- 3com Network Interface Card User Guide

Using Windows 2000 Offload Features 73
miniport icon name. If a miniport is associated with an
ungrouped NIC, you can identify the NIC by its MAC
address as follows:
1 In the Network and Dial-up Connections window,
right-click the miniport icon and select Properties
from the menu.
2 In the DynamicAccess Properties window, click the
General tab.
3 In the General tab, move the cursor over the miniport
name. (Do not click the name.)
After a short pause, the MAC address of the associated NIC
appears in a pop-up window.
Using Windows 2000 Offload Features
The 3CR990 NIC supports Windows 2000 offload features
in an IP environment. The Windows 2000 offload features
are designed to enhance the Windows 2000 operating
system capabilities by off loading key TCP/IP networking
and security tasks from the Windows 2000 operating
system:
■ 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.
■ IP and TCP Checksum Offload—reduced 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.
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 will not occur during an IPSec session.