New Features for TCP/IP in Windows Server 2003 Service Pack 1

Performance Enhancements

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  Protocol stack tuning, including increased default window sizes and new algorithms for high-delay and high-loss links, which increases throughput
  
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  TCP-scalable window sizes (described in RFC 1323)
  
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  Selective acknowledgments (SACK) (described in RFC 2018)
  
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  TCP fast retransmit and fast recovery (described in RFC 2581)
  
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  Round Trip Time (RTT) and Retransmission Timeout (RTO) calculation improvements
  
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  Improved performance for management of large numbers of connections
  
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  Hardware task offload mechanisms including checksum offload and large send offload (LSO)