3Com CoreBuilder 3500, Getting Started Manual

Page: 44 / 96

44 C
HAPTER
4: C
ABLING
Figure 20 Cabling the SAS Connection
For more information about single-attached stations,
see the
CoreBuilder 3500 Implementation Guide
.
Cabling a Dual-Attached Station
An FDDI module connected as a dual-attached station
(DAS) is connected to both the primary and secondary
rings of an FDDI network. Use DAS connections
where reliability is important and additional fault
tolerance is required. Each DAS connection consists of
an A port and a B port. In a typical DAS configuration:
■
The primary ring’s light signal is received on Port A
and reenters the primary ring through Port B.
■
The secondary ring’s light signal is received on
Port B and reenters the secondary ring through
Port A.
The six FDDI ports are labelled A1 through A3 and
B4 through B6, as shown in Figure 21.
Figure 21 FDDI Module Front Panel
Table 10 shows the associated ports that comprise
each possible DAS connection.
C
100 BASE - FX
3C54321
PWR
INS
ERR
1X
L
E
T
2X
L
E
T
3X
L
E
T
6X
L
E
T
5X
L
E
T
4X
L
E
T
INS
MODEM TERMINAL
ETHERNET
10BT
Duplex
SC connector
Network cable
SAS port
Table 10 DAS Connection Port Assignments
DAS Connection Port A Port B
1 A1 B4
2 A2 B5
3 A3 B6
FDDI MMF
3C35410
PWR
INS
ERR
L
E
T
L
E
T
L
E
T
L
E
T
L
E
T
L
E
T
A1 A2 A3
B4 B5 B6