3Com SuperStack 3 3870 Getting Started Manual page 14

12 C 1: I S 3870
HAPTER NTRODUCING THE WITCH
connect RJ-45 data connectors, network telephony systems, or network
telephones to these sockets.
Either shielded or unshielded data cables with shielded or unshielded
jacks can be connected to these data sockets.
10BASE-T/100BASE-TX/1000BASE-T Ports
The 10BASE-T/100BASE-TX/1000BASE-T ports have RJ-45 connectors and
are configured as Auto MDIX (cross-over).
The default state for these ports is auto-negotiation enabled, where the
speed, duplex, and flow control modes of a link are automatically
detected to provide the highest available bandwidth with the link partner.
Alternatively, auto-negotiation can be disabled. These ports can be
manually configured to 10 Mbps half-duplex, 100 Mbps half-duplex,
10 Mbps full-duplex or 100 Mbps full-duplex. It is not possible to
manually configure a 1000 Mbps link as auto-negotiation is mandatory in
the 1000 Mbps standard. If auto-negotiation is disabled, Auto MDIX
cannot function and the ports are fixed as MDIX (cross-over) mode.
If auto-negotiation is disabled on a 1000 Mbps port, the speed will drop
to the highest available speed. By default this is 100 Mbps.
Dual Personality SFP Ports
The 4 dual personality SFP (Small Form Factor Pluggable) ports support
fiber Gigabit Ethernet short-wave (SX), long-wave (LX) and long-haul
(LH70) 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 SFP ports are capable of auto-negotiating flow control. As the speed
and duplex modes are fixed by the media type, only the flow control is
negotiated with the link partner. Alternatively, auto-negotiation can be
disabled and the flow control setting can be manually configured.
Console Port
The console port allows you to connect a terminal and perform remote or
local out-of-band management. As the console port on the Switch is an
RJ-45 port, you will need to connect an RJ-45 to DB9 converter cable to a
standard null modem cable to connect a terminal.