- From: <jg@zorch.w3.org>
- Date: Mon, 12 Aug 96 10:29:38 -0400
- To: Koen Holtman <koen@win.tue.nl>
- Cc: Paul Leach <paulle@microsoft.com>, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com, hallam@etna.ai.mit.edu
Specialized compression schemes always beat general ones, usually hands down, as they know much more about the content of messages than a general one can. The algorithms in modems can't use the best compression algorithms in any case, due to constraints on modem's behavior. For example, many compression schemes only compress on a character by character basis; in HTTP's case, you have a dictionary for long words, reducing a string in the 8-10 byte range down to a single byte. So arguing that modem compression makes protocol compression meaningless is almost always incorrect (example; TCP header compression, that knows about the details of TCP, gets about a 7:1 compression; compression in modems is at best in the 2-3X range). However, I agree with the sentiment that getting real data is a good idea, though it can be work to get the data. To encourage real data, read on... I will assert that Paul's scheme over modems with data compression will beat the modem alone by at least a factor of two in savings of bytes actualy transmitted... These should be real requests, including Accept: and similar protocol features, to qualify. First person to prove me wrong with running code and real data gets $50. At worst, I'll learn something about how HTTP works... - Jim Gettys - Jim Gettys
Received on Monday, 12 August 1996 07:47:33 UTC