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



    
    
    Why should we?  The way it is the parameters can be checked without
    relation one to another.
    The is no logical flaw in having FirstBurstSize <> 0 and no use for it.
    
    Julo
    
    
                                                                                                 
                        Santosh Rao                                                              
                        <santoshr@cup.       To:     Eddy Quicksall <Eddy_Quicksall@ivivity.com> 
                        hp.com>              cc:     IPS Reflector <ips@ece.cmu.edu>             
                        Sent by:             Subject:     Re: ips : Is FirstBurstSize valid when 
                        owner-ips@ece.        InitialR2T=yes ?                                   
                        cmu.edu                                                                  
                                                                                                 
                                                                                                 
                        06-02-02 23:32                                                           
                                                                                                 
                                                                                                 
    
    
    
    
    I think this needs changing then. There's no reason the following
    should'nt be allowed :
    
    I -> T :
               InitialR2T=no
               ImmediateData=yes
               FirstBurstSize=65536
    
    T -> I :
               InitialR2T=yes
               ImmediateData=no
               FirstBurstSize=0
    
    Julian :
    Can we change the allowed valid range for FirstBurstSize from :
    
    FirstBurstSize=<number-512-to-(2**24-1)>
    
    to :
    
    FirstBurstSize=<number-0-to-(2**24-1)>
    
    
    - Santosh
    
    
    Eddy Quicksall wrote:
    >
    > Draft 10 says:
    >
    > FirstBurstSize=<number-512-to-(2**24-1)>
    >
    > So that means you can't send a 0, doesn't it?
    >
    > Eddy
    >
    > -----Original Message-----
    > From: Santosh Rao [mailto:santoshr@cup.hp.com]
    > Sent: Wednesday, February 06, 2002 3:01 PM
    > To: Fischer, Michael
    > Cc: 'Eddy Quicksall'; IPS Reflector
    > Subject: 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
    ##################################
    
    
    
    
    
    
    


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Last updated: Thu Feb 07 07:18:06 2002
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