Determining Task Offload Capabilities

NDIS supports task offload services that are enhanced forms of the NDIS 5.1 and earlier task offload services. For more information about how to determine connection offload capabilities, see Determining Connection Offload Capabilities.

NDIS provides the offload hardware capabilities and the current configuration of the underlying miniport adapter to protocol drivers in the NDIS_BIND_PARAMETERS structure. NDIS provides the task offload hardware capabilities and current configuration of the underlying miniport adapter to filter drivers in the NDIS_FILTER_ATTACH_PARAMETERS structure.

Administrative applications use object identifier (OID) queries to obtain task offload capabilities of a miniport adapter. However, overlying drivers should avoid using OID queries. Protocol drivers must handle changes in the task offload capabilities that underlying drivers report. Miniport drivers can report changes in task offload capabilities in status indications. For a list of status indications, see NDIS 6.0 TCP/IP Offload Status Indications.

Administrative applications (or overlying drivers) can determine the current task offload configuration of a network interface card (NIC) by querying the OID_TCP_OFFLOAD_CURRENT_CONFIG OID.

The NDIS_OFFLOAD structure that is associated with OID_TCP_OFFLOAD_CURRENT_CONFIG specifies the following:

• The header information, which includes the task offload version that the TCP/IP transport supports.

• The checksum offload information, in an NDIS_TCP_IP_CHECKSUM_OFFLOAD structure.

• The large send offload version 1 (LSOV1) information, in an NDIS_TCP_LARGE_SEND_OFFLOAD_V1 structure.

• The Internet protocol security (IPsec) information, in an NDIS_IPSEC_OFFLOAD_V1 structure.

• The large send offload version 2 (LSOV2) information, in an NDIS_TCP_LARGE_SEND_OFFLOAD_V2 structure.

• The Internet protocol security (IPsecvOV) information in an NDIS_IPSEC_OFFLOAD_V2 structure.

The following topics contain specific information for each type of offload service:

• Reporting a NIC's Checksum Capabilities
• Reporting a NIC's LSOV1 TCP-Packet-Segmentation Capabilities
• Reporting a NIC's LSOV2 TCP-Packet-Segmentation Capabilities
• Reporting a NIC's IPsec Capabilities
  • [The IPsec Task Offload feature is deprecated and should not be used.]