Our prototype uses the general purpose lossless compression algorithm - gzip[7] in the Compression Module. Gzip is a standard compression utility commonly used on Unix operating system platforms. It does not consider domain specific information and uses a simple, bitwise algorithm to compress file. It can work in stream mode, that is, at the time that the compression starts, not all data has to be available. In our implementation, we simply incorporate the gzip library into our application code. The performance parameters that this module needs to provide are compression speed and compression ratio. We use empirical method to get their value; see Section 3.2 for details.