ZyXEL Communications VES1724-56 User Manual page 88

Chapter 8 Basic Setting
Table 17 Basic Setting > Port Setup (continued)
LABEL
Speed/Duplex
Rate Limit
Profile
per Port
per Queue
Flow Control
802.1p Priority This priority value is added to incoming frames without a (802.1p) priority queue tag. See
BPDU Control
Remote
Configuration
Apply
Cancel
88
DESCRIPTION
Select the speed and the duplex mode of the Ethernet connection on this port. Choices are
Auto, 10M/Half Duplex, 10M/Full Duplex, 100M/Half Duplex, 100M/Full Duplex and
1000M/Full Duplex (Gigabit connections only).
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.
These fields display the rate limit profile names you configure in the Rate Limit Profile
Setup screens. Refer to Section 8.10 on page 95
Select a rate limit profile from the drop-down list box. You can define the maximum incoming
and outgoing transmission data rate on a per-port basis.
Select a per queue rate limit profile from the drop-down list box. You can define the maximum
incoming and outgoing transmission data rate on a per-queue basis.
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 field
is available for an Ethernet port only.
Priority Queue Assignment in
Configure the way to treat BPDUs (Bridge Protocol Data Units) received on this port. You must
activate bridging control protocol transparency in the Switch Setup screen first.
Select Peer to look at the information in the received BPDUs. For example, the root bridge's
existence, if any bridge was added or removed from the STP (Spanning Tree Protocol)
network, if any loop occurred in the STP network.
Select Tunnel to add the incoming port's PVID on the received BPDUs and then forward them
to the next Switch.
Select Discard to drop all BPDUs received on this port. Set this only on an edge port of a STP
network.
Select Network to forward VLAN-tagged BPDUs to the next Switch directly and handle VLAN-
untagged BPDUs as the Peer option.
See Section 14.1.2 on page 161
Click Setting of a VDSL port to take you to a screen where you can configure settings for the
connected CPE device.
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 Save link on the top navigation panel to
save your changes to the non-volatile memory when you are done configuring.
Click Cancel to begin configuring this screen afresh.
for more information.
Table 12 on page 78 for more information.
for more information about BPDU.
VES1724-56 User's Guide