I have a scenario in which need to calculate the Server Time for uploading files as per the Connection speed.

Example:

Need to calculate time to upload files with Connection speed 256Kbps and more If connection breaks then checking the remaining time and restart the download or upload operation where it was break

You cannot do this properly without using some kind of ActiveX control or Java Applet from a browser (especially if you want the file size before you start your upload).