If there an easy way to limit the download / upload speed of particular PCs on a network. We have some staff working offsite, and are quite within our ADSL connection capacity under normal circumstances. Unfortunately, whenever those in the office send a large email or ftp files from somewhere, vnc becomes unusable. We would like to reserve 5k upload and 5k download or so for each vnc user to alleviate this, or prevent the other users (normally only the two of them) from eating the whole pipe. The guys in the office do not wish to use the entire bandwidth, they just get no say in how the bandwidth is allocated. As an interim, I am also interested if anyone knows of an ftp client which can limit download / upload speed as ftp is the main culprit.

http://www.youngzsoft.net/ccproxy/ bandwidth limiter built in ,try this link , useful ? regards Jr

Looks interesting. I will keep it in mind for some of my other sites. Sorry, I should have mentioned in my question that I am running Smoothwall linux on the gateway PC. I presume that this is a common issue, and I was surprised that this feature wasnt built into the system (I might just not be looking hard enough though) :) Thanks anyway

Trafic shaping (QOS) may be done in Linux platform using FreeSwan. I am not sure if it is included latest distros.

If you study queuing theory (applies to all parts of internet connections) you would understand that maximum throughput is the objective, and that there is no "fairness" concept in the use of such resources other than the "first in, first out" logic. While what you want to do can be done, it is difficult to do. One thing you can do to help if you have several specific systems that "hog" your downstream link when using it, is to go into those systems and reduce their TCP/IP RWIN (Receive buffer WINdow size) value. On normal Ethernet networks the RWIN setting is some multiple of the MSS size (1460). Try setting these systems to a lower multiple that is below 8K. You will have to test to see what the best compromise value is. This only helps with the downstream link. This will restrict the number of packets queued up in the ISP's buffers waiting on the downstream link, and allow other systems packets to get through quicker. While it will reduce the maximum throughput of these "restricted" systems some, it should not cause any real problems for them.

Here is the web address where you'll find a specific software that complies your needs: www.netlimiter.com Program's name is NetLimiter v1.25