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Cisco CGS 2520 Hardware Installation Guide
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Chapter 1 Product Overview
Cable Side
PoE ports. When both the power supply modules are installed, the system has enough power to support
all the eight ports as PoE ports. In case one of the power supply module fails, the power to the low
priority PoE ports is dropped, while power to the high priority PoE ports remains uninterrupted.
On a per-port basis, you control whether or not a port automatically provides power when an IP phone
or an access point is connected.
The 10/100 PoE ports use RJ-45 connectors with Ethernet pinouts. The maximum cable length is 328
feet (100 meters). The 100BASE-TX and 1000BASE-T traffic requires Category 5, Category 5e, or
Category 6 unshielded twisted pair (UTP) cable. The 10BASE-T traffic can use Category 3 or
Category 4 UTP cable.
For information about configuring and monitoring PoE ports, see the switch software configuration
guide on Cisco.com.
For information about port connections and port specifications, see the Connecting Devices to the
Ethernet Ports, page 2-24 and the Connector and Cable Specifications, page B-1.
Note The output of the PoE circuit has been evaluated as a Limited Power Source (LPS) per IEC 60950-1.
Dual-Purpose Ports
You can configure the dual-purpose ports on the switch as either 10/100/1000 ports or as SFP-module
ports. You can set the 10/100/1000 ports to autonegotiate, or you can configure them as fixed 10, 100,
or 1000 Mb/s (Gigabit) Ethernet ports.
By default, the switch selects the medium for each dual-purpose port (10/100/1000BASE-T or SFP).
When a link is achieved on one media type, the switch disables the other media type until the active link
goes down. If links are active on both media, the SFP-module port has priority, but you can use the
media-type interface configuration command to manually designate the port as an RJ-45 port or an SFP
port.
You can configure the speed and duplex settings consistent with the selected media type. For information
on configuring interfaces, see the switch software configuration guide.

SFP Modules

The switch Ethernet SFP modules provide connections to other devices. These field-replaceable
transceiver modules provide the uplink interfaces.The modules have LC connectors for fiber-optic
connections or RJ-45 connectors for copper connections. You can use any combination of the supported
SFP modules listed in Table 1-2 .