GarrettCom 500-Series - Manual (Page 27)

Magnum 500-Series Switching Hubs Installation and User Guide (08/98)
GARRETT
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may be made for each port separately. If the Magnum 528’s Fast Ethernet copper ports
are internally set for auto-negotiation (AUTO LED is ON), then the F/H switch selection
has no effect. The adjacent F/H LED will indicate the full- or half-duplex operating status
of the port as determined by the internal auto-negotiation logic.
4.4 Auto-negotiation option for Fast Ethernet copper ports
The Magnum 528 Switching Hub’s Fast Ethernet copper ports can be set for
either fixed 100Mb speed or for 10/100 speed F/H auto-negotiation per the IEEE802.3u
standard. The selection is made via an internal jumper (see Section 3.4 for jumper-setting
instructions ). The factory default setting is for fixed 100Mb speed.
At 100Mb-fixed speed, the user may select half- or full-duplex mode manually
on each Fast Ethernet port separately. The two Full/Half duplex manual switches are
located on the front panel next to their corresponding ports. See Section 4.3 above for
F/H manual switch description.
One frequently-used application for the Magnum 528’s Fast Ethernet ports is to
connect one of them using fiber cabling to another switching hub in the network
backbone, or some other remote 100Mb device. In this case, it is desirable to operate the
fiber link at 100Mb speed, and at either half- or full duplex mode depending on the
capabilities of the remote device. Standard commercially-available Fast Ethernet media
converters do not support auto-negotiation, and require that the switched port to which
they are connected be at 100Mb fixed speed. Attachment to 10/100 auto-negotiation
ports will not work properly. The Magnum 528’s Fast Ethernet ports handle this
situation easily in the default setting..
When the Fast Ethernet copper ports are set in the auto-negotiation mode, the
F/H manual switches have no effect. The AUTO LED will be ON. The operating speed
and F/H mode of the high speed ports can change at any time to adapt to (real or
imagined) changes in the network. The “10” and “100” LEDs will indicate the operating
speed.
When Magnum 528’s Fast Ethernet copper ports are set for auto-negotiation
and connected to an another auto-negotiating device, there are 4 different speed and F/H
modes selectable depending on what the other device supports. These are: (1) 100Mb
full-duplex, (2) 100Mb half-duplex, (3) 10Mb full-duplex and (4) 10Mb half-duplex.