| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 2697.1 | Tree of PEswitches connected to external ring.... | NETCAD::BATTERSBY | | Thu Aug 31 1995 13:29 | 4 |
| It looks like a tree of PEswitch 900TX's connected to an external
ring via a DECswitch 900EF.
Bob
|
| 2697.2 | Yes, but is it supported ? | BERN02::DEY | Walter Dey, MCS NS, Berne Switzerland | Thu Aug 31 1995 13:50 | 2 |
| Yes; but is this a supported configuration; I have 4 point to point
connection over the backplane.
|
| 2697.3 | You have only 1 ring here! | NETCAD::IANNARONE | | Thu Aug 31 1995 14:27 | 13 |
| Walter,
Your picture shows only 1 ring. Since your 5 modules are connected
together over the backplane, they are 5 stations on a single ring. This
configuration is valid and should be supported if you have the most recent
firmware release. You CAN form 4 independent rings on the backplane since there
are 8 slots in the dechub 900 backplane; each of the 4 rings would require 2 of
the available slots, and the 2 modules in each of those slot pairs would be
connected to each other over the backplane. In order to be independent rings,
however, the 4 pairs would NOT be connected to each other...
Hope this helps...
John
|
| 2697.4 | Slight correction, it's a tree topology on the backplane.. | NETCAD::BATTERSBY | | Thu Aug 31 1995 14:44 | 8 |
| Walter, as John said this is a supported configuration.
If you take a peek at note #2340 (Karl Pieper's FDDI config rules),
you will see that your config is similar to diagram #13 of the rules
except that your's has 2 more PEswitch 900TX's. So what you have is
a TREE topology on your backplane consisting of 4 PEswitches connected
to an external ring via a DECswitch 900EF.
Bob
|
| 2697.5 | | BERN02::DEY | Walter Dey, MCS NS, Berne Switzerland | Thu Aug 31 1995 14:54 | 12 |
| Thanks for your answer John !
I very much hoped that this is the case, but all the drawings I've seen
only connected maximum 3 modules over the backplane FDDI.
btw. this implies that a configuration with 7 PE and 1 FE connected over
the backbone FDDI is also possible, where the FE does the external link
to the backbone FDDI ?
Cheers
Walter.
|
| 2697.6 | Power limitation would not support this... | NETCAD::BATTERSBY | | Thu Aug 31 1995 15:12 | 9 |
| Well, this won't quite work. The limitation will be power available
to the backplane. Each PEswitch requires 50.5 watts, and a DECswitch
requires 67.5. with 3 power supplies there is 420 watts availiable.
Now 15 watts goes to the MAM, so there is 405 watts left over.
Seven Peswitches requires 353.5 watts, plus a DECswitch at 67.5 watts
adds up to 421 watts. So you can only have 6 PEswitches and a DECswitch
in your backplane.
Bob
|
| 2697.7 | The infamous new power supply should fix that problem | THEPUB::JRS | John SHADE - 'Attila the Nun' | Wed Sep 06 1995 09:49 | 8 |
| RE: .-1
The new H7894-MA power supply is rated for 163 watts of output power, so
a 7PE and 1 FE configuration should be possible. No?
3 * 163 = 489 > 421
-John
|
| 2697.8 | | STRWRS::KOCH_P | It never hurts to ask... | Wed Sep 06 1995 10:10 | 5 |
|
Yes, it may be possible, but I believe work needs to be done for
firmware support for power management. Other notes seem to indicate
this support will be forthcoming, but I wouldn't sell any short term
projects based on the availability of updated firmware...
|
| 2697.9 | See note #2436 for more on new power supply..... | NETCAD::BATTERSBY | | Wed Sep 06 1995 13:30 | 11 |
| <------ RE: .7
John, Ted is correct in his statement when he refers to other
notes in here which discuss the new power supply. Topic #2436
discusses the new features in the H7894-MA and the thread of
replies discusses that there is some work under way to work on
the changes needed to the MAM firmware to support a new power
allocation algorythm. As usual, there will probably be no discussion
in here of when this will be available in an updated release.
Bob
|