Subject: IPFC ARP WWN Proposal

From: "Witkowski, Mike" <[email-masked]>
Date: Fri, 4 Dec 1998 15:48:54 -0600

All,

After the IPFC draft had a chance to circulate among my colleagues,  we have
discovered an issue that we would like to discuss with other members of the
IPFC Working Group :

The current draft states that only devices with World Wide Names using an
NAA value of 0001 (IEEE) would be supported by the standard. 

The FC-PH-3 standard has added several new NAA values including 0101 (0x5)
for IEEE Registered. The difference is that the previously unused 12-bits in
the IEEE format can now be used giving a full 60-bit (24-bit OUI + 36-bit
Vendor Defined) address space. It has been brought to my attention that
vendors exist (my employer being one) that have standardized on and are
currently building and distributing FC devices that use the IEEE Registered
format. 

Proposal:

We would like to propose that the standard allows the use of WWNs using the
IEEE Registered NAA as well. 

Rationale: 

We feel that the entire FC WWN space as defined by ANSI can and should be
freely used by the FC vendor community. Limiting IPFC to just the IEEE
48-bit address space potentially limits the entire FC WWN address space
because vendors will be reluctant to use any other address format because of
the precedent set by this standard. 

Specifically, FC devices that use IEEE Registered WWNs would like to manage
and be managed by other FC interconnect devices (switches, bridges, etc.) as
a minimum. 
 
Issues:

We are aware that this might be an issue for bridging between traditional
LANs and FC networks, but we feel this is a surmountable problem.
Specifically, devices that use IEEE Registered WWNs could be managed via
proxy or router from devices that implement IEEE 48-bit WWNs. 

This proposal would also require that ARP layer software for FC devices be
able to handle the full 60-bit address vs. the 48-bit address that most ARP
layer software is designed to handle. This brings up the question of which
environments will allow the ARP layer to be modified. Obviously, we won't be
able to get Microsoft to change their ARP layer software in NT or Win '98
any time soon. But, in other environments, such as Compaq UNIX, LINUX,
embedded systems (e.g. switches, array controllers, etc.), access to the ARP
layer will exist. 

Summary:

We would like to spur discussion by the IPFC WG membership to see what
interest, issues, and concerns this proposal raises. I would also like to
discuss this at the IPFC WG meeting next Wednesday. 

I apologize for the late notice. 

Thank you.

Mike Witkowski
Interconnect and Technology
Storage Products Division
Compaq Computer Corporation
20555 SH 249, MS140901
Houston, Texas 77070
Fax:	(281) 514-3888
Tel: 	(281) 514-8590
Email: 	[email-masked] <mailto:[email-masked]> 
WWW: 	www.compaq.com <http://www.compaq.com>

---

From: "Infante, Jon" <[email-masked]>
Date: Mon, 7 Dec 1998 09:08:42 -0800

Mike,

This issue has come up numerous times during the evolution of
the IPFC draft. The major stumbling block to expanding WWPN 
support has been most IP/ARP interfaces we have dealt with,
to date, only support a 48-bit hardware address.

That is, packets the driver recieves from IP to transmit, are tagged with a
48 bit physical destination address  and  packets a driver recieves from 
the network typically need a 48 bit physical address identifier added before
passing the packet up to IP.

At the Fibre Channel driver level, we are using FC network headers
which allow the full 64-bit WWPN to be passed between nodes. However,
when the driver registers with the IP protocol stack (either as Ethernet,
802.3, FDDI, Token ring ) it is limited to 48 bits.  Currently most IP stacks
don't have a category of Fibre Channel (or 64 bit hardware address) to
register a driver.

In order to make our draft work in all existing IP environments we are limited
to using IEEE format for WWPN and a type field of 5 (8802-2 LLC/SNAP)
in the FC header.

Jon Infante
Emulex

----------
From: 	Witkowski, Mike
Sent: 	Friday, December 04, 1998 1:48 PM
To: 	[email-masked]
Subject: 	IPFC ARP WWN Proposal

All,

Proposal:

Rationale: 

 
Issues:

Summary:

Thank you.

Mike Witkowski