| 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 |
Hi,
Is this a valid configuration for a DECconcentrator
We want to use a DECconcentrator as a standalone module to interconnect
two systems (4000/300 with Fiber FDDI and an AXP 3000/xx with Twisted
Pair FDDI).
We use for that purpose a DECconcentrator 900MX in DECHUBONE with only
two PMD's (One for UTP and one for Fiber FDDI)
+------------------+
| DECconcentrator|
| in DEChubOne |
+---2-----3--------+
UTP MMode
We upgraded the DECconcentrator to the version 2.8
What we see is no LED activity on the UTP port with a loopback plug.
The questions:
1. Is this a valid configuration ?
2. Should we see some activity on the UTP with only loopback plug
connected ?
(We see no difference with or without loopback plug)
With the systems connected, we see activity on the fiber PMD but no
activity on the UTP PMD.
So we can't determine for the moment if there is a problem with the
Alpha FDDI controller or with the DECConcentrator or the cable.
3. Should be configured something other than the default with HUBwatch?
Thanks in advance,
Robert
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1587.1 | FRS Supports UTP Mod PMD's | NETCAD::TOWNLEY | Tue Oct 18 1994 16:52 | 8 | |
Hi,
The DEChub ONE-MX has not been released as of yet, where did you
get this unit from? We know in some of the earlier protos that the
UTP mod MD's did not work. We have implemented the changes that
allow all mod PMD's to work in the DEF1H (DEChub-ONE-MX) for FRS Nov
94.
Regards, Tom DEF1H Design Engineer
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| 1587.2 | It's a valid config | NETCAD::B_CRONIN | Tue Oct 18 1994 17:38 | 20 | |
It looks like a legal configuration, using ports 2 and 3 of the
concentrator. It should work OK.
The UTP loopback should be working, asuming that you used an FDDI
loopback, not a 10BASE-T loopback plug. The loopback should be
rejecting the connection, because the port thinks that it is
receiving an M-M connection, which is always rejected.
The FDDI twisted pair products transmit on pins 1&2 of the RJ45,
and receive on pins 7&8; the crossover is in the cabling, usually
in one of the patch cords - you choose whether it is at the office
end or the wiring closet end. The important thing is that 1&2 talk
to 7&8.
This may also be the problem with the cables - if 1&2 don't see 7&8
then it won't connect, so be sure that the cabling is correct. Straight
thru cabling won't work....
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