| >>1 6610 VAX cpu, 1 DECbridge 900MX and 3 DECconcentrator 900MX's. All
>>of these are in the same room so distance is not an issue. I would
>>like to keep everything at UTP due to fiber costs.
Not possible. The DECbridge 900MX has two MMF DAS ports (A and B) so
you need to run fiber at least from the DECbridge to the GIGAswitch.
Also, what bus type does the 6610 use? I don't believe we make UTP
FDDI adapters except for EISA (DEFEA), TURBOchannel (DEFTA), and PCI
(DEFPA) buses.
>>The DECbridge 900MX only has a DAS port so I'm assuming I'm going to
>>need at least 1 DAS linecard (DEFGL-AB) to connect to the DECbridge.
>>The 6610 probably also has a DAS adapter. I know it has a SAS adapter
>>(You cant connect the 6610 with a SAS adapter to a DAS linecard can
>>you?)
I'm not sure of the GIGAswitch line options, but I thought you could
configure DAS (A and B) or SAS (S) ports, depending on your needs. You
can most certainly attach a SAS (S) port to the A or B port of a DAS.
That's actually one way of avoiding the cost of a concentrator. If, for
example, you wanted to connect two SAS and one DAS devices you can
just connect each S port to one of the DAS ports. It's not very fault
tolerant (if the DAS dies, the two S ports can no longer communicate)
but it's supported.
>>Now for the DECconcentrator 900's I'm a little confused. They will be
>>used to connect 6 PC's using the UTP option. What do I do for the
>>actual connection to the Gigaswitch. Is a DAS linecard the only
>>option? They will be in a DEChub 900 with HUBwatch software so I have
>>a feeling this gets in to A and B ports (DAS) and M ports (?).
First, you have to make sure the 6 PC's are running Digital FDDI EISA
cards (sorry, I just had to throw that in!) :-) Next, you have some
choices. You could dual-attach the concentrators so that the A port of
the concentrator attaches to a B port of the GIGAswitch and vice-versa.
Or, you can attach the A or B port of the concentrator to an S port of
the GIGAswitch. This isn't as fault tolerant as the first choice, but
it is supported. By the way, each concentrator has 6 ports, with at
least 4 M ports, so why do you need 3 concentrators?
>>If I can/should use DAS linecards for all devices, then I would simply
>>put 3 DEFGL-AB's into the GIGAswitch? (5 devices = 3 cards @ 2 ports
>>each).
You don't HAVE to dual-attach any of the nodes to the GIGAswitch.
Dual-attaching is more fault tolerant, and allows you to create a dual
ring, or implement dual homing, etc, but for mere connectivity you can
more or less ignore the fact that you have DAS ports and connect either
the A or B port of each node to an S port on the GIGAswitch, and leave
the other DAS port dangling.
Did I make this confusing enough? :-)
- Larry
|
| Thanks for the replies - I will look int he hub-mgnt file for the
specifics on the DECbridge configuration.
From what I can tell - and I do understand there are several ways to
approach this but if I don't dual attach everything (personally I think
this is BIG overkill but the customer wants to see the cost for this),
the following will work:
1 DEFGL-AB - 2 port DAS MM - the DECbridge 900 will connect to this
1 DEFFL-BB - 4 port SAS MM - 6610, and 3 DECconcentrators will connect
to this (I need 3 concentrators because I have a total of 13 PCs to
connect via UTP FDDI - yes, the PCs do have the DEFEA FDDIcontrollers
configured)
With this configuration I will have an unused DAS port which I could
connect a DAS device or 2 SAS devices, right?
Larry - thanks for the clear explanation. It's all starting to make
sense now (I think).
Cindy
|
|
As I indicated in the cross-post in the GIGAswitch notes,
conference, FGL-2 cards provide (A,B,M,S) ports. FGL-4 cards currently
provide S ports, although it is expected that they will eventually also
provide M port support. At this time, the modular PMDs which snap onto
the FGL cards come in three flavors: multi mode fiber, single mode
fiber, and unshielded twisted pair.
You are not required to use a DAS port to connect to a DAS port,
although in most circumstances, it makes more sense.
At this time, for configuring GIGAswitch FDDI ports, I'd use the
following rules of thumb:
DAS (A or B) required - FGL-2
M port required - FGL-2
Cost effective S ports - FGL-4
Most flexibility - FGL-2
FGL-2s can be converted from DAS to SAS and vice versa by taking
the card out and removing or adding PMDs. FGL-2s are made into M port
via SNMP network management (which can be done on the fly).
FGL-4s can not be converted to DAS. At this time, they can't be
made into M ports.
Note that FGL-4 cards may only be placed in certain GIGAswitch
slots - a maximum of 6 in a GIGAswitch.
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