🚀 go-pugleaf

To continue the thread about concentrators and why use them:
>
> |>I want to test a FDDI ring, but I have only SAS cards, and I don't
> |>want to buy a concentrator. Can I do this?, and how ?
>
> SAS to SAS is allowed, ie.; a two `node' ring.  While not `legal', I suppose
> that some implementations will support rings with more than two SAS nodes,
> although I suspect that they would more legitimately be called `A' ports.
>
To answer the original question, can a ring of SAS cards be formed,
the answer is yes, with qualifications. You would have to disable
Connection Management (CMT) in all the SAS stations and would end up
with a single, uni-directional ring.

Most fiber FDDI stations use MIC type recepticles with which to attach
to the ring. A MIC recepticle has the ring in and ring out connectors
housed in a single, rectangular-looking unit. The other type of
connector available is an ST type connector. It looks sort of like a
BNC connector for fiber. An SAS would have two ST connections or a
single MIC recepticle. Fiber cabling is available that breaks the MIC
type connector out to two ST type connectors. Using ST connectors and
a small plastic jumper that allows you to connect two ST connectors
together, one could connect the ring out of the upstream station into
the ring in of the downstream station. In this way, a ring of SAS's
could be created.

David Sips
gator@vnet.ibm.com

My views do not represent the views of my employer.