Re: Efficiency of FTP URLs

Rick Troth (
Mon, 25 Jul 1994 18:57:52 +0200

> ... I got to thinking that this would be
> an obvious place for an optimization: leave the FTP open until done parsing
> the HTML document in case any inlined images (or whatever) might be needed.
> This morning I confirmed that MacWeb 1.0a2, MacMosaic 2.0a2, XMosaic
> 2.4, and WinMosaic 2.0a2 take the inefficient approach of a separate ftp
> connection for each inlined image. It would seem that optimizing this would
> help the load on ftp servers, and response time to the user.

And Dan suggested that we rewrite TCP for similar reasons.

Yeah ... it's overhead. I say, leave it in there for the
sake of compatibility. Let each transaction be a separate TCP (FTP)
connection for the sake of uniformity. I'm not advocating waste,
but bandwidth is getting cheaper, CPU cycles are getting cheaper,
and storage is getting cheaper. The economics are against some
kinds of optimizations.

Now ... if the library had some "trick" whereby it could
leave that FTP control socket open across URLs, fine. There'd have to
be some kind of time-out so that if the control socket remained unused
it would close automatically. But I strongly suspect that this all
serve to hinder the portability of the library code. Then too,
everyone should bear in mind that not all WWW clients and servers
are using the same library nor even any of its derivatives.

> -Robert Lentz
> --
> "You have to push as hard as the age that pushes against you."
> -Flannery O'Connor

Rick Troth <>, Rice University, Information Systems