WCF Performance tuning resources

http://blogs.msdn.com/b/wenlong/archive/2009/07/26/wcf-4-higher-default-throttling-settings-for-wcf-services.aspx

http://weblogs.asp.net/paolopia/archive/2008/03/23/wcf-configuration-default-limits-concurrency-and-scalability.aspx

http://kennyw.com/work/indigo/150

http://csharp-codesamples.com/2009/04/configuring-wcf-throttling-behaviors/
It is advisable to keep MaxConcurrentCalls and MaxConcurrentSessions equal.

http://www.codeproject.com/Articles/33362/WCF-Throttling

http://msdn.microsoft.com/en-us/library/7w2sway1.aspx
Setting ProcessModel parameters.

Testing and finding the limits of Windows:
http://blogs.technet.com/b/markrussinovich/archive/2009/07/08/3261309.aspx