Chapter 8 Basic Setting
GS1920v2 Series User’s Guide
87
8.8 Po E Sta tus
Note: The following screens are available for the PoE model(s) only. Some features are only
available for the Ethernet ports (1 to 8 for GS1920-8HPv2, 1 to 24 for GS1920-24HPv2, and
1 to 48 for GS1920-48HPv2).
O ve rvie w
The PoE model(s) supports the IEEE 802.3at High Power over Ethernet (PoE) standard.
A powered device (PD) is a device such as an access point or a switch, that supports PoE (Power over
Ethernet) so that it can receive power from another device through an Ethernet port.
In the figure below, the IP camera and IP phone get their power directly from the Switch. Aside from
minimizing the need for cables and wires, PoE removes the hassle of trying to find a nearby electric
outlet to power up devices.
Fig ure 64
Powered Device Examples
You can also set priorities so that the Switch is able to reserve and allocate power to certain PDs.
Flow Control
A concentration of traffic on a port decreases port bandwidth and overflows buffer memory
causing packet discards and frame losses.
Flo w C o ntro l
is used to regulate transmission of signals
to match the bandwidth of the receiving port.
The Switch uses IEEE802.3x flow control in full duplex mode and backpressure flow control in half
duplex mode.
IEEE802.3x flow control is used in full duplex mode to send a pause signal to the sending port,
causing it to temporarily stop sending signals when the receiving port memory buffers fill.
Back Pressure flow control is typically used in half duplex mode to send a "collision" signal to the
sending port (mimicking a state of packet collision) causing the sending port to temporarily stop
sending signals and resend later. Select
Flo w C o ntro l
to enable it.
802.1p Priority
This priority value is added to incoming frames without a (802.1p) priority queue tag. See
Prio rity
Q ue ue Assig nm e nt
in
Table 15 on page 82
for more information.
Apply
Click
Apply
to save your changes to the Switch’s run-time memory. The Switch loses these
changes if it is turned off or loses power, so use the
Sa ve
link on the top navigation panel to save
your changes to the non-volatile memory when you are done configuring.
Cancel
Click
C a nc e l
to begin configuring this screen afresh.
Table 17 Basic Setting > Port Setup (continued)
LABEL
DESC RIPTIO N
