Whenever you are on the move, you probably check your mail over GPRS.
Mostly, GPRS providers offer you a data plan where you pay for the amount of data that is being transferred between your mobile device and the server you are accessing through the ISP.

Now, if the data is somehow comŽpressed and sent across your mobile deŽvice, then the amount of data transferred will be lesser. And that will result in better experience of browsing and less expenditure on your GPRS bill as well. Apart from these, it can also help in WAN optimization where you have to connect two different machines over a low bandwidth network for sharing content over HTTP. It also helps when you are connecting over dial-up to your ISP. For example, you are working from your home computer which is connected to the Internet via dial-up connection. ow if the ziproxy server is installed at your enterprise, then you can simply route the HTTP traffic through ziproxy server for remote users. It will compress the data before sending it to you and that will save a good amount of time and money.

Using Ziproxy, the HTML content is compressed before sending it to your mobile device or computer. The images are compressed; which means convertŽing the image to low quality JPEG and compressing the text or css using gzip. The compres-
sion ratio can be set by you dependŽing upon the rquirement of your users or client. The deployment of Ziproxy is quite simple. Place the Ziproxy server on a public IP so that it can be accessed from anywhere on the globe. But for sure, place this behind the firewall for security reasons. Reason for placing the server on public IP is be cause the mobile device or remote client can directly access the proxy server for accessing the Internet. The other option would be to connect to the proxy server through your corporate VP.

We installed Ziproxy on Debian 4 machine with Intel Core2 Duo processor, 1 GB RAM and 80 GB HOD. Before installing Ziproxy, there are some prerequisites that need to be installed, such as libungif, libpng, libjpeg-6b, zlib and libjasper. Libungif contains library of functions for loading and saving GIF file formats and libjasper is for implementing the JPEG 2000 compression standards into Ziproxy. Mostly, latest Linux distros already have these installed but for those which don't have, you can get those from rpmfind.net. You also require to inŽstalls lex compiler. For installing it in debian 4 run the following command;

Once all the pre-requisites are inŽstalled, it's time to build up theZiproxy server. Download ziproxy from Ziproxy homepage. Since there are no binaries available for DeŽbian. we have to first compile the source and then install it. After you have downloaded the file. untar the downloaded file and run the following command:

# .jconfigure # make

# make install

After Ziproxy is installed. it's time to start the proxy server. For this. run the following command on the tenninal:

Now you have to configure something at client side also to get things working. Open up the Internet explorer (configuration can be different for different web browsers) go to Tools> InŽternet option. Next go to Connection tab and click on the 'LA setting' butŽton. On the 'Proxy server' box, check the "Use the proxy server .... " checkbox and provide the address of the Ziproxy server The default port of Ziproxy is 8080 which is configurable. Provide this on the 'port' textbox and save the settings.

Open up any web page that you visit the most and you will find the difference. especially if the website contains lots of images. The image you see below shows you the difference in the quality of the images. First with ziproxy server and second without ziproxy server.

Here are some configuration tips you may like to have on your ziproxy server: For changing the default port find the following line and uncomment the port = 8080 and replace the 8080 to the port number you like. But be sure no other application is using that port.

Name: Speed up Browsing on Mobile Devices.jpg Views: 190 Size: 35.0 KB

## Port to listen for proxy connections

## default: 8080

# Port = 8080

You can also implement the authentication option using ziproxy, i.e. users need to identify themselves in order to access the In ternet. For this, find the following line in the ziproxy.conf file:

# AccessLogFileName =

"/va r /log/zi proxy /access.log"

## HTTP auth file

## Should contain userass pairs, lines no longer than 128 chars

## Password is unencrypted

# Passwd Fi le=" /etc/zi proxy/http. passwd"

Uncomment the 'PasswdFile' in orŽder to implement user authentication and 'AccessLogFileName' to enable logging. Once this is done open up the file http.passwd which can be found under . / etc/ziproxy /'.

This file contains username and password of those users who are allowed to access. Enter you username and password here, in a format 'username:.password' and save the file. Now open any web site at the client machine and it will ask for user authentication. Provide 'username and password to authorize yourself.