Microsoft Working to Deliver New Scalable Networking Enhancements for Windows Server 2003
Server CPU capacity dedicated to networking overhead has caused significant application scaling issues, as a result of continued customer emphasis on better business responsiveness through interconnected systems and people. To solve this challenge, Microsoft started the Scalable Networking Initiative to eliminate operating system networking bottlenecks and provides new APIs for hardware developers to leverage.
The Scalable Networking Initiative will deliver in two initial areas: the Microsoft Chimney Offload architecture, which enables hardware vendors to offload to hardware the work associated with TCP/IP data movement; and Receive Side Scaling (RSS), a technology developed to make the networking stack scale better on multi-processor systems.
Chimney Offload, TCP Chimney, and Receive-Side Scaling
Together, TCP Chimney Offload and RSS will allow customers to do more with less by enabling seamless support of TCP Offload Engine (TOE) hardware and TCP acceleration hardware, while maintaining compatibility with applications and standard network management practices.
The first Chimney architecture to ship will be TCP Chimney offload, which will be available through OEMs, IHVs, and via Web download. It is an operating system interface to a new class of advanced Ethernet network adapters that can completely manage TCP data transfer, including acknowledgement processing and TCP segmentation and reassembly. Such adapters are under development by Gigabit Ethernet industry leaders as well as innovative startups.
While virtually all server customers will benefit from TCP Chimney and TOE technology, servers with network backup and data replication workloads, file serving or remote file access (SMB/NFS) workloads, and iSCSI (for storage consolidation on IP SANs) workloads, will especially benefit.
Receive Side Scaling enables the receive processing of networking traffic to be load balanced across multiple CPUs by leveraging new hardware in the NIC. It will dynamically balance the load as either system load, or network traffic patterns vary. Any application that has significant networking traffic and runs on a multiprocessor host will benefit from RSS.
To help ensure application compatibility and security protection, TCP connection setup is not offloaded to the network adapter, only TCP data transfer. If any security policies conflict with a request to offload data transfer, the network connection will not be offloaded to the NIC, and will instead remain on the host TCP/IP stack, to ensure the system maintains robust security protection.
Scalable Networking Pack
The Microsoft Windows Server 2003 Scalable Networking Pack (currently in beta) is breakthrough networking technology that for the first time enables TCP Offload Engines (TOE) hardware to be deployed while maintaining application and network management compatibility. The Scalable Networking Pack will be useful both to customers receiving new servers with TOE NICs, and to customers who have older servers and are interested in extending the lives of the servers by adding a TOE NIC and the new Microsoft software.
Customers receive the benefit of a TOE NIC via Chimney offload simply by installing a TOE NIC and the Scalable Networking Pack, or by buying a new server with TOE on the motherboard. Microsoft is providing a complete Windows Hardware Quality Lab test suite to help IHVs test their TOE implementation for compatibility with the TCP Chimney.
The Scalable Networking Pack will also add native Windows support for Intel’s I/O Acceleration Technology. Intel I/OAT helps move network data more efficiently through Intel Xeon servers.
Microsoft also anticipates incorporating these features into future operating systems.