Physical Features 11
can be connected to either a 10BASE-T, or 100BASE-TX
device.
For each port, the speed and duplex mode (half duplex
or full duplex for 10BASE-T and 100BASE-TX) are
automatically determined by the capabilities of the
connected device.
CAUTION: The Switch supports full duplex
auto-negotiation. If auto-negotiation is disabled for
1000BASE-T, then the Switch uses the forced-mode
default of 100 full duplex mode. If the connected device
does not support auto-negotiation, the Switch will
operate in half duplex mode (even if the attached device
is operating in full duplex mode). In such a
configuration, you may notice some degradation of
network performance. 3Com recommends that you use
devices that are capable of auto-negotiation (and that
you ensure that auto-negotiation is enabled, if it is a
configurable option).
(2) Gigabit Combo Ports (RJ-45/SFP)
The Gigabit combo ports (RJ-45/Small Form Factor
Pluggable (SFP) ports) are numbered 25 and 26. If the
link connections on the SFP ports are active, the
associated RJ-45 port of the same number is disabled.
The two SFP ports support fiber Gigabit Ethernet
short-wave (SX) and long-wave (LX) SFP transceivers in
any combination. This offers you the flexibility of using
SFP transceivers to provide connectivity between the
Switch and remote 1000 Mbps workgroups or to create
a high-capacity aggregated link backbone connection.
The default active port is the SFP port. The selection of
active ports can be configured via the Web interface.
The SFP port supports full duplex mode only.
SFP ports are numbered 25 and 26 on the Switch.
When an SFP port is active it has priority over the
10/100/1000 port of the same number. The
corresponding 10/100/1000 port is disabled when an
SFP link connection is active.
(3) Link/Activity Status LEDs
The first (top) and third row of LEDs, which are colored
yellow or green, show the link, activity and speed status
of the related ports:
10/100/1000BASE-T Ports
Status Meaning
Green The link is operating at 1000 Mbps.
Yello w The link is operating at 10 or 100 Mbps.
Flashing
Green
Packets are being received or transmitted on the
port at 1000 Mbps.
Flashing
Yello w
Packets are being received or transmitted on the
port at 10 or 100 Mbps.