ZyXEL Communications ES-1552 Switch User Manual


 
Chapter 6 Port Settings
ES-1552 User’s Guide
57
Flow Control 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 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 Enable to turn this
feature on or select Disable to turn it off.
Default Priority This priority value is added to incoming frames without a priority queue tag.
PVID Enter a number identifying an existing VLAN. The switch tags the incoming untagged
frames on that port so that the frames are forwarded to the VLAN group that the tag
defines.
Apply Click Apply to save your changes to the switch.
Table 9 Port Configuration (continued)
LABEL DESCRIPTION