Re: SNMP support

In article <47628B0E.4080308@xxxxxxxxxxxxx>,
svein@xxxxxxxxxxxxx (Svein Skogen) wrote:

(I took the liberty of removing the lower half of this mail. See
previous mails in this thread for complete history)
David L. Mills wrote:
Heiko,

A couple of comments about this mission. First, last I looked SNMP had
a
really hard time with floating point and the scaling issues are
dangerous. Second, as mentioned several times on the NTP hackers wire,

we would very much like to shoot ntpdc and its fascist (mode 7)
protocol. As of now, many configuration issues can be performed using
the mode-6 (ntpq) protocol. While many ntpdc related issues can be
easily moved to the mode-6 protocol, which is based on UDP, the monlist

function of ntpdc really needs TCP, as experience with monlist and UDP

demonstrates. This paritcular combination of UDP and TCP would not be
friendly to SNMP.

I continue to speculate that an SNMP agent in an expert system would be

an ideal shotgun marriage between mode-6 and SNMP.

Dave


Disclaimer: I know parts of this has already been answered in the
thread, and I know that a lot of the basis for my comments are made
solely based on my memory of things, and memory (when you start to get
my age) isn't a perfect match of things that were, but rather some
guidlines to how things might have been. Thus I may be totally wrong, or
answering the wrong question. (Now, I can get to the point. :) )

One of the tricks I used in the old days for handling decimal numbers
(which is why we need the floating point, isn't it?) was to use two
variables, or to use a different (moving the decimal point) internal
value, and dividing by 10^x for display.

I'm guessing that what we need the floating point for, is the precision
on our peers, and the precision of our drift. These values are (iirc)
today a float number of milliseconds. And for all simplicity, they
should remain that way for human presentation, to avoid unnecessary
confusion.

An alternative that comes to mind is to use the scaled binary
representation of the base two logarithm of the millisecond value in
question. Zero would need to be handled as a special case. If the
value is signed, then a sign field will also be needed.

For example, one could express 274591 milliseconds as 1000*Log2(274591)=
18066.9248, or rounded to the integer 18067.

Joe Gwinn
.

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