3Com SuperStack II Switch 3000 10/100, User Manual

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1-2 C
HAPTER
1: G
ETTING
S
TARTED
Port Connections
10BASE-T / 100BASE-TX Ports
The Switch has 12 auto-negotiating 10BASE-T /
100BASE-TX ports configured as MDIX (cross-over).
These ports can be set to 10BASE-T, 100BASE-TX, or
they can automatically detect the speed of a link
and provide a 10Mbps connection to Ethernet
devices or a 100Mbps connection to Fast Ethernet
devices. The maximum segment length is 100m
(328ft) over category 5 twisted pair cable.
As these ports are configured as MDIX (cross-over),
you need to use a cross-over cable to connect to
devices whose ports are MDIX-only. Most of the
10BASE-T and 100BASE-TX ports in 3Com devices
are MDIX-only.
Plug-in Module
A slot at the rear of the unit can take a Plug-in
Module, providing an additional high-speed port.
This could be used, for example, to provide a Fast
Ethernet or Asynchronous Transfer Mode (ATM)
backbone connection to the rest of your network.
Switch Operation and Features
The Switch 3000 10/100 uses the same algorithm as
a conventional 802.1d bridge for filtering, forward-
ing and learning packets.
Intelligent Flow Management
Intelligent Flow Management (IFM) is a system for
controlling congestion on your network. Conges-
tion can be caused by one or more devices sending
traffic to an already busy port on the Switch 3000
10/100. If a port on the Switch 3000 10/100 is con-
nected to another switch or endstation, IFM pre-
vents packet loss and inhibits the device from
generating more packets until the period of conges-
tion ends.
IFM should be enabled on a port if it is connected
to another switch, or an endstation. IFM should be
disabled on a port connected to a repeater.
For more information about enabling IFM on a
port, refer to
“Setting Up the Switch Ports” on
page 4-12 .