DelXy: Your Premium HTTP Compression Service

DELXY

Introduction

Delxy is a Compression Service to Compress your Internet traffic so as to reduce your bandwidth requirements. Delxy will normally reduce your bandwith requirements by a facor of at least three (3) improving your browsing response times significantly. This also has significant financial benefits as you can accommodate more clients at a fraction of the cost.

The Problem

The connection to the Internet Backbone for a number of Developing Countries and Rural Regions of even some developed countries is normally over inter-continental submarine fibre optic cables or satellite links. This and the relatively low usage levels make bandwidth for a lot of these regions very expensive (typically in the region of $5,000 per 2Mbps / Month).

Meanwhile, websites are increasingly becoming media rich, requiring bigger bandwidth to effectively use them. A lot more content is now dynamic, rather than static, which by default is non-cacheable. This makes the use of traditional Proxy/Cache engines not as effective as they used to be when Internet Content was in the main, static. Currently, most traditional cache engines have Byte Hit Rates in the region of 10% - 30%.

Technical Assessment And Solution

Four important characteristics of the content on the web which Delxy is exploiting are:

Despite some content being served as dynamic objects, they essentially remain static over very long periods (eg images, music, video from say www.youtube.com).
Even when content change, some often do so in piecemeal (say the front page of a news websites, eg: www.cnn.com).
A significant percentage of the Internet still remain text which is highly compressible.
Repeat visits still remain a strong characteristics of the Internet, most visits are to a few sites. For example, an analysis of the traffic of an ISP showed that 66% of requests went to only 100 of the 6,800 sites that were visited and 75% of the traffic came from these 100 sites.

Based on the characteristics above, Delxy uses several technologies to achieve very high bandwidth saving.

Caching: Cacheable content is cached and served by the integrated Squid Proxy/Caching engine. Client settings are occasionally synchronised with our servers to ensure that refresh patterns are optimal as a result of analysis of logs from several other clients. This ensures higher hit rate for all clients.
Differential Compression: Some non-cacheable content either change very little or not at all. Using differential compression (such as is done in Rsync and xdelta) we are able to make savings of over 90% on a number of objects.
Compression: Significant percentage of content on the web is still text (such as html, javascript, css, etc.). Such content is highly compressible, often to 20%-30% of the original size. Where there is no historical copy to do a diffential compression against, such text content is simply compressed by our servers and delivered to the client for decompression.
Other techniques are employed to ensure that we offer best compression service. Indeed we are still developing more to ensure that we give you greater value for your money.

Delxy is a client-server service for http traffic, so the equipment we sell to you will be communicating with our servers in the US to provide the Service.
We are in the process of making an installable package available for Ubuntu Server, so that you can install the software on your hardware and peer it to our server. This should be available during the first quarter of 2009.

Target

Delxy is useful for Educational Campuses, ISPs, Large Corporate Institutions, Large Internet Cafes, etc in developing regions where bandwidth costs remain high. If you pay more than $2000 per 2Mbps / Month, you may want to evaluate Delxy for the considerable savings you will realise.

Requirements

Minimum Required Bandwith from your existing ISP should be 1Mbps upload / 1Mbps download. You will loose some performance if the link is asynchronous (say 1Mbps/256Kbps).

Performance

You should expect a performace factor of about 2 after 1 week and a factor of about 3 after 4 weeks of usage. A Performance Factor (PF) of 2 means getting out of your Delxy equipment an average bandwidth of twice what you get from your ISP. Similarly, a PF of 3 means getting out of your Delxy equipment an average bandwidth of three times what you get from your ISP.

Demo

Limited 1-2 week demo can be arranged. We may refer you to an existing demo if one is running elsewhere.

Technical Specifications
Interface Type	2 x 100 Mbps Ethernet, Full Duplex, RJ45 Connector
Processor Speed	> 2GHz
Memory	>2GB
Disk Capacity	>200 GB
Protocol	HTTP 1.1
HTTP Compression	>2 after one week, >3 after four weeks.
System Mode	Bridged Interfaces, Transparent Proxy
Server Availability	>99.9%
Local Ports	HTTP Poxy TCP 3128, Transparent Proxy TCP 8080
Outgoing Ports	TCP 8080, UDP 1194
Location On Network	Behind firewall, No Public IP required
Security	HTTP Traffic is transported as is. System communication between server and client equipment is over a secured VPN.