Enabling Task-Offload Capabilities (NDIS 5.1)
Note NDIS 5. x has been deprecated and is superseded by NDIS 6. x. For new NDIS driver development, see Network Drivers Starting with Windows Vista. For information about porting NDIS 5. x drivers to NDIS 6. x, see Porting NDIS 5.x Drivers to NDIS 6.0.
The TCP/IP transport enables a NIC's task-offload capabilities by setting OID_TCP_TASK_OFFLOAD. In this set operation, the TCP/IP transport passes, in the InformationBuffer, an NDIS_TASK_OFFLOAD_HEADERstructure that is followed immediately by an NDIS_TASK_OFFLOADstructure for each offload task that it is enabling.
The miniport driver must examine each NDIS_TASK_OFFLOAD structure in the InformationBufferto determine which offload tasks (checksum, IPsec, and/or large packet segmentation) are being enabled. The miniport driver must also examine the task-specific structure (NDIS_TASK_TCP_IP_CHECKSUM, NDIS_TASK_IPSEC, or NDIS_TASK_TCP_LARGE_SEND) in the TaskBufferof each NDIS_TASK_OFFLOAD structure to determine which specific capabilities for a particular offload task are being enabled.
The TCP/IP transport enables all offload capabilities for a NIC with a single set of OID_TCP_TASK_OFFLOAD. The miniport driver must fail any subsequent attempts to set OID_TCP_TASK_OFFLOAD.