GarrettCom 500-Series User Manual
Page 18
Magnum 500-Series Switching Hubs
Installation and User Guide (08/98)
GARRETT
13
Example 4 : Magnum 528F
In another situation similar to Example 3 above, the network may need to be
linked with fiber cabling to a Fast Ethernet backbone. This application is handled by the
Magnum 528F, using one 100Mb switched copper port for local high speed servers and
users, while using the fiber 100Mb switched port for the fiber backbone connection.
Using the Magnum 528F’s 100Mb switched fiber port, one can implement a
Fast Ethernet switched fiber connection that runs in full-duplex mode. The result is a
high-speed LAN connection upstream with switched 100Mb full-duplex performance and
maximum fiber distance – all without a 100Mb media converter. Alternatively, two
Magnum 528Fs can be connected with switched 100Mb fiber to form a larger LAN.
When using a Magnum 528F’s 100Mb switched fiber port as a link, it is
frequently desirable to operate the connection to the upstream device in full-duplex mode
since 100Mb fiber cable has severe distance limitations at half-duplex. In this situation, it
is necessary to operate both ends of the fiber link with ports that have fixed 100Mb-speed
and user-determined full-duplex capability (no auto-negotiation).
Many low-end “commodity” switching hubs that only have RJ-45 ports with
auto-negotiation cannot support this application. They have no built-in fiber, and they do
not properly support 100Mb media converters. Even if they did support media
converters properly, the converters are awkward extra items that add substantially to the
cost. But the Magnum 528F models . . . with fixed 100Mb speed as a default setting on
the Fast Ethernet ports, and with manually-selected half- or full-duplex mode per Fast
Ethernet port . . . handle this application readily and economically.
Figure 2.4e: The Magnum 528F provides a 100Mb port for backbone connection.
100Mb Hub
10Base-T
F
H
F
H
1 2 3 4 5 6 7 8
LINK
RX
UPLINK
10Mb
Magnum 500-series
Switching Hub
GARRETT
L K RX
PW R
F/H
100
1 0
TX
RX
100 Mb
RX
LK
AUTO
F/H
Internet
100Mb Servers
and Workstations
10Mb Workgroup
Router
1 2 3 4 5 6 7 8
Magn um 800E
Workgrou p Hub
10 0 Mb/ s
GA RRETT
LI NK
RX
LI NK
RX
PWR COL
1 2 3
4
5 6 7
8
100Mb Fiber Link
100Mb Media
Converter