Re: iscsi: unsolicited data question

[Priya Viswambharan <priya@npd.hcltech.com>]

Hi Dennis,

These parameters ImmediateData and InitialR2T are session 
specific parameters that are negotiated during the Leading 
Only negotiations. Once negotiated they hold true for the 
life of the session because parameters once negotiated 
cannot be renegotiated.

If a target is operating in unsolicited mode, then the 
unsolicited mode is only for the initial data that the 
initiator wants to send to the target. In other words, for 
a target in unsolicited mode, the initiator does not have 
to wait for an R2T from the target to start sending data. 
Such unsolicited data may be sent either in the form of 
immediate data or through DATA Out PDUs. The maximum amount 
of unsolicited data that can be sent is up to the 
FirstBurstSize negotiated. If the initiator has more data 
to send then it must necessarily be solicited by the target 
through R2Ts.

Hope this clarifies.

Thanks
Priya

On Wednesday 12 June 2002 08:50 am, Dennis Young wrote:
> I have a question which has been asked before, but I
> couldn't find a direct answer in the archive.  The table
> on page 200 of draft 12 doesn't directly answer this
> question either.
>
> The first paragraph on page 36 of draft 12 says "Targets
> operate in either solicitied (R2T) data mode or
> unsolicited (non R2T) data mode." tells me that a target,
> at all times during a data sequence transfer, can be
>
> one or the other, but not both (non R2T for the initial
> data out, R2T for the
> remaining data).  Is this correct?
>
> Thanks,
> Dennis
>
> ---snip from an old email dated 3/30/2001---
>
> " Hi Julian
> Sorry if I'm covering old ground... Is it possible to use
> unsolicited data for the first burst and then request any
> remaining data using R2T? For example, if the target has
> a previously allocated buffer available (length defined
> by FirstBurstSize) for unsolicited data, then once the
> initiator has sent unsolicited data up to and including
> this amount then the remaining data (if any) can be
> requested using R2T once the target has the buffer space
> available.
> ...Matthew Burbridge Hewlett Packard, Bristol Telnet: 312
> 7010 E-mail: matthewb@bri.hp.com "

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