My personal opinions on the matter of "when should we allow multiple
protocols for the same thing" are roughly:
1) No hard and fast rule will work. This is something the relevant ADs,
and sometimes the whole IESG, must judge.
2) It is reasonable to allow two (or even more) protocols when they have
clear and distinct areas of applicability. Thus, while I may technically
like a routing solution that applies to intra and inter domain, it is quite
reasonable from a standardization perspective to have two different
protocols for the two spaces.
3) History is relevant. We frequently get solutions evolving independently
that turn out to have significant overlap. It requires significant care to
determinewhat should be used, when, and how. Often, this will require
allowing more than one standard for a time while we determine what works,
is technically complete, ...
In general, multiple protocols for the exact same thing are a bad
idea. Translating that into practice is complicated.
Joel M. Halpern
At 07:34 AM 4/16/2002 +0200, Harald Tveit Alvestrand wrote:
--On 15. april 2002 19:55 -0700 todd glassey
Harald - what is the IETF's policy on this question.
How many of any one protocol will the IETF allow to be push through to
standard. And the IESG? Is it that there is only one standard for each
type of protocol or what?
This is an official resuest,
Since this is an official request asking for what the IETF will allow, I
think it is best to ask the IETF community. Thus the CC to ietf(_at_)ietf(_dot_)org(_dot_)
The obvious (but meaningless) answer is "as many as needed".
Speaking for myself, I think it would be foolish of the IETF to create a
hard rule about this question - the circumstances may differ a lot.
Consider a few "multiple protocol" scenarios the IETF has faced recently.
- In the IPNG discussions, we decided to pursue IPv6 only.
- In the SNMP vs CMOT discussions, we decided to pursue two approaches.
One died, the other remains.
- In the OSPF vs IS-IS discussions, we decided to pursue two approaches.
Both survive, with little apparent harm to the community.
- In the SNMPv2 discussions, we decided to pursue one, then to pursue
multiple and "let the market decide", and then to pursue one again.
- In the case of CR-LDP vs RSVP-TE, we seem to be pursuing two.
One seems to be winning, but the market has not decided yet.
- In the PGP vs S/MIME discussions, we decided to pursue two, arguing
that they have different fields of applicability. Both survive so
far, but neither has become ubiquitous.
When we pursue multiple approaches, there is one very hard question -
which is when we take the decision to drop the pursuit of one approach.
Sooner or later the answer is usually obvious. But the cost of pursuit is
substantial; it would often be advantageous to concentrate on one as soon
as one is clearly superior to the others.
I'd like to hear the IETF community's input on the topic.
PS: The mail being responded to was addressed to the chair of the IETF in
his IETF role, and is thus a "contribution" under the terms of the NOTE
WELL statement you've all seen.