The phrase WAN optimization refers to two related, but distinct tasks. One task is to maximize the performance of selected applications, and the other is to minimize the cost of the WAN.

In a recent survey by Webtorials of 200 companies, 25% of respondents said they have deployed TCP acceleration as a WAN optimization technique. TCP acceleration focuses on overcoming the limitation of the TCP window size. 

To understand the potential value of TCP acceleration, consider a company that has a T-1 that is experiencing a one-way delay of 100 milliseconds. Further assume that the packet size is 128 octets and that due to occasional packet loss, the window size is 2. The maximum possible throughput on this T-1 link is roughly 10,000 bit/sec. Increasing the size of the link will have a negligible impact on throughput, while increasing the window size will increase throughput.

TCP acceleration is just one of the topics that will be covered at the forthcoming WAN Technology Tour being produced by Network World and hosted by Jim.  This seminar will look at WAN optimization and detail some of the major WAN optimization techniques including caching, compression and the use of wide area file services. The seminar will also discuss how the use of Web services makes the problem of WAN performance management all that more difficult.

The tour is going to Atlanta (April 19), Philadelphia (April 21), Denver (April 26) and Los Angeles (April 28). If you live in one of those areas, kindly plan on participating at one of these highly interactive seminars.

For more information about the WAN tour and details of how to apply to attend, please go to: http://www.nwfusion.com/events/wan/index.html .

Next time, we look at TCP acceleration and spoofing acknowledgements.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Jim Metzler is vice president of Ashton, Metzler & Associates.