jgp@moscom.UUCP (Jim Prescott) (07/20/90)
Now that we are looking to expand our network I figure I should try to
get some answers to some of the questions that aren't answered in my
(very scanty) ethernet references.
We have a single segment ethernet that is part thick and part thin (just
a BNC to N connector between them, no repeater). I believe the allowed
limits for segments are:
thick 500m 100 stations
thin 185m 30 stations
and when mixed the thin lengths count 2.7 times.
How many stations can we put on such a network? Are we limited to 30 (the
pure thinnet limit) or can we "pro-rate" the station counts based on the
length of thin cable (eg. 15 stations on 90m of thin and 50 stations on
250m thick for a total of 65 on the segment).
What counts as a station? Is it just places where a reflection can happen
or do actual machines count? Would a delni be 1 station or 8 (or 9?)?
Is it ok to have more than one BNC<->N connector? Ie. can we mix and match
cable types freely or should all the thick be in one continuous run.
When you combine thick cables does the 2.5m spacing continue through
the barrel connector? I notice that the preferred lengths are not
even multiples of 2.5m. How important are the preferred thick lengths
(23.4m, 70.2m and 117m)?
How do multiport repeaters interact with the 5 segment maximum? Do all
the segments coming off a multiport count as 1? Or is the rule actually
that no 2 segments can be separated by more than 4 repeaters?
We have inherited some used thicknet cable that has had vampire taps
removed. Is this bad? I thought vampire taps were meant to be permanent.
Thanks for any help you can provide.
--
Jim Prescott moscom!jgp@cs.rochester.edu
{rutgers,ames,harvard}!rochester!moscom!jgp