ZyXEL Communications MGS3520 Series, Руководство пользователя

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Chapter 3 Hardware Overview
MGS3520 Series User’s Guide
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3.1.2 Ethernet Ports
The Switch has 24 or 44 10/100/1000 Mbps auto-negotiating, auto-crossover Ethernet ports. In
10/100/1000 Mbps Gigabit Ethernet, the speed can be 10 Mbps, 100 Mbps or 1000 Mbps and the
duplex mode can be half duplex or full duplex.
An auto-negotiating port can detect and adjust to the optimum Ethernet speed (10/100/1000
Mbps) and duplex mode (full duplex or half duplex) of the connected device.
An auto-crossover (auto-MDI/MDI-X) port automatically works with a straight-through or crossover
Ethernet cable.
The Switch has two or four 1000Base-T Ethernet ports, which are paired with a mini-GBIC slot to
create a dual personality interface. The Switch uses up to one connection for each mini-GBIC and
1000Base-T Ethernet pair. The mini-GBIC slots have priority over the Gigabit ports. This means that
if a mini-GBIC slot and the corresponding GbE port are connected at the same time, the GbE port
will be disabled.
When auto-negotiation is turned on, an Ethernet port negotiates with the peer automatically to
determine the connection speed and duplex mode. If the peer Ethernet port does not support auto-
negotiation or turns off this feature, the Switch determines the connection speed by detecting the
signal on the cable and using half duplex mode. When the Switch’s auto-negotiation is turned off,
an Ethernet port uses the pre-configured speed and duplex mode when making a connection, thus
requiring you to make sure that the settings of the peer Ethernet port are the same in order to
connect.
3.1.2.1 Default Ethernet Negotiation Settings
The factory default negotiation settings for the Gigabit ports on the Switch are:
• Speed: Auto
• Duplex: Auto
• Flow control: Off
• Link Aggregation: Disabled
3.1.2.2 Auto-crossover
All ports are auto-crossover, that is auto-MDIX ports (Media Dependent Interface Crossover), so
you may use either a straight-through Ethernet cable or crossover Ethernet cable for all Gigabit port
connections. Auto-crossover ports automatically sense whether they need to function as crossover
or straight ports, so crossover cables can connect both computers and switches/hubs.
3.1.3 Transceiver Slots
These are slots for mini-GBIC (Gigabit Interface Converter) transceivers or 100 Mbps Small Form-
factor Pluggable (SFP) transceivers. A transceiver is a single unit that houses a transmitter and a
receiver. The Switch does not come with transceivers. You must use transceivers that comply with
the SFP Transceiver MultiSource Agreement (MSA). See the SFF committee’s INF-8074i
specification Rev 1.0 for details.
You can change transceivers while the Switch is operating. You can use different transceivers to
connect to Ethernet switches with different types of fiber-optic or even copper cable connectors.