CONFIGURATION AND INSTALLATION
Page 2-4
2.3.1
FDCMIMs Exclusively
By mixing FDCMIMs, you can create a stand-alone FDDI network of 4
to 56 nodes (7 FDCMIM-X8s in an MMAC-M8FNB = 56 master ports).
Depending on MMAC shunting capabilities, you may have to install
your FDCMIMs in adjacent slots to ensure continuity.
Two types of MMACs currently support FNB architecture — shunting
and non-shunting. Shunting MMAC-FNBs allow modules to continue
communicating on their perspective buses, regardless of whether
there is an empty slot between them in the chassis.
For example, let’s say you have FDCMIMs in slots 2, 3, 4, 6, and 7 of
an MMAC-M8FNB (slot 5 is empty). In a non-shunting MMAC, you
have two stand-alone networks (i.e., FDCMIMs in slots 2, 3, and 4
would constitute one network, and FDCMIMs in slots 6 and 7 would
constitute the other). Slot 5, the empty slot, breaks the continuity of
the non-shunting MMAC FDDI bus, separates it into two distinct
buses, and two separate networks.
However, with the same configuration in a shunting MMAC-M8FNB,
you would have one stand-alone network consisting of five FDCMIMs.
You don’t need to worry about empty MMAC slots, since the MMAC
FDDI bus, and FDCMIM communication remains intact.
The following table gives the part numbers of the MMAC chassis that
have shunting capabilities.
Table 2-1. MMACs with Shunting Capabilities
MMAC Chassis
Part #
MMAC-3FNB
FC000000000 or above
MMAC- 5FNB
CC000000000 or above
MMAC-8FNB
CG000000000 or above
MMAC-M8FNB
DK000000000 or above
MMAC-M5FNB
all
MMAC-M3FNB
all
