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    Re: iSCSI: FirstBurstSize, etc



    Eddy,
    
    I am going to make some changes related to PDUsize. I will fix this 
    discrepancy and publish the suggested 09 text soon.
    
    Thanks,
    Julo
    
    
    
    
    "Eddy Quicksall" <Eddy_Quicksall@iVivity.com>
    11-10-01 22:22
    Please respond to "Eddy Quicksall"
    
     
            To:     Julian Satran/Haifa/IBM@IBMIL, <ips@ece.cmu.edu>
            cc: 
            Subject:        iSCSI: FirstBurstSize, etc
    
     
    
    I am wondering about the following statement:
    
      FirstBurstSize MUST NOT exceed MaximumBurstSize.
    
    It doesn't seem to fit the various definitions. I made the following 
    diagram
    from the definitions and FirstBurstSize came out larger then MaxBurstSize.
    
    Here are the definitions I am going by:
    
    25 FirstBurstSize
     Initiator and target negotiate the maximum amount of unsolicited data
     an iSCSI initiator may send to the target, during the execution of a
     single SCSI command, in units of 512 bytes.
    
    24 MaxBurstSize
     Initiator and target negotiate maximum SCSI data payload in an iSCSI
     sequence (a sequence of Data-In or Data-Out PDUs ending with a Data-In
     or Data-Out PDU with the F bit set to one) in units of 512 bytes.
    
    I get the definition of a sequence from "2.2.2.3 Data Sequencing":
    
     For output data PDUs, DataSN starts with 0 for the first data PDU of a
     sequence (the initial unsolicited sequence or any data PDU sequence
     issued to satisfy an R2T) and advances by 1 for each subsequent data
     PDU.
    
             |<------------------ Unsolicited data ------------------->|
             |                    |<------------ Sequence ------------>|
    |Command | Immediate Data  |  |<---- Remaining unsolicited ------->|
    |========|=================|  |================|  |F===============|
             |<-DataPDULength->|  | DataPDULength  |  | DataPDULength  |
                                  |<--------- MaxBurstSize ----------->|
             |<------------------- FirstBurstSize -------------------->|
    
    
    Eddy_Quicksall@iVivity.com
    
    
    
    
    


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