Chapter 8 Basic Setting

Table 14 Basic Setting > Port Setup (continued)

LABEL

DESCRIPTION

Speed/

Select the speed and the duplex mode of the Ethernet connection on this

Duplex

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. 12G/Full Duplex is supported by the 10GBase-CX4

 

connections in the XGS-4528F or XGS-4728F.

 

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.

 

 

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

 

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.

 

 

802.1p

This priority value is added to incoming frames without a (802.1p) priority

Priority

queue tag. See Priority Queue Assignment in Table 12 on page 108 for

 

more information.

 

 

BPDU

Configure the way to treat BPDUs received on this port. You must activate

Control

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.

 

 

CX4 Cable

For the XGS-4526, this field is available when you install an EM-412

 

module in the Switch’s optional uplink module slot (see Section 3.2 on

 

page 41).

 

Select the number of meters for the length of the 10GBASE-CX4 cable you

 

use to connect between the Switch and another switch for stacking.

 

 

114

 

XGS-4526/4528F/4728F User’s Guide