Because of
what Chuck pointed out, my feeling is that the TTT should be provided when the
A bit is set. It also makes the association faster since the ITT would require
a search by the target.
Eddy
-----Original
Message-----
From: Julian Satran
[mailto:Julian_Satran@il.ibm.com]
Sent: Saturday, February 16, 2002
2:52 AM
To: Chuck Micalizzi
Cc: ips@ece.cmu.edu
Subject: RE: iSCSI: DataACK SNACK
Chuck,
The Initiator Task Tag is thhe only
reliable indicator the protocol provides today.
If nobody shouts against it we might
let the target provide a Target Transfer Task for Data-In PDUs that have the A
bit set
to be returned with the ACK for
target convenience.
Julo
|
|
"Chuck
Micalizzi" <chuck.micalizzi@qlogic.com>
15-02-02 23:14
|
To: Julian Satran/Haifa/IBM@IBMIL
cc: <ips@ece.cmu.edu>
Subject: RE: iSCSI: DataACK SNACK
|
Julian,
Thank you for the response.
Let me try to be more direct.
If a target has been issued multiple
read commands, with transfer counts
that exceed the negotiated
maxBurstSize. After the target
sends a data sequence for one of these
commands must it wait for a DataACK
before sending a data sequence
for another command. Or is it free
to send a data sequence for each outstanding
command?
If the target can have a
data sequence in flight for each active command then
it must expect a DataACK for each
sequence sent with the Acknowledge
bit set. If the DataACK
SNACK doesn't include a task Tag the target can't be
certain as to which data sequence
the initiator is acknowledging. So how can
the target determine
which resources to free or which sequence to send next?
chuck
-----Original Message-----
From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
Sent: Friday, February 15, 2002 9:30 AM
To: Chuck Micalizzi
Cc: ips@ece.cmu.edu; owner-ips@ece.cmu.edu
Subject: Re: iSCSI: DataACK SNACK
DataACK is a "bulk ack". Answering the last (in case of several) is
good enough.
I fail to see your point.
Julo
|
|
"Chuck
Micalizzi" <chuck.micalizzi@qlogic.com>
Sent by: owner-ips@ece.cmu.edu
14-02-02 21:02
|
To: <ips@ece.cmu.edu>
cc:
Subject: iSCSI: DataACK
SNACK
|
All,
I have a question regarding DataACK.
Rev. 10 section 10.16.1 states:
For a Data/R2T SNACK, the Initiator Task Tag MUST be set
to the Initiator Task Tag of the referenced Command.
Otherwise, it is reserved.
it also states:
The DataACK is used to free resources at the target and
not to request or imply data retransmission.
Is the target allowed to have more than one DataACK
outstanding on a connection?
If multiple outstanding DataACKs are allowed per connection
then in my opinion the DataACK must have a valid task tag
inorder for the target to associate the DataACK with the
appropriate resources to be freed.
chuck micalizzi
Qlogic Corp.
