office: (770) 432-4580
fax: (770) 234-4182
skype: pcausa

Welcome to PCAUSA

PCAUSA is a small (one person...) company specializing in products and services in the narrow field of Windows kernel-mode filter and protocol drivers. Our goal is to provide simple products (advanced Windows filter and protocol driver samples) and personalized consulting services to customers who have requirements in this area.

Our experience covers these areas:

  • NDIS Protocol Drivers
  • NDIS Filter Drivers
  • Windows Filtering Platform (WFP)
  • Winsock Kernel (WSK)
  • Transport Data Interface (TDI - Windows XP Only)

PCAUSA has been working exclusively in this area since 1988.

Our Products

PCAUSA products are sample and reference Windows device drivers and companion user-mode components that basically pick up where the Microsoft Windows Driver Kit (WDK) leave off.

While the WDK sample drivers can be safely called "tutorials", the PCAUSA samples are "functional". For example, a WDK NDIS filter sample may illustrate packet "passthru" without inspection or modification, a similar PCAUSA sample would illustrate inspection and logging or redirection to a user-mode application.

If the customer is a Windows driver developer, then hopefully the techniques illustrated in these samples may lead to that "Ah Ha!" moment where the developer finds a method that helps understand how to implement some desired functionality. The sample licenses encourage use of PCAUSA code when deriving a customer's proprietary driver.

In some cases the customer is primarily a Windows application developer who desires a driver with functionality similar to that of a PCAUSA sample driver. Although the PCAUSA samples are not promoted as being fit for any specific purpose, several are fairly widely used as-is in commercially deployed products.

We view the products that we offer as "enabling technology". Our customers have the bright functional ideas; we provide samples that assist in turning these ideas into functional products.

Our products are licensed with no recurring royalty for product distribution in executable form. The "Professional" version includes complete source and it is provided with the intent that the customer adapt and modify it to derive their own proprietary solutions.

Rawether for Windows

Rawether for Windows is a fifth-generation framework for development of Windows products that allow a user-mode application to "directly" access NDIS network interface card (NIC) drivers from Win32 applications. Rawether is typically used in two types of applications:

  • Network Monitoring - Selected packets are passed to your user-mode application for inspection and logging.
  • Custom Network Protocols - Your user-mode application can send and receive RAW Ethernet packets.
  • Miniport Driver Management - Your user-mode application can make OID requests to query and set information.

Rawether uses NDIS protocol drivers that act as a "relay" between an application and the NDIS miniport driver. Using Rawether for Windows, your application can send and receive raw Ethernet packets on a selected miniport and can make NDIS requests to query and set a miniport's information.

There is a dedicated website for the PCAUSA Rawether for Windows product. Please visit

Kernel-Mode Filter Driver Sample Collection

These samples illustrate filtering of network traffic in kernel-space. The samples include:

  • Transport-Level Filters (Above the TCP/IP Protocol Driver)
  • NDIS Filters (Below the TCP/IP Protocol Driver)

The samples support Windows platforms from Windows XP through Windows Server 2008, including 64-bit Editions. The samples generally illustrate the same functionality across the supported platforms and use a common control application for the platforms.

More Information...

Our Services

PCAUSA is pleased to support customers who have development requirements in the narrow field of PCAUSA's expertise. Whether your requirement is simple (making an OEM build of a PCAUSA sample driver) or an innovative new requirement, give us a call.

We will be glad to offer an initial consultation at no cost and our rates are competitive even when compared with "offshore" development houses.

More Information...

Thank you for visiting PCAUSA!

Thomas F. Divine
President, PCAUSA

Visit the website dedicated specifically to the PCAUSA Rawether for Windows product: