RE: Towards Consensus on TCP Connections

["Douglas Otis" <dotis@sanlight.net>]

Peter,

Firewire has many strikes against it for broad acceptance.  It uses an
imbalanced pair to identify the PHY.  Licensed PHY from Apple at a cost per
port with mode use restricted.  Limited range of the copper solution does
not satisfy most commercial environments.  No aggregation as Firewire is a
half-duplex daisy chain.   Although possible to use as a typical SCSI target
with IP, it is not for storage.  With that said, indeed, implementing any IP
standard on any medium would be encouraged.

Doug

> -----Original Message-----
> From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
> Peter Johansson
> Sent: Saturday, August 12, 2000 9:29 AM
> To: IP Storage
> Subject: RE: Towards Consensus on TCP Connections
>
>
> At 11:14 AM 8/11/00, Douglas Otis wrote:
>
> >Firewire does not scale and has a limited reach.
>
> Doug, I take exception to the first part of your statement, both
> because I
> believe that IEEE 1394 does scale and for another reason (see below). As
> for limited reach, I agree that point-to-point connections
> measured in the
> hundreds of meters are not adequate for a MAN / WAN. But I also
> don't think
> that consideration is relevant to iSCSI (from the protocol perspective),
> whose purpose is to permit a diversity of media solutions appropriate to
> each user's needs.
>
> >Firewire also places scatter/gather on the drive together with
> direct access.
>
> I think you're confusing SBP-2 (which does locate the scatter / gather
> chore in the disk drive) with IEEE 1394 (which is agnostic about such
> matters). SBP-2 cannot be "native" iSCSI any more than can FCP!
>
> It's my understanding that the charter of iSCSI is to be
> transport neutral.
> That is, iSCSI is supposed to run over anything---copper, fibre, tautly
> stretched string---that supports Internet protocol. Is this
> belief in error?
>
> If that assumption is correct, then when it comes time to compare and
> contrast the cost and efficiency of different media, IEEE 1394
> ought to be
> in the matrix along with Ethernet, FC, UTP-5, etc., etc.
>
>
> Regards,
>
> Peter Johansson
>
> Congruent Software, Inc.
> 98 Colorado Avenue
> Berkeley, CA  94707
>
> (510) 527-3926
> (510) 527-3856 FAX
>
> PJohansson@ACM.org
>