ZyXEL Communications XGS-4728F User Manual page 90

Chapter 8 Basic Setting
Table 15 Basic Setting > Port Setup (continued)
LABEL
Name
Type
Speed/
Duplex
Flow Control
802.1p
Priority
90
DESCRIPTION
Type a descriptive name that identifies this port. You can enter up to 64
alpha-numerical characters.
Note: Due to space limitations, the port name may be truncated in
some web configurator screens.
This field displays 10/100/1000M for a 1000Base-T connection and 10G
for a 10 Gigabit Ethernet connection.
Select the speed and the duplex mode of the Ethernet connection on this
port. The choices are Auto, 10M/Half Duplex, 10M/Full Duplex,
100M/Half Duplex and 100M/Full Duplex for a 1000Base-T
connection. 1000M/Full Duplex is supported by both 1000Base-T and
1000Base-X connections. 10G/Full Duplex is supported by the 10 Gigabit
Ethernet connections.
Selecting Auto (auto-negotiation) allows one port to negotiate with a peer
port automatically to obtain the connection speed and duplex mode that
both ends support. When auto-negotiation is turned on, a port on the
Switch negotiates with the peer automatically to determine the connection
speed and duplex mode. If the peer 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, a 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 port are the same in order to
connect.
A concentration of traffic on a port decreases port bandwidth and overflows
buffer memory causing packet discards and frame losses. Flow Control is
used to regulate transmission of signals to match the bandwidth of the
receiving port.
The Switch uses IEEE 802.3x flow control in full duplex mode and
backpressure flow control in half duplex mode.
IEEE 802.3x 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 Flow Control to enable it.
This priority value is added to incoming frames without a (802.1p) priority
queue tag. See Priority Queue Assignment in
more information.
Table 13 on page 85 for
XGS-4728F User's Guide