Allied Telesis AT-9000/24, Руководство по установке

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Chapter 1: Overview
18
Ports
The AT-9000/24 Gigabit Ethernet Switch features 24 twisted pair ports
and four combo SFP ports.
Twisted Pair
Ports
The twisted pair ports feature 8-pin RJ-45 connectors. (For the port
pinouts, refer to “Connectors and Port Pinouts” on page 50.)
The ports on the AT-9000/24 switch are 10Base-T, 100Base-TX, and
1000Base-T compliant and are capable of 10 megabits per second
(Mbps), 100 Mbps, and 1000 Mbps speeds.
The ports are IEEE 802.3u Auto-Negotiation compliant. With Auto-
Negotiation, the switch automatically matches the highest possible
common speed between each switch port and each end node. For
example, if an end node is capable of only 10 Mbps, the switch sets the
port connected to the end node to 10 Mbps.
Each twisted pair port on the switches can operate in either half- or full-
duplex mode. The twisted pair ports are IEEE 802.3u-compliant and Auto-
Negotiate the duplex mode setting.
Note
In order for the switch to set the duplex mode for each port correctly,
the end nodes that you connect to the switch ports should also use
Auto-Negotiation. Otherwise, a duplex mode mismatch can occur,
affecting network performance. For further information, refer to
“Duplex Mode” on page 23.
Each twisted pair port has a maximum operating distance of 100 m
(328 feet).
For 10 Mbps operation, Category 3 or better 100 ohm shielded or
unshielded twisted pair cabling is required. For 100 or 1000 Mbps
operation, Category 5 and Enhanced Category 5 (5E) 100 ohm shielded
or unshielded twisted pair cabling is required.
The twisted pair ports are auto-MDI. They automatically configure
themselves as either MDI or MDI-X. This feature allows you to use either
straight-through or crossover twisted pair cables to connect devices to the
ports.
SFP Ports
The four SFP ports can operate in place of their twisted pair port
equivalents to provide fiber optic connectivity. When an SFP is inserted in
the SFP ports (ports 21 through 24) and a fiber optic cable is connected,
the corresponding twisted pair port is disabled.