15
Duplex Mode (Optional)
Duplexing is a performance option that lets you choose how the adapter sends
and receives data packets over the network. The adapter can operate at full
duplex only when connected to a full duplex 10BASE-T or 100BASE-TX
switch, or to another full duplex adapter.
The possible settings for duplexing are:
•
Auto (requires a full duplex adapter or switch with auto-negotiation capa-
bility). The adapter negotiates with the switch to send and receive packets
at the highest rate. This is the default setting. If the switch does not provide
auto-negotiation, the adapter runs at half duplex.
•
Full duplex (requires a full duplex switch or adapter). The adapter can
send and receive packets at the same time. This mode can increase adapter
performance capability. If the full duplex switch provides auto-negotiation,
the adapter runs at full duplex. If the full duplex switch does not provide
auto-negotiation, you need to set the adapter duplex mode manually (see
the following sections), because it defaults to half duplex.
•
Half duplex. The adapter performs one operation at a time; it either sends
or receives.
NOTE:
If an adapter is running at 100 Mbps and half duplex, your potential
bandwidth is higher than if you run it at 10 Mbps and full duplex.
Manually Configuring for Full Duplex
If your switch supports auto-negotiation with the NWay* standard, duplex con-
figuration is automatic and no action is required on your part. However, many
currently-installed switches do not support auto-negotiation. Check with your
network system administrator to verify whether your switch supports this fea-
ture. Most installations require manual configuration to change to full duplex.
Configuration is specific to the driver you’re loading for your network operating
system (NOS).
To set up the duplex mode, refer to the section below that corresponds to your
operating system.
CAUTION: Adapter performance may suffer or your adapter may not operate if
your switch doesn’t support full duplex and you configure the adapter
to full duplex. The switch settings must always agree with the adapter.
Also, make sure to always set the speed when you configure duplex.