| Title: | FDDI - The Next Generation |
| Moderator: | NETCAD::STEFANI |
| Created: | Thu Apr 27 1989 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2259 |
| Total number of notes: | 8590 |
I have a customer requirement to support the following on a Linden
configration (Sable with VME instead of EISA):
"Redundant Simultaneous connection to any two of the following LANs: FDDI,
E'net or TR"
With the new DEFPA (PCI/FDDI) is it possible to configure two on the
PCI, both with one active and one in backup mode to the same FDDI
ring(a) or connected to seperate rings with only one board active the other beimg
in standby (b) ??
(a) ======[Conc]======[Conc]===== (b) ====[conc]=====[conc]===
| : : | | :
| : : | | :
-+-----------+- | +----------+
P-----|DAS(DEFPA) | | P-----|DAS(DEFPA)| active
--------------- | ------------
C : | C
-+-----------+- ------------
I--------|DAS(DEFPA) | I-----|DAS(DEFPA | Stnby
--------------- +----------+
| :
| :
=====[conc]=====[conc]===
Any comments greatfully recieved !!
JanZ
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1456.1 | 56821::STEFANI | Have the # for the Mars Observer? | Tue Sep 27 1994 12:25 | 27 | |
re: .0
>>With the new DEFPA (PCI/FDDI) is it possible to configure two on the
>>PCI, both with one active and one in backup mode to the same FDDI
>>ring(a) or connected to seperate rings with only one board active the other beimg
>>in standby (b) ??
Assumptions: The DEFPA A and B ports are being connected to the
concentrator M ports.
In ring a, both DAS adapters are dual-homed to the two concentrators,
so the B port of each DEFPA will be active and the A port of each DEFPA
will be in standby...behaving the same as in all of our DAS adapters.
In ring(s) b, again, both DEFPA's are being dual-homed (except on
different rings), so the B port of each DEFPA will be active and the A
port will be in standby. From your picture, for card 2 to be standby
(not even port B active) you would need the help of some upper layer
software which would enable/disable the card at the right time. There
is nothing in the FDDI specifications that would cover separate FDDI
devices turning on after another one dies.
Also, even in ring a, if both DEFPA's are in the same system you will
need to have OS support to handle having multiple NICs on the same FDDI
ring and all that that entails (way too much to go into here).
- Larry
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