Dear all, In my app developed in Lion using XCode, I need to determine the speed of the internet connection (upload speed) and for that I upload an file using NSURLConnection. I extracted the code for formatting the xml and uploading from http://blog.grio.com/2009/09/uploading-files-from-iphone.html I am using the async version of NSURLConnection to free up the main UI and also as I want the progress of the uploading process. I have implemented the delegate methods provided by NSURLConnection they are. Code: //1. Method fired after upload is complete along with response code. - (void)connection:(NSURLConnection *)theConnection didReceiveResponse:(NSURLResponse *)response //2. Method fired when upload process fails. - (void)connection:(NSURLConnection *)theConnection didFailWithError:(NSError *)error //3. Method fired when upload process is completed. - (void)connectionDidFinishLoading:(NSURLConnection *)theConnection //4. Fired periodically indicating no. of bytes sent/uploaded to the server (can be used to determine upload speed). - (void)connection:(NSURLConnection *)connection didSendBodyData:(NSInteger)bytesWritten totalBytesWritten:(NSInteger)totalBytesWritten totalBytesExpectedToWrite:(NSInteger)totalBytesExpectedToWrite I find that even if I configure an invalid Upload URL for uploading of an file, the delegate method 4. above gets fired periodically during the uploading process giving the impression that the uploading is being performed successfully. However during the end of the upload process with an invalid upload URL(when totalBytesWritten == totalBytesExpectedToWrite), the method 1. fires with an error http 404 indicating that the upload process has failed. Is there a mechanism by which I can find whether the uploading of is being carried out successfully during the actual uploading of the file rather than waiting till the entire file is uploaded?.