On Tue, 11 May 2004 10:32:46 +0530 "Suresh"
<[EMAIL PROTECTED]> babbled:
> Hi,
>
> Has anyone come across X applications re-engineered for low bandwidth
> networks, This in the context of thin clients.
you will find the vast majority of x clients unusable over "low bandiwdth
connections"
by this i mean 64-128kbit, with 200ms-500ms latency (ie a lot of modems and
mobile phone networks, or running an application from the other side of the
world).
basically there are 2 problems
1. x (and xlib) can be EXTREMELY chatty. this means x server and client talk
back and forth waiting on eachothers responses, holding the x client in limbo
while protocol is underway. this is mostly affected by latency, and NOT
bandwidth. this is a hug factor
2. doing anything other than basic primitives (lines, boxes, polys etc.) is
unusable over a low bandwidth connection. most x clients like to make an app a
little friendlier with a few icons etc. these are not compressed and even if
they are do not undergo lossy compression and thus eat bandwidth like no
tomorrow. every time the app starts it needs to upload the pixmap data afresh.
it is never cached on the server.
some of this is solved in xrender with alpha blends being done server-side,
avoiding extra pixel transfers, and allowing shared glyph indicies - but in
general you are going to have a hard time having a usable app at all over really
low bandwidth. (mind you "usable" is a subjective matter).
how low bandwidth are you thinking - and what kind of latency?
--
------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler) [EMAIL PROTECTED]
熊耳 - 車君 (数田) [EMAIL PROTECTED]
Tokyo, Japan (東京 日本)
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