Conference netcad::hub_mgnt

1970.0. "next FDDI firmware questions" by TLSE01::SELLES (Pierre-Jean - Toulouse -France) Tue Feb 07 1995 06:35

	will next firmware for FDDI dec900MX allow "auto-healing"
and "redundant root configuration" with TREE configurations ?

from the Karl Pieper configuration guide , those functions are
perfectly suited for a highly redundant and reliable configuration .


my favorite customer wants to achieve maximum availability ( optical bypass ,
dual homing ... ) 

now, with existing firmware , inside a chassis , 
if 3 concentrators are dual-ringed together and attached to 
an external ring , then , if the middle one fails , then the left and right 
ones are going to wrap  ; and if this occurs in 2 separate chassis ,
then i risk having two separate rings , even with optical bypasses ( that 
is in this case are of no use ) .   [ there are 14 chassis interconnected ]

now if we can configure the conc900s in one chassis as "redundant root
configuration" with 2 modules connected to external dual-ring 
and others in internal tree , in case any of the module fails , this reduces 
the "separate rings" problem .
 

well even in the case of a simple tree inside the hub , or 
even with dual-ring inside the hub , with auto-healing 
this would dramatically reduces this problem .



thanks for any ideas about  this very hot topic for my customer 



PS : by the way , we thought of replacing the existing configuration with all the 14 
hubs interconnected by dual-ring and each equiped with an optical bypass ; by 
another configuration of only 3 hubs with dual-ring interconnections , and all other 
hubs "dual-homed" to this 3 "core" hubs ;
 but with existing firmware it should not be possible as
we cannot "dual-home" the  3dual-ringed conc900s of one hub ;
 so it should be 
possible with "tree" configuration as only one Conc of the 3 is going to be dual-homed 

	re-thanks for any confirmation of this behaviour