I'm developing a ASP.Net 2.0 web service. I am using windows XP sp2 version 5.1
When testing the service, I created a number of threads that access the web
service at the same time. When I increase the number of threads to more than
10, I get the errrors below. I've found out that the exceptions are thrown
before it gets to my program.

I suspect that I have to do some configuration but I need help to find out
where to start looking.

------- Errors -----------
"The request failed with HTTP status 403: Access Forbidden"
  at
System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
  at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
methodName, Object[] parameters)
--------
or
--------
System.Net.WebException: The underlying connection was closed: An unexpected
error occurred on a receive. ---> System.IO.IOException: Unable to read data
from the transport connection: An established connection was aborted by the
software in your host machine. ---> System.Net.Sockets.SocketException: An
established connection was aborted by the software in your host machine
  at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32
size, SocketFlags socketFlags)
  at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset,
Int32 size)
  --- End of inner exception stack trace ---
  at System.Net.ConnectStream.Read(Byte[] buffer, Int32 offset, Int32 size)
  at System.Net.HttpWebRequest.MakeMemoryStream(Stream stream)
  --- End of inner exception stack trace ---
  at
System.Web.Services.Protocols.WebClientProtocol.GetWebResponse(WebRequest
request)
  at
System.Web.Services.Protocols.HttpWebClientProtocol.GetWebResponse(WebRequest
request)
  at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String
methodName, Object[] parameters)