   Duplex support


Duplex support
==============

Duplexing is a performance option that lets you choose how
the adapter sends and receives packets over the network.


PRO/100+ adapter duplex choices:
--------------------------------

Auto. The adapter negotiates with the full duplex
switch to send and receive packets at the highest
rate. The switch must support auto-negotiation. If the switch
does not support auto-negotiation, the adapter defaults to half
duplex.

Full duplex (requires full-duplex switch). The
adapter sends and receives packets simultaneously by using a
different wire to perform each function. This feature can
improve adapter performance by eliminating collisions.

Half duplex. The adapter performs one operation at a time
(because send and receive lines are shared); it either sends
or receives.


Configuring for full-duplex
===========================

If you have an auto-negotiating switch (an NWay* switch), 
the PRO/100+ adapter will automatically match the
duplex setting at the switch. If you don't have an auto-
negotiating switch, you'll need to manually configure the
adapter for full duplex support.

Configuration is specific to the driver you're loading for
your network operating system (NOS). See the sections for
your NOS below.

NOTE: If you're using the PRO/100+ adapter,
you must set the Speed when configuring for full-duplex
support. Don't leave the Speed set to Auto.

To set up the duplex mode, refer to the section below that
corresponds to your operating system. For example, if you
are running Windows NT on a Novell network, choose the
Windows NT method below.

Note that performance may suffer if your switch is not full
duplex and you configure the adapter to full duplex. Leave
the adapter on half duplex if you are not sure what type of
switch you are connected to.


DOS/ODI clients
---------------

Edit the NET.CFG file. Add the SPEED and FORCEDUPLEX
parameters under the link driver section. For example
   
   Link Driver E100BODI
   
   SPEED 100 (or 10 for 10 Mbps operation)
   
   FORCEDUPLEX 2


Windows* NT 3.51
----------------

Use the PROSet adapter setup utility:

1  Double-click the PROSet icon in the Control Panel.

2  Click Settings.

3  Set Network Speed on the adapter to 10 Mbps or 100 Mbps.
   
   If Network Speed is set to Auto, then Duplex drop-down
   box is disabled.

4  Set Duplex Mode to Full.

5  Click OK until prompted to restart. Restart Windows NT.


Windows* NT 4.0
---------------

1  Double-click the Network control panel icon in the
   Control Panel.

2  Go to the Adapters tab and click Properties.

3  Select an adapter from the list and click Settings.

4  Set Network Speed on the adapter to 10 Mbps or 100 Mbps.

5  Set Duplex Mode to Full.

6  Click OK until prompted to restart. Restart Windows NT.
   


Windows 95
----------

Use the PROSet adapter setup utility:

1  Double-click the PROSet icon in the Control Panel.

2  Click Settings.

3  Set Speed on the adapter to 10 Mbps or 100 Mbps.

4  Set Duplex Mode to Full.

5  Click OK until prompted to restart. Restart Windows 95.


Other NDIS 2.x based clients
----------------------------

Edit the PROTOCOL.INI file. Add the FORCEDUPLEX and SPEED
parameters to the E100B section. For example:
   
   [E100B_NIF]          ; varies depending on your NOS
   
   SPEED = 100          ; or 10 for 10 Mbps operation
   
   FORCEDUPLEX = 2







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