Internet over high latency connection

VSAT can be the only mean to connect to Internet in some parts of the world. The most annoying feature is the high latency (minimum 500ms) and the relatively slow speed.
The TCP layer is not optimized by default to cope with high latency link and performances can decrease.

The latest Linux kernels use an autotuning algorithm and without manual intervention you'll get the best performances from your computer. Check the kernel version by typing : uname -a in a terminal, if the kernel version is higher than 2.6.7 you do not have to do anything. If you have a version lower than 2.6.7 it's recommended to update.

On windows vista you can activate the Compound TCP (CTCP) option by running :

netsh interface tcp set global congestionprovider=ctcp

You can find more information on CTCP at Microsoft Research. An article on Bandwidth-delay product at Wikipedia will give you details on the problem and a list of proposed algorithms to improve the situation.

How to speed up your internet connection ?

Using low speed internet either trough 2G/3G phone or being in a foreign country where internet connections are slow and expensive can be an exercise in patience.

Most of the websites are designed for broadband and they are not optimized for low speed connections. Following the simple steps presented here you can speed up your connection and reduce the time needed to display the webpages you are browsing.

A typical web page such as http://times.com/ weights 679kB in total. In the following articles we will see how to reduce it to 554kB in order to speed up the display but also to reduce your data usage which is really helpful if you do not subscribe to an unlimited data plan. A reduction of 20% must not be missed!

• First : Tweaking cache settings of your browser
• Second : Remove advertisement
• Third : Remove web bugs

All the instructions are given for Firefox 3.6 You can download it at Mozilla.

Tweaking cache for Firefox

Web caches reduce the amount of information that needs to be transmitted across the network, as information previously stored in the cache can often be re-used. This reduces bandwidth and processing requirements of the web server, and helps to improve responsiveness for users of the web.

By default the cache size on Firefox is 50MB. If this amount of cache is adequate for general usage, increasing the cache size to 300MB or more can help on low speed connections.


At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....

Then Network tab:

Modify the Offline Storage to 300MB instead of 50MB and close the window.

Remove advertisement

All advertisement on the New York Times main page is over 150kB. You can easily remove this overweight by using Ad Block Plus.

Here is the video explaining how to install it :

Remove web bugs

A web bug is an object that is embedded in a web page and is usually invisible to the user but allows checking that a user has viewed the page.
Web bugs are typically used by third parties to monitor the activity of customers at a site. Originally, a web bug was a small (usually 1×1 pixel) transparent GIF or PNG image (or an image of the same color of the background) that was embedded in an HTML page, usually a page on the web or the content of an e-mail. Modern web bugs also use the HTML IFrame, style, script, input link, embed, object, and other tags to track usage. Whenever the user opens the page with a graphical browser, the image or other information is downloaded. This download requires the browser to request the image from the server storing it, allowing the server to take notice of the download. As a result, the organization running the server is informed when the HTML page has been viewed.

In short : web bugs are eating your bandwidth and they invade your privacy. Why would you want them ?

With Ghostery it's easy to get ride of them. Download the Firefox Add-On it will install, and after restarting Firefox all trackers and web bugs will be removed.
You will see all the objects removed on each page and you can of course easily enable or disable Ghostery.

On the New York Times main page, Ghostery removes 3 web bugs and it's 25kB less to download.