RE: profiles - a way to simplify iSCSI

[Black_David@emc.com]

> iSCSI keeps getting richer in negotiable parameters/features.
> Although flexibility is a great thing every new negotiable
> parameter/feature get us all worrying about:
> 
>    what it will break when used in combination with other
>    parameters/features
>    how are we going to test that all our combinations work as we think
that
>    they are specified
>    are we understanding/specifying the combinations the same way as
anybody
>    else

All worthy questions, but I think one important one
is left out - Why does iSCSI have so many negotiable
parameters/features? This leads into ...

> I assume that many of you are wondering, as I do, if all this flexibility
> is really worth it's price.

If it leads to implementations that fail to
interoperate, the answer is "no".

> Would the community not be better served by specifying profiles that are a
> complete-and-invariable combination of features and very small set of
> numerical parameters?

I think it's incumbent on the WG to reduce the amount
of flexibility by removing things and restricting
implementation flexibility (e.g., specifying that for a
certain set of features implementations MUST support
all of the features in the set if they support any one
of them).  This belongs in the main body of the
specification, not a separate profile.  See RFC 2119
for the appropriate terms to use in specifying requirements
for implementations.

IMHO, if a specification requires profiles in order to
obtain interoperable implementations, then the specification
itself is insufficiently precise and needs to be tightened
in order to merit approval as a proposed standard RFC.

It's time to start thinking about what we can take out ...

Writing as an IPS WG co-chair,
--David

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David L. Black, Senior Technologist
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