I had a horrible performance issue where every web service call was
taking sometimes 20-30 seconds working from home over VPN.  I stuck
WireShark (used to be called Ethereal) to sniff the network traffic and
see a time slice of traffic.  What I found were tons of LDAP/SPNEGO
packets that looked wrong.

I was seeing LDAP packets hitting AD that had the following error in
it:

"U8009030C: LdapErr: DSID-0C0903E2, comment: AcceptSecurityContext
error, data 0, v893.0"

To get around the issue, I found two ways:
o) Drop my machine from the corporate AD.  This immediately gave at
least a 30x increase in performance and my test cases (hundreds of
them) ran in seconds as opposed to 1/2 hour.
o) Re-add my machine to the domain.  Continued to have good performance
and noticed via WireShark that all the LDAP/AD errors went away.
Instead, I would see just a few LDAP packets when my tests first
started and would not see any more.

Again, EITHER of the options above worked for me.

I never fully determined exactly what the errors mean, but my guess is
that my .NET app was trying to authenticate with my corporate domain
frequently, kept erroring out, and would continue only to try again on
some other operation.  Sorry, not very specific here as I never figured
it out 100% which drove me nuts.

ALSO, can't stress enough the importance of turning of WSE tracing if
you don't need it.  One of our tests went from 45 seconds down to 6
seconds after I realized the trace file was 18megs in size (doesn't
take long to get there!).  We turned off tracing until an issue comes
up and we need it to reproduce the issue and troubleshoot.

Hope this helps?

-Dustin

Yes.

<diagnostics>
     <trace enabled="true" input="InputTrace.webinfo"
output="OutputTrace.webinfo" />
   </diagnostics>