High Speed Wide Area Networks - WANcompress Technology · High Speed Wide Area Networks - WANcompress Technology - WHITE PAPER Abstract This paper describes UDcast’s WANcompress

High Speed Wide Area Networks - WANcompress Technology -

WHITE PAPER

Abstract

This paper describes UDcast’s WANcompress technology, a compression system that dramatically improves IP communications over Satellite, wireless, wired and WiMAX networks for wide area networks (WANs). In satellite communications particularly the latency introduced by the satellite link results in slow performance. WANcompress Technology allows Branch Offices connected via satellite to work in a LAN-like environment, saving on average 50% of bandwidth consumption and accelerating data transfers by more than 20x. WANcompress is also being applied to terrestrial, cellular and WiMAX environments where it also dramatically accelerates data rates and reduces volume of transferred data.

UDcast Confidential - November 2008

2 - UDcast Confidential - November 2008

1. Introduction ...................................................................................................... 3

2. Challenges for End Users ..................................................................................... 3

3. What is WANcompress technology? .................................................................... 4

4. The UDcast WANcompress Solution .................................................................... 7

5. UDcast WANcompress Performance .................................................................... 7

5. Conclusions ..................................................................................................... 8

TABLE OF CONTENTS


Two issues continue to challenge WAN communications (specially satellite links) despite their wide deployment: the high cost of bandwidth (or the lack of bandwidth) and long transmission delays. Acceleration solutions are already in use to increase the efficiency of the links and minimize the effects of the transmission delay on the applications using the WAN network. These solutions can either be incorporated into the WAN or satellite equipment itself or installed in an external appliance.

UDcast has gone beyond this traditional approach and developed “WANcompress”, a unique technology combining compression and caching techniques for WAN communications. WANcompress provides performance levels never achieved before on satellite links and matching or exceeding those of an equivalent terrestrial connection. In addition the technology will improve data transmission in wireless links like WiMAX or cellular as well as in terrestrial networks.

WAN networks face issues of performance when compared to traditional LAN networks. A longer delay introduced by the network and the smaller available bandwidth often make the applications work in a degraded mode.

There are two major challenges when WAN links are used to link remote sites. The first is the technical challenge; how can I ensure users and applications are not overly penalized compared with my LAN network? The second is the commercial challenge; how can the bandwidth, sometimes very expensive and other times just very small, be offset by increasing the efficiency of the link?

With WANcompress Technology, both of these questions will be answered by unprecedented levels of acceleration and minimizing the amount of bandwidth consumed by redundant data.

1. INTRODUCTION

2. CHALLENGES FOR END USERS


UDcast has developed technology for improving compression levels for data transmission. Based on a combination of compression and caching techniques to eliminate redundant data, the technique can save on average 50% of the bandwidth on a given communications link. The WANcompress data compression engine stores all transmitted data at each end of the link, so that next time the same data or file is sent, only a reference will be transmitted over the WAN link. The data can be retrieved after several days or even weeks when the same information is transferred.

In order to perform the compression in real time, data matching is done at the byte level. This can provide very high compression ratios when redundant data is found in the file, even the first time a file is transmitted. Subsequently, when a file has been transmitted through the link and then modified and transmitted again, only a marker indicating the modifications will be sent, greatly reducing the amount of bandwidth consumed.

The following diagram shows how WANcompress works the first time data (for example a file) is transmitted. If the file, or any part of it, is not found in the local cache, a gzip compression technique is applied to the file before transmission.

Data Transfer - first timeOn the fly compression

WANcompress®WANcompress®

File saved to disk on both ends

WAN

3. WHAT IS WANCOMPRESS TECHNOLOGY?


The next diagram shows how WANcompress technology works when data is transferred a second time. Since the data is already stored locally, only a label indicating the file’s location will be sent over link.

The key to the operation of WANcompress is that it operates at the byte level. In the next diagram an edited file is transmitted again. Rather than resending the edited file, only a label will be sent to signal to the other end that part of the file is already in the cache, and only the new information is sent over the link compressed by gzip technology.

Data Transfer - second timeOnly data label

reference transferred

WANcompress®WANcompress®WAN

Synchronized

Full file transferredLabel + Modifications

Edited file transferred

WANcompress®WANcompress®WAN

Synchronized

Modifications +


The following examples show applications of WANcompress Technology:

• Transferring data for the first time. For example, a Power Point presentation with redundant information such as the slide background on every page, etc. Medium compression rates will be achieved the first time data is transferred. Even higher compression rates are achieved the second time the data is transferred.

• Subsequent transfer of a file. Only a label indicating data location is sent, greatly reducing the amount of bandwidth consumed on the link.

• Workingonupdateddocuments.Veryoftenthereareseveralpeopleworkingonthesamedocument,doing modifications and updates and sending them back and forth between them. Each time a file is sent, only the most recent updates and modifications are transferred.

• Inthecaseofemailwithanattachmentthat issenttoanumberofusersattheremotelyconnectedsite,the attachment will only be sent across the link with the first email. In subsequent email downloads only the label indicating the location of the original attachment will be sent.

• Backupofdataacrossthenetworkcanalsobecomefarmoreefficientintermsoftimeandbandwidthsinceonly data that has been modified since the last backup will be transmitted across the network.

• Reducingapplicationresponsetimesduetothereductionofrepetitiveapplicationtraffic.

• Reducingcostoflinkincaseofdatavolumebilling.


WANcompress is designed to act on all protocols running on TCP, even if the same data is transmitted via a different application the second time (e.g. first transmission via HTTP and second via FTP).

WANcompress is highly scalable as it finds the optimal trade-off between compression and latency, providing the highest compression ratios at the lowest delays.

Equipment from UDcast equipped with WANcompress technology automatically detects whether its peers support WANcompress or not, enabling hybrid networks compatible with UDcast’s other appliances.

The local WANcompress cache is managed through dictionaries. The encoding and decoding dictionaries are separate. Each appliance equipped with WANcompress has one encoding dictionary and several decoding dictionaries (one per peer).

Memory and disk space reserved for WANcompress are configurable and can be adapted to the processing power of the hardware used.

All the information on the disk is encrypted to ensure data security. The encryption key is erased after power loss, ensuring maximum confidentiality.

The local cache is re-initialized when the equipment is reinitialized (or if the WANcompress service is restarted) and the peers are synchronized automatically.

WANcompress Technology is independent of the application used over TCP.

25,8x6,3x

24,5x

8,6x

19,9x7,4x

19,3x

4,7x

0 5 10 15 20 25 30

WANcompress transfer acceleration rates (x times)

FTP

HTTP

Windows FileSharing

EmailFirst transferSecond transfer

The key benefits of the WANcompress Technology from UDcast are:• Increased productivity: users and applications at remote sites work more efficiently due to a more efficient communications link.• Data Centre Consolidation: with a current tendency to locate most of the application and data servers at the headquarters, WANcompress allows remote Branch Offices to exchange data in an efficient way with the central points of the network. • Reduction of helpdesk complaints thanks to the possibility for all user applications to function correctly over the satellite network.• Bandwidth savings resulting in decreased operating expenses for the communications link.• Reduction of data volume allowing usage of lower data volume limits or lower billing.

4. THE UDCAST WANCOMPRESS SOLUTION

5. THE UDCAST WANCOMPRESS PERFORMANCEThe following graph indicates the level of acceleration that can be expected when downloading a MS Word file of 3.4 MB over a SCPC satellite link of 1Mbps (dedicated). The acceleration experienced by the end user varies depending on the application used and whether it is the first or subsequent time that the file has been sent.


WANcompress is a powerful technology allowing WAN networks to work in a LAN-like way. Those links where there are constraints in terms of bandwidth will benefit of a higher virtual bandwidth. For satellite users, where the cost of the bandwidth is very high, WANcompress provides additional enhancements in comparison with the normal UDgateway. The transferred data volume is reduced, allowing faster transfers and applications to work with much better response times.

UDcast is a leading software company providing IP broadcast solutions for the delivery of content to a broad range of devices over existing and emergingwireless networksworldwide. UDcast’sMobile TV technology is a key component in the end-to-end solutions from major systems providers including Motorola, Nokia, NSN, Alcatel-Lucent, Tandberg-Ericsson, Cisco-Scientific Atlanta, Harris Broadcasting and others. UDcast’s satellite-aware IP appliances are widely deployed at thousands of sites around the globe. The Company was recognized in 2007 as a leading European technology company by the prestigious Red Herring Hot 100 award. The Company maintains its global headquarters in Sophia-Antipolis, France with offices in Algeria, Italy and Spain. For more information, visit www.udcast.com.

6. CONCLUSIONS

ABOUT UDCAST


Headquarters: 2455 route des Dolines BP 355 06906 Sophia Antipolis CedexFRANCE

Tel. +33 (0)493 001 660 Fax. +33 (0)493 001 661

[email protected]

For more information please visit our website:

www.udcast.com

Iñigo López

AUTHOR

CONTACT UDCAST

©2008 UDcast SA. All rights reserved. UDadmin, UDauth, UDboost, UDbox, UDcast, UDcrypt, UDgateway, UDkit, UDpush, UDredundancy, UDroutecast, UDstation, iSplicer, WANcompress, the UDcast corporate logo, are trademarks of UDcast SA. All other trademarks are the property of their respective owners. Information is subject to change without notice, in equipment design as engineering or manufacturing methods warrant. Text, pictures & schema are not contractual.

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High Speed Wide Area Networks - WANcompress Technology · High Speed Wide Area Networks - WANcompress Technology - WHITE PAPER Abstract This paper describes UDcast’s WANcompress