Specifications

A.11 FDDI Tree Configuration Examples

A–22 FDDI Configuration Capabilities

A.11.4 Example 4 — Dual Homing and Connection to an External Dual

Ring

In some cases it is desirable to connect the hub to an external dual ring, and config-

ure the network modules as FDDI trees within the hub backplane. In other cases, it is

also desirable to have a redundant connection from the hub to higher level concentra-

tors.

This second case (see Figure A–16) is commonly referred to as dual homing. Either

of these configurations requires the use of a concentrator at the top level of the FDDI

tree configuration.

NOTE

The network modules that are connected through the hub backplane are sin-

gle attachment station (SAS) modules. The term dual homing, in this case,

refers to the connection between the hub based tree and the external concen-

trators.

Figure A–16 External Dual Homed Connections to an FDDI Network

Figure A–17 shows the building block representation of the configuration example

described in Figure A–16.

Front Panel Ports

LKG-10080-96F

Switch

Backplane Ports

Switch Concentrator

SMSM

MMM