This
story appeared on Network World Fusion at
http://www.nwfusion.com/columnists/2000/0904bradner.html
'Net
Insider:
Over
specification?
By Scott Bradner
Network World, 09/04/00
Standards
are good things. Standards are good for customers and good for vendors. They
are good for customers because they ensure that there are compatible
alternative products. They are good for vendors because they can significantly
increase the market for a technology. But there can be too much of a good
thing.
There has certainly been a problem with some vendors deciding
to "embrace and extend" standards, in the words of one, in a way that
negates any reasonable standards process, but some of that can be fought in the
marketplace. A more systemic problem is that standards organizations have a
tendency to produce standards that overspecify, reducing the ability of vendors
to develop innovative products that are still interoperable.
A few
years ago I, with a bunch of help from Internet Engineering Task Force mailing
list discussions, put together an IETF document that tries to give guidance
about when to mandate features in standards. This document (RFC 2119,
www.ietf.org/rfc/rfc2119.txt) ostensibly defines some key words for use in
standards documents, such as MUST, MAY and MUST NOT. But a key part of the
request for comment is a paragraph of guidance in the use of the specific
terms: "Imperatives of the type defined in this memo must be used with
care and sparingly. In particular, they MUST only be used where it is actually
required for interoperation or to limit behavior which has potential for
causing harm (such as limiting retransmissions). For example, they must not be
used to try to impose a particular method on implementers where the method is
not required for interoperability."
This guidance came to mind
yesterday when I took a look at a new TIA/ EIA interim standard on
"Performance and Interoperability Requirements for Voice-over-IP Feature
Telephones" (www.tiaonline.org/standards/ip/).
This is a
well-done document. It does an excellent job of how voice-over-IP phones need
to work. It does so for three types of voice-over-IP technologies: the
International Telecommunication Union's H.323, the IETF's SIP and megaco/H.248
which is the product of a joint IETF/ITU effort. But I think it goes a little
too far.
The document has a table (Table 5.2) that is an overview of
telephony features. It has a list of 23 features and subfeatures, each with a
requirement level. These range from the "mandatory" ability to
originate and accept calls to the "recommended" ability to encrypt
calls. I see too many features that are labeled mandatory which are not needed
for interoperability. I see no interoperability or harm-avoiding reason to
mandate a message-waiting indicator, for example.
To steal from
Einstein, standards should be as complete as they need to be and no more
complete. Going over the fuzzy line is counterproductive and will ensure less
innovate products.
Disclaimer: Harvard, like any good university,
ensures that lines are rarely sharp, but the above worry is my own.
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