NDIS 5.0 and ATM Support in WindowsUpdated: March 10, 2004 .gif) Microsoft launched the industry's first logo and compatibility testing program for Asynchronous Transfer Mode (ATM) LAN Emulation solutions for Microsoft Windows 95 and Microsoft Windows NT 4.0, and also released Network Driver Interface Specification (NDIS) extensions for native ATM support. (See the Network/ATM Test Kit on NDIS 5.0 and supporting ATM components are available in the Windows DDK.) Support is included in the current Windows operating systems: Microsoft Windows XP, Microsoft Windows Server 2003, Microsoft Windows 2000, Windows NT 4.0, Microsoft Windows Millennium Edition, and Microsoft Windows 98. The NDIS 5.0 extensions will enable direct access to any connection-oriented media, such as ATM with full Quality of Service (QoS) support for media that can support QoS. Note:
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Introduction to ATMATM technology has been deployed rapidly throughout the telecommunications industry. ATM enables a spectrum of new applications, including greatly enhanced multimedia, video conferencing, and movie-on-demand type video streaming, as well as telephony and other real-time voice services. ATM has been developed to ensure smooth integration with numerous existing network technologies at several levels, including Frame Relay, Ethernet, and TCP/IP. ATM accommodates the simultaneous transmission of data, voice, and video, allowing for the unification of the separate voice and data networks, while also easily coexisting in mixed network environments. This is good news for network administrators, because it means that networks can be incrementally upgraded to ATM. ATM represents a significant advance in network communications. There is nothing faster on the horizon or better geared to support QoS-based applications, and it has been designed from the outset to have the flexibility and scalability that will enable it to match future advances in telecommunications and computer technology. An ATM Call Manager and a LAN emulation module allow ATM adapters to function in an Ethernet environment, with the ATM adapter appearing to overlying applications and protocols as if it were Ethernet. The LAN emulation module and Call Manager work together to accept Ethernet headers and addresses, and translate them for ATM, allowing legacy LAN applications and protocols to work transparently in an ATM network. Deploying ATM with Microsoft WindowsMicrosoft's support of LAN emulation makes Windows the communications platform of choice. The logo testing and qualification programs for Windows provide a standard measure of compatibility and performance for ATM adapter vendors. The logo testing program means that customers will be able buy ATM adapter products that have earned the "Designed for Microsoft Windows" logo with confidence that the ATM adapters will perform reliably with a broad set of applications. ATM adapter vendors can make use of the logo testing process also, to ensure a higher degree of customer satisfaction with their products. Microsoft has released the NDIS 5.0 extensions for native ATM support and now offers native ATM drivers. Native ATM support at the operating system level enables a new class of guaranteed QoS-based applications. Native support means that the Call Manager and LAN emulation module are provided in Windows. Therefore, developers do not need to develop or license their own call managers and LAN emulation modules. This should allow ATM hardware to be more easily and more quickly developed and will lower the costs to develop and deploy ATM-based solutions. ATM and NDIS 5.0 DDKThe NDIS extensions provide kernel-mode NDIS 5.0 "client" drivers with direct access to connection-oriented media such as ATM. The NDIS 5.0 API accommodates three objects:
The new architecture for Windows extends native ATM support to Windows Sockets 2.0 (WinSock) and DirectShow-based applications by providing system-level components that map the applicable WinSock and DirectShow APIs to NDIS 5.0, extending direct ATM access to user-mode applications. WinSock and DirectShow are Win32 APIs that enable development of transport-independent network applications. Microsoft plans to extend NDIS to support ATM natively in the operating system. On the left side of Figure 1 is the previous version of NDIS. Third-party ATM solution vendors provide their own LAN emulation clients (LEC), User Network Interface (UNI) Call Manager, and hardware interface software. (UNI is the signaling protocol standardized by the ATM Forum.)
On the right in Figure 1 is NDIS today, showing the new Windows architecture view of native ATM support in which Microsoft provides the LEC, UNI Call Manager, and IP over ATM support (IETF RFC 1577, 2022, and extensions) natively in the operating system. The Windows TCP/IP protocol stack runs over the LEC, or the IP over ATM module which provides added efficiency in running TCP/IP over an ATM network. The Win32 WinSock 2.0 and DirectShow support for ATM will enable more QoS-based applications to run over ATM. ATM DeliverablesATM network adapter manufacturers can immediately begin development and testing of NDIS 5.0 ATM miniport drivers using the Windows DDK. The DDK includes additional design guide information for writing NDIS 5.0 Call Managers and Clients. Native ATM support from Microsoft consists of two products: NDIS 5.0 in the Windows DDK (for ATM adapter vendors), which enables development, testing, and logo awards for ATM media adapters. This product consists of the following:
Windows ATM Services, which consists of the following:
Call to action for ATM and NDIS 5.0:
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