| 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 |
Where can I find configuration information for the new fibre modules?
We are in the process of working with a customer on their LAN design and we
have currently sold them a Thickwire backbone with hubs using DECbridge 90s.
With the new fibre modules, we have found a simpler solution and want to go
back to the customer with the new design, as we have not yet installed and the
customer is interested in a fibre solution.
But I need to confirm configuration rules so we don't violate the
2 repeater rule. How many repeaters can you have on a segment using the
fibre modules? My concern in the following design is the segment with the
DEMPR on it. The original design had a Thickwire instead of the DR90FLs and
used DEREN-RCs to link to the SNA Gateway CT.
DR90FL
+--+ +--+
| >------------< |DB90FL in hub
| | +--+
| |
| | +--+
| >------------< |DB90FL in hub
| | +--+
| |
| | +--+
| >------------< |DB90FL in hub
| | +--+
| |
| | +--+
| >------------< |DB90FL in hub
+---T | +--+
| +--+
| DR90FL
| +--+ +--+DR90FA +----------+
+---T >------------< [----------] DEMPR |
| | +--+ +-++++++++-+
| | |
| | +--+DR90FA | +-----+
| >------------< T------------+- +---T VAX |
| | +--+ | +-----+
| | |
| | +--------+
| >-----+ |SNA GTWY|
| | | +--------+
| | |
| | | +--+DB90FL in hub
| > +------< |
| | +--+
+--+
T = Thinwire connection
[ = Thickwire connection
> = Fibre connection
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 69.1 | Looks ok. | CGOS01::DMARLOWE | PDP 11: MOV -(PC),-(PC) | Wed Oct 28 1992 01:31 | 70 |
Well, lets look at the worst case path. I like to follow the
3 coax/2 link segment rule but the 4 repeater rule is good too.
8^)
First I don't think that you can connect the DR90FA via thickwire
to a DEMPR. The DR90FA AUI port is meant to connect to a DESTA
or H400x. Same goes for the DEMPR. The only way these two can
connect is thru a DELNI or 2 transceivers. Correct me if I'm wrong.
Start at the top DB90FL. The bridge renews the rules so who cares
what is to the right of the bridge. Go left to the top DR90FL.
That's link segment #1. Now out the coax to the lower DR90FL.
That's coax segment #1 and repeater #1. We will work towards the
DEMPR. We leave the lower DR90FL via fiber so that's link segment
#2 and repeater #2 in the chain. Into the DR90FA and out via thinwire.
That's repeater #3 and coax segment #2. Into the DEMPR and then
out any other thinwire port. That's repeater #4 and coax segment
#3 in the chain.
So you are ok by the 4 repeater rule and also by the 3 coax and
2 link segment rule. Going from the VAX to the SNAGWY also yields
the same count. If you replace any of the DB90FLs with DR90FLs
then you break the rules.
Assuming I'm right about the DR90FL and DEMPR AUI ports, I have
redrawn your diagram and put the counts in.
DR90FL
+--+ Link #1 +--+
| >------------< |DB90FL in hub
| | +--+
| |
| | +--+
| >------------< |DB90FL in hub
| | +--+
| |
Rep #1| | +--+
| >------------< |DB90FL in hub
| | +--+
| |
| | +--+
Coax #1 | >------------< |DB90FL in hub
+---T | +--+
| +--+
| DR90FL REP #3 REP #4
| +--+ Link #2 +--+DR90FA +----------+
+---T >------------< T--------- | DEMPR |
| | +--+ Coax #2| +-++++++++-+
REP #2| | | | |Coax #3
| | +--+DR90 --- | +-----+
| >------------< T------------+- +---T VAX |
| | +--+ | +-----+
| | |
| | +--------+
| >-----+ |SNA GTWY|
| | | +--------+
| | |
| | | +--+DB90FL in hub
| > +------< |
| | +--+
+--+
T = Thinwire connection
[ = Thickwire connection
> = Fibre connection
Hope that helps.
dmm
| |||||
| 69.2 | Thanks. | TROFS::WEBSTER | I joined AA...Acronyms Anonymous | Wed Oct 28 1992 16:49 | 7 |
Thanks. Glad you noticed that config error with the DEMPR/DEFAR connection. -Larry | |||||