H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 110)

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Item Description
MDI
Set the Medium Dependent Interface (MDI) mode for the interface.
Two types of Ethernet cables can be used to connect Ethernet devices: crossover
cable and straight-through cable. To accommodate these two types of cables, an
Ethernet interface on the device can operate in one of the following three MDI
modes:
• Across mode.
• Normal mode.
• Auto mode.
An Ethernet interface is composed of eight pins. By default, each pin has its
particular role. For example, pin 1 and pin 2 are used for transmitting signals; pin 3
and pin 6 are used for receiving signals. You can change the pin roles through
setting the MDI mode.
• In across mode, the default pin roles are kept, that is, pin 1 and pin 2 for
transmitting signals, and pin 3 and pin 6 for receiving signals.
• In auto mode, the pin roles are determined through auto negotiation.
• In normal mode, pin 1 and pin 2 are used for receiving signals while pin 3 and
pin 6 are used for transmitting signals.
To enable normal communication, you should connect the local transmit pins to the
remote receive pins. Therefore, you should configure the MDI mode depending on
the cable types.
• Generally, the auto mode is recommended. The other two modes are useful only
when the device cannot determine the cable types.
• When straight-through cables are used, the local MDI mode must be different
from the remote MDI mode.
• When crossover cables are used, the local MDI mode must be the same as the
remote MDI mode, or the MDI mode of at least one end must be set to auto.
Flow Control
Enable or disable flow control on the interface.
After flow control is enabled on both ends, if there is traffic congestion on the device
on the local end, it sends information to notify the peer end to stop sending packets
temporarily; upon receiving the information, the peer end stops sending packets;
and vice versa. This is used to avoid packet loss.
IMPORTANT:
Flow control can be realized only when it is enabled on both ends.
Jumbo Frame Enable or disable the forwarding of jumbo frames.
Max MAC Count
Set the maximum number of MAC addresses the interface can learn. Available
options include:
• User Defined—Select this option to set the limit manually.
• No Limited—Select this option to set no limit.
Broadcast Suppression
Set broadcast suppression. You can suppress broadcast traffic by percentage or by
PPS as follows:
• ratio—Sets the maximum percentage of broadcast traffic to the total transmission
capability of an Ethernet interface. When this option is selected, you need to
enter a percentage in the box below.
• pps—Sets the maximum number of broadcast packets that can be forwarded on
an Ethernet interface per second. When this option is selected, you need to enter
a number in the box below.