stds-1394: RE: SBP-2 Study Group

Atsushi Nakamura Atsushi_Nakamura at
Wed Aug 9 18:22:15 PDT 2000

* From the T10 Reflector (t10 at, posted by:
* "Atsushi Nakamura" <Atsushi_Nakamura at>

If it is decided that work is done on a peer to peer SBP-2, I would like to
see the outcome

1) not be "yet another protocol", and it remains "SBP-2" as we see it today
2) does not sacrifice the effeciency and simpleness it has today as
    a master-slave transport.

I believe there are/will be master/slave applications which
will make full use of the characteristic of SBP-2, well tuned for
Though it would be ideal if SBP-2 can handle both, it would not be worth
much if too much burden (inclucing compatibility) is put on the original
protocol, or significant changes are required for the new protocol which
results in something drastically different from what we have now.

Afterall, we already have good peer to peer symmetric protocols in
the world of 1394.

Atsushi Nakamura

$B08 at h(B: "'Peter Johansson'" <PJohansson at>, NCITS T10 <T10 at>
cc:   IEEE 1394 <STDS-1394 at>, 1394 TA <1394-SIG at>, "P1394.3"
       <STDS-1394-3 at> (bcc: Atsushi Nakamura/B/Canon Inc/JP)
$B7oL>(B: stds-1394: RE: SBP-2 Study Group

The biggest criticism I always get about SBP-2 is that it is
Master/Slave (Initiator/Target) in a world where many
appliances might prefer to operate peer to peer. I realize
that for SBP-2 this also has many advantages.

Any chance of discussing alternative ways to address this issue?
Besides just saying that a device support both roles.

Alan Berkema
Engineer Scientist
Hewlett Packard MS# 5558
8000 Foothills Blvd
Roseville California
Phone 916 785-5605
Fax   916 785-1968

-----Original Message-----
From: Peter Johansson [mailto:PJohansson at]
Sent: Thursday, August 03, 2000 1:53 PM
Cc: IEEE 1394; 1394 TA; P1394.3
Subject: SBP-2 Study Group

With the approval of the T10 Chair, I intend to convene a study group to
discuss amendment, extension or revision of SBP-2. The meeting will take
place in Huntington Beach, CA, during the T10 meeting the week of September
11 - 15, 2000.

THE PURPOSE of this message is TO POLL prospective participants with
respect to one of two meeting times:

A) 9:00 AM to 2:00 PM, Wednesday, September 13

      --- OR ---

B) 9:00 AM to 2:00 PM, Friday, September 15

Note that in both cases the meeting is likely to be much shorter, on the
order of two to four hours. The times I give above are merely the maximum
time we would have a room.

A possible negative against choice A) is that the SCSI CAP meeting occurs
concurrently (we may lose some otherwise interested parties to that working
group) while a possible negative against choice B) is that many T10
participants would rather be gone by Friday (at least it's an AM meeting,
so you can catch a flight home). If the study group meeting is not too
long, perhaps it's possible to arrange the CAP agenda to avoid conflict of

To help you assess your interest in this study group, a tentative agenda
for discussion is:

a) Reduced start-up latency from idle condition
b) Explicit description of how to transport 16-byte or larger CDBs
c) SBP modifications necessary for IEEE P1394.1 environment (Serial Bus
d) Isochronous facilities in SBP
e) Bi-directional data transfer (new ORB type)
f) Other items suggested by participants

There would be educational presentations made on a) and c) above.

The goal of the study group is to determine if a new work item should be
initiated and, if so, what should be its scope.

I have copied this to more than just the T10 reflector because possible
revisions to SBP-2 are of interest to a wider audience.

PLEASE RESPOND DIRECTLY TO ME and keep the reflectors uncluttered.


Peter Johansson

Congruent Software, Inc.
98 Colorado Avenue
Berkeley, CA  94707

(510) 527-3926
(510) 527-3856 FAX

PJohansson at

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