Waters Network Systems GSM2109-1009-8PoE, Руководство по эксплуатации

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Waters Network Systems GSM2109-1009-8PoE User’s Manual Page 9
PoE ports eliminates the need to run 110/220 VAC power to other devices on the LAN.
The same CAT5 Ethernet cable that carries data to each device can also deliver power
over the same cable. This allows greater flexibility in the location of network devices
and can help reduce installation costs.
There are two system components for PoE: the power sourcing equipment (PSE) which
initiates the connection to the second component--the powered device (PD). The current
is transmitted over two of the four twisted pairs of wires in a CAT5 cable.
The PoE ports follow the IEEE 802.3af standard and are completely compatible with
existing Ethernet switches and networked devices. Because the PSE tests whether a
networked device is PoE-capable, power is never transmitted unless a PD is located at
other end of the cable. It also continues to monitor the channel. If the PD does not draw a
minimum current because it has been unplugged or physically turned off, the PSE shuts
down the power to that port. Optionally, the standard permits PDs to send a signal to
the PSEs for their power requirement.
The switch will automatically detect the speed of connected devices to accommodate 10,
100, 1000Mbps on the RJ45 ports. All RJ45 ports support the Auto MDI/MDIX function.
With the built-in Web-based management functionality, managing and configuring the
switch is easy. From cabinet management to port-level control and monitoring, you can
visually configure and manage your network via your Web Browser. The switch can be
managed via a web browser, Telnet, CLI or SNMP Management.
Ethernet switching technology dramatically boosted the total bandwidth of a network,
eliminating congestion problems inherent with the carrier sense multiple access with the
collision detection (CSMA/CD) protocol and greatly reduced unnecessary transmissions.
This revolutionized networking. First, by allowing two-way, simultaneous transmissions
over the same port (full-duplex), bandwidth was essentially doubled. Second, by