The above sections describe the process for constructing a copy of one file on a remote system. If we have a several files to copy, we can gain a considerable latency advantage by pipelining the process.
This involves 
initiating two independent processes. One
of the processes generates and sends the checksums to 
while the
other receives the difference information from and reconstructs the
files.
If the communications link is buffered then these two processes can proceed independently and the link should be kept fully utilised in both directions for most of the time.