3com 3848 사용자 설명서

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C
HAPTER
 1: I
NTRODUCING
 
THE
 S
UPER
S
TACK
 3 S
WITCH
3812, S
WITCH
3824, 
AND
 S
WITCH
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 
dua1740-0aaa03.book  Page 14  Thursday, December 23, 2004  9:23 PM