What is the aivalability criteria ? You could create a dummy web method to
do that ?

The key point if that if what you test is not a web method call, then you
can't tell a web method call would work but only that whatever possibly
unrelated operations you tried works (for example if you just get an htm
page or "ping" the server, it means that getting an htm page works, not that
calling a web service method would work). And if it fails, it doesn't mean
that calling a web method would fail (for example I saw lastly someone
trying to ping a web server to test for internet availabilty but it was not
working because the server disabled ping responses likely for safety
reasons).

What is the overall purpose ? To check availability at regular intervals and
mail an alert if not ? My preference would be likely to have a "test"
service or web method for this purpose...

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Patrice