3Com 3848 Switch User Manual


 
14 CHAPTER 1: INTRODUCING THE SUPERSTACK 3 SWITCH 3812, SWITCH 3824, AND SWITCH 3848
Figure 3 Switch 3848 — front view
WARNING: RJ-45 Ports. These are shielded RJ-45 data sockets. They
cannot be used as standard traditional telephone sockets, or to connect
the unit to a traditional PBX or public telephone network. Only 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 four 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
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