Hi, Latency is not an issue, I am looking at a deployment where I have a 1MBPS upstream and 6MBPS downstream bandwidth, The bandwidth issue comes from the fact that the number of users is going be high, a few hundreds. Hence the effective bandwidth per user is going to drop with the number of simultaneous users going up, that's when the response is going to become less predictable.
----- Original Message ----- From: "Carsten Haitzler (The Rasterman)" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; "NX Developers" <[EMAIL PROTECTED]> Sent: Tue, May 11, 04 11:05 Subject: Re: Reengineering X applications > 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] > çè - èå (æç) [EMAIL PROTECTED] > Tokyo, Japan (æä ææ) > > _______________________________________________ Devel mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/devel
