9000

Chapter 1 21

HP FDDI/9000 Resources

FDDI Concepts

Figure 1-1 FDDI Architecture

FDDI Devices

To promote ease of installation and maintenance, FDDI allows for

several types of networking devices. These include dual ring and single

ring concentrators, and dual ring and single ring stations. Concentrators

are the building blocks of an FDDI network. These stations and

concentrators connect to the FDDI ring as follows:

• Dual Attachment Concentrator (DAC): Connects to the dual ring and

serves as a hub for single or dual attachment devices. Also allows

stations to be added and removed from the ring with minimal

interruption of network trafﬁc.

• Single Attachment Concentrator (SAC): Connects to the primary ring

through a DAC and serves as a single ring hub. SACs can be stacked

to form a span of trees topology.

• Dual Attachment Station (DAS): Connects to a dual ring. Both

primary and secondary paths are connected.

Concentrator

DAS

FDDI-LAN Bridge

SAS

DAS

Dual Ring

DAC

Concentrator

SAS

SAC

Concentrator

SAS