Re: iscsi: unsolicited data question

[Thanu Skariah <tskariah@npd.hcltech.com>]

A target can operate in nonR2T (unsolicited) mode for initial data out
and 
in solicited mode for the remaining data.
Also if the ImmediateData=Yes is the agreed value during negotiation,
then it will
operate in unsolicited mode upto a data size of negotiated maximum PDU
size.
If during login negotiation, InitialR2T=No is the agreed value, then 
the initiator and the target will operate in unsolicited mode upto a
data size of 
negotiated FirstBurstSize.
If InitialR2T is Yes, and immediate data also yes, then target can
operate in nonR2T
mode for a size of data upto the maxmimum PDU size only.
If initialR2T is yes and immediate data is no, then the target cannot
operated in
nonR2T mode at all. All the data must be solicited in this case.
(draft - 12.97,Sec 2.2.3, page 35, last paragraph)

Thanks,
Thanu


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 "

-- 
Thanu Skariah
Member Technical Staff
HCL Technologies
http://san.hcltech.com