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    Re: iscsi: Text keys



    
    
    comments/answers in text.
    
    Thanks,
    Julo
    
    sandeepj@research.bell-labs.com (Sandeep Joshi) on 02-05-2001 06:49:53
    
    Please respond to sandeepj@research.bell-labs.com (Sandeep Joshi)
    
    To:   ips@ece.cmu.edu
    cc:
    Subject:  iscsi: Text keys
    
    
    
    
    Julian,
    
    Some comments on the text keys defined in Appendix E.
    
    thanks,
    -Sandeep
    
    1) There are several text keys which have been specified
       with Use=ALL.  Such keys can be negotiated during
       full-feature phase, which raises interesting questions
       about their effect on currently outstanding tasks.
    
       For example,
       a) maxOutstandingR2T : what is the effect on currently
          outstanding R2Ts ?
       b) LoginLogoutMaxTime : how does it affect connections
           which just got dropped and need to be recovered ?
       c) DataPDULength : effect on data PDUs in flight.
    
       Similar questions need to be answered for practically
       all the keys which have this behaviour.  For the sake of
       simplicity, it may be better to forbid such usage and
       allow these keys to be only negotiated in the connection
       or session login phase.
    
    +++ some of the parameters you mentioned are SCSI mode-page parameters.
    Even if we
    restricted them to login they can be changed by a SCSI mode-set.  I agree
    that keeping them all
    restricted to login would simplify implementations but I am not convince it
    would make them better. Evidently a negotiated change will apply to all
    packets that are sent after the negotiation ended (and a negotiation end is
    known to both parties) and an initiator will avoid sending things in
    violation of its last offering.
    Except that we will have to find a way to reject mode set I am open to
    restrict those parameters to login if that is what the majority of
    implementors tells me.
    +++
    
    2) The paragraph on TargetAddress seems to indicate that one
       or more text responses could be sent to satisfy a SendTargets
       command.
          "If the list cant be delivered as a single text
          response PDU, ..several text response PDUs can
          be sent..logical merge of the individual lists".
    
       How does the initiator know more than one TextResponse PDUs
       are expected for that TextCommand PDU ?  If the final bit is
       to be used, does it imply that the initiator should keep
       sending the sendTargets TextCommand with f=1 until it
       receives the last TextResponse PDU ?
    
       Could you please clarify...
    
    +++ the value 0 in the F bit of a text commands tells you that there is
    more to come.
    I addition I think that the naming and discovery folks are looking at a
    "list syntax"
    ++++
    
    3) SendTargets again.  The ordering within the text response
       currently is implied and needs to be specified so that
       the initiator can correlate the target alias with the
       target addresses.
    
       Something along these lines may help
         "The order within a text response should be
           (targetName, targetAlias(if any), list of addresses)"
    
    +++ I have to coordinate this with the Naming and discovery team.  +++
    
    4) The section on InitiatorName seems to imply that the
       target can also propose the value for this key ??
       I presume this is a typo.
          See "Who: Initiator and Target"
    +++ it is a typo thanks +++
    
    
    
    


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Last updated: Tue Sep 04 01:04:48 2001
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