| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE |
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 |
| Moderator: | NETCAD::COLELLA DT |
| Created: | Wed Nov 13 1991 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 4455 |
| Total number of notes: | 16761 |
Is this an appropriate place to discuss configuration questions with
DEChub90's and their associated modules? If not, would someone mind
directing me elsewhere? If so, thank you for considering the
following:
Everything in our bones tells us that this in an illegal configuration.
However, we would like to know what rules apply. In particular, we're
quite confused as to whether we use the 2-repeater rule, counting the
DR90C's as one and the DR90FL link segments as one, or whether we use
the DR90C's as a thinwire/aui segment with the 5-4-3 rule??????
DEChub90 -- Used as the "hub" in a "star"
DR90FL
-- DR90FL
/ DR90FL
fiber DR90FL
/ DR90FL
DEChub90 DR90FL
DR90C DR90FL DEChub90 DEChub90
| DR90FL --fiber-- DR90FL --fiber--DR90FL
thin DR90C DR90C
| DR90C DR90C --thin-- PC
PC |
thin
|
PC
To further show our confusion, would different rules apply if we where
using DEChub900's? In particular, how do we count the backplane, DR90C
to DR90FL?
Is there a good online guide to such configurations? We have the
Owners' Manuals for each of the products, but it is still unclear.
Any efforts to set us straight would be greatly appreciated.
Nancy Henderson
TBU Networks Internal Support
CSC/CS
PS: Our recommendation in this case was to bridge the additional hubs
beyond the "hub" DEChub90 connections, thus also allowing management
in those hubs.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 395.1 | answer | CGOS01::DMARLOWE | dsk dsk dsk (tsk tsk tsk) | Tue Sep 21 1993 17:20 | 58 |
Putting fiber bridges into the other hubs is goodness as you throw
out the repeaters rules so it's a legal config plus hub management.
DEChub90 -- Used as the "hub" in a "star"
DR90FL
-- DR90FL
/ DR90FL
fiber DR90FL
/ DR90FL
DEChub90 / DR90FL
DR90FA DR90FL
DR90C DR90FL DEChub90 DEChub90
| DR90FL --fiber-- DR90FL --fiber--DR90FA
thin DR90C DR90C
| DR90C DR90C --thin--PC Z
PC A |
thin
|
PC
It's illegal because the longest path PC A to PC Z goes through
90C, 90FA, 90FL, 90FL, 90FL, 90FA and a 90C. That's 7 repeaters.
I had to add one repeater the the left hub to get the fiber into
the hub (only had a 90C in it). As for segments there are thinwire,
fiber, fiber, fiber, thinwire which is legal as there are 5 segments
of which 3 or less are coax. Terminated hubs count as a zero length
coax so are not counted as a segment. Daisy chained hubs or hubs
with extended coax out of the side must be counted as a segment.
Now it could be legal if you want to calculate out delays through
all the repeaters and fiber and coax. But that's dangerous as the
customer could break the network in the future by just adding another
repeater of some fiber or coax. Rules are somewhere in the back
of the blue Open DECconnect book.
Change the diagram to the following:
DEChub90 -- Used as the "hub" in a "star"
DB90
-- DR90FL
/ DR90FL
fiber DR90FL
/ DR90FL
DEChub90 / DR90FL----------fiber--------
DB90FL DR90FL \
DR90C DR90FL DEChub90 \ DEChub90
| DR90FL --fiber-- DB90FL --DB90FL
thin DR90C DR90C
| DR90C DR90C --thin--PC Z
PC A |
thin
|
PC
Regards,
dave
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