KASHTAN@IU.AI.SRI.COM (David L. Kashtan) (02/01/89)
While we are fighting about STRU VMS, I would like to propose another FTP extension (and this one I WOULD like to make interoperable with other vendor FTPs). We have implemented in our FTP for VMS a non-standard mode "LZ-COMPRESS" which places an adaptive L-Z data compression module between FTP (both client and server) and the network. Why do this you ask?? Well, there are some sites that are connected to the internet by VERY slow communication paths (my particular concern was a machine that had effectively a 4800 baud communication path). Now L-Z compression usually gets between 50% and 80% data compression (depending on the how structured the data is). So by turning on MODE LZ we typically see 8Kbaud to 32Kbaud transfer rates on this pitiful line (which actually makes the line quite usable). So, I am proposing a new transfer mode LZ in which the data on the data connection is in L-Z form. Now if you want to have a specific "MODE LZ" or want a sub-mode of the already specified FTP compress mode is fine with me -- but I WOULD very much like to be able take advantage of this most useful transfer mode when communicating with machines that don't have our software. David -------
casey@gauss.llnl.gov (Casey Leedom) (02/13/89)
| I would like to propose a ``MODE LZ'' extension to FTP.
Don't forget that some hosts can't decode 16 bit LZ compressed
streams. Maybe your mode had better be ``MODE LZ [BITS]'' with the
default BITS = 16.
Casey