[HECnet] FDDI and DECNET, clustering

[Sampsa Laine]

On 8 Apr 2009, at 21:34, Paul Koning wrote:
Sampsa> Anybody know how I would go about cabling such a beast, there
Sampsa> are four fibre optic ports on these things?

Wow, that takes me back a bunch of years...

Well I do try, I'm going to wire up a CBM 128D running CP/M as the OPA0: on one of these eventually :)


There are two basic FDDI cabling approches: dual ring, and tree of
concentrators.   The DEFPA can be hooked up either way because it has
the two ports (type A and B ports).

If you have other FDDI devices that also have A or B ports, just plug
A to B in a circular fashion, and you have a dual ring.   This is the
topology that FDDI originally started with early in its development.

So if I have two dual port PCI cards, one in machine 1, one in machine 2, I wire them:

1.A. 	-> 		2.B
2.A		-> 		1.B

To create a circle? Do I HAVE to do this, i.e. can I just wire one cable between machine 1 and 2 (the cables are EXPENSIVE, like 3x what the adapter cost me)?

Sampsa