[plug] Modems & X

[Andrew Francis]

On Tue, 20 Mar 2001, Campbell, David (Ex AS17) wrote:
> What applications that spring to mind that could compress the X bandwith
> across the modem (the remote end is a POSIX but non-Linux OS, the
> application is heavy on the Motif widgets if that is any help).

There are a number of solutions you could give a go, ranging in
complexity. Someone's already mentioned SSH; this will do deflate (a la
gzip & pkzip) compression on the X stream, however you need the sshd on
the server (the X client) to be configured to do this, and I've recently
come across servers that won't do it for you.

The next simplest alternative is to use something else to tunnel the
connection, compressing in the process. I use zebedee for this, it's
available from http://www.winton.org.uk/zebedee/ and compiles pretty
cleanly. It can do deflate compression using zlib, or bzip2 compression.

If using something like zebedee, you'll want to set DISPLAY=localhost:10
and forward port 6010, DISPLAY=localhost:23 and forward port 6023, etc.

There's also low bandwidth X, which I understand is generally implemented
as an extension in the X server itself. And there's DXPC, which basically
'filters' the X connection and compresses it (in an X-savvy way, rather
than simple zip compression, so the gains are apparantly pretty
good). I think the best and most recent DXPC variant is the one that got
slashdotted earlier this month, it's at
http://www.medialogic.it/projects/mlview/

I never took a look at the more X-specific compression stuff, I was kind
of short on time when I approached this so I just settled for Zebedee
which works pretty well over a 56k connection; please let me know how you
go if you experiment with all of this :)

Cheers

-- 
Andrew Francis (locust at fastlane.net.au)