26
C
HAPTER
1: I
NTRODUCTION
Windows 2000 Offload Features
Additionally, 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.
For more information on enabling and disabling offloads
for Windows 2000, see Using Windows 2000 Offload
Features on page 73.
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.