ZyXEL Communications GS-2750 - Manual (Page 42)

Chapter 3 Hardware Overview
GS-2750 User’s Guide
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3.1.1 1000Base-T Ports
The Switch has 48 1000Base-T auto-negotiating, auto-crossover Ethernet ports (4 of which are
part of the Dual Personality interfaces). In 10/100/1000 Mbps Gigabit Ethernet, the speed can
be 10 Mbps, 100 Mbps or 1000 Mbps. The duplex mode can be both half or full duplex at 10
and 100 Mbps and full duplex only at 1000 Mbps.
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.
3.1.1.1 Default Ethernet Settings
The factory default negotiation settings for the Ethernet ports on the Switch are:
• Speed: Auto
• Duplex: Auto
• Flow control: Off
3.1.2 Dual Personality Interfaces
There are 4 Dual Personality interfaces, comprising 4 1000Base-T/mini-GBIC combo ports.
For each interface you can connect either to the 1000Base-T port or the mini-GBIC port. The
mini-GBIC ports have priority over the 1000Base-T ports. This means that if a mini-GBIC
port and the corresponding 1000Base-T port are connected at the same time, the 1000Base-T
port will be disabled.
3.1.3 Mini-GBIC Slots
These are 6 slots for Small Form-Factor Pluggable (SFP) transceivers. Four of them are part of
the Dual Personality interfaces and two are used for high speed uplink.
A transceiver is a single unit that houses a transmitter and a receiver. Use a transceiver to
connect a fiber-optic cable to the Switch. The Switch does not come with transceivers. You
must use transceivers that comply with the Small Form-Factor Pluggable (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 connectors.
• Type: SFP connection interface
• Connection speed: 1 Gigabit per second (Gbps)
1
To avoid possible eye injury, do not look into an operating fiber-optic module’s
connectors.