VSTS 2010 Web Performance Test -Fix the issue of A connection attempt failed because the connected party did not properly respond

Today I used VSTS 2010 web performance test to validate if passing city code to API provided by ARCGIS Online Service can return the expected result. I noticed that running the test was slow and I got the following error

Request failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 58.68.148.182:443

I added the following proxy setting.

this.PreAuthenticate = true

this.Proxy = “XXX.XXX.com";

I noticed that running the test was slow and I got the following error.

Request failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 10.5.18.19:80

It made me think of the following proxy setting I used before. Finally it works.

  this.PreAuthenticate = true;

  NetworkCredential credential = (NetworkCredential)CredentialCache.DefaultCredentials;

  WebProxy proxy = new WebProxy("Proxy", 8080);

  proxy.Credentials = credential;

  this.WebProxy = proxy;