Buffers

I noticed that tcp ports have a refinement of buffer-size. How do we use that option and how do we manipulate buffers. I am confused why we have to create buffers with i.e. make string! 1024 etc... We do we find more information on these capabilities. I discovered a util referenced in the book called net-util and net-install that was used to implement new schemes. Has anyone had success using these utils as I never see them used in scripts on the list. Paul