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.
Sent: Saturday, February 16, 2002 2:52
iSCSI: DataACK SNACK
Task Tag is thhe only reliable indicator the protocol provides
shouts against it we might let the target provide a Target Transfer Task for
Data-In PDUs that have the A bit set
be returned with the ACK for target convenience.
Subject: RE: iSCSI:
you for the response.
Let me try to be more direct. If a target has been issued
commands, with transfer counts that exceed the negotiated
maxBurstSize. After the target sends a data sequence for one of
commands must it wait for a DataACK before sending a data
another command. Or is it free to send a data sequence for each
If the target can
have a data sequence in flight for each active command then
expect a DataACK for each sequence sent with the
bit set. If the
DataACK SNACK doesn't include a task Tag the target can't
as to which data sequence the initiator is acknowledging. So how
the target determine
which resources to free or which sequence to send next?
Sent: Friday, February 15, 2002 9:30
Subject: Re: iSCSI: DataACK
a "bulk ack". Answering the last (in case of several) is good
I fail to
see your point.
Subject: iSCSI: DataACK
I have a question regarding DataACK.
Rev. 10 section
For a Data/R2T SNACK, the Initiator Task Tag
MUST be set
to the Initiator Task Tag of the referenced
Otherwise, it is reserved.
The DataACK is used to free resources at the target and
not to request or imply data retransmission.
target allowed to have more than one DataACK
outstanding on a
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
appropriate resources to be freed.