SORT BY:

LIST ORDER
THREAD
AUTHOR
SUBJECT


SEARCH

IPS HOME


    [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

    RE: MaxRecvPDULength question



    Robert,
    
    The reason for size rather than length in the name is that the other parameters limiting length/size of data transfers use size (MaxBurstSize and FirstBurstSize). I don't really care whether "size" or "length" is used to describe the number of bytes sent, but we should consistantly use the same term for the same meaning. 
    
    The rest of the document uses a mix of length and size. Length appears more frequently (largely because of its use in field names in packet formats), but size predominates in the key names where a change affects implementations.
    
    Regards,
    Pat
    
    -----Original Message-----
    From: Eddy Quicksall [mailto:eddy_quicksall@ivivity.com]
    Sent: Monday, June 10, 2002 1:58 PM
    To: Robert D. Russell; Julian_Satran@il.ibm.com; ips@ece.cmu.edu
    Subject: RE: MaxRecvPDULength question
    
    
    Below it says:
    
     "The DataSegmentLength in a Text *Request* MUST NOT exceed the
     iSCSI initiator's MaxRecvDataSegmentLength (a per connection and per
     direction negotiated parameter)."
    
    But it seems it should say "Response".
    
    Eddy
    
    -----Original Message-----
    From: Robert D. Russell [mailto:rdr@io.iol.unh.edu]
    Sent: Monday, June 10, 2002 3:43 AM
    To: Julian_Satran@il.ibm.com; ips@ece.cmu.edu
    Subject: Re: MaxRecvPDULength question
    
    
    
    Julian:
    
    It has been stated several times that at this late stage we
    should not be requesting changes that are just preferences.
    
    Nevertheless, due to apparent misunderstandings of its meaning,
    the key named MaxRecvPDULength in draft 12 is apparently going
    to have its name changed in draft 13.
    
    Fine.  No problem.
    
    However, to remove all possibility of future misunderstandings,
    why don't we give it a name that says precisely what it is:
    
    MaxRecvDataSegmentLength
    
    That way, the first sentence in the third paragraph of section
    9.7.1 would begin:
    
    "DataSegmentLength MUST not exceed MaxRecvDataSegmentLength
     for the direction it is sent ..."
    
    which seems to me to be the classic definition of a maximum.
    
    The issue of changing the name from MaxRecvPDULength started with an
    e-mail sent by Luben Tuikov on 21 May (who, by the way, did NOT want
    to change the name, just its meaning), and was followed by a short
    flurry of e-mails under the thread "MaxRecvPDULength question".
    
    Some of the names suggested on that thread were:
      MaxRecvDataLength        (21 May by Paul Konig)
      MaxRecvDataSegmentSize   (21 May by Pat Thaler)
      MaxRecvDataSegSize       (21 May by Pat Thaler)
      MaxRecvPDUDataSize       (22 May by Pat Thaler)
    
    and what got into the draft was this last suggestion by Pat.
    
    I don't believe there was a consensus for this choice (probably, as
    was stated by Pat several times, because most people don't really see
    the need for a renaming and didn't bother to participate in the thread).
    Therefore, I would ask you to reconsider the new name and ask for
    consensus on the new choice.
    
    I believe the name MaxRecvDataSegmentLength is so closely linked to the
    name DataSegmentLength that its meaning should be clear to even a
    first-time reader, especially given the statement in section 9.7.1
    quoted above.
    
    Furthermore, there clearly is the concept of DataSegmentLength elsewhere
    in the standard -- every PDU has a DataSegmentLength field.
    I could find no concept of PDUDataSize (or even "data size") elsewhere in
    the current draft.
    
    
    Whether or not this renaming happens (again), I believe there should be
    the following rewordings to be more precise in order to avoid any
    ambiguities and/or future misinterpretations.
    
    The first sentence in section 9.10.5 should be changed to read:
    
     "The DataSegmentLength in a Text Request MUST NOT exceed the
     iSCSI target's MaxRecvDataSegmentLength (a per connection and per
     direction negotiated parameter)."
    
    and the first sentence in section 9.11.6 should be changed to read:
    
     "The DataSegmentLength in a Text Request MUST NOT exceed the
     iSCSI initiator's MaxRecvDataSegmentLength (a per connection and per
     direction negotiated parameter)."
    
    Finally, two sentences in section 11.13 should be changed to read:
    
     "The initiator or target declares the maximum DataSegmentLength in
     bytes it can receive in an iSCSI PDU."
    
    and
    
     "The transmitter (initiator or target) is required to send PDUs with a
     DataSegmentLength not exceeding MaxRecvDataSegmentLength of the receiver."
    
    
    Thank you for your consideration,
    
    
    Bob Russell
    InterOperability Lab
    University of New Hampshire
    rdr@iol.unh.edu
    603-862-3774
    


Home

Last updated: Wed Jun 12 20:18:49 2002
10740 messages in chronological order