Network Adapter Basic Features

This section defines requirements for basic hardware features.

5. Support NDIS 4.0 using a miniport driver

For PC 97, the driver must be an NDIS 4.0 miniport driver that is compatible with Windows NT 4.0 and Windows 95. If the device is switched WAN card (for example, ISDN, X.25, or S56), it must have an NDIS 4.0 NDIS WAN miniport driver which has a TAPI service provider compatible with Win32 TAPI applications. It must support Windows remote access or other WAN services over WAN media.

All enhancements to NDIS can be only used by miniport drivers, including all the features added in NDIS 4.0. All new media are being supported only in the miniport model, including ATM, WAN (ISDN, X.25, and so on), wireless WAN, IrDA, cable modem, ADSL, and so on.

This support also provides for dynamically starting and stopping the network adapter, and includes support for cable sense (see the following requirement). Because the operating system is performing a larger portion of the functionality in the miniport driver model, NDIS is safer, more efficient and binary compatible across operating systems than with other driver models. Writing miniport drivers is easier and requires less time and resources than drivers created under other driver models.

For information about NDIS and required driver support for the network adapter, see the Microsoft Windows NT 4.0 DDK and the Microsoft Windows 95 Device Driver Reference available by way of MSDN Professional membership.

6. Automatically sense presence of link or carrier to the network

The network adapter must be capable of determining whether it is connected to a functional network. If the adapter is on an expansion card not used as a boot device, the presence of the cable can be determined by device drivers. If a cable is not attached, the miniport driver must provide appropriate NDIS status indication, using support for cable sense in NDIS 4.0. For information about NDIS Status codes and indication mechanism, see the Microsoft Windows NT 4.0 DDK.

No time durations are specified for the required detection or status indication.

7. Automatically sense transceiver type (TP, AUI, BNC)

Network adapters that support multiple transceivers must be capable of automatically detecting which transceiver is connected to the network and then use that transceiver automatically. In all cases, the user must not be required to set jumpers or manually enter information to inform the operating system of the transceiver type.

8. Support quad-word buffer alignment or better for receive and support byte buffer alignment for send

Recommended: byte alignment. All allocated memory will be quad-word alignment so the receive buffers must be quad-word aligned or better (can be byte or word aligned). For the send buffer, it must be capable of handling byte-aligned buffers. The network adapter must have minimal buffer alignment restrictions. This refers to the allowed offset addresses (boundaries) where packets can begin and end. Byte alignment is recommended, because it imposes fewer limitations on overlying software components.

9. Adapter communicates with driver across any bridge

If the adapter uses a bridge, all communications must be free of errors across any bridge such as a PCI bridge adapter.