[comp.dcom.lans] FDDI follow-up

kwe@bu-cs.BU.EDU (kwe@bu-it.bu.edu (Kent W. England)) (04/15/89)

In article <8137@boulder.Colorado.EDU> 
bobk@boulder.Colorado.EDU (Bob Kinne) writes:
>
>The purpose of the dual ring is to recover from a cut or damaged
>connection between nodes.  If a node fails or powers down, the
>optical bypass permits the ring to continue to function in normal,
>non-wrap mode, bypassing the failed or removed station.  Any ring
>architecture needs to provide this bypass functionality.  

	I don't think it does.  If a node fails, as opposed to a link,
then the adjacent nodes wrap and the ring continues without the failed
node.

	I guess I am just not convinced that optical bypass buys you
that much.  I think the hundreds and hundreds of workstations are
going to be put on single ring FDDIs using star concentrators with
bypass capability (not optical I think).  These concentrators will be
on the dual ring backbone.
	But that's enough on that.  Just let me be in my own misguided
world.  I'll learn the truth soon enough.