Look for the HTTP reason code.... you can readily find this information on the internet.... The message you are getting is from the fact that the request attempt has been sent a specific number of times (i.e. 3 in silkperformers case). If there is no response from your target server then that's the error you get or a Winsock [number] error.
I am not sure what kind of Timeout Error you are talkin about..... But this might help to close in...
The "Connection timed out" error is normally associated with the winsock error 10060 and is caused when the system under test does not respond to the clients request within a specified time, normally 21 seconds.
However,If, for example, the setting for ' Connect Timeout ' is changed in SP Internet/Network Tab from the system default and during the test a connect timeout occurs, then SilkPerformer will raise a "winsock connection timeout error" but instead of using the error code of 10060, it now uses its own error of 21 because the timeout which was exceeded was set by SilkPerformer.