Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rutgers!cbmvax!grr From: grr@cbmvax.commodore.com (George Robbins) Newsgroups: comp.mail.uucp Subject: Re: What use is Trailblazer compression? Keywords: uucp, Trailblazer, LZW, data compression Message-ID: <13050@cbmvax.commodore.com> Date: 5 Jul 90 05:52:25 GMT References: <1990Jul4.195351.9324@tsa.co.uk> Reply-To: grr@cbmvax (George Robbins) Organization: Commodore, West Chester, PA Lines: 27 In article <1990Jul4.195351.9324@tsa.co.uk> domo@tsa.co.uk (Dominic Dunlop) writes: > Is Trailblazer compress any use with uucp for mail transfer? Although I'm > pretty sure it would be counter-productive with compressed news batches, is > there likely to be any increase in throughput if I have my Trailblazer > attempt to negotiate compression when exchanging plaintext mail with sites > which are not newsfeeds? Has anybody run tests? Was it a win? It is probably of some benefit, however mail is transfered in two files, one tiny command file and one usually small data file. UUCP queue search and other per file overhead usually swamps any effective transfer rate on this sort of activity. The only way to full honest thruput is to send large compressed news batches or uucp file transfers. I suppose one could try a uncompressed new feed with compression enabled as a lark, but motivation is lacking. The one place where compression in the modem really pays of is sending CAD or DP flavor printouts where there is a lot of redundancy/repetition. Even here, the trailblazer suffers because it doesn't support 38.4 Kbps and the 19.2 Kbps interface rate is too close to the nominal transmission rate to see any impressive compression factors. It would help more on international or other ratty connections that usually see speeds considerably less that 12-14Kbps. -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)