ZyXEL Communications VDSL SWITCH VES-1616F-3X User Manual
Page 74
Chapter 6 Basic Setting
VES-1616F-3x Series User’s Guide
74
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 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.
802.1P Priority This priority value is added to incoming frames without a (802.1p) priority queue tag.
See Priority Queue Assignment in
for more information.
BPDU Control
Configure the way to treat BPDUs received on this port. You must activate bridging
control protocol transparency in the Switch Setup screen first.
Select Peer to process any BPDU (Bridge Protocol Data Units) received on this port.
Select Tunnel to forward BPDUs received on this port.
Select Discard to drop any BPDU received on this port.
Select Network to process a BPDU with no VLAN tag and forward a tagged BPDU.
Ports 17, 18
Port
This is the port index number.
Active
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.
Name
Enter a descriptive name that identifies this port. You can enter up to 64 alpha-
numerical characters.
Note: Due to space limitation, the port name may be truncated in
some web configurator screens.
Type
This field displays 10/100/1000M for the Gigabit/ mini GBIC combo ports or 1000M for
the mini GBIC ports.
Speed/Duplex
Select the speed and the duplex mode of the connection on this port. Choices are
Auto, 10M/Half Duplex, 10M/Full Duplex, 100M/Half Duplex, 100M/Full Duplex
and 1000M/Full Duplex.
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.
Table 13 Port Setup (continued)
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