The proposal defines this using an
NAA field value of 0101.  

The second provides a simple to manage 124 bit id, separated into two
octlets.  The first octlet uses the same format as above.  The additional
64-bits are also managed by the assignee of the identifier, but may be
managed such that a relatively sparse name space is created.  The 
actual location of the additional 64-bit field is not yet defined by the
present Fibre Channel standards, but will be defined within the SCSI
INQUIRY vital product data page for identifiers.


2.0	TEXT OF PROPOSAL:


Several authorities have been identified by the Fibre Channel committee as
registrars for unique Worldwide names.  The authorities
are identified by the NAA_ID field.  Six formats for worldwide 
names have previously been defined.  Two new worldwide
name formats based on the IEEE 24-bit registered identifier 
are proposed.

Some companies have suggested the possibility of
extending the world wide name concept to removable recordable
media, including tape cartridges, removable magnetic media, and
removable optical media.  Other companies have suggested that
the worldwide names should be extended to cover virtual
objects such as multi-disk RAID volumes.  These and similar
requirements encourage the use of large name spaces which may be
created in such a manner that the space is sparse and not
exhaustively used.

For these reasons, two new formats are proposed.  The first format,
IEEE-registered name, provides a powerful and flexible
name space that is convenient for SCSI and Fibre Channel devices and
ports to use.  The 
IEEE-registered name space is expected to be used almost
completely.  The second format, IEEE-registered extended name,
provides a 128-bit name space that is large enough to allow sparse
name assignments. 



NAA = 5		IEEE registered name

	Format:

        __________________________________________________________
       |  NAA  | IEEE Registered Field |   Vendor Specific Field  |
       |  0101 |       24 bits         |           36 bits        |
       |_______|_______________________|__________________________|


This format is defined to provide a set of contiguous identifiers
under vendor specific management for each of 2**24-1 registered name spaces.
The registered field is assigned to the vendor by the IEEE
registration authority.  The vendor is urged to use the same
registered field value for all worldwide names it creates within the
scope of IEEE's registration authority, including but not limited to
Ethernet addresses and SCSI and Fibre Channel worldwide names.
The vendor specific field is intended to be used exhaustively by 
the vendor.  IEEE should continue the policy of not assigning a new
registered field value to a vendor until the name space assignable 
using the IEEE registered name is essentially exhausted.

The vendor specific field may be subdivided and assigned to 
the named objects in a vendor specific manner, as long as uniqueness
is assured across all objects of any type named by that vendor.

Sparse assignments of the values in this field are allowed up 
to 25% of the name space.  This allows a dual port devices to use 
a 2-bit field to define unique worldwide names for two ports and
for the device node. 

NAA = 6		IEEE-registered extended name

	Format:
        ____________________________________________________________
       |  NAA  |  IEEE Registered Field  |   Vendor Specific Field  |
       |  0110 |       24 bits           |           36 bits        |
       |_______|_________________________|__________________________|
       |                Vendor Specific Field Extension             |
       |                          64 bits                           |
       |____________________________________________________________|	


This format is defined to provide a set of contiguous identifiers
under vendor specific management for each of 2**24-1 name spaces.
The registered field is assigned to the vendor by the IEEE
registration authority. The vendor specific field is
intended to be used exhaustively by the vendor.  New registered
field values will not be made available to a vendor until the
vendor specific field is essentially exhausted.  

The vendor  specific field may be subdivided and assigned to objects or groups
of objects in a vendor specific manner as long as the full IEEE-registered
extended name is guaranteed to be unique for each named object.  

Sparse assignments of the values in the vendor specific field is
not allowed.  The vendor specific field 
extension may be subdivided and assigned by the vendor as desired.
Sparse assignments of this space are allowed, making the 
format usable for virtual and constructed objects, recording media 
cartridges, and for other sparsely populated name spaces.

The location of the vendor specific field extension is specific 
to the class of object.  The location has not yet been assigned
for Fibre Channel devices.  It is expected that the SCSI 
identifier field will be 128 continguous bits for the
IEEE-registered extended name.


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