3Com 3CR990-FX-97 manual Using Windows Offload Features, Enabling Offloads, Click Configure

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Using Windows Offload Features

	This chapter provides instructions for enabling offloads in a Windows 2000 environment.
	It also describes configuring IPSec offloads in a Windows 2000 environment.
	The 3CR990-FX-97 NIC supports offload features for Windows 2000 and Windows XP in
	an IP environment. The offload features are designed to enhance the Windows operating
	system capabilities by off-loading key TCP/IP networking and security tasks from the
	operating system:
NIC Offload Features	Description
IPSec Offload	Reduces CPU utilization by allowing the 3XP processor and a crypto chip on the NIC to
	perform data encryption operations.
TCP Segmentation Offload	Reduces CPU utilization by allowing the 3XP processor on the NIC to perform segmentation
	of TCP packets.

NOTE: Windows 2000 does not allow IPSec offloads and TCP Segmentation offloads for the same session. Though all offload types may be enabled, TCP Segmentation offloading does not occur during an IPSec session.

IP and TCP Checksum Offload	Reduces CPU utilization by allowing the 3XP processor on the NIC to perform the checksum
	calculation of TCP/IP and UDP/IP packets.
802.1P Packet Priority Offload	Reduces CPU utilization by allowing the 3XP processor on the NIC to perform the insertion of
	the 802.1Q tag header into the packet.

For more information on enabling and disabling offloads for Windows 2000, see

Chapter 4, “Using Windows Offload Features.”

Enabling Offloads

Windows 2000 provides the capability to individually enable or disable each of the four offload features. (The default setting for these features is enabled.)

To enable or disable individual offload settings in Windows 2000:

1Right-click the My Network Places desktop icon and select Properties. The Network and Dial-up Connections screen appears.

2Right-click the Local Area Connection icon and select Properties. The Local Area Connection Properties screen appears.

3Click Configure.

The 3Com NIC screen appears.

4Click the Advanced tab.

5Select Enable Offloads in the Property list box.

6Select the appropriate value in the Value entry box (shown in the following table) for the desired offload state.

7Close all open windows.

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