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58 SunFDDI/P1.0 Adapter User’s Guide—May 1997
6
FDDI ConcentratorsFDDI concentrators are multiplexers that attach multiple single-attached
stations to the FDDI ring. An FDDI concentrator is analogous to an Ethernet
hub.
The FDDI protocols define two types of concentrators:
•Single-attached concentrator (SAC)
•Dual-attached concentrator (DAC)
Single-Attached Concentrator (SAC)
A single-attached concentrator (SAC) is attached to the FDDI network through
a single connector,which is identical to the S-port on a single-attached station.
It has multiple M-ports, to which single-attached stations are connected, as
shown in Figure6-6.
Figure6-6 Single-Attached Concentrator (SAC)
Single-attached station
(SAS)
Pin
Pout Data from upstream stationData to downstream station
Single-attached
concentrator
(SAC)
S-port
Single-attached station
(SAS)
S-port
S-port
Single-attached station
(SAS)
S-port
M-port M-port M-port