Subject: Comments on CAP requirements draft

From: John Stracke <[email-masked]>
Date: Tue, 09 Mar 1999 07:48:33 +0000

Comments on draft-ietf-calsch-capreq-02:

   * Points of confusion:
        o It's never made clear what sub-calendars are for.  Is it the
          case that a calendar component contained in a sub-calendar is
          automatically contained in the parent calendar?
        o Section 4.1 lists points that CAP MUST specify; some of them
          seem to me to be either implicit or out of scope for a
          protocol spec.  For example:
             + "How to allow a CUA to be developed independently of a CS
               and a CS independently of a CUA."  Isn't this what a
               protocol is for?
             + "any CUA...MUST be able to interoperate with any CS."
               Again, this is motherhood and apple pie; if you don't
               have interop, you don't have a protocol.
             + "How to allow for a single CUA to access multiple CSs or
               calendars."  Isn't this an implementation detail? I can
               imagine a protocol which would prevent this capability,
               but you'd have to work pretty hard at it (e.g., by using
               broadcast instead of unicast).
             + "How to allow for interpersonal applications to be
               calendar enabled" and "How to allow for non-interpersonal
               applications to be calendar enabled".  I don't see why
               this belongs in a protocol spec; whether or not the CUA
               is combined in a larger program should not affect how it
               participates in CAP.
        o In 4.2.2, I think the various single/multiple, local/remote
          models can be simplified into two requirements:
             + CAP MUST enable a CUA to maintain a local CS and
               synchronize it with a remote CS.
             + CAP MUST enable a CUA to provide the user with a view
               which aggregates multiple CSes to appear and behave as if
               they were one CS.
        o 4.2.3: If CAP does not define users, then what's the user name
          in the CSID?
        o
   * Nits:
        o "A CSID consists of the user, password, host and port...".
          Should password be included in the ID, or should it be
          discussed under access control? If it's part of the ID, that
          implies that you might have two different stores that differ
          only in the password.
        o "Connected Mode" and "Disconnected Mode" are described in
          terms of mobile computing.  It might be worthwhile to omit
          this, because there are uses for disconnected mode even in a
          non-mobile environment.  A few examples:
             + The CS is not always available, so the users want to
               download their calendars for use when it isn't.
             + The user's favorite machine does not have a network
               connection for some reason, so they download the calendar
               on a machine that does and copy it over by floppy.  (Yes,
               it's ugly, but I know companies that have only one
               machine with an outside connection, and no internal LAN.)
             + The user's machine does have a connection, but it's a
               (slow, metered) PPP line, so offline work is a good
               thing.  (Again, it's ugly, but I know one company that
               does just this: rather than maintain their own network,
               they give everybody a modem and have them dial up an
               ISP.)
        o Do we need to define "the operational hours of a calendar"?
        o 4.4, "How the CUA can send an attachment to the CS"--it would
          probably be a Good Thing for a CUA to be able to specify an
          attachment which is shared among components.
        o 4.4.1--how about being able to delete a range of recurrences?
        o 4.4.1, "the CS MUST terminate the expansion
          eventually"--should there be an "etc." flag, so the CUA knows
          there's more that got suppressed?
   * Spelling/grammar points (which I will bring up only once, and will
     not argue about :-):
        o Plural of "CS" is "CSes", not "CSs".
        o 4.2.2, "MULTIPLE REMOTE CS"--plural.  (Also at the end of the
          first sentence in the paragraph.)
        o 4.3.1, "How a group operations on a set of calendars"--seems
          to be missing a verb.
        o 4.4.3, "CAP would permdit"--"permit".
        o 4.5.2, "How the CUA to retrieve any named property"--"can
          retrieve"

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