Winsock Direct and Protocol Offload on SANs
Updated: March 3, 2001
File name: WinsockDirect-ProtocolOffload.doc
About This Download
This download white paper provides information for system designers, high-speed interconnect hardware developers, and driver developers about protocol offload and how Microsoft Winsock Direct (WSD) over System Area Networks (SANs) can radically reduce network protocol CPU and memory bottlenecks. This can increase system performance by freeing up CPU and memory bandwidth resources to be used by the application. The information in this paper applies for Microsoft Windows 2000 Advanced Server (requires Service Pack 2), Windows 2000 Datacenter Server, Windows Server Appliance Kit (requires Service Pack 2), and all versions of the Windows Server 2003 operating system.
This paper summarizes traditional CPU and memory bottlenecks and provides a simplified version of the WSD protocol, called Trivial Transport Protocol (TTP), to help provide insight into solutions to the issues. Finally, it provides an analysis of the TTP protocol for how well it solves system bottlenecks. Note that while the TTP analysis applies directly to WSD, WSD is much richer in its message exchange than TTP to handle issues regarding cloning of sockets, small message optimizations, accumulated acknowledgements, and other issues.