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    Re: ips : Is FirstBurstSize valid when InitialR2T=yes ?



    
    IMO, the FirstBurstSize key value negotiated during login is a don't
    care if *BOTH* immediate data and un-solicited data have been disabled. 
    
    However, if the target knows up-front that it does not support either
    immediate or un-solcited and it receives the key FirstBurstSize during
    login negotiation, it should return a 0 value as the result of the
    negotiation for FirstBurstSize. 
    
    (Note that the special semantics of 0 implying no limit is no longer
    true for FirstBurstSize and hence, the target can just return 0 iff both
    immediata data and un-solicited data are disabled in login negotiation.)
    
    - Santosh
    
    
    "Fischer, Michael" wrote:
    > 
    > What if the sequence is as follows:
    > 
    > I->T    FirstBurstSize=512; T=0; NSG=CSG;
    > T->I    FirstBurstSize=512; T=0; NSG=CSG;
    > I->T    InitialR2T=no, ImmediateData=no; T=1; NSG=FULL
    > 
    > If the target does not support InitialR2T=no..  Does login now fail?  There
    > does not seem to be a way for the target to say that it requires R2T.  Why
    > did the Initiator send FirstBurstSize if it was setting InitialR2T to no?
    > There is no negotiation with an AND function.
    > 
    > Michael Fischer
    > 
    > -----Original Message-----
    > From: Eddy Quicksall [mailto:Eddy_Quicksall@ivivity.com]
    > Sent: Wednesday, February 06, 2002 9:47 AM
    > To: Santosh Rao; IPS Reflector
    > Subject: RE: ips : Is FirstBurstSize valid when InitialR2T=yes ?
    > 
    > That is how I am interpreting it.
    > 
    > BTW: How about this one ...
    > 
    > I->T FirstBurstSize=512, InitialR2T=no, ImmediateData=no
    > 
    > If the target does not support InitialR2T=no, how should it respond to
    > FirstBurstSize?
    > 
    > Should the target do this (for draft >= 9)?
    > 
    > T->I FirstBurstSize=irrelevant, InitialR2T=yes, ImmediateData=no
    > 
    > Eddy
    > 
    > -----Original Message-----
    > From: Santosh Rao [mailto:santoshr@cup.hp.com]
    > Sent: Tuesday, February 05, 2002 2:56 PM
    > To: IPS Reflector
    > Subject: ips : Is FirstBurstSize valid when InitialR2T=yes ?
    > 
    > Hello,
    > 
    > Can someone clarify if the login key FirstBurstSize is valid when :
    > InitialR2T=yes  and ImmediateData=yes ?
    > 
    > i.e. if immediate data is enabled and un-solicited data is disabled
    > during login negotiation, is the value of FirstBurstSize received in the
    > login response to be interpreted ?
    > 
    > My current understanding is that FirstBurstSize is inclusive of the
    > immediate data portion, and so, if immediate data is enabled, but
    > un-solicited data is disabled, then, FirstBurstSize *must* be valid and
    > must be <= DataPDULength. (after rev 09, it would be <=
    > (MaxRecvPDULength - the header components size)).
    > 
    > For example, a target implementation may offer a FirstBurstSize <
    > DataPDULength, in which case, the immediate data size is the
    > MIN(DataPDULength, FirstBurstSize, bytes_to_send).
    > 
    > Can someone clarify if this is a correct interpretation or set me right
    > on this ?
    > 
    > Thanks,
    > Santosh
    > 
    > --
    > ##################################
    > Santosh Rao
    > Software Design Engineer,
    > HP-UX iSCSI Driver Team,
    > Hewlett Packard, Cupertino.
    > email : santoshr@cup.hp.com
    > Phone : 408-447-3751
    > ##################################
    
    -- 
    ##################################
    Santosh Rao
    Software Design Engineer,
    HP-UX iSCSI Driver Team,
    Hewlett Packard, Cupertino.
    email : santoshr@cup.hp.com
    Phone : 408-447-3751
    ##################################
    


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Last updated: Wed Feb 06 17:17:57 2002
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