ZyXEL Communications ENTERPRISE NETWORK CENTER Manual page 217

Table 100 Port Management > Basic Setting (continued)
LABEL
Copy
Port
Active
Speed/Duplex
Flow Control
802.1p
Priority
ENC User's Guide
DESCRIPTION
Click this to copy the selected port's settings to another port. The screen appears as
shown next.
Figure 165 Copy
Specify the port number to which you want to copy the selected port's settings. You
can use a hyphen and/or comma (,) to specify multiple ports. For example, 1,3-5,7
means ports 1, 3, 4, 5 and 7. Click OK to apply the changes to the Port
Management > Basic Setting screen.. Otherwise, click Cancel to discard the
change and close this screen.
This is the port index number.
Select this check box to enable a port. The factory default for all ports is enabled. A
port must be enabled for data transmission to occur.
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 device 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 device
determines the connection speed by detecting the signal on the cable and using half
duplex mode. When the device'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 device uses IEEE 802.3x flow control in full duplex mode and Back Pressure 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.
Chapter 8 Application
219